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. 2025 Sep 26;10(39):45718–45728. doi: 10.1021/acsomega.5c06133

Discrete μ4‑Oxido Mn(II) Clusters with Controlled Nuclearity: On-Demand Synthesis, Molecular and Self-Assembled Structures

Dominik Jabłoński †, Maciej Jacyna †, Michał Terlecki †,*, Arkadiusz Kornowicz ‡, Iwona Justyniak ‡, Janusz Lewiński †,‡,*
PMCID: PMC12508945  PMID: 41078759

Abstract

Discrete heterovalent manganese-oxido clusters are widely used as building blocks and precursors of modern functional materials, such as molecular magnets, polyoxometalates (POMs), metal-oxide nanocrystals, and metal–organic frameworks (MOFs). While access to various heterovalent Mn­(II)/Mn­(III) oxido clusters is well established, the rational synthesis of similar compounds composed exclusively of Mn­(II) centers remains a significant challenge. Herein, we present an on-demand synthesis of homovalent [Mn4 II(μ4-O)­L6]-type clusters via a transmetalation/hydrolysis approach. Interestingly, by tuning the coordination properties of selected model organic ligands, we achieved control over the nuclearity of the resulting manganese oxide clusters, leading to the formation of either tetranuclear [Mn4(μ4-O)­(LNN)6] or octanuclear [Mn4(μ4-O)­(LON)6]2 clusters, depending on the use of N,N′- or O,N-bidentate ligands, respectively. Furthermore, a detailed analysis of the supramolecular structures of these new complexes, in comparison with selected examples of widely studied zinc-oxido clusters and to a lesser extent with Co­(II) and Fe­(II) analogues, provided deeper insight into the factors controlling solvation and noncovalent interaction-driven self-assembly.

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Introduction

Metal-oxido clusters offer a diverse landscape of functional molecular moieties due to their structural diversity, physicochemical properties, and rich chemistry. To date, polyoxometalates (POMs) have been extensively exploited as catalysts , and building blocks of desired materials; − however, the application of lower nuclearity clusters remains a highly underexplored area. Discrete O-centered metal-oxido clusters incorporating organic ligand shells can be utilized as building blocks or precursors for the fabrication of more complex functional systems, , including polyoxometalate (POM) nanoclusters, , metal-oxide nanocrystals, − and porous metal–organic frameworks (MOFs). − Moreover, these small molecular clusters can be regarded as soluble representations of fundamental structural units of higher-nuclearity POMs and the crystal lattices of metal oxides. As such, they can serve as a valuable predesigned platform for investigating various aspects of metal-oxide chemistry, like unveiling intimate steps in (co)­polymerization of epoxides, expanding knowledge on the factors governing phase transitions and polymorph-controlled syntheses, modeling MOFs’ reactivity toward water and small donor molecules, mapping pathways in MOFs and metal–organic gel assembly, and searching the growth mechanism of nanocrystals , and the coordination dynamics of ligands on their surface. , More recently, molecular metal clusters have emerged as promising building units for noncovalent functional supramolecular frameworks, such as the noncovalent porous materials (NPMs) − or molecular porous assemblies, − and metal hydrogen-bonded organic frameworks, , which are easily processable , and may exhibit interesting flexible behavior , or highly selective gas adsorption. These frameworks are organized via intermolecular noncovalent interactions governed by the secondary coordination sphere (SCS), which remains challenging to control. Harnessing the SCS in combination with intermolecular noncovalent interactions provides an additional level of tailorability of metal-oxido clusters and their deliberate utilization as well-defined building blocks of functional materials. To advance these applications, it is essential to facilitate access to molecular metal-oxide clusters with tailored characteristics and deepen the understanding of their chemical behavior, including the interplay between the primary and secondary coordination spheres.

One of the most ubiquitous building units of metal-oxido structures is the tetrahedral oxido-centered [M4(μ4-O)]n+ species. This structural motif is particularly widespread in zinc coordination chemistry, where discrete clusters with a general formula of [Zn4(μ4-O)­L6] form an extended family of hybrid organic–inorganic compounds incorporating a vast array of stabilizing ligands (L) with various steric and electronic characteristics. , Such diversity in structural features results in highly tunable optoelectronic, − coordination, ,,− and self-assembly properties, ,,,, which turn these μ4-oxido metal clusters into suitable candidates for luminescent materials, ,, catalysts, − and precursors of isoreticular MOFs. , In turn, the versatility of ligands that can be incorporated into [Zn4(μ4-O)­L6]-type clusters makes them ideal platforms for a systematic study of how controlled modifications in the SCS affect their noncovalent interaction-driven self-assembly. For example, simple zinc-oxido carboxylates and amidinates incorporating various substituents in the aromatic backbone in the distal SCS can form diverse types of noncovalent assemblies ranging from structures representing zeolitic topologies to soft porous materials with gated voids or open channels. , On the other hand, we demonstrated that the NH groups in the proximal SCS are prone to the formation of intermolecular hydrogen bonds, which can be used to tailor the packing of [Zn4(μ4-O)­L6]-type clusters toward NPMs in the crystal structure. , While research on the physicochemical properties of molecular metal-oxido clusters has been extensively conducted for decades, the crystal engineering of noncovalent frameworks involving this family of metal clusters remains a challenging and highly undeveloped field. Noncovalent interactions between molecules give rise to molecular recognition and self-assembly processes, and often play a dominant role in the synthesis, catalysis, and design of materials. − For example, adjusting both the character of the metal center along with the secondary coordination sphere in building-block clusters can provide a promising means to control the properties of the resulting materials. Thus, in-depth understanding of these interactions is crucial across various fields of chemistry and materials science.

Strikingly, while the facile access to [M4(μ4-O)­L6]-type complexes based on Zn­(II) ions is provided by well-established synthetic procedures, , the rational preparation of similar oxido clusters based on open-shell transition metal ions, like Fe­(II), Co­(II), or Mn­(II), is still highly challenging, which significantly hampers the development of [M4(μ4-O)]-based materials. , Only very recently, we have successfully introduced a novel efficient procedure, called the transmetalation/hydrolysis approach, for the efficient preparation of homometallic [M4(μ4-O)­L6]-type clusters based not only on Zn­(II) but also other divalent transition metal ions. On this week, we demonstrated the first on-demand synthesis of new isostructural Fe­(II) and Co­(II) amidato clusters [M4(μ4-O)­(LON)6] (M = Co, Fe; H-LON = benzamide) as well as the known Zn­(II) analogue. Now, we extended the application of this approach to the rational synthesis of new Mn­(II)-oxido clusters, tetranuclear [Mn4(μ4-O)­(LNN)6] (1-Mn) and octanuclear [Mn4(μ4-O)­(LON)6]2 (2 2 ) stabilized by N,N′-bidentate benzamidinato (LNN) and O,N-bidentate benzamidato (LON) ligands, respectively.

Multinuclear manganese-oxido clusters are of particular interest due to their structural tunability , and intriguing magnetic and redox properties. For instance, a dodecanuclear cluster [Mn12O12(OAc)16(H2O)4] has emerged as a prototypical single-molecule magnet, paving the way for the development of the field of molecular magnetism, and currently, various manganese-oxido species serve as building units of modern magnetic materials. ,, In turn, the CaMn4O x cluster constitutes the active site of photosystem II (PSII), catalyzing the water oxidation reaction and, by mimicking its mode of action, various manganese-oxido clusters demonstrate promising catalytic activity in oxidation processes. , More recently, manganese-oxido clusters have also been used as promising precursors for the fabrication of manganese oxide nanocrystals.

The [Mn4(μ4-O)]n+ species are typical building units of heterovalent Mn­(II)/Mn­(III) manganese-oxido clusters with higher nuclearity, which readily form during the oxidation of Mn­(II) carboxylates or inorganic salts. In these reactions, the oxidation agent, usually KMnO4 or O2 from the air, acts as the source of the O2– anions, simultaneously increasing the oxidation state of some metal centers. For instance, [Mn4 IIMn2 IIIO2(L)10(X)n]-type clusters (L = e.g., RCOO, X = neutral ligands, e.g., RCOOH, H2O, pyridine) bearing {Mn4 IIMn2 III(μ4-O)}10+ core composed of two edge-sharing {Mn2 IIMn2 IIIO}8+ tetrahedra (Figure c) are common products of the oxidation of simple Mn­(II) carboxylates. − In turn, introducing various multidentate stabilizing ligands into the reaction system resulted in manganese-oxido clusters with higher nuclearity and a variety of core structures. The examples include a series of decanuclear [Mn4 IIMn6 IIIO4(L) y (X) x ]z+-type clusters (X = N3, Br, or I) comprising supertetrahedral cores built from four vertex-sharing [MnIIMn3 IIIO]9+ tetrahedra stabilized by various tripodal alcoholates (Figure d), − a dodecanuclear cluster [Mn4 IIMn8 IIIO4(H2O)2(Cl)8(edte)4] (edteH4 =N,N,N′,N′-tetrakis­(2-hydroxyethyl)­ethylenediamine) with a twisted saddle-like core built from four vertex-sharing [MnIIMn3 IIIO]9+ tetrahedra (Figure e), and a highly symmetrical tridecanuclear cluster [MnIIMn12 IIIO8(Cl)6(O3PtBu)8] comprising a cuboctahedral core composed of eight edge-fused [MnIIMn3 IIIO]9+ tetrahedra sharing one centrally located MnII vertex (Figure f). Contrary to partially oxidized heterovalent manganese-oxido clusters, the rational synthesis of homovalent Mn­(II)-oxido clusters is still challenging due to the high reactivity of the Mn­(II) species. To our knowledge, there are only two reports on the isolation of discrete [Mn4 II(μ4-O)­L6]-type clusters, both incorporating monoanionic amidinato ligands (N,N′-diphenylformamidine , and N,N′-dimethylformamidine anions). Moreover, Wright et al. reported on the isolation and structural characterization of a dimeric octanuclear cluster [Mn4 II(μ4-O)­L6]2 (LH = 2-amino-3-bromo-5-methyl-pyridine), in which two [Mn4 II(μ4-O)]6+ units are connected by bridging organic N,N′-ligands. Strikingly, all of these Mn­(II)-oxido clusters were obtained serendipitously due to the water contamination of the reactants or the reaction system.

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Previously isolated homovalent manganese-oxido [Mn4 II(μ4-O)]6+-based clusters (a, b) and selected examples of heterovalent manganese-oxido clusters composed of [Mn4 II/III(μ4-O)]n+ building units (c–f).

Herein, we present the first synthetic approach enabling the on-demand preparation of homovalent [Mn4(μ4-O)­(LNN)6]-type oxido clusters. We demonstrated its effectiveness by preparing two new clusters, tetranuclear [Mn4(μ4-O)­(LNN)6] (1-Mn) and octanuclear [Mn4(μ4-O)­(LON)6]2 (2 2 ) stabilized by N,N′-bidentate benzamidinato (LNN) and O,N-bidentate benzamidato (LON) ligands, respectively. The selected model ligands exhibit distinct coordination properties, enabling control over the nuclearity of the resulting manganese-oxido clusters. Furthermore, they introduce varying numbers of hydrogen-bond donor and acceptor sites into the proximal secondary coordination sphere of the clusters, which plays a substantial role in directing their self-assembly.

Results and Discussion

Transmetalation/Hydrolysis Approach for Mn­(II)-Oxido Clusters

Applying the previously designed one-pot three-step transmetalation/hydrolysis approach two new homovalent Mn­(II)-oxido clusters, tetranuclear [Mn4 II(μ4-O)­(LNN)6] (1-Mn) and octanuclear [Mn4 II(μ4-O)­(LON)6]2 (2 2 ), were obtained. The synthetic procedure involves (i) the generation of potassium salt from the selected proligand L-H via the reaction with KH, (ii) the transmetalation reaction with MnCl2, and (iii) the stoichiometric hydrolysis of the received homoleptic [MnII(L)2] x -type derivative (Figure ). The respective Mn­(II)-oxido products were obtained in the form of well-defined yellowish crystals after extraction with the mixture of DMF/THF (1:3, v/v) and subsequent crystallization upon slow diffusion of hexane vapor. Notably, while cluster 1-Mn was isolated with a high yield (73%) through a single extraction process, in the case of cluster 2 2 , due to its low solubility, the extraction had to be repeated three times to obtain a satisfactory yield of 69% (see the Experimental Section). The phase purity of isolated products was confirmed by powder X-ray diffraction (PXRD) analysis (Figure S11). Both Mn­(II) complexes were highly sensitive toward O2 and turned brown immediately under slight exposure to air. Clusters 1-Mn and 2 2 were characterized by single-crystal X-ray diffraction (SC-XRD), 1H NMR and FTIR spectroscopy, and elemental analysis (for details, see the SI; note that due to the low solubility of 2 2 , 1H NMR analysis was performed only for 1-Mn).

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General scheme of the transmetalation/hydrolysis approach for the preparation of metal-oxido [M4(μ4-O)­(L)6]-type clusters.

Structure and Self-Assembly of Mn­(II) Amidinato Cluster 1-Mn and Its Zn­(II) Analogue

The molecular structure of cluster 1-Mn is isostructural with the previously reported Zn­(II) analogue [Zn4(μ4-O)­(LNN)6]. It comprises a highly symmetrical tetrahedral μ4-oxido-centered [Mn4 II(μ4-O)]6+ core stabilized by six benzamidinate anions (Figure a) (for a detailed structure description, see the SI). Cluster 1-Mn crystallizes from a DMF/THF solution (1:3, v/v) as a DMF-only solvate 1-Mn·3DMF in the orthorhombic space group Pna21. In the crystal lattice, there are two crystallographically independent molecules of 1-Mn and six molecules of DMF. Both symmetry-unique clusters form similar 1-Mn·3DMF solvates via N–H···O hydrogen bonds (the O···H distances are in the range of 2.309–2.540 Å), involving four of six DMF molecules (two DMF molecules form H-bonds with both crystallographically distinct clusters of 1-Mn) (Figures b,c and S4a,b). Two additional DMF molecules are tightly enclosed within the crystal lattice (only one could be modeled from the SC-XRD data; see the SI), resulting in the overall crystal formula of {2­[Mn4(μ4-O)­(LNN)6]·4DMF}·2DMF. The individual solvated clusters 1-Mn·3DMF further self-assemble into 1D zigzag chains via cooperative pairs of intermolecular N–H···N interactions (Figures g and S5a), similar to that previously observed in a series of amidato clusters [M4(μ4-O)­(LON)6] (M = Fe, Zn, Co) , (vide infra). These chains are further connected into a deformed honeycomb-like 2D supramolecular lattice (Figure e) via less specific intermolecular interactions involving phenyl rings in the distal secondary coordination sphere (Figure h).

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Structure and self-assembly of [M4(μ4-O)­(LNN)6]-type clusters (M = Zn­(II), Mn­(II)): (a) molecular structure; (b, c) H-bonded DMF solvates; (d) H-bonded THF solvate; (e) supramolecular 2D honeycomb-like layer formed by DMF-solvated metal-oxido clusters in [M4(μ4-O)­(LNN)6]·3DMF; (f) supramolecular 2D honeycomb layer formed by THF-solvated metal-oxido clusters in [Zn4(μ4-O)­(LNN)6]·5THF; (g–i) intermolecular noncovalent interactions between clusters within supramolecular 2D honeycomb layers.

Interestingly, the observed supramolecular structure of 1-Mn·3DMF contrasts with the previous results obtained for Zn­(II) amidinato analogue [Zn4(μ4-O)­(LNN)6] (1-Zn), which crystallized from a THF solution as the [Zn4(μ4-O)­(LNN)6]·5THF solvate in the trigonal space group P31c. In this crystal structure, each zinc-oxido cluster forms hydrogen bonds with four THF molecules (Figure d), and the resulting 1-Zn·4THF solvates self-assemble via cooperative CH···π and π–π noncovalent interactions mediated by the phenyl rings in the distal secondary coordination sphere (Figure i), affording a honeycomb-like supramolecular structure (Figure f). Another THF molecule is encapsulated within the crystal lattice without specific hydrogen interactions, leading to an overall 1-Zn·5THF ({1-Zn·4THF}·THF) crystal formula.

To determine whether the observed formation of various solvatomorphs by Mn­(II) and Zn­(II) oxido analogues results from the differing chemical character of these metal centers, we carried out the synthesis and purification of cluster 1-Zn according to the transmetalation/hydrolysis procedure utilizing ZnCl2 instead of MnCl2 (previously this cluster was obtained by an organometallic procedure and crystallized from THF solution). Eventually, crystallization of the product from a DMF/THF (1:3, v/v) solution led to the isolation of a new solvatomorph of 1-Zn, in high yield, which was isostructural with 1-Mn·3DMF. Crystals of 1-Zn·3DMF were characterized by SC-XRD, FTIR, NMR spectroscopy, and elemental analysis (for details on the synthesis and characterization of 1-Zn·3DMF, see the SI and Experimental Section).

The isolation of the isostructural DMF solvates for Zn­(II) and Mn­(II) amidinato [M4(μ4-O)­(LNN)6]-type clusters indicates that, in this case, their self-assembly is likely determined by the crystallization conditions rather than the type of metal center. Specifically, we found that the hydrogen bonding solvation by DMF or THF molecules competes with the formation of intercluster bridges via N–H···N interactions within the proximal secondary coordination sphere of the metal-oxide clusters, thereby affecting their interlocking. In the crystal structure of 1-Zn·5THF, the H-bonded THF molecules efficiently block access to the interior of the clusters, hampering the formation of intermolecular N–H···N bridges (Figure d). Thus, THF-solvated clusters 1-Zn·4THF are organized only by interactions involving phenyl rings in the distal secondary coordination sphere, forming 2D honeycomb layers with accurate trigonal symmetry (Figure f,i). In turn, DMF molecules in the solvatomorphs 1·3DMF only partially block access to the interior of the metal clusters, which are organized by utilizing both the intermolecular N–H···N bridges (Figures g and S5) and the interactions involving phenyl rings (Figure h), leading to distorted 2D honeycomb-like layers with reduced symmetry to orthorhombic (Figure e). Furthermore, these observations contrast nicely with the structure of amidato clusters [M4(μ4-O)­(LON)6] (M = Zn­(II), Co­(II), Fe­(II)), which in the same conditions (DMF/THF solution) self-assemble into 2D honeycomb layers with accurate trigonal symmetry utilizing only intermolecular N–H···X (X = N or O) bridges (vide infra, Figure h). Amidato ligands introduce O-donor centers to the secondary coordination sphere of metal-oxido clusters, which serve as stronger hydrogen-bond acceptors than the NH groups found exclusively in amidinato analogues. This likely increases the competitiveness of intermolecular N–H···X interactions over hydrogen-bonded solvation by DMF molecules in amidinato [M4(μ4-O)­(LON)6]-type clusters.

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Structure and self-assembly of [Mn4(μ4-O)­(LON)6]2 and [M4(μ4-O)­(LON)6] (M = Zn­(II), Co­(II), Fe­(II)) clusters: (a) molecular structure of 2 2 ; (b) molecular structure of [M4(μ4-O)­(LON)6] (M = Zn­(II), Co­(II), Fe­(II)); (c) coordination position isomerism of LON ligands in metal-oxido clusters; (d, g) self-assembly of 2 2 into the DMF-solvated 1D supramolecular chains via cooperative hydrogen bonds; (e, f) cooperative hydrogen-bond systems in supramolecular assemblies of [Mn4(μ4-O)­(LON)6]2 and [M4(μ4-O)­(LON)6] clusters [the presented case shows only NH groups; however, considering the possible position coordination isomerism of the ligands, the same sites may be also occupied by O atoms, which would reduce the number of hydrogen bonds]; (h) self-assembly of [M4(μ4-O)­(LON)6] (M = Zn­(II), Co­(II), Fe­(II)) clusters into the THF-solvated honeycomb-like framework.

Structure and Self-Assembly of Mn­(II) Amidato Cluster 2 2

In contrast to 1-Mn, the molecular structure of Mn­(II)-oxido benzamidato analogue 2 2 is a centrosymmetric dimer composed of two [Mn4 II(μ4-O)­(LON)6] units connected via coordination bridges formed by organic ligands (Figure a). Both manganese-oxido [Mn4 II(μ4-O)]6+ cores are arranged face-to-face with an approximately 60° axial rotation (e.g., the Mn01–Mn04–Mn04′-Mn03′ torsion angle is 62.90(3)°), resulting in a pseudo S 6 molecular symmetry. The two [Mn4 II(μ4-O)]6+ units in 2 2 are stabilized by an overall 12 monoanionic benzamidato ligands. Six of them adopt the μ2-κ1(O):κ1(N) coordination mode and are positioned along the external edges of both tetrahedral Mn4O units, similarly to what is observed in monomeric [M4(μ4-O)­(L)6]-type complexes. These ligands likely exhibit coordination position isomerism, acting either as O,N- or N,O-donors (Figure c), as previously demonstrated in the case of amidato [M4(μ4-O)­(LON)6]-type clusters (M = Zn­(II), Co­(II), Fe­(II)). This phenomenon leads to positional disorder of the N and O atoms within the μ2-ligands in the crystal structure (for details, see the SI). The other six benzamidato ligands in complex 2 2 are located around the middle part of the cluster, adopting a μ3-μ2(O):κ1(N) coordination mode. Each of these ligands acts as a μ3-OCN bridge between both manganese-oxido units, forming a single Mn–N bond with one of the Mn4O tetrahedra and two Mn–O bonds with the second one (Figures a and b). Interestingly, the formation of μ3-OCN bridges between two manganese-oxido units in 2 2 dimer contrasts with most of the previously reported dimeric [M4(μ4-O)­(L)6]2-type structures of metal-oxido clusters, including the Mn­(II) cluster incorporating an N,N′-bidentate pyridin-azanido ligand (Figure b) and Co­(II) and Zn­(II) clusters stabilized by O,O′-donor carboxylato and carbamato ligands (Figure a). In all of these dimeric structures, the connection between two [M4(μ4-O)]6+ units is achieved through μ2-X-type bridges (X = O or N) mediated by single donor centers of ligands (Figure a). Notably, this connection is established via the simple formation of additional M–X bonds through one of the donor centers of the ligands. In contrast, the formation of μ3-OCN bridges requires a significant rearrangement of ligands compared with the initial monomeric [M4(μ4-O)­L6] species and, to the best of our knowledge, has previously been observed only in an exceptional pivalato Mg­(II) cluster [Mg4(μ4-O)­(O2CMe3)6]2. The type of bridging between metal-oxide units is also reflected in their spatial separation, which can be visualized by the (μ4-O)···(μ4-O) distances (Figure ). In structures featuring μ2-X-type bridges, the respective distances are significantly shorter (3.45–3.64 Å) compared to the structures with μ3-OCN bridges (5.34–5.65 Å). The observed variation in the separation of [M4(μ4-O)]6+ units may have further implications for the physicochemical properties of the formed dimeric clusters.

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Two types of intercluster bridges: μ2-X (a) and μ3-XCY (b), formed within dimeric [M4(μ4-O)­(L)6]2-type clusters.

Complex 2 2 crystallizes as a DMF solvate 2 2 ·6DMF in the monoclinic C2/c space group. In the crystal lattice, molecules of 2 2 self-assemble into linear 1D supramolecular chains oriented along the crystallographic c-axis (Figure d). This organization is driven by intermolecular N–H···N­(O) hydrogen bonds, which act cooperatively, forming systems involving up to six interactions (Figures e and S5c). The NH groups function as both H-donor and H-acceptor sites, whereas the O atoms may only act as H-acceptors. Consequently, the number of hydrogen bonds may vary due to the coordination position isomerism of the μ2-LON ligands (vide supra). Additionally, each molecule of 2 2 is solvated by six DMF molecules via N–H···O hydrogen bonds with the bridging μ3-μ2(O):κ1(N) amidato ligands. The solvated 1D chains further form a close-packed lattice through additional intermolecular noncovalent interactions between aromatic rings (Figure g). The self-assembly of cluster 2 2 interestingly contrasts with the supramolecular structures formed by monomeric amidato [M4(μ4-O)­(LON)6]-type analogues (M = Zn­(II), Co­(II), Fe­(II)), which organize into hexagonal honeycomb-like frameworks (Figure b,h). In these structures, the metal-oxido clusters form bridges involving only two N–H···N­(O) hydrogen bonds (compared with six between 2 2 ) within the proximal secondary coordination sphere, likely due to the presence of additional π···π interactions in the distal secondary coordination sphere (Figure ). This leads to an angular arrangement of molecules instead of the linear architecture observed in the crystal structure of 2 2 .

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Comparison of intermolecular connections in supramolecular structures of dimeric (a) and monomeric (b) [M4(μ4-O)­(LON)6]-type clusters.

Conclusions

In conclusion, we have demonstrated the successful application of a previously developed transmetalation/hydrolysis procedure for the synthesis of new Mn­(II) oxido clusters, [Mn4(μ4-O)­(LNN)6] and [Mn4(μ4-O)­(LON)6]2. Notably, while the synthesis of mixed-valence Mn­(II)/Mn­(III) oxido clusters has been readily achievable, access to homovalent Mn­(II) oxido clusters has remained challenging and was previously accomplished only serendipitously. The presented approach enabled not only the rational, on-demand synthesis of Mn­(II) oxido clusters but also provided control over their nuclearity, which was dictated by the electronic properties of the anchoring groups in the supporting ligands, affording monomeric cluster [Mn4(μ4-O)­(LNN)6] and dimeric cluster [Mn4(μ4-O)­(LON)6]2 for N,N′-bidentate amidinato and O,N-bidentate amidato ligands, respectively. Furthermore, a detailed analysis of the supramolecular structures of these new complexes, in comparison with previously reported metal-oxido clusters, provided deeper insight into their noncovalent interaction-driven self-assembly. Notably, we found that [M4(μ4-O)­(L)6] x -type clusters (M = Zn­(II), Co­(II), Fe­(II), Mn­(II); x = 1 or 2) stabilized by both amidinato or amidato ligands exhibit a similar tendency for the self-assembly via specific cooperative intermolecular N–H···X (X = N or O) hydrogen bonds in their proximal secondary coordination sphere, which compete with H-bonded solvation by DMF or THF molecules. However, there are significant differences in the self-assembly of monomeric [M4(μ4-O)­(L)6] and dimeric [M4(μ4-O)­(L)6]2 clusters. In the former, the N–H···X intermolecular bridges are further reinforced by π···π interactions between aromatic rings in the distal secondary coordination sphere, leading to angular supramolecular connections and the formation of honeycomb-like frameworks. In contrast, the dimeric cluster [M4(μ4-O)­(LON)6]2 lacks such π···π stabilization, likely due to the geometry of its secondary coordination sphere, and instead forms one-dimensional supramolecular chains through linear bridges involving six cooperative intermolecular N–H···X interactions. Overall, the presented studies not only introduce an efficient new approach to the synthesis of homovalent Mn­(II) oxido clusters but also reveal novel structural features within this family of compounds, which may have broader implications for the design and development of new functional materials.

Experimental Section

General Considerations

All manipulations were conducted under a dry, oxygen-free argon atmosphere using either standard Schlenk techniques or a glovebox. All reagents, benzamide (Sigma), benzamidine (Sigma), KH (Sigma), manganese­(II) chloride (ABCR), and zinc chloride (ABCR), were purchased from commercial vendors and used as received. Solvents were purified by using an MBraun SPS-5 system.

Synthesis of 1-Mn

Equimolar amounts of benzamidine (0.480 g, 4 mmol) and KH (0.160 g, 4 mmol) were placed in a Schlenk flask cooled to 0 °C and dispersed in THF (15 mL). After a few minutes, the reaction mixture was allowed to warm to room temperature and stirred for 24 h. Then, MnCl2 (0.250 g, 2 mmol) was added. After another 8 h of stirring, 9 μL (0.5 mmol) of Millipore water was added, followed by 5 mL of DMF. The reaction mixture was stirred for an additional 24 h. The product was isolated as yellow crystals after filtration and crystallization in the presence of hexane vapor at room temperature (Yield = 73%, 348 mg). 1H NMR (600 MHz, d 8-THF): δ [ppm] = 11–9 (bs, Ph), 6–3 (bs, NH); FTIR (ATR): ν/cm–1 = 3356 (w), 3053 (w), 1587 (m), 1539 (s), 1506 (m), 1466 (m), 1407 (w), 1339 (w), 1320 (w), 1259 (m), 1119 (w), 1078 (w), 1029 (w), 924 (w), 788 (w), 745 (m), 658 (m), 631 (w), 582 (w), 465 (s). Elemental analysis: calcd (%) for 1-Mn·2.73DMF (C50.2H61.1N14.7O3.7Mn4) (1150.18): C 52.41, H 5.36, N 17.94;found (%): C 52.40, H 5.51, N 17.43.

Synthesis of 1-Zn

The same procedure as for 1-Mn was applied, but with ZnCl2 (0.272 g, 2 mmol) instead of MnCl2. The product was isolated as colorless crystals after filtration and crystallization in the presence of hexane vapor at room temperature (Yield = 77%, 381 mg). 1H NMR (600 MHz, d 8-THF): δ [ppm] = 7.62–7.55 (m, 12H, Ph), 7.34–7.25 (m, 18H, Ph), 4.71 (s, 12H, NH); 13C NMR (150 MHz, CDCl3): δ [ppm] = 174.54 (NCN), 144.78 (IVCAr), 129.37 (CAr), 128.91 (CAr), 126.74 (CAr); FTIR (ATR): ν/cm–1 = 3363 (w), 3063 (w), 1599 (s), 1557 (s), 1502 (m), 1450 (s), 1342 (w), 1320 (w), 1303 (w), 1278 (w), 1233 (m), 1185 (w), 1158 (w), 1131 (m), 1069 (w), 1028 (w), 1002 (w), 934 (w), 829 (w), 804 (w), 779 (w), 695 (s), 672 (s), 620 (w), 604 (w), 521 (m), 487 (s), 440 (w), 408 (w). Elemental analysis: calcd (%) for 1-Zn·2.64DMF (C49.9H60.5N14.6O3.6Zn4) (1185.37): C 50.58, H 5.14, N 17.30; found (%): C 50.63, H 5.18, N 17.25.

Synthesis of 2 2

The same procedure as that for 1-Mn was applied, but with benzamide (0.484 g, 4 mmol) instead of benzamidine. The obtained suspension was separated, and the precipitate was extracted twice with 10 mL of THF/DMF mixture (1:3, v/v). All three solutions were combined and crystallized in the presence of hexane vapor at room temperature, yielding yellow crystals of the product (Yield = 69%, 332 mg). FTIR (ATR): ν/cm–1 = 3340 (w), 3053 (w), 1610 (w), 1590 (m), 1540 (s), 1436 (m), 1410 (m), 1250 (w), 1235 (w), 1200 (m), 1156 (w), 1118 (m), 1073 (w), 1058 (w), 1026 (w), 929 (w), 851 (w), 809 (w), 699 (s), 618 (w), 574 (w), 531 (w), 461 (m), 434 (w). Elemental analysis: calcd (%) for 2 2 ·6.49DMF (C103.5H117.4N18.5O20.5Mn8) (2387.46): C 52.05, H 4.96, N 10.85; found (%): C 51.85, H 5.01, N 10.75.

Characterization

FTIR spectra were measured with a Bruker Tensor II spectrometer by using the ATR technique. Elemental analyses were performed using a UNICUBE elemental analyzer (Elementar Analysensysteme GmbH). The 1H and 13C NMR spectra were acquired on a JEOL JNM-ECZL (600 MHz) spectrometer. The Continuous Shape Measurement (CShM) parameters were calculated utilizing SHAPE software. The closer the calculated CShM is to zero, the closer the given coordination environment is to the ideal given geometry.

X-ray Structure Determination

The crystals were selected under Paratone-N oil, mounted on the nylon loops, and positioned in the cold stream on the diffractometer. The X-ray data for complexes 1-Mn, 1-Zn, and 2 2 were collected at 100(2)K on a SuperNova Agilent diffractometer using graphite monochromated MoKa radiation (λ = 0.71073 Å). The data were processed with CrysAlisPro. The structures were solved by direct methods using the SHELXS-97 program and were refined by full-matrix least-squares on F 2 using the program SHELXL-2018/3 implemented in the Olex2 suite. All non-hydrogen atoms were refined with anisotropic displacement parameters. Hydrogen atoms were added to the structure model at geometrically idealized coordinates and refined as riding atoms.

Supplementary Material

ao5c06133_si_001.pdf (1.5MB, pdf)
ao5c06133_si_002.cif (4.4MB, cif)
ao5c06133_si_003.cif (3.5MB, cif)
ao5c06133_si_004.cif (474KB, cif)

Acknowledgments

The authors acknowledge the National Science Center, Poland, Grants OPUS No. 2021/41/B/ST4/04414, for financial support.

The Supporting Information is available free of charge at https://pubs.acs.org/doi/10.1021/acsomega.5c06133.

  • Crystallographic data and crystal structure analysis, FTIR and NMR spectra (PDF)

  • 1-Mn (CIF)

  • 1-Zn (CIF)

  • 22 (CIF)

The authors declare no competing financial interest.

References

  1. Wang S.-S., Yang G.-Y.. Recent Advances in Polyoxometalate-Catalyzed Reactions. Chem. Rev. 2015;115(11):4893–4962. doi: 10.1021/cr500390v. [DOI] [PubMed] [Google Scholar]
  2. Ogiwara N., Uchida S.. Metal–Oxo-Cluster-Based Crystals as Solid Catalysts. Chem. Catal. 2023;3(7):100607. doi: 10.1016/j.checat.2023.100607. [DOI] [Google Scholar]
  3. Liu K., Shi W., Cheng P.. Toward Heterometallic Single-Molecule Magnets: Synthetic Strategy, Structures and Properties of 3d-4f Discrete Complexes. Coord. Chem. Rev. 2015;289–290(1):74–122. doi: 10.1016/j.ccr.2014.10.004. [DOI] [Google Scholar]
  4. Liu Q., Wang X.. Cluster-assembled Materials: Ordered Structures with Advanced Properties. InfoMat. 2021;3(8):854–868. doi: 10.1002/inf2.12213. [DOI] [Google Scholar]
  5. Cameron J. M., Guillemot G., Galambos T., Amin S. S., Hampson E., Haidaraly K. M., Newton G. N., Izzet G.. Supramolecular Assemblies of Organo-Functionalised Hybrid Polyoxometalates: From Functional Building Blocks to Hierarchical Nanomaterials. Chem. Soc. Rev. 2022;51(1):293–328. doi: 10.1039/D1CS00832C. [DOI] [PubMed] [Google Scholar]
  6. Yu B., Zhao X., Ni J., Yang F.. Multiscale Assembly of Polyoxometalates: From Clusters to Materials. ChemPhysMater. 2023;2:20. doi: 10.1016/j.chphma.2022.03.006. [DOI] [Google Scholar]
  7. Marcano D. E. S., Savić N. D., Declerck K., Abdelhameed S. A. M., Parac-Vogt T. N.. Reactivity of Metal–Oxo Clusters towards Biomolecules: From Discrete Polyoxometalates to Metal–Organic Frameworks. Chem. Soc. Rev. 2024;53(1):84–136. doi: 10.1039/D3CS00195D. [DOI] [PubMed] [Google Scholar]
  8. Gross S.. Oxocluster-Reinforced Organic-Inorganic Hybrid Materials: Effect of Transition Metal Oxoclusters on Structural and Functional Properties. J. Mater. Chem. 2011;21(40):15853–15861. doi: 10.1039/c1jm10579e. [DOI] [Google Scholar]
  9. Vendrame D., Bragaggia G., Carraro M., Gross S.. Metal Oxocluster-Based Organic–Inorganic Hybrid Materials: From Design Principles to Applications. Chem. Mater. 2024;36(19):9259–9278. doi: 10.1021/acs.chemmater.4c01141. [DOI] [Google Scholar]
  10. Long D.-L., Burkholder E., Cronin L.. Polyoxometalate Clusters, Nanostructures and Materials: From Self Assembly to Designer Materials and Devices. Chem. Soc. Rev. 2007;36(1):105–121. doi: 10.1039/B502666K. [DOI] [PubMed] [Google Scholar]
  11. Vilà-Nadal L., Cronin L.. Design and Synthesis of Polyoxometalate-Framework Materials from Cluster Precursors. Nat. Rev. Mater. 2017;2:17054. doi: 10.1038/natrevmats.2017.54. [DOI] [Google Scholar]
  12. Lee J., Yang J., Kwon S. G., Hyeon T.. Nonclassical Nucleation and Growth of Inorganic Nanoparticles. Nat. Rev. Mater. 2016;1(8):16034. doi: 10.1038/natrevmats.2016.34. [DOI] [Google Scholar]
  13. Chang H., Kim B. H., Jeong H. Y., Moon J. H., Park M., Shin K., Chae S. I., Lee J., Kang T., Choi B. K., Yang J., Bootharaju M. S., Song H., An S. H., Park K. M., Oh J. Y., Lee H., Kim M. S., Park J., Hyeon T.. Molecular-Level Understanding of Continuous Growth from Iron-Oxo Clusters to Iron Oxide Nanoparticles. J. Am. Chem. Soc. 2019;141(17):7037–7045. doi: 10.1021/jacs.9b01670. [DOI] [PubMed] [Google Scholar]
  14. Krupiński P., Kornowicz A., Sokołowski K., Cieślak A. M., Lewiński J.. Applying Mechanochemistry for Bottom-Up Synthesis and Host-Guest Surface Modification of Semiconducting Nanocrystals: A Case of Water-Soluble β-Cyclodextrin-Coated Zinc Oxide. Chem. - Eur. J. 2016;22(23):7817–7823. doi: 10.1002/chem.201600182. [DOI] [PubMed] [Google Scholar]
  15. Zhang L., Fan X., Yi X., Lin X., Zhang J.. Coordination-Delayed-Hydrolysis Method for the Synthesis and Structural Modulation of Titanium-Oxo Clusters. Acc. Chem. Res. 2022;55(21):3150–3161. doi: 10.1021/acs.accounts.2c00421. [DOI] [PubMed] [Google Scholar]
  16. Wang X., Ou P., Zheng Q., Wang L., Jiang W.. Embedding Multiple Magnetic Components in Carbon Nanostructures via Metal-Oxo Cluster Precursor for High-Efficiency Low-/Middle-Frequency Electromagnetic Wave Absorption. Small. 2024;20(15):2307473. doi: 10.1002/smll.202307473. [DOI] [PubMed] [Google Scholar]
  17. Assi H., Mouchaham G., Steunou N., Devic T., Serre C.. Titanium Coordination Compounds: From Discrete Metal Complexes to Metal-Organic Frameworks. Chem. Soc. Rev. 2017;46(11):3431–3452. doi: 10.1039/C7CS00001D. [DOI] [PubMed] [Google Scholar]
  18. Kalmutzki M. J., Hanikel N., Yaghi O. M.. Secondary Building Units as the Turning Point in the Development of the Reticular Chemistry of MOFs. Sci. Adv. 2018;4(10):eaat9180. doi: 10.1126/sciadv.aat9180. [DOI] [PMC free article] [PubMed] [Google Scholar]
  19. Prochowicz D., Sokołowski K., Justyniak I., Kornowicz A., Fairen-Jimenez D., Friščić T., Lewiński J.. A Mechanochemical Strategy for IRMOF Assembly Based on Pre-Designed Oxo-Zinc Precursors. Chem. Commun. 2015;51(19):4032–4035. doi: 10.1039/C4CC09917F. [DOI] [PubMed] [Google Scholar]
  20. Hausdorf S., Baitalow F., Böhle T., Rafaja D., Mertens F. O. R. L.. Main-Group and Transition-Element IRMOF Homologues. J. Am. Chem. Soc. 2010;132(32):10978–10981. doi: 10.1021/ja1028777. [DOI] [PubMed] [Google Scholar]
  21. Han W., Shi M., Jiang H.. Scalable and Low-Energy Synthesis of Metal–Organic Frameworks by a Seed-Mediated Approach. Angew. Chem., Int. Ed. 2025;64(13):e202421942. doi: 10.1002/anie.202421942. [DOI] [PubMed] [Google Scholar]
  22. Gupta V., Justyniak I., Chwojnowska E., Szejko V., Lewiński J.. Multinuclear Zinc-Magnesium Hydroxide Carboxylates: A Predesigned Model System for Copolymerization of CO2 with Epoxides. Inorg. Chem. 2023;62(40):16274–16279. doi: 10.1021/acs.inorgchem.3c02177. [DOI] [PMC free article] [PubMed] [Google Scholar]
  23. Terlecki M., Sobczak S., Leszczyński M. K., Katrusiak A., Lewiński J.. Stepwise Stress-Induced Transformations of Metal-Organic Polyhedral Cluster-Based Assemblies: Where Conformational and Supramolecular Features Meet. Chem. - Eur. J. 2021;27(55):13757–13764. doi: 10.1002/chem.202101732. [DOI] [PubMed] [Google Scholar]
  24. Bury W., Justyniak I., Prochowicz D., Wróbel Z., Lewiński J.. Oxozinc Carboxylates: A Predesigned Platform for Modelling Prototypical Zn-MOFs’ Reactivity toward Water and Donor Solvents. Chem. Commun. 2012;48(59):7362. doi: 10.1039/c2cc33094f. [DOI] [PubMed] [Google Scholar]
  25. Carpenter B. P., Talosig A. R., Rose B., Di Palma G., Patterson J. P.. Understanding and Controlling the Nucleation and Growth of Metal–Organic Frameworks. Chem. Soc. Rev. 2023;52(20):6918–6937. doi: 10.1039/D3CS00312D. [DOI] [PubMed] [Google Scholar]
  26. Wang Z., Qian K., He L., Huang H., Gu Y., Li F., Zeng J., Wu Y.. Self-Driven Seeding, Acid Stalling, and Solidifying: Time-Resolved Mapping of Nonclassical Pathways in Metal–Organic Gel Assembly. Angew. Chem., Int. Ed. 2025;64(33):e202503855. doi: 10.1002/anie.202503855. [DOI] [PubMed] [Google Scholar]
  27. Schubert U.. Surface Chemistry of Carboxylato-Substituted Metal Oxo Clusters – Model Systems for Nanoparticles. Coord. Chem. Rev. 2017;350:61–67. doi: 10.1016/j.ccr.2017.05.002. [DOI] [Google Scholar]
  28. Sokołowski K., Bury W., Justyniak I., Fairen-Jimenez D., Sołtys K., Prochowicz D., Yang S., Schröder M., Lewiński J.. Permanent Porosity Derived from the Self-Assembly of Highly Luminescent Molecular Zinc Carbonate Nanoclusters. Angew. Chem., Int. Ed. 2013;52(50):13414–13418. doi: 10.1002/anie.201306785. [DOI] [PubMed] [Google Scholar]
  29. Bury W., Walczak A. M., Leszczyński M. K., Navarro J. A. R.. Rational Design of Noncovalent Diamondoid Microporous Materials for Low-Energy Separation of C6-Hydrocarbons. J. Am. Chem. Soc. 2018;140(44):15031–15037. doi: 10.1021/jacs.8b09522. [DOI] [PubMed] [Google Scholar]
  30. Sołtys-Brzostek K., Sokołowski K., Justyniak I., Li A., Fairen-Jimenez D., Supeł A., Terlecki M., Lewiński J.. Tunable Self-Assembly of Decanuclear Ni­(II) Carbonato Clusters with a Hydroxyquinolinato Shell: Robust Porous Networks with Reversible Solvent/Temperature-Driven Phase Transitions and Selective Gas Separation. J. Am. Chem. Soc. 2025;147(22):19073–19083. doi: 10.1021/jacs.5c04096. [DOI] [PMC free article] [PubMed] [Google Scholar]
  31. Song Y., Long D., Cronin L.. Noncovalently Connected Frameworks with Nanoscale Channels Assembled from a Tethered Polyoxometalate–Pyrene Hybrid. Angew. Chem., Int. Ed. 2007;46(21):3900–3904. doi: 10.1002/anie.200604734. [DOI] [PubMed] [Google Scholar]
  32. Wasson M. C., Zhang X., Otake K. I., Rosen A. S., Alayoglu S., Krzyaniak M. D., Chen Z., Redfern L. R., Robison L., Son F. A., Chen Y., Islamoglu T., Notestein J. M., Snurr R. Q., Wasielewski M. R., Farha O. K.. Supramolecular Porous Assemblies of Atomically Precise Catalytically Active Cerium-Based Clusters. Chem. Mater. 2020;32(19):8522–8529. doi: 10.1021/acs.chemmater.0c02740. [DOI] [Google Scholar]
  33. Tandekar K., Tripathi A., Prasad M. D., Supriya S.. Keggin Based Self-Assembled Mesoporous Materials for the Capture of Selective Guest Molecules. Mater. Adv. 2022;3(13):5521–5531. doi: 10.1039/D1MA01092A. [DOI] [Google Scholar]
  34. Zhu Z. H., Wang H. L., Zou H. H., Liang F. P.. Metal Hydrogen-Bonded Organic Frameworks: Structure and Performance. Dalton Trans. 2020;49(31):10708–10723. doi: 10.1039/D0DT01998D. [DOI] [PubMed] [Google Scholar]
  35. Konovalov D. I., Ivanov A. A., Vorotnikov Y. A., Kuratieva N. V., Eltsov I. V., Kovalenko K. A., Shestopalov M. A.. Self-Assembled Microporous M-HOFs Based on an Octahedral Rhenium Cluster with Benzimidazole. Inorg. Chem. 2021;60(19):14687–14696. doi: 10.1021/acs.inorgchem.1c01771. [DOI] [PubMed] [Google Scholar]
  36. Terlecki M., Justyniak I., Leszczyński M. K., Lewiński J.. Effect of the Proximal Secondary Sphere on the Self-Assembly of Tetrahedral Zinc-Oxo Clusters. Commun. Chem. 2021;4(1):133. doi: 10.1038/s42004-021-00574-3. [DOI] [PMC free article] [PubMed] [Google Scholar]
  37. Haiduc I.. Inverse Coordination – An Emerging New Chemical Concept. Oxygen and Other Chalcogens as Coordination Centers. Coord. Chem. Rev. 2017;338:1–26. doi: 10.1016/j.ccr.2017.02.016. [DOI] [Google Scholar]
  38. Prochowicz D., Sokołowski K., Lewiński J.. Zinc Hydroxides and Oxides Supported by Organic Ligands: Synthesis and Structural Diversity. Coord. Chem. Rev. 2014;270–271:112–126. doi: 10.1016/j.ccr.2013.12.003. [DOI] [Google Scholar]
  39. Bury W., Justyniak I., Prochowicz D., Rola-Noworyta A., Lewiński J.. Oxozinc Carboxylate Complexes: A New Synthetic Approach and the Carboxylate Ligand Effect on the Noncovalent-Interactions-Driven Self-Assembly. Inorg. Chem. 2012;51(13):7410–7414. doi: 10.1021/ic300864n. [DOI] [PubMed] [Google Scholar]
  40. Lee C.-F., Chin K.-F., Peng S.-M., Che C.-M.. A Luminescent Tetrameric Zinc­(II) Complex Containing the 7-Azaindolate Ligand. Photophysical Properties and Crystal Structure. J. Chem. Soc., Dalton Trans. 1993;(3):467. doi: 10.1039/dt9930000467. [DOI] [Google Scholar]
  41. Cheng G., So G. K. M., To W. P., Chen Y., Kwok C. C., Ma C., Guan X., Chang X., Kwok W. M., Che C. M.. Luminescent Zinc­(II) and Copper­(I) Complexes for High-Performance Solution-Processed Monochromic and White Organic Light-Emitting Devices. Chem. Sci. 2015;6(8):4623–4635. doi: 10.1039/C4SC03161J. [DOI] [PMC free article] [PubMed] [Google Scholar]
  42. Thakur N., Vockenhuber M., Ekinci Y., Watts B., Giglia A., Mahne N., Nannarone S., Castellanos S., Brouwer A. M.. Fluorine-Rich Zinc Oxoclusters as Extreme Ultraviolet Photoresists: Chemical Reactions and Lithography Performance. ACS Mater. Au. 2022;2:343. doi: 10.1021/acsmaterialsau.1c00059. [DOI] [PMC free article] [PubMed] [Google Scholar]
  43. Pike S. D., White E. R., Shaffer M. S. P., Williams C. K.. Simple Phosphinate Ligands Access Zinc Clusters Identified in the Synthesis of Zinc Oxide Nanoparticles. Nat. Commun. 2016;7(1):13008. doi: 10.1038/ncomms13008. [DOI] [PMC free article] [PubMed] [Google Scholar]
  44. Dunaway L. A., Davis A. G., Carter V. J., Korir A. K., Zeller M., Kiernicki J. J.. Defining the Speciation, Coordination Chemistry, and Lewis Acid Catalysis of Electronically Diverse Zinc Benzoates. Organometallics. 2025;44:46. doi: 10.1021/acs.organomet.4c00358. [DOI] [PMC free article] [PubMed] [Google Scholar]
  45. Brozek C. K., Michaelis V. K., Ong T. C., Bellarosa L., López N., Griffin R. G., Dincă M.. Dynamic DMF Binding in MOF-5 Enables the Formation of Metastable Cobalt-Substituted MOF-5 Analogues. ACS Cent. Sci. 2015;1(5):252–260. doi: 10.1021/acscentsci.5b00247. [DOI] [PMC free article] [PubMed] [Google Scholar]
  46. Kadota K., Hong Y. L., Nishiyama Y., Sivaniah E., Packwood D., Horike S.. One-Pot, Room-Temperature Conversion of CO2into Porous Metal-Organic Frameworks. J. Am. Chem. Soc. 2021;143(40):16750–16757. doi: 10.1021/jacs.1c08227. [DOI] [PubMed] [Google Scholar]
  47. Chen S. C., Yu R. M., Zhao Z. G., Chen S. M., Zhang Q. S., Wu X. Y., Wang F., Lu C. Z.. A Series of Polynuclear Complexes of D10 Metals with Interesting Luminescent Properties. Cryst. Growth Des. 2010;10(3):1155–1160. doi: 10.1021/cg901031x. [DOI] [Google Scholar]
  48. Ohshima T., Iwasaki T., Mashima K.. Direct Conversion of Esters, Lactones, and Carboxylic Acids to Oxazolines Catalyzed by a Tetranuclear Zinc Cluster. Chem. Commun. 2006;(25):2711. doi: 10.1039/b605066b. [DOI] [PubMed] [Google Scholar]
  49. Maegawa Y., Ohshima T., Hayashi Y., Agura K., Iwasaki T., Mashima K.. Additive Effect of N-Heteroaromatics on Transesterification Catalyzed by Tetranuclear Zinc Cluster. ACS Catal. 2011;1(10):1178–1182. doi: 10.1021/cs200224b. [DOI] [Google Scholar]
  50. Agura K., Hayashi Y., Wada M., Nakatake D., Mashima K., Ohshima T.. Studies of the Electronic Effects of Zinc Cluster Catalysts and Their Application to the Transesterification of β-Keto Esters. Chem. - Asian J. 2016;11(10):1548–1554. doi: 10.1002/asia.201600062. [DOI] [PubMed] [Google Scholar]
  51. Nakatake D., Yokote Y., Matsushima Y., Yazaki R., Ohshima T.. A Highly Stable but Highly Reactive Zinc Catalyst for Transesterification Supported by a Bis­(Imidazole) Ligand. Green Chem. 2016;18(6):1524–1530. doi: 10.1039/C5GC02056E. [DOI] [Google Scholar]
  52. Prochowicz D., Nawrocki J., Terlecki M., Marynowski W., Lewiński J.. Facile Mechanosynthesis of the Archetypal Zn-Based Metal–Organic Frameworks. Inorg. Chem. 2018;57(21):13437–13442. doi: 10.1021/acs.inorgchem.8b02026. [DOI] [PubMed] [Google Scholar]
  53. Krupiński P., Terlecki M., Kornowicz A., Justyniak I., Prochowicz D., van Leusen J., Kögerler P., Lewiński J.. Tetrahedral M4(μ4-O) Motifs Beyond Zn: Efficient One-Pot Synthesis of Oxido–Amidate Clusters via a Transmetalation/Hydrolysis Approach. Inorg. Chem. 2022;61(20):7869–7877. doi: 10.1021/acs.inorgchem.2c00456. [DOI] [PMC free article] [PubMed] [Google Scholar]
  54. Whitesides G. M., Grzybowski B.. Self-Assembly at All Scales. Science. 2002;295(5564):2418–2421. doi: 10.1126/science.1070821. [DOI] [PubMed] [Google Scholar]
  55. Lu T., Wheeler S. E.. Harnessing Weak Interactions for Enantioselective Catalysis. Science. 2015;347(6223):719–720. doi: 10.1126/science.aaa5624. [DOI] [PubMed] [Google Scholar]
  56. Loh C. C. J.. Exploiting Non-Covalent Interactions in Selective Carbohydrate Synthesis. Nat. Rev. Chem. 2021;5(11):792–815. doi: 10.1038/s41570-021-00324-y. [DOI] [PubMed] [Google Scholar]
  57. Peluso P., Chankvetadze B.. Recognition in the Domain of Molecular Chirality: From Noncovalent Interactions to Separation of Enantiomers. Chem. Rev. 2022;122(16):13235–13400. doi: 10.1021/acs.chemrev.1c00846. [DOI] [PubMed] [Google Scholar]
  58. Liu M., Han X., Chen H., Peng Q., Huang H.. A Molecular Descriptor of Intramolecular Noncovalent Interaction for Regulating Optoelectronic Properties of Organic Semiconductors. Nat. Commun. 2023;14(1):2500. doi: 10.1038/s41467-023-38078-4. [DOI] [PMC free article] [PubMed] [Google Scholar]
  59. Szejko V., Justyniak I., Jędrzejewska M., Jędrzejczyk G., Precht T. L., Kubas A., Wheatley A. E. H., Lewiński J.. Luminescent Alkylaluminium Anthranilates Reaching Unity Quantum Yield in the Condensed Phase. Angew. Chem., Int. Ed. 2025;64:202501985. doi: 10.1002/anie.202501985. [DOI] [PubMed] [Google Scholar]
  60. Tretiakov S., Nigam A., Pollice R.. Studying Noncovalent Interactions in Molecular Systems with Machine Learning. Chem. Rev. 2025;125(12):5776–5829. doi: 10.1021/acs.chemrev.4c00893. [DOI] [PMC free article] [PubMed] [Google Scholar]
  61. Haywood P. F., Hill M. R., Roberts N. K., Craig D. C., Russell J. J., Lamb R. N.. Synthesis and Isomerisation Reactions of Tetranuclear and Octanuclear (Carbamato)Zinc Complexes. Eur. J. Inorg. Chem. 2008;2008(12):2024–2032. doi: 10.1002/ejic.200700736. [DOI] [Google Scholar]
  62. Kostakis G. E., Ako A. M., Powell A. K.. Structural Motifs and Topological Representation of Mn Coordination Clusters. Chem. Soc. Rev. 2010;39(6):2238–2271. doi: 10.1039/b918192j. [DOI] [PubMed] [Google Scholar]
  63. Mukhopadhyay S., Mandal S. K., Bhaduri S., Armstrong W. H.. Manganese Clusters with Relevance to Photosystem II. Chem. Rev. 2004;104(9):3981–4026. doi: 10.1021/cr0206014. [DOI] [PubMed] [Google Scholar]
  64. Zdilla, M. J. Electronic Structure of Paramagnetic Iron and Manganese Cluster Compounds: Historical Developments and Current Understanding. In Comprehensive Coordination Chemistry III; Elsevier, 2021; pp 45–81. [Google Scholar]
  65. Sessoli R., Gatteschi D., Caneschi A., Novak M. A.. Magnetic Bistability in a Metal-Ion Cluster. Nature. 1993;365(6442):141–143. doi: 10.1038/365141a0. [DOI] [Google Scholar]
  66. Yang C. I., Zhang Z. Z., Lin S. B.. A Review of Manganese-Based Molecular Magnets and Supramolecular Architectures from Phenolic Oximes. Coord. Chem. Rev. 2015;289–290(1):289–314. doi: 10.1016/j.ccr.2014.12.011. [DOI] [Google Scholar]
  67. Maniaki D., Pilichos E., Perlepes S. P.. Coordination Clusters of 3d-Metals That Behave as Single-Molecule Magnets (SMMs): Synthetic Routes and Strategies. Front. Chem. 2018;6(SEP):461. doi: 10.3389/fchem.2018.00461. [DOI] [PMC free article] [PubMed] [Google Scholar]
  68. Najafpour M. M., Renger G., Hołyńska M., Moghaddam A. N., Aro E.-M., Carpentier R., Nishihara H., Eaton-Rye J. J., Shen J.-R., Allakhverdiev S. I.. Manganese Compounds as Water-Oxidizing Catalysts: From the Natural Water-Oxidizing Complex to Nanosized Manganese Oxide Structures. Chem. Rev. 2016;116(5):2886–2936. doi: 10.1021/acs.chemrev.5b00340. [DOI] [PubMed] [Google Scholar]
  69. Sarkar, A. ; Roy, M. ; Dey, S. G. ; Dey, A. . Iron and Manganese Biomimetic Compounds. In Comprehensive Coordination Chemistry III; Elsevier, 2021; pp 774–823. [Google Scholar]
  70. He Y., Liu Y., Zheng H., Xiang Z., Zhou Z., Geng F., Geng L., Dikarev E. V., Han H.. From Cubane-Assembled Mn-Oxo Clusters to Monodispersed Manganese Oxide Colloidal Nanocrystals. Chem. Sci. 2024;15(27):10381–10391. doi: 10.1039/D4SC01451K. [DOI] [PMC free article] [PubMed] [Google Scholar]
  71. Baikie A. R. E., Howes A. J., Hursthouse M. B., Quick A. B., Thornton P.. Preparation, Crystal Structure, Magnetic Properties, and Chemical Reactions of a Hexanuclear Mixed Valence Manganese Carboxylate. J. Chem. Soc., Chem. Commun. 1986;(21):1587. doi: 10.1039/c39860001587. [DOI] [Google Scholar]
  72. Kim J., Cho H.. Reductive Coupling of Trinuclear [MnIIMn2 IIIO] Core to Form Hexanuclear [Mn4 IIMn2 IIIO2] Cluster. Inorg. Chem. Commun. 2004;7(1):122–124. doi: 10.1016/j.inoche.2003.10.020. [DOI] [Google Scholar]
  73. Ovcharenko V., Fursova E., Romanenko G., Ikorskii V.. Synthesis and Structure of Heterospin Compounds Based on the [Mn6(O)2Piv10]-Cluster Unit and Nitroxide. Inorg. Chem. 2004;43(11):3332–3334. doi: 10.1021/ic049859y. [DOI] [PubMed] [Google Scholar]
  74. Ma C. B., Hu M. Q., Chen H., Chen C. N., Liu Q. T.. Aggregation of Hexanuclear, Mixed-Valence Manganese Oxide Clusters Linked by Propionato Ligands to Form a One-Dimensional Polymer [Mn6O2(O2CEt)10(H2O)4]n . Eur. J. Inorg. Chem. 2008;2008(33):5274–5280. doi: 10.1002/ejic.200800508. [DOI] [Google Scholar]
  75. Seth P., Ghosh A.. A Mixed-Valence Mn6 Cluster Exhibiting Self-Assembled Vesicular Structure and Catecholase-like Activity in Solution State. RSC Adv. 2013;3(11):3717–3725. doi: 10.1039/c3ra22710c. [DOI] [Google Scholar]
  76. Kornowicz A., Komorski S., Wróbel Z., Justyniak I., Nedelko N., Ślawska-Waniewska A., Balawender R., Lewiński J.. Efficient Synthesis of Manganese­(II) Carboxylates: From a Trinuclear Cluster [Mn3(PhCO2)6(THF)4] to a Unique [Mn­(PhCO2)2]n Chiral 3D Network. Dalton Trans. 2014;43(8):3048–3051. doi: 10.1039/C3DT53211A. [DOI] [PubMed] [Google Scholar]
  77. Kar P., Ida Y., Kanetomo T., Drew M. G. B., Ishida T., Ghosh A.. Synthesis of Mixed-Valence Hexanuclear Mn­(II/III) Clusters from Its Mn­(II) Precursor: Variations of Catecholase-like Activity and Magnetic Coupling. Dalton Trans. 2015;44(21):9795–9804. doi: 10.1039/C5DT00709G. [DOI] [PubMed] [Google Scholar]
  78. Manoli M., Johnstone R. D. L., Parsons S., Murrie M., Affronte M., Evangelisti M., Brechin E. K.. A Ferromagnetic Mixed-Valent Mn Supertetrahedron: Towards Low-Temperature Magnetic Refrigeration with Molecular Clusters. Angew. Chem., Int. Ed. 2007;46(24):4456–4460. doi: 10.1002/anie.200701027. [DOI] [PubMed] [Google Scholar]
  79. Manoli M., Collins A., Parsons S., Candini A., Evangelisti M., Brechin E. K.. Mixed-Valent Mn Supertetrahedra and Planar Discs as Enhanced Magnetic Coolers. J. Am. Chem. Soc. 2008;130(33):11129–11139. doi: 10.1021/ja802829d. [DOI] [PubMed] [Google Scholar]
  80. Stamatatos T. C., Poole K. M., Abboud K. A., Wernsdorfer W., O’Brien T. A., Christou G.. High-Spin Mn4 and Mn10 Molecules: Large Spin Changes with Structure in Mixed-Valence Mn4 IIMn6 III Clusters with Azide and Alkoxide-Based Ligands. Inorg. Chem. 2008;47(11):5006–5021. doi: 10.1021/ic800268z. [DOI] [PubMed] [Google Scholar]
  81. Stuiber S., Wu G., Nehrkorn J., Dreiser J., Lan Y., Novitchi G., Anson C. E., Unruh T., Powell A. K., Waldmann O.. Inelastic Neutron Scattering on an Mn10 Supertetrahedron: Assessment of Exchange Coupling Constants, Ferromagnetic Spin Waves and an Analogy to the Hückel Method. Chem. - Eur. J. 2011;17(33):9094–9106. doi: 10.1002/chem.201100500. [DOI] [PubMed] [Google Scholar]
  82. Zhou A. J., Qin L. J., Beedle C. C., Ding S., Nakano M., Leng J. D., Tong M. L., Hendrickson D. N.. New Mn12 Clusters with Tunable Oxidation States via the Use of N,N,N′,N′-Tetrakis­(2-Hydroxyethyl)­Ethylenediamine. Inorg. Chem. 2007;46(20):8111–8113. doi: 10.1021/ic7011588. [DOI] [PubMed] [Google Scholar]
  83. Zhang L., Clérac R., Heijboer P., Schmitt W.. Influencing the Symmetry of High-Nuclearity and High-Spin Manganese Oxo Clusters: Supramolecular Approaches to Manganese-Based Keplerates and Chiral Solids. Angew. Chem., Int. Ed. 2012;51(12):3007–3011. doi: 10.1002/anie.201107358. [DOI] [PubMed] [Google Scholar]
  84. Cotton F. A., Daniels L. M., Falvello L. R., Matonic J. H., Murillo C. A., Wang X., Zhou H.. Transition Metal (Mn, Co) and Zinc Formamidinate Compounds Having the Basic Beryllium Acetate Structure, and Unique Isomeric Iron Compounds. Inorg. Chim. Acta. 1997;266(1):91–102. doi: 10.1016/S0020-1693(97)05538-2. [DOI] [Google Scholar]
  85. Cotton F. A., Daniels L. M., Jordan G. T., Murillo C. A., Pascual I.. Structural Variations in the Ligands around a Simple Oxo-Centered Building Block, the Tetrahedral [M4O]6+ Unit, M = Mn and Fe. Inorg. Chim. Acta. 2000;297(1–2):6–10. doi: 10.1016/S0020-1693(99)00252-2. [DOI] [Google Scholar]
  86. Stokes F. A., Kloo L., Harford P. J., Peel A. J., Less R. J., Wheatley A. E. H., Wright D. S.. Towards the Synthesis of Guanidinate- and Amidinate-Bridged Dimers of Mn and Ni. Aust. J. Chem. 2014;67(7):1081–1087. doi: 10.1071/CH14271. [DOI] [Google Scholar]
  87. Alvarez C. S., Bond A. D., Cave D., Mosquera M. E. G., Harron E. A., Layfield R. A., McPartlin M., Rawson J. M., Wood P. T., Wright D. S.. Syntheses and Magnetic Properties of Hexanuclear [Cp2Mn3(L1)4]2 and Octanuclear [Mn8(L2)12(μ4-O)2] (L1 = 2-HNC5H5N, L2 = 2-NH-3-Br-5-MeC5H3N, Cp = C5H5) Chem. Commun. 2002;3(24):2980–2981. doi: 10.1039/B209496G. [DOI] [PubMed] [Google Scholar]
  88. Belli Dell’Amico D., Bradicich C., Calderazzo F., Guarini A., Labella L., Marchetti F., Tomei A.. New μ-Oxo Octanuclear Complexes of 3d Elements Stabilized by Dialkylcarbamato Ligands. Synthesis and x-Ray Crystal and Molecular Structures. Inorg. Chem. 2002;41(11):2814–2816. doi: 10.1021/ic015626k. [DOI] [PubMed] [Google Scholar]
  89. Hernán-Gómez A., Herd E., Hevia E., Kennedy A. R., Knochel P., Koszinowski K., Manolikakes S. M., Mulvey R. E., Schnegelsberg C.. Organozinc Pivalate Reagents: Segregation, Solubility, Stabilization, and Structural Insights. Angew. Chem., Int. Ed. 2014;53(10):2706–2710. doi: 10.1002/anie.201309841. [DOI] [PubMed] [Google Scholar]
  90. Llunell, M. ; Casanova, D. ; Cirera, J. ; Alemany, P. ; Alvarez, S. . SHAPE, version 2.1, 2013. [Google Scholar]
  91. Zabrodsky H., Peleg S., Avnir D.. Continuous Symmetry Measures. J. Am. Chem. Soc. 1992;114(20):7843–7851. doi: 10.1021/ja00046a033. [DOI] [Google Scholar]
  92. Technologies, A. CrysAlisPro . Data Collection and Processing Software for Agilent X-ray Diffractometers, version 1.171.35.21b, 2012.
  93. Sheldrick G. M.. A Short History of SHELX. Acta Crystallogr., Sect. A: Found. Crystallogr. 2008;64(1):112–122. doi: 10.1107/S0108767307043930. [DOI] [PubMed] [Google Scholar]
  94. Bourhis L. J., Dolomanov O. V., Gildea R. J., Howard J. A. K., Puschmann H.. The Anatomy of a Comprehensive Constrained, Restrained Refinement Program for the Modern Computing Environment – Olex2 Dissected. Acta Crystallogr., Sect. A: Found. Adv. 2015;71(1):59–75. doi: 10.1107/S2053273314022207. [DOI] [PMC free article] [PubMed] [Google Scholar]

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Supplementary Materials

ao5c06133_si_001.pdf (1.5MB, pdf)
ao5c06133_si_002.cif (4.4MB, cif)
ao5c06133_si_003.cif (3.5MB, cif)
ao5c06133_si_004.cif (474KB, cif)

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