Skip to main content
NCBI home page
ACS AuthorChoice logoLink to ACS AuthorChoice
. 2026 Jan 6;45(2):188–196. doi: 10.1021/acs.organomet.5c00441

Reactivity of Diaryl Bismuth Cations toward a Platinum(0) Complex: Oxidative Aryl Transfer

Johannes Schwarzmann 1, Cissie Slopianka 1, Crispin Lichtenberg 1,*
PMCID: PMC12848974  PMID: 41613621

Abstract

Reactions of three aryl-substituted bismuth cations, [BiPh2(SbF6)], [BiMes2(SbF6)], and [BiDipp2(SbF6)], with the Pt0 complex Pt­(PCy3)2 have been investigated (Mes = 2,4,6-trimethyl-phenyl; Dipp = 2,6-di-iso-propyl-phenyl; Cy = cyclohexyl). Unexpectedly, and in contrast with the reactivity of the recently reported methyl analogue [BiMe2(SbF6)], the formation of isolable metal-only Lewis pairs [(Cy3P)2Pt→BiAr2(SbF6)] is not observed (Ar = aryl). Instead, an unprecedented bismuth-to-platinum oxidative aryl transfer is witnessed to give the PtII complexes [PtAr­(PCy3)2(SbF6)], along with the suggested bismuthinidene intermediates BiAr. Attempts to trap these fleeting intermediates with an ortho-quinone led to a PtII semiquinone radical complex.

graphic file with name om5c00441_0008.jpg

graphic file with name om5c00441_0006.jpg

Introduction

Metal–metal interactions in dinuclear organometallic compounds show a multifaceted and broad spectrum of characteristics in terms of the nature of bonding, bond order, and bond strength, resulting in a diverse coordination chemistry and well-tunable reactivity patterns. − In bismuth chemistry, compounds containing Bi–TM interactions (TM = transition metal) − have created cases of trapped reactive species, − metallacycle formation, , selective CH activation events, electrocatalytic CO2 reduction, reversible elementary reactions, , as well as catalytic applications in cyclopropanation, − O2 activation, and radical cyclo-isomerization. , The analysis of Bi–TM bonding interactions reveals three major scenarios that may be distinguished: covalent Bi–TM bonding, ,, Bi→TM dative bonding (with the bismuth component acting as the donor, covering BiI and BiIII species), ,, and TM→Bi dative bonding (with the bismuth component representing the acceptor) − (Scheme a). In addition to the bonding schemes of Bi–TM complexes, fundamental reactivity patterns should also be discussed (Scheme b). The oxidative addition of Bi–Bi, Bi–C, or Bi–X bonds to electron-rich transition metal centers typically leads to the formation of covalent Bi–TM bonding (X = halide; Scheme b.I). ,,− In contrast, adduct formation between suitable bismuth compounds and transition metal complexes has been reported to result in dative bonding scenarios (Scheme b.II,III). ,− ,− In the context of fundamental reactivity patterns, redox-neutral transmetalation events (i.e., ligand exchange reactions) also need to be mentioned, which do not necessarily invoke any Bi–TM bonding, but play a key role in utilizing bismuth compounds as aryl sources in transition-metal-catalyzed crosscoupling reactions (Scheme b.IV). − In our efforts to investigate the reactivity of cationic diaryl bismuth compounds toward an electron-rich transition metal precursor, we have uncovered the oxidative arylation of a transition metal complex as a new facet in the reactivity of bismuth compounds toward well-defined transition metal compounds (Scheme b.V).

1. (a) Bonding Scenarios of Compounds with Bi–TM Interactions. (b) Reactivity Patterns Involving Bismuth Compounds and Transition Metal Complexes. Ar, Ar′ = Aryl; X = Halide, Acetate; L = Neutral Ligand or Vacant Coordination Site.

1

Open in a new tab

Results and Discussion

In the quest to further elucidate the parameters that influence bonding interactions between transition metal Lewis bases and bismuth Lewis acids, ,− , the electron-rich platinum complex Pt­(PCy3)2 was chosen as a model substrate to ensure a reliable comparison with previous results. In view of the apparent robustness of neutral aryl bismuth compounds such as BiPh3 that can conveniently be handled under air compared to their alkyl analogs such as BiMe3 and BiEt3, which are highly air-sensitive or even pyrophoric, ,, we aimed at cationic complexes [Bi­(aryl)2]+ as potential bonding partners. However, compounds of the type [Bi­(aryl)2]+ with simple hydrocarbons as aryl groups and sufficiently weakly coordinating counteranions are surprisingly rare. In fact, only two compounds of this type are known to the literature, the catalytically active parent compound [BiPh2(SbF6)] and the strongly Lewis acidic [BiDipp2(SbF6)] (Dipp = 2,6-di-iso-propyl-phenyl). , Even though other diarylbsimuth compounds like BiPh2OTf are accessible, they are of minor relevance in this context due to the (OTf)− anion being a significantly stronger donating counteranion than (SbF6)−. ,

In order to expand this series of reactive compounds, the synthesis of the [BiMes2]+ complex cation was targeted (Mes = 2,4,6-trimethyl-phenyl). Attempts to isolate [Bi­(Mes)2(SbF6)] from salt elimination reactions of BiMes2Cl with AgSbF6 in dichloromethane led to the precipitation of a mixture of [Bi­(Mes)2(SbF6)] and AgCl (Scheme a, left). The formation of [Bi­(Mes)2(SbF6)] could be demonstrated by single-crystal X-ray analysis (proof of connectivity only, vide infra and Supporting Information), but the separation of AgCl and solvent-free [Bi­(Mes)2(SbF6)] in weakly coordinating solvents could not be obtained. Using the same synthetic approach with a more Lewis basic solvent such as THF allowed for the isolation of analytically pure [Bi­(Mes)2(thf)2(SbF6)] (2) (Scheme a, right). After removal of the precipitated silver salt by filtration, 2 was crystallized from the THF solution at −30 °C. NMR spectroscopic analyses show the expected signal patterns. The relative integral values and chemical shifts of the signals due to the THF units indicate the coordination of two equivalents of these ligands to the central atom, with changes in chemical shifts of the α-CH2 THF groups by 0.02 ppm (1H) and 2.4 ppm (13C) compared to free THF. The 19F NMR spectrum shows one broad resonance without resolved 1 J FSb coupling, suggesting bonding interactions between the Lewis acidic bismuth center and the (SbF6)− counteranion.

2. (a) Synthesis of [BiMes2(thf)2]­[SbF6] (2) and Attempted Isolation of [BiMes2(SbF6)]; *: The Solubility of [BiMes2(SbF6)] in Weakly Coordinating Solvent Was Low, Prohibiting Separation from the By-Product AgCl in the Absence of More Polar Solvents Such as THF. (b) Molecular Structure of 2. Displacement Ellipsoids are Drawn at 50% Probability Level. Only One Out of Two Chemically Identical, but Crystallographically Distinct Molecules in the Unit Cell is Shown. For Clarity, Hydrogen Atoms are Omitted and Carbon Atoms of THF Are Shown as Wireframe. Selected Bond Lengths [Å] and Angles [deg]: Bi–C1 2.273(8), Bi–C10 2.273(7). Bi–O1 2.469(5), Bi–O2 2.454(5), Bi···F1 3.692(5), C1–Bi–C10 108.9(3), C1–Bi–O1 81.4(2), O1–Bi–O2 171.21(17).

2

Open in a new tab

In order to elucidate the molecular structure of the diaryl bismuth cation in the solid state, compounds [BiMes2(SbF6)] (monoclinic space group P2/c, Z = 4; only proof of connectivity) and [Bi­(Mes)2(thf)2(SbF6)] (2) (orthorhombic space group Pca21, Z = 8), were analyzed by single-crystal X-ray diffraction. The donor-free compound exhibits a bisphenoidal coordination geometry around the bismuth center with two mesityl substituents in the equatorial positions and two fluorine atoms of bridging (SbF6)− counterions in the axial positions, leading to a one-dimensional coordination polymer in the solid state (Supporting Information). The central atom in [Bi­(Mes)2(thf)2(SbF6)] (2) interacts with two mesityl and two THF ligands, which also results in a bisphenoidal coordination geometry with the neutral ligands in the axial positions (Scheme b). The C–Bi–C angle of 108.9(3)° is significantly larger than that in related compounds such as [BiMe2(NC5H5)2]­[SbF6] (C–Bi–C, 92.3°) due to the steric demand of the mesityl substituents. The bond angles around the central atom that involve the THF ligands are close to the ideally expected values of 90° C–Bi–O (81.4(2)-94.3(2)°) and 180°, respectively, O–Bi–O (171.21(17)°). , The closest Bi···F distance amounts to 3.53 Å, which is close to the sum of the van-der-Waals radii (3.54 Å), indicating that weak interactions should also be possible in the solid state. Comparing the relatively long Bi–C bonds in 2 (2.273(7) Å and 2.273(8) Å) to those of aryl bismuth cations without neutral ligands ([BiPh2(SbF6)]: 2.247(2)-2.257(2) Å, [BiDipp2(SbF6)] 2.257(2)-2.260(2) Å) or to similar compounds with a low steric profile of the hydrocarbon group ([BiMe2(NC5H5)2]­[SbF6] 2.235(12)-2.223(12) Å) ,, underscores the impact of neutral ligands and the sterically demanding mesityl group.

With compounds [BiPh2(SbF6)] (1), [BiMes2(SbF6)­(thf)2] (2), and [BiDipp2(SbF6)­(tol)] (3) in hand, we set out to investigate the potential formation of Pt → Bi metal-only Lewis pairs. To this end, solutions of bismuth compounds 1–3 in toluene or difluorobenzene were added to solutions of Pt­(PCy3)2 in the same solvent. Upon addition, the color of the reaction mixtures turned from pale yellow to bright red (in the case of 1 and 2) or red-orange to deep-red (in the case of 3), but then changed to light orange over a period of two (for 1) to 4 h (for 2 and 3), while forming a black precipitate.

31P NMR spectroscopic reaction monitoring revealed the formation of a main compound (62% relative signal intensity) in the case of starting material 1 and exclusively one phosphorus-containing species in the case of 2 and 3. No significant change in the spectra was observed over the course of the reaction (despite the precipitation of increasing amounts of a dark solid). The selective reactions of 2 and 3 were tested for solvent effects, but the rapid and selective formation of one new product was observed irrespective of the choice of solvent (toluene, 1,2-difluorobenzene, and THF).

The 31P NMR chemical shifts of the new compounds formed in reactions with 1, 2, and 3, amount to 18.8, 27.0, and 31.2 ppm, respectively. This speaks against the formation of Pt → Bi Lewis pairs (δ­([(PCy3)2Pt→BiMe2(SbF6)]) = 53.4 ppm), but rather for the formation of PtII bis(phosphane) complexes, PtX2(PR3)2 (X = monoanionic ligand), in a square planar or “masked T-shaped” coordination geometry. − The 1 J PtP coupling constants (2796, 2801, and 2871 Hz) clearly favor a trans- over a cis-configuration. In the case of the less selective reaction (with starting material 1) only trace amounts of product 4 could be obtained, which was sufficient for crystallographic analyses (vide infra). For the highly selective reactions (with starting materials 2 and 3), products 5 and 6 could be isolated and fully characterized. Single-crystal X-ray diffraction experiments revealed the products 4-6 to show the composition [Pt­(PCy3)2(Ar)­(SbF6)] (Ar = Ph (4, triclinic space group P1̅, Z = 2), Mes (5, orthorhombic space group Cmc2 1, Z = 4) or Dipp (6, monoclinic space group P21/c, Z = 4); Figure ). For 4 and 5 the platinum atom shows a square planar coordination geometry with two PCy3 ligands trans to each other, in agreement with the 31P NMR spectroscopic data. The aryl group and the (SbF6)− unit occupy the remaining positions. For compound 6, a T-shaped geometry is found due to the lack of a Pt···F contact trans to the Dipp substituent. This is ascribed to the higher steric demand of the Dipp group, which is supported by an analysis of the relevant bond lengths and angles. For instance, the P–Pt–P angle decreases in the order 4 (175.79(4)°) > 5 (169.68(8)°) > 6 (166.184(14)°) and the Pt–C bond lengths increase in the same order 4 (1.982(4) Å) < 5 (2.005(6) Å) < 6 (2.0081(15) Å). The Pt–P bond lengths are only marginally affected by the variations in steric bulk. Indications for agostic Pt···(H–C) interactions in the 14 valence-electron-compound 6 with its three-coordinate platinum center could not be deduced from structural parameters, since the shortest Pt···(H–C) and Pt···(H–C) distances amount to 2.4651–2.989 and 2.941(5)–3.187(3) Å, respectively. These interatomic distances are similar to those in a platinum boryl complex [Pt­(PCy3)2(BBrFc)]­[B­(3,5-(CF3)2-C6H3)4] (Fc = ferrocenyl), for which agostic interactions have been ruled out (Pt···H, 2.542 Å; Pt···C, 3.117 Å) and exceed those of compounds, for which agostic interactions have been reported (e.g.,: [PtMe­(PiPr3)2]­[1-H-closo-CB11Me11] (Pt···H, 2.24 Å; Pt···C, 2.859 Å) and [Pt­(PCy2(2,6-Me2-C6H3))­(κ2-P,C-P­(2-Me-6-CH2C6H3)­Cy2)]­[B­(3,5-(CF3)2-C6H3)4] ((Pt···H, 2.057 Å; Pt···C, 2.432 Å))). ,

1.

1

Open in a new tab

Molecular structures of 4, 5, and 6 in the solid state. Displacement ellipsoids are drawn at the 50% probability level. Hydrogen atoms, lattice-bound solvent molecules, and the (SbF6)− counterion in 6 are omitted, and cyclohexyl groups shown as wireframe for clarity. Selected bond lengths (Å) and angles (deg) for 4: Pt–C1 1.982(4), Pt–F1 2.419(2), Pt–P1 2.3420(10), P1–Pt–P2 175.79(4), C1–Pt–F1 179.62(14), C1–Pt–P1 91.42(12), F1–Pt–P1 88.91(6); for 5: Pt–C1 2.005(6), Pt–F1 2.504(4), Pt–P1 2.3435(10), P1–Pt–P1′ 169.68(8), C1–Pt–F1 163.49(19), C1–Pt–P1 93.15(4), F1–Pt–P1 88.15(4); for 6: Pt–C1 2.0081(15), Pt–P1 2.3531(4), P1–Pt–P2 166.184(14), C1–Pt–P1 96.79(4), Pt···F 5.9240(10).

In solution, compounds 4–6 do not show strong bonding interactions between the platinum atoms and the (SbF6)− units, as indicated by 19F NMR spectroscopy. In the 19F NMR spectra, the distinct resonance for non- or very weakly coordinating (SbF6)− was detected between −106 and −145 ppm. This NMR spectroscopic signal results from two overlaying multiplets, one sextet due to the 1 J SbF coupling between 19F and 121Sb (natural abundancy 57%, I = 5/2) and one octet due to the 1 J SbF coupling between 19F and 123Sb (natural abundancy 43%, I = 7/2). Only if a potential coordination between the central atom and its (SbF6)− counteranion is weak or fluxional enough, a well-resolved resonance for an (SbF6)− anion with apparent O h symmetry will be obtained.

The sequence of reactions that yields compounds 4–6 formally corresponds to the oxidative addition of the Bi–C bond of a bismuth complex cation [BiAr2(SbF6)] to a Pt0 center (Pt0 → PtII), followed by a reductive elimination that yields low-valent bismuth compounds “BiR” (BiIII → BiI), which are subject to subsequent redox-disproportionation (3 BiI → BiIII + 2 Bi0) (Scheme , bottom). This contrasts with the simple Lewis pair formation Pt­(PCy3)2 + BiR2(SbF6) → [(Cy3P)2Pt→BiR2]­[SbF6] that has been observed under identical conditions for the methyl analog (R = Me) (Scheme , top). Interestingly, the originally targeted adduct formation between Pt­(PCy3)2 and the model compound [BiPh2]+ to give [(PCy3)2Pt→BiPh2]+ is strongly exergonic according to DFT calculations (ΔG = −47.4 kcal·mol; Supporting Information). When analyzing subsequent reactions of compounds [(PCy3)2Pt→BiR2]+, however, oxidative aryl transfer from Bi to Pt (R = Ph, experimentally observed) is thermodynamically more favorable than the transfer of an alkyl group (R = Me, experimentally not observed). The calculations suggest the redox disproportionation of bismuthinides BiR to give BiR3 and Bi0 to be an important thermodynamic driving force of the reaction (Supporting Information). In order to experimentally evaluate the ability of different types of bismuth cations to be involved in the net oxidation of the platinum center, [BiMe2(SbF6)] and 1–3 were analyzed by cyclic voltammetry. Under reducing conditions, an irreversible electron transfer with a peak potential of −2.34 ([BiMe2(SbF6)]), −2.02 (1), −2.31 (2), −2.12 (3) V vs Fc/Fc+ was observed, indicating a cathodic shift by 30–320 mV for the aryl species compared to the methyl compound. This points toward the less electron-donating character of the aryl groups (as compared to methyl ligands) as a relevant factor in facilitating the sequence of reactions leading to compounds 4–6. The reactions described herein are equivalent to a net oxidative aryl transfer from a bismuth center to a transition metal atom. While redox-neutral transmetalation events have been reported in a significant number of cases with a focus on Cu and Pd catalysis, ,,, the net oxidative transfer of a simple aryl ligand from a well-defined bismuth precursor to give an isolable bismuth-free transition metal complex adds a new facet to the reactivity between bismuth compounds and transition metal complexes. −

3. Reactions of 1–3 with Pt­(PCy3)2 to Give 4–6 .

3

Open in a new tab

a 1,2-DFB = 1,2-difluorobenzene. Low isolated yields of 5 are due to difficulties in separating bismuth-containing byproducts of the reaction.

Importantly, the formation of 4-6 formally also generates low-valent bismuth compounds BiR as byproducts (Scheme , bottom). HRMS analyses of samples withdrawn at early stages of the reaction support the formation of these reactive intermediates, and 1H NMR spectroscopy indicated the formation of BiR3 at later stages of the reaction (in the case of R = Mes, Dipp), which is the expected product of the redox-disproportionation of BiR (according to 3 BiR → BiR3 + 2 Bi0). ,

Attempts to trap the suggested reactive intermediate BiR have not been successful to date. Also in the presence of trapping reagents, compounds BiR3 have been detected by NMR spectroscopy and HRMS analyses as a result of redox disproportionation events (cf. Scheme , bottom left). Instead, trapping reactions with 3,5-di-tert-butyl-1,2-benzoquinone led to the formation of [Pt­(PCy3)2(O2-3,5-tBu2-C6H2)]­[SbF6] (7) (Scheme a). This compound was identified through single crystal X-ray diffraction analysis (monoclinic space group P21/n, Z = 4; Scheme b) and shows a distorted square planar coordination geometry around the platinum center. The chelating nature of the oxygen-based ligand enforces a small bite angle and a cis arrangement (O–Pt–O, 78.48(13)°), leading to a larger P–Pt–P angle of 105.89(4)°. The (SbF6)− anion does not show directional bonding interactions with the platinum center, as judged by distance criteria. The Pt–P bond lengths do not differ significantly (2.2633(12)–2.2666(13) Å) and are very close to those reported for the PtII catecholate complex [Pt­(PCy3)2(O2C6H4)] (I) (Pt–P, 2.266(2)-2.268(2) Å). In contrast, the Pt–O distances show considerable variations (2.060(3)-2.109(3) Å) and are on average significantly longer than those in PtII catecholates such as I (Pt–O, 2.033(5)-2.051(5) Å) or [Pt­(dppe)­(O2C6H4)] (II) (Pt–O, 2.039(3)-2.056(3) Å; dppe = Ph2PC2H4PPh2). , In turn, the C–O bond lengths in 7 (1.301(6)-1.281(6) Å) are between those in PtII catecholates (I: C–O, 1.338–1.347 Å; II: C–O, 1.340(5)-1.370(5) Å) and those in the free quinone O2-3,5-tBu2-C6H2 (C–O, 1.214(3)–1.217(3) Å). Altogether, this points toward the formation of a cationic PtII species coordinated by a radical semiquinolate ligand (O2-3,5-tBu2-C6H2)•. In agreement with this, compound 7 was NMR silent. Its composition was confirmed by HRMS analysis, with m/z = 975.573, corresponding to the molecular ion peak, and supported by its rational synthesis from Pt­(PCy3)2, 3,5-di-tert-butyl-1,2-benzoquinone, and AgSbF6 (see Experimental Section). To probe the radical nature of 7, EPR spectroscopic experiments with solutions of isolated 7 were performed. Indeed, a broad resonance was detected, unambiguously confirming the radical character of compound 7 (Scheme d). The g iso value of 2.0024 is in agreement with values reported for related compounds that have been generated in situ. The broadness of the resonance indicates coupling of the unpaired spin with multiple coupling partners. This was confirmed by DFT calculations at the B3LYP-D3/def2-TZVP level of theory, which indicate the spin density to be delocalized through the semiquinolate ligand, with additional low spin density being found at the P and Pt atoms (Scheme c). With slight modifications of the instrumental parameters of the EPR spectrometer, the presence of hyperfine interactions could be confirmed. However, only a moderate resolution could be obtained due to the presence of multiple coupling partners so that the assignment of coupling constants has to be taken as a tentative suggestion (Supporting Information). While the synthesis and isolation of diamagnetic platinum catecholates have previously been achieved, ,,, reports on the more challenging-to-handle platinum semiquinolates are rare. To the best of our knowledge, such species have only been generated in situ so far, followed by spectro-electrochemical characterization; thus, compound 7 represents the first example of an isolated platinum semiquinolate complex, suggesting further explorations of this class of platinum compounds with redox-active ligands should be possible.

4. (a) Reaction of Pt­(PCy3)2 with 2 or 3 and O2-3,5-tBu2-C6H2 to Give 7 (1,2-DFB = 1,2-Difluorobenzene) Instead of the Desired Bismuth Catecholate. (b) Molecular Structure of 7 in the Solid State. Displacement Ellipsoids are Drawn at 50% Probability Level, Hydrogen Atoms and Lattice-Bound Solvent Molecules are Omitted, Cyclohexyl Groups Shown as Wireframe for Clarity. Selected Bond Lengths [Å] and angles [deg]: Pt–P1 2.2666(13), Pt–P2 2.2633(12), Pt–O1 2.109(3), Pt–O2 2.060(3), O1–C1 1.301(6), O2–C2 1.281(6), P1–Pt–P2 105.89(4), O1–Pt–O2 18.48(13), O1–Pt–P1 91.03(10), O1–Pt–P2 162.98(10). (c) Spin Density Distribution of [Pt­(PCy3)2(O2-3,5-tBu2-C6H2)]+ (7 + ) as Determined by DFT Calculations (Isovalue = 0.0001; H Atoms Omitted for Clarity). (d) Continuous-Wave X-Band EPR Spectrum of a THF Solution of 7 (c = 4·10–4 mol/L). The Observed Resonance Shows a g iso Value of 2.0024. Spectrometer Settings: Microwave Frequency = 9.473621 GHz, 0.02 mT Modulation Amplitude at 100 kHz, Microwave Power = 1.0 mW, Number of Accumulated Scans = 1, Conversion Time = 1 ms.

4

Open in a new tab

Conclusions

In conclusion, we have investigated a small series of simple diaryl bismuth cations [BiR2(L) n ]+ (R = Ph, Mes, or Dipp; L = neutral ligand, n = 0–2) in the context of metal-only Lewis pair formation. This includes a new member that has been added to this series of rare compounds (R = Mes). Surprisingly, the aryl species [BiR2(L) n ]+ do not undergo simple Lewis pair formation with the electron-rich platinum compound Pt­(PCy3)2, which is in stark contrast to the behavior of the alkyl complex cation [BiMe2]+. The diaryl bismuth cations undergo a sequence of reactions, resulting in the net oxidative aryl transfer to give [PtR­(PCy3)2(SbF6)]. This adds a new facet to the interaction of bismuth compounds with transition metal complexes, for which Lewis pair formation, oxidative addition reactions, and redox-neutral aryl transfer (i.e., ligand exchange reactions) have previously been reported. The bismuth-containing products of these reactions are suggested to be short-lived bismuthinidenes, BiR, which is supported by in situ mass spectrometry and the analysis of follow-up products. Attempted trapping reactions unexpectedly gave the first example of an isolable cationic platinum­(II) complex featuring a semiquinolate radical ligand.

Experimental Section

All experiments were conducted under an atmosphere of dry argon using Schlenk and glovebox techniques. Solvents were degassed and purified according to standard laboratory procedures. NMR spectra were recorded on Bruker Avance spectrometers operating at 300 or 500 MHz with respect to 1H. 1H and 13C NMR chemical shifts are reported relative to SiMe4 using the residual signal of the deuterated solvent as a secondary standard. The assignment of resonances in 1H and 13C NMR spectra has been underlined by 2D experiments, such as HSQC and HMBC NMR spectroscopy. 19F and 31P NMR chemical shifts are reported relative to CFCl3 or 85% aqueous H3PO4, respectively, as external standards. Mass spectrometry was conducted on a Thermo Fischer Scientific Orbitrap Q Exactive Plus using ESI as an ionization method. The samples were infused into the mass spectrometer under an inert atmosphere through a syringe pump. Elemental analyses (C, H, N) were performed on a vario MICRO cube. Cyclic voltammograms were recorded by using a Gamry Interface 1010 potentiostat and a three-electrode setup and a concentration of 0.1 mol/L NBu4PF6 as a conductive salt. EPR spectra were recorded on a Bruker Magnettech ESR5000 spectrometer operating in the X-Band (9.4 GHz). Samples were prepared in an argon-filled glovebox and transferred into a quartz glass tube prior to data collection. All measurements were performed under an atmosphere of purified argon. Simulations of the obtained EPR spectra were done with the EasySpin software package, running in the MATLAB software environment. Single-crystals suitable for X-ray diffraction were coated with polyisobutylene or perfluorinated polyether oil in a glovebox, transferred to a nylon loop, and then transferred to the goniometer of a Bruker D8 Quest or D8 Venture diffractometer equipped with a molybdenum (λ = 0.71073 Å) X-ray tube. Using Olex2, the structures were solved with the XT structure solution program using intrinsic phasing and refined with the XL refinement package using least-squares minimization. All non-hydrogen atoms were refined anisotropically. Hydrogen atoms were included in the structure factor calculations. All hydrogen atoms were assigned to idealized geometric positions. Deposition numbers 2500345–2500349 contain the supplementary crystallographic data for this paper. These data are provided free of charge by the joint Cambridge Crystallographic Data Centre and Fachinformationszentrum Karlsruhe Access Structures service www.ccdc.cam.ac.uk/structures.

Preparation of [BiMes2(SbF6)­(thf)2] (2)

BiMes2Cl (50 mg, 0.104 mmol, 1.0 equiv) was dissolved in THF (2 mL) and combined with a solution of AgSbF6 (36 mg, 0.104 mmol, 1.0 equiv) in THF (3 mL). Upon addition, the solution turns bright yellow, and a colorless precipitate is formed. After filtration and extracting the precipitate with THF (2 mL), the THF phases were combined and stored at −30 °C. After 20 h needle-like crystals of [BiMes2(SbF6)­(thf)2] had formed that were isolated by filtration and dried in vacuo (50 mg, 0.60 mmol, 58%). 1H NMR (500 MHz, CD2Cl2) δ = 1.84 (m, 8 H, thf), 2.30 (s, 6 H, para–CH 3), 2.43 (s, 12 H, ortho–CH 3), 3.71 (m, 8 H, thf), 7.59 (s, 4 H, meta–CH) ppm. 13C­{1H}-NMR (125 MHz, CD2Cl2): δ = 21.74 (s, para-CH3), 25.99 (s, thf), 26.70 (s, ortho-CH3), 70.51 (s, thf), 133.82 (s, meta-CH), 141.53 (s, para-C), 147.06 (s, ortho-C), 206.94 (s, ipso-C) ppm. 19F-NMR (283 MHz, CD2Cl2): δ = −124.0 (br, SbF 6) ppm. Elemental analysis: calcd for [C26H38BiF6O2Sb] (827.31 g/mol): C 37.75, H 4.63; found: C 37.39, H 4.71.

Attempts to prepare BiMes2(SbF6) (i.e., free of neutral ligands) were unsuccessful to date, presumably due to the poor solubility of this species in weakly coordinating solvents such as dichloromethane and 1,2-difluorobenzene.

Attempted Preparation of [Pt­(PCy3)2(Ph)­(SbF6)] (4)

[Bi­(Ph)2(SbF6)] (16 mg, 0.026 mmol, 1.0 equiv) was dissolved in 1,2-difluorobenzene (2 mL) and added to a solution of Pt­(PCy3)2 (20 mg, 0.026 mmol, 1.0 equiv) in 1,2-difluorobenzene (3 mL). The reaction mixture turned bright red at the beginning and yellowish brown after a few seconds. After 2 h, a dark precipitate had formed. The solution was filtered, dried in vacuo and redissolved in dichloromethane. Layering this solution with n-pentane (5 mL) at −30 °C led to the formation of a small amount of yellow crystals after 4 d that allowed the unambiguous confirmation of the connectivity in 4 by single-crystal X-ray analysis. All attempts to isolate 4 in larger amounts have been unsuccessful to date due to the presence of inseparable byproducts.

19F-NMR (283 MHz, CD2Cl2): δ = −106 bis −145 (br, m, SbF 6) ppm. 31P­{1H}-NMR (122 MHz, CD2Cl2): δ = 18.82 (s, 1 J PPt = 2796 Hz) ppm. HRMS (ESI): calcd for [C42H71P2Pt]+: m/z = 832.4677, found: m/z = 832.4660; calculated for [C18H33P] + H+: m/z = 281.2393, found: 281.2387.

Preparation of [Pt­(PCy3)2(Mes)­(SbF6)] (5)

[BiMes2(SbF6)­(thf)2] (50 mg, 0.06 mmol, 1 equiv) was dissolved in toluene and added to a solution of Pt­(Pcy3)2 (46 mg, 0.06 mmol, 1 equiv) in toluene. The dark orange reaction mixture was stirred for 4 h. During this time, the color brightened up and a dark precipitate was formed. After filtration, all volatiles were removed under reduced pressure and the remaining solid was washed with pentane (3 × 2 mL) and extracted with a mixture of dichloromethane and n-pentane (1:3, 2 × 2 mL). Slow evaporation of the solvent mixture at −30 °C led to the formation of orange crystals of [Pt­(PCy3)2(Mes)­(SbF6)], which were isolated by filtration and dried in vacuo (15 mg, 0.013 mmol, 22%).

1H NMR (500 MHz, CD2Cl2) δ = 1.19–1.26 (br, m, 18 H, overlap of 12 H of 2,6-PCy3, and 6 H of 4-PCy3), 1.34–1.42 (br, m, 12 H, 3,5-PCy3) 1.72–1.82 (br, m, 30 H, overlap of 12 H of 2,6-PCy3, 12 H of 3,5-PCy3 and 6 H of 4-PCy3), 2.18 (s, 3 H, Mes-para–CH 3), 2.21–2.28 (br, m, 6 H, 1-PCy3), 2.71 (s, 6 H, Mes-ortho–CH 3), 6.49 (s, 2 H, Mes-meta–CH) ppm. 13C­{1H}-NMR (126 MHz, CD2Cl2) δ = 19.95 (s, Mes para-CH3, detected via 1H–13C-HSQC spectrum), 26.32 (s, 4-PCy3), 27.84 (vt, 2 J PC = 5.3 Hz, 2,6-PCy3), 28.46 (s, Mes ortho-CH3, detected via 1H–13C-HSQC spectrum) 30.66 (s, 3,5-PCy3), 35.57 (vt, 1 J PC = 12.7 Hz, 1-PCy3), 121.73 (s, Mes ortho-C, detected via 1H–13C-HMBC spectrum), 127.74 (s, Mes meta-CH), 134.65 (s, Mes ipso-C, detected via 1H–13C-HMBC spectrum), 134.69 (s, Mes para-C, detected via 1H–13C-HMBC spectrum) ppm. 19F-NMR (283 MHz, CD2Cl2): δ = −106 bis −145 (br, m, SbF 6) ppm. 31P­{1H}-NMR (122 MHz, CD2Cl2): δ = 27.01 (s, 1 J PPt = 2801 Hz) ppm. HRMS (ESI): calculated for [C45H77P2Pt]+: m/z = 874.5147, found: m/z = 874.5120; calculated for [C18H33P] + H+: m/z = 281.2393, found: 281.2384.

Preparation of [Pt­(PCy3)2(Dipp)­(SbF6)] (6)

[Bi­(Dipp)2(SbF6)­(tol)] (60 mg, 0.070 mmol, 1 equiv) was dissolved in 1,2-difluorobenzene (3 mL) and added to a solution of Pt­(PCy3)2 (53 mg, 0.070 mmol, 1 equiv) in 1,2-difluorobenzene (4 mL), leading to a darkening of the red color. The reaction mixture was thoroughly stirred for 4 h at room temperature. During this time, the color brightened up, and a dark precipitate was formed. All volatiles were removed under reduced pressure. The crude product was dissolved in dichloromethane (1 mL) and filtered. The filtrate was layered with a mixture of diethyl ether (3 mL) and n-pentane (5 mL). After 5 days, red crystals of [Pt­(PCy3)2(Dipp)­(SbF6)] had formed, were isolated by filtration, and dried in vacuo (49 mg, 0.042 mmol, 61%).

1H NMR (500 MHz, CD2Cl2) δ = 1.18–1.50 (br, m, 30 H, overlap of 12 H of 2,6-PCy3, 12 H of 3,5-PCy3 and 6 H of 4-PCy3), 1.37 (d, 12 H, 3 J HH = 6.7 Hz, Dipp iso-propyl–CH 3, in overlap with the PCy3 signals), 1.55–2.04 (br, m, 30 H, overlap of 12H of 2,6-PCy3, 12 H of 3,5-PCy3 and 6 H of 4-PCy3), 2.23–2.52 (br, s, 6 H, 1-PCy3), 4.18 (sept, 2 H, 3 J HH = 6.7 Hz, Dipp iso-propyl–CH), 6.60 (d, 2 H, 3 J HH = 7.4 Hz, Dipp meta CH), 6.94 (t, 1 H, 3 J HH = 7.4 Hz, Dipp para CH) ppm. 13C­{1H}-NMR (126 MHz, CD2Cl2) δ = 25.52 (s, Dipp iso-propyl-CH3), 26.22 (s, 4-PCy3), 27.61 (t, 2JPC = 5.2 Hz, 2,6-PCy3), 31.25 (br, s, 3,5-PCy3), 34.41 (br, t, 1JPC = 11.4 Hz, 1-PCy3), 40.13 (s, Dipp iso-propyl-CH), 124.01 (s, Dipp meta-CH), 124.83 (s, Dipp ortho-C), 127.94 (s, Dipp para-CH), 144.26 (s, Dipp ipso-C) ppm. 19F-NMR (283 MHz, CD2Cl2): δ = −106 bis −143 (br, m, SbF 6) ppm. 31P­{1H}-NMR (122 MHz, CD2Cl2): δ = 31.21 (s, 1 J PPt = 2871 Hz) ppm. Elemental analysis: calcd for [C48H83F6P2PtSb] (1152.97 g/mol): C 50.00, H 7.26; found: C 50.33, H 7.17.

Preparation of [Pt­(PCy3)2(O2-3,5-tBu2-C6H2)­(SbF6)] (7)

Pt­(PCy3)2 (60 mg, 0.079 mmol, 1 equiv) was dissolved in THF (3 mL) and added to a solution of 3,5-di-tert-butyl-1,2-benzoquinone (17 mg, 0.079 mmol, 1 equiv) in THF (1 mL). Upon addition, a yellow solution was obtained, to which AgSbF6 (30 mg, 0.079 mmol, 1 equiv) was added. The formation of a black precipitate was observed, which was filtered off after 5 min. The remaining dark greenish solution was layered with n-pentane and stored at −30 °C to form colorless crystals of [Pt­(PCy3)2(O2-3,5-tBu2-C6H2)­(SbF6)] that were isolated by filtration and dried in vacuo (52 mg, 0.043 mmol, 54%). Due to the paramagnetic nature of the compound, no resonances could be detected via NMR spectroscopy. EPR spectra are presented and discussed in the main part and in the Supporting Information. HRMS (ESI): calcd for [C50H86O2P2Pt]+: m/z = 975.5750, found: m/z = 975.5734.

Supplementary Material

om5c00441_si_001.pdf (2.1MB, pdf)
om5c00441_si_002.xyz (46.1KB, xyz)

Acknowledgments

The authors thank Sangeetha Satheesh for helping in the acquisition of cyclic voltammograms.

Glossary

Abbreviations

Mes

2,4,6-trimethyl-phenyl

Dipp

2,6-di-iso-propyl-phenyl

Ph

phenyl

NMR

nuclear magnetic resonance

EPR

electron paramagnetic resonance

1,2-DFB

1,2-difluorobenzene

The Supporting Information is available free of charge at https://pubs.acs.org/doi/10.1021/acs.organomet.5c00441.

  • NMR Spectra, mass spectra, EPR spectroscopic, crystallographic and computational details, cyclic voltammograms, experimental details of trapping reactions (PDF)

  • Cartesian coordinates of DFT-geometry-optimized structures (XYZ)

Conceptualization: J.S. and C.L. Funding acquisition, project administration, and resources: C.L. Investigation: J.S., C.S., and C.L. Visualization: J.S. and C.L. Supervision: J.S. (minor) and C.L. (major). Writingoriginal draft: J.S. and C.L. Writingreview and editing. All authors have given approval to the final version of the manuscript.

Funding by the Deutsche Forschungsgemeinschaft (DFG, grant number LI2860/5–1) and the LOEWE program (LOEWE/4b//519/05/01.002(0002)/85) is gratefully acknowledged. This project has received funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation program (grant agreement No 946184).

The authors declare no competing financial interest.

Published as part of Organometallics special issue “Organometallic Chemistry Beyond the Transition Metals: Fundamentals and Applications of the P-Block”.

References

  1. Parkin, G. Metal-Metal Bonding, Structure and Bonding Ser, v.136; Springer: Berlin/Heidelberg, 2010. [Google Scholar]
  2. Berry J. F., Lu C. C.. Metal-Metal Bonds: From Fundamentals to Applications. Inorg. Chem. 2017;56:7577–7581. doi: 10.1021/acs.inorgchem.7b01330. [DOI] [PubMed] [Google Scholar]
  3. Krogman J. P., Thomas C. M.. Metal-metal multiple bonding in C3-symmetric bimetallic complexes of the first row transition metals. Chem. Commun. 2014;50:5115–5127. doi: 10.1039/c3cc47537a. [DOI] [PubMed] [Google Scholar]
  4. Chisholm M. H.. Recent advances in the chemistry of metal-metal multiple bonds. Polyhedron. 1987;6:665–801. doi: 10.1016/S0277-5387(00)86872-2. [DOI] [Google Scholar]
  5. Breunig H. J.. Organometallic Compounds with Homonuclear Bonds between Bismuth Atoms, 70 Years after Paneth’ Report on the Violet Dimethyl Bismuth Compound. Z. Anorg. Allg. Chem. 2005;631:621–631. doi: 10.1002/zaac.200400476. [DOI] [Google Scholar]
  6. Fackler, J. P., Jr. Metal-Metal Bonds and Clusters in Chemistry and Catalysis, Industry-University Cooperative Chemistry Program Symposia Ser.; Springer, 1990. [Google Scholar]
  7. Green J. C., Green M. L. H., Parkin G.. The occurrence and representation of three-centre two-electron bonds in covalent inorganic compounds. Chem. Commun. 2012;48:11481–11503. doi: 10.1039/c2cc35304k. [DOI] [PubMed] [Google Scholar]
  8. Resa I., Carmona E., Gutierrez-Puebla E., Monge A.. Decamethyldizincocene, a stable compound of Zn­(I) with a Zn-Zn bond. Science. 2004;305:1136–1138. doi: 10.1126/science.1101356. [DOI] [PubMed] [Google Scholar]
  9. Green S. P., Jones C., Stasch A.. Stable magnesium­(I) compounds with Mg-Mg bonds. Science. 2007;318:1754–1757. doi: 10.1126/science.1150856. [DOI] [PubMed] [Google Scholar]
  10. Tokitoh N., Arai Y., Okazaki R., Nagase S.. Synthesis and Characterization of a Stable Dibismuthene: Evidence for a Bi-Bi Double Bond. Science. 1997;277:78–80. doi: 10.1126/science.277.5322.78. [DOI] [Google Scholar]
  11. Cotton F. A.. Metal-Metal Bonding in [Re2X8]2‑ Ions and Other Metal Atom Clusters. Inorg. Chem. 1965;4:334–336. doi: 10.1021/ic50025a016. [DOI] [Google Scholar]
  12. Nguyen T., Sutton A. D., Brynda M., Fettinger J. C., Long G. J., Power P. P.. Synthesis of a stable compound with fivefold bonding between two chromium­(I) centers. Science. 2005;310:844–847. doi: 10.1126/science.1116789. [DOI] [PubMed] [Google Scholar]
  13. Benjamin S. L., Reid G.. Neutral organoantimony­(III) and organobismuth­(III) ligands as acceptors in transition metal complexes – Role of substituents and co-ligands. Coord. Chem. Rev. 2015;297–298:168–180. doi: 10.1016/j.ccr.2015.02.003. [DOI] [Google Scholar]
  14. Greenacre V. K., Levason W., Reid G.. Developments in the chemistry of stibine and bismuthine complexes. Coord. Chem. Rev. 2021;432:213698. doi: 10.1016/j.ccr.2020.213698. [DOI] [Google Scholar]
  15. Champness N. R., Levason W.. Coordination chemistry of stibine and bismuthine ligands. Coord. Chem. Rev. 1994;133:115–217. doi: 10.1016/0010-8545(94)80058-8. [DOI] [Google Scholar]
  16. Roggan S., Limberg C.. Molecular molybdenum/bismuth compounds. Inorg. Chim. Acta. 2006;359:4698–4722. doi: 10.1016/j.ica.2006.04.030. [DOI] [Google Scholar]
  17. Braunschweig H., Cogswell P., Schwab K.. Synthesis, structure and reactivity of complexes containing a transition metal–bismuth bond. Coord. Chem. Rev. 2011;255:101–117. doi: 10.1016/j.ccr.2010.07.002. [DOI] [Google Scholar]
  18. Ramler J., Lichtenberg C.. Bismuth species in the coordination sphere of transition metals: synthesis, bonding, coordination chemistry, and reactivity of molecular complexes. Dalton Trans. 2021;50:7120–7138. doi: 10.1039/D1DT01300A. [DOI] [PubMed] [Google Scholar]
  19. Arif A. M., Cowley A. H., Norman N. C., Pakulski M.. A tungsten-bismuth cluster featuring dibismuth as a four-electron donor and a bridging bismuthinidene. J. Am. Chem. Soc. 1985;107:1062–1063. doi: 10.1021/ja00290a054. [DOI] [Google Scholar]
  20. Arif A. M., Cowley A. H., Norman N. C., Pakulski M.. Reactivity of bulky alkyldichlorostibines and alkyldichlorobismuthines toward [W­(CO)­5]­2-: synthesis of compounds containing stibinidene, bismuthinidene, and dibismuth ligands. Inorg. Chem. 1986;25:4836–4840. doi: 10.1021/ic00247a012. [DOI] [Google Scholar]
  21. Balazs L., Breunig H. J., Lork E., Silvestru C.. Low-Valent Organobismuth Compounds with Intramolecular Coordination: cyclo-R3Bi3, cyclo-R4Bi4, RBi­[W­(CO)5]2, and R4Bi2 [R = 2-(Me2NCH2)­C6H4] Eur. J. Inorg. Chem. 2003;2003:1361–1365. doi: 10.1002/ejic.200390176. [DOI] [Google Scholar]
  22. Wolf R., Fischer J., Fischer R. C., Fettinger J. C., Power P. P.. Reactions of Terphenylbismuth Dihalides with KSi­(SiMe3)3, K2Si2(SiMe3)4 and Na2[Fe­(CO)]4: Reduction vs. Metathesis. Eur. J. Inorg. Chem. 2008;2008:2515–2521. doi: 10.1002/ejic.200701334. [DOI] [Google Scholar]
  23. Meleschko D., Palui P., Gomila R. M., Schnakenburg G., Filippou A. C., Frontera A., Bismuto A.. Light-dependent Reactivity of Heavy Pnictogen Double Bonds. Angew. Chem., Int. Ed. 2024:e202405400. doi: 10.1002/anie.202405400. [DOI] [PubMed] [Google Scholar]
  24. Roggan S., Limberg C., Ziemer B., Brandt M.. Intramolecular C-H activation in complexes with Mo-Bi metal bonds. Angew. Chem., Int. Ed. 2004;43:2846–2849. doi: 10.1002/anie.200353576. [DOI] [PubMed] [Google Scholar]
  25. Yoshida T., Ahsan H. M., Zhang H.-T., Izuogu D. C., Abe H., Ohtsu H., Yamaguchi T., Breedlove B. K., Thom A. J. W., Yamashita M.. Ionic-caged heterometallic bismuth-platinum complex exhibiting electrocatalytic CO2 reduction. Dalton Trans. 2020;49:2652–2660. doi: 10.1039/C9DT04817K. [DOI] [PubMed] [Google Scholar]
  26. Ramler J., Geist F., Mihm C., Lubczyk L., Reith S., Herok C., Fantuzzi F., Lichtenberg C.. Bismuth Bound to Transition Metals: Visible-Light-Induced Olefin Coordination, Reductive Elimination, and Oxidative Addition. Chem. - Eur. J. 2025;31:e202403253. doi: 10.1002/chem.202403253. [DOI] [PubMed] [Google Scholar]
  27. Cassidy J. M., Whitmire K. H.. Syntheses and structures of the phenylbismuth/transition-metal carbonyl compounds [PPN]­[Ph2BiFe­(CO)4], (Ph2Bi)2Fe­(CO)4, [PhBiFe­(CO)4]2 and Ph2BiMn­(CO)5 . Inorg. Chem. 1991;30:2788–2795. doi: 10.1021/ic00013a016. [DOI] [Google Scholar]
  28. Hansen J., Li B., Dikarev E., Autschbach J., Davies H. M. L.. Combined experimental and computational studies of heterobimetallic Bi-Rh paddlewheel carboxylates as catalysts for metal carbenoid transformations. J. Org. Chem. 2009;74:6564–6571. doi: 10.1021/jo900998s. [DOI] [PubMed] [Google Scholar]
  29. Collins L. R., van Gastel M., Neese F., Fürstner A.. Enhanced Electrophilicity of Heterobimetallic Bi-Rh Paddlewheel Carbene Complexes: A Combined Experimental, Spectroscopic, and Computational Study. J. Am. Chem. Soc. 2018;140:13042–13055. doi: 10.1021/jacs.8b08384. [DOI] [PubMed] [Google Scholar]
  30. Collins L. R., Auris S., Goddard R., Fürstner A.. Chiral Heterobimetallic Bismuth-Rhodium Paddlewheel Catalysts: A Conceptually New Approach to Asymmetric Cyclopropanation. Angew. Chem., Int. Ed. 2019;58:3557–3561. doi: 10.1002/anie.201900265. [DOI] [PubMed] [Google Scholar]
  31. Materne K., Braun-Cula B., Herwig C., Frank N., Limberg C.. Bismuthanes as Hemilabile Donors in an O2 -Activating Palladium(0) Complex. Chem. - Eur. J. 2017;23:11797–11801. doi: 10.1002/chem.201703489. [DOI] [PubMed] [Google Scholar]
  32. Ramler J., Krummenacher I., Lichtenberg C.. Bismuth Compounds in Radical Catalysis: Transition Metal Bismuthanes Facilitate Thermally Induced Cycloisomerizations. Angew. Chem., Int. Ed. 2019;58:12924–12929. doi: 10.1002/anie.201904365. [DOI] [PubMed] [Google Scholar]
  33. Martínez S., Junghanns M. A., Dunaj T., Lichtenberg C.. Bismuth Radical Catalysis: Thermally Induced Intramolecular C­(sp3)–C­(sp) Cyclization of Unactivated Alkyl Iodides and Alkynes. ACS Catal. 2025;15:14976–14982. doi: 10.1021/acscatal.5c02812. [DOI] [PMC free article] [PubMed] [Google Scholar]
  34. Breunig H. J., Borrmann T., Lork E., Moldovan O., Rat C. I., Wagner R. P.. Syntheses, crystal structures and DFT studies of [Me3EM­(CO)5] (E = Sb, Bi; M = Cr, W), cis-[(Me3Sb)2Mo­(CO)4], and [tBu3BiFe­(CO)4] J. Organomet. Chem. 2009;694:427–432. doi: 10.1016/j.jorganchem.2008.11.022. [DOI] [Google Scholar]
  35. Vránová I., Alonso M., Jambor R., Růžička A., Erben M., Dostál L.. Stibinidene and Bismuthinidene as Two-Electron Donors for Transition Metals (Co and Mn) Chem. - Eur. J. 2016;22:7376–7380. doi: 10.1002/chem.201601272. [DOI] [PubMed] [Google Scholar]
  36. Lin T.-P., Ke I.-S., Gabbaï F. P.. σ-Accepting properties of a chlorobismuthine ligand. Angew. Chem., Int. Ed. 2012;51:4985–4988. doi: 10.1002/anie.201200854. [DOI] [PubMed] [Google Scholar]
  37. Tschersich C., Limberg C., Roggan S., Herwig C., Ernsting N., Kovalenko S., Mebs S.. Gold- and platinum-bismuth donor-acceptor interactions supported by an ambiphilic PBiP pincer ligand. Angew. Chem., Int. Ed. 2012;51:4989–4992. doi: 10.1002/anie.201200848. [DOI] [PubMed] [Google Scholar]
  38. Tschersich C., Hoof S., Frank N., Herwig C., Limberg C.. The Effect of Substituents at Lewis Acidic Bismuth­(III) Centers on Its Propensity to Bind a Noble Metal Donor. Inorg. Chem. 2016;55:1837–1842. doi: 10.1021/acs.inorgchem.5b02740. [DOI] [PubMed] [Google Scholar]
  39. Schwarzmann J., Eskelinen T., Reith S., Ramler J., Karttunen A. J., Poater J., Lichtenberg C.. Bismuth as a Z-Type Ligand: an Unsupported Pt-Bi Donor-Acceptor Interaction and its Umpolung by Reaction with H2 . Angew. Chem., Int. Ed. 2024;63:e202410291. doi: 10.1002/anie.202410291. [DOI] [PubMed] [Google Scholar]
  40. Braunschweig H., Brenner P., Cogswell P., Kraft K., Schwab K.. Oxidative addition of the bismuth-chloride bond: synthesis and structure of trans-PtCl­(PCy3)2{BiCl2} Chem. Commun. 2010;46:7894–7896. doi: 10.1039/c0cc00639d. [DOI] [PubMed] [Google Scholar]
  41. Shimada S., Wang X.-B., Tanaka M.. Oxidative addition of Bi-C bonds to Pt(0): reaction of Pt­(PEt3)3 with cyclic organobismuth compounds. Chem. Commun. 2020;56:15216–15219. doi: 10.1039/D0CC07408J. [DOI] [PubMed] [Google Scholar]
  42. Tschersich C., Braun B., Herwig C., Limberg C.. PBiP Pincer Complexes of Platinum, Palladium, and Iridium Featuring Metal–Metal Bonds Synthesized by Oxidative Addition of Bismuth–Halide Bonds. Organometallics. 2015;34:3782–3787. doi: 10.1021/acs.organomet.5b00439. [DOI] [Google Scholar]
  43. Schumann H., Eguren L.. Synthesis and characterization of [C5H5Fe­(CO)2(ER3)]­BF4 complexes (E = N, P, As, Sb and Bi): crystal structure determination of [C5H5Fe­(CO)2(Bi­(C6H5)3)]­BF4 . J. Organomet. Chem. 1991;403:183–193. doi: 10.1016/0022-328X(91)83099-P. [DOI] [Google Scholar]
  44. Benjamin S. L., Karagiannidis L., Levason W., Reid G., Rogers M. C.. Hybrid Dibismuthines and Distibines: Preparation and Properties of Antimony and Bismuth Oxygen, Sulfur, and Nitrogen Donor Ligands. Organometallics. 2011;30:895–904. doi: 10.1021/om1010148. [DOI] [Google Scholar]
  45. Desnoyers J., Rivest R.. Coordination Complexes of Niobium Pentachloride with Triphenyl Derivatives of Group V Elements. Can. J. Chem. 1965;43:1879–1880. doi: 10.1139/v65-246. [DOI] [Google Scholar]
  46. Gagnon A., Dansereau J., Le Roch A.. Organobismuth Reagents: Synthesis, Properties and Applications in Organic Synthesis. Synthesis. 2017;49:1707–1745. doi: 10.1055/s-0036-1589482. [DOI] [Google Scholar]
  47. Kutudila P., Linguerri R., Ponce-Vargas M., Pichon C., Condon S., Hochlaf M.. Three-phenyl transfer in palladium-catalyzed C C coupling reactions by triarylbismuths: A mechanistic study. Mol. Catal. 2020;482:110649. doi: 10.1016/j.mcat.2019.110649. [DOI] [Google Scholar]
  48. Rao M. L. N., Venkatesh V., Jadhav D. N.. Palladium-Catalyzed Synthesis of 4-Arylcoumarins Using Triarylbismuth Compounds as Atom-Efficient Multicoupling Organometallic Nucleophiles. Eur. J. Org. Chem. 2010;2010:3945–3955. doi: 10.1002/ejoc.201000134. [DOI] [Google Scholar]
  49. Kobiki Y., Kawaguchi S.-I., Ogawa A.. Palladium-Catalyzed Synthesis of α-Diimines from Triarylbismuthines and Isocyanides. Org. Lett. 2015;17:3490–3493. doi: 10.1021/acs.orglett.5b01566. [DOI] [PubMed] [Google Scholar]
  50. Bauer J., Braunschweig H., Dewhurst R. D.. Metal-only Lewis pairs with transition metal lewis bases. Chem. Rev. 2012;112:4329–4346. doi: 10.1021/cr3000048. [DOI] [PubMed] [Google Scholar]
  51. Hébert M., Petiot P., Benoit E., Dansereau J., Ahmad T., Le Roch A., Ottenwaelder X., Gagnon A.. Synthesis of Highly Functionalized Triarylbismuthines by Functional Group Manipulation and Use in Palladium- and Copper-Catalyzed Arylation Reactions. J. Org. Chem. 2016;81:5401–5416. doi: 10.1021/acs.joc.6b00767. [DOI] [PubMed] [Google Scholar]
  52. Marquardt A.. Ueber Wismuthalkyle. Ber. Dtsch. Chem. Ges. 1887;20:1516–1523. doi: 10.1002/cber.188702001332. [DOI] [Google Scholar]
  53. Dunaj T., Schwarzmann J., Ramler J., Stoy A., Reith S., Nitzsche J., Völlinger L., von Hänisch C., Lichtenberg C.. Bismuth Cations: Fluoride Ion Abstraction, Isocyanide Coordination, and Impact of Steric Bulk on Lewis Acidity. Chem. - Eur. J. 2023;29:e202204012. doi: 10.1002/chem.202301354. [DOI] [PubMed] [Google Scholar]
  54. Wang R., Martínez S., Schwarzmann J., Zhao C. Z., Ramler J., Lichtenberg C., Wang Y.-M.. Transition Metal Mimetic π-Activation by Cationic Bismuth­(III) Catalysts for Allylic C-H Functionalization of Olefins Using CO and CN Electrophiles. J. Am. Chem. Soc. 2024;146:22122–22128. doi: 10.1021/jacs.4c06235. [DOI] [PMC free article] [PubMed] [Google Scholar]
  55. Labrouillère M., Le Roux C., Gaspard H., Laporterie A., Dubac J., Desmurs J. R.. An efficient method for the preparation of bismuth­(III) trifluoromethanesulfonate. Tetrahedron Lett. 1999;40:285–286. doi: 10.1016/S0040-4039(98)02397-1. [DOI] [Google Scholar]
  56. Beckmann J., Bolsinger J., Duthie A., Finke P., Lork E., Lüdtke C., Mallow O., Mebs S.. Mesityltellurenyl cations stabilized by triphenylpnictogens MesTe­(EPh3)+ (E = P, As, Sb) Inorg. Chem. 2012;51:12395–12406. doi: 10.1021/ic3017722. [DOI] [PubMed] [Google Scholar]
  57. Fulmer G. R., Miller A. J. M., Sherden N. H., Gottlieb H. E., Nudelman A., Stoltz B. M., Bercaw J. E., Goldberg K. I.. NMR Chemical Shifts of Trace Impurities: Common Laboratory Solvents, Organics, and Gases in Deuterated Solvents Relevant to the Organometallic Chemist. Organometallics. 2010;29:2176–2179. doi: 10.1021/om100106e. [DOI] [Google Scholar]
  58. Ramler J., Fantuzzi F., Geist F., Hanft A., Braunschweig H., Engels B., Lichtenberg C.. The Dimethylbismuth Cation: Entry Into Dative Bi-Bi Bonding and Unconventional Methyl Exchange. Angew. Chem., Int. Ed. 2021;60:24388–24394. doi: 10.1002/anie.202109545. [DOI] [PMC free article] [PubMed] [Google Scholar]
  59. Mantina M., Chamberlin A. C., Valero R., Cramer C. J., Truhlar D. G.. Consistent van der Waals radii for the whole main group. J. Phys. Chem. A. 2009;113:5806–5812. doi: 10.1021/jp8111556. [DOI] [PMC free article] [PubMed] [Google Scholar]
  60. Ortuño M. A., Conejero S., Lledós A.. True and masked three-coordinate T-shaped platinum­(II) intermediates. Beilstein J. Org. Chem. 2013;9:1352–1382. doi: 10.3762/bjoc.9.153. [DOI] [PMC free article] [PubMed] [Google Scholar]
  61. Fornies J., Green M., Spencer J. L., Stone F. G. A.. Synthesis and some oxidative-addition reactions of bis­(tricyclohexylphosphine)­platinum. J. Chem. Soc., Dalton Trans. 1977:1006–1009. doi: 10.1039/dt9770001006. [DOI] [Google Scholar]
  62. Al-Najjar I. M.. 31P and 195Pt NMR characteristics of new binuclear complexes of [Pt2X4]­(PR3)2] cis/trans isomers and of mononuclear analogs. Inorg. Chim. Acta. 1987;128:93–104. doi: 10.1016/S0020-1693(00)84701-5. [DOI] [Google Scholar]
  63. Jasim N. A., Perutz R. N.. Hydrogen Bonding in Transition Metal Complexes: Synthesis, Dynamics, and Reactivity of Platinum Hydride Bifluoride Complexes. J. Am. Chem. Soc. 2000;122:8685–8693. doi: 10.1021/ja0010913. [DOI] [Google Scholar]
  64. Haar C. M., Nolan S. P., Marshall W. J., Moloy K. G., Prock A., Giering W. P.. Synthetic, Structural, and Solution Thermochemical Studies in the Dimethylbis­(phosphine)­platinum­(II) System. Dichotomy between Structural and Thermodynamic Trends. Organometallics. 1999;18:474–479. doi: 10.1021/om9807001. [DOI] [Google Scholar]
  65. Nilsson P., Plamper F., Wendt O. F.. Synthesis, Structure, and Reactivity of Arylfluoro Platinum­(II) Complexes. Organometallics. 2003;22:5235–5242. doi: 10.1021/om030524i. [DOI] [Google Scholar]
  66. Braunschweig H., Radacki K., Rais D., Scheschkewitz D.. A T-shaped platinum­(II) boryl complex as the precursor to a platinum compound with a base-stabilized borylene ligand. Angew. Chem., Int. Ed. 2005;44:5651–5654. doi: 10.1002/anie.200501588. [DOI] [PubMed] [Google Scholar]
  67. Ingleson M. J., Mahon M. F., Weller A. S.. PtMe­(iPr3P)2 +: a Pt­(II) complex with an agostic interaction that undergoes C-H activation. Chem. Commun. 2004:2398–2399. doi: 10.1039/B410846A. [DOI] [PubMed] [Google Scholar]
  68. Baratta W., Stoccoro S., Doppiu A., Herdtweck E., Zucca A., Rigo P.. Novel T-shaped 14-electron platinum­(II) complexes stabilized by one agostic interaction. Angew. Chem., Int. Ed. 2003;42:105–108. doi: 10.1002/anie.200390035. [DOI] [PubMed] [Google Scholar]
  69. Matsumura M., Yamada M., Tsuji T., Murata Y., Kakusawa N., Yasuike S.. Palladium-catalyzed cross-coupling reactions of triarylbismuthanes with terminal alkynes under aerobic conditions. J. Organomet. Chem. 2015;794:70–75. doi: 10.1016/j.jorganchem.2015.06.029. [DOI] [Google Scholar]
  70. Adams R. D., Pearl W. C.. Rhenium-bismuth carbonyl cluster compounds. Inorg. Chem. 2009;48:9519–9525. doi: 10.1021/ic901176x. [DOI] [PubMed] [Google Scholar]
  71. Adams R. D., Pearl W. C.. Osmium-bismuth complexes from the reaction of Os3(CO)11(NCMe) with BiPh3 . Inorg. Chem. 2010;49:7170–7175. doi: 10.1021/ic100994t. [DOI] [PubMed] [Google Scholar]
  72. Adams R. D., Kan Y., Zhang Q.. Facile cleavage of phenyl groups from BiPh3 in its reactions with Os3(CO)10(NCMe)2 and evidence for localization of π-bonding in a bridging benzyne ligand. J. Organomet. Chem. 2014;751:475–481. doi: 10.1016/j.jorganchem.2013.07.027. [DOI] [Google Scholar]
  73. Hu X.-H., Fang W.-Z., Yang M., Li C., Yi X.-Y.. Unexpected transfer of phenyl from a phenylbismuth complex to iridium in [Cp*IrCl2]2 . J. Coord. Chem. 2014;67:779–786. doi: 10.1080/00958972.2014.908189. [DOI] [Google Scholar]
  74. Bresien J., Schulz A., Thomas M., Villinger A.. A Bismuth–Arene σ-Complex – On the Edge of Menshutkin-Type Complexes. Eur. J. Inorg. Chem. 2019;2019:1279–1287. doi: 10.1002/ejic.201900003. [DOI] [Google Scholar]
  75. Oberdorf K., Hanft A., Xie X., Bickelhaupt F. M., Poater J., Lichtenberg C.. Insertion of CO2 and CS2 into Bi-N bonds enables catalyzed CH-activation and light-induced bismuthinidene transfer. Chem. Sci. 2023;14:5214–5219. doi: 10.1039/D3SC01635H. [DOI] [PMC free article] [PubMed] [Google Scholar]
  76. Lesley M. J. G., Clegg W., Marder T. B., Norman N. C., Orpen A. G., Scott A. J., Starbuck J.. Three Pt II catecholate and 1,2-dithiocatecholate complexes. Acta Crystallogr., Sect. C: Cryst. Struct. Commun. 1999;55:1272–1275. doi: 10.1107/S0108270199005715. [DOI] [Google Scholar]
  77. Best J., Sazanovich I. V., Adams H., Bennett R. D., Davies E. S., Meijer A. J. H. M., Towrie M., Tikhomirov S. A., Bouganov O. V., Ward M. D., Weinstein J. A.. Structure and ultrafast dynamics of the charge-transfer excited state and redox activity of the ground state of mono- and binuclear platinum­(II) diimine catecholate and bis-catecholate complexes: a transient absorption, TRIR, DFT, and electrochemical study. Inorg. Chem. 2010;49:10041–10056. doi: 10.1021/ic101344t. [DOI] [PubMed] [Google Scholar]
  78. Horng D.-N., Chyn J.-P., Shieh K.-J., Chou J.-L., Wen Y.-S.. 3,5-Di- tert -butyl-1,2-benzoquinone. Acta Crystallogr., Sect. C: Cryst. Struct. Commun. 1999;55:652–653. doi: 10.1107/S010827019801436X. [DOI] [Google Scholar]
  79. Loughrey J. J., Patmore N. J., Baldansuren A., Fielding A. J., McInnes E. J. L., Hardie M. J., Sproules S., Halcrow M. A.. Platinum­(ii) complexes of mixed-valent radicals derived from cyclotricatechylene, a macrocyclic tris-dioxolene. Chem. Sci. 2015;6:6935–6948. doi: 10.1039/C5SC02776D. [DOI] [PMC free article] [PubMed] [Google Scholar]
  80. Cenini S., Ugo R., La Monica G.. Zerovalent platinum chemistry. Part V. Bistriphenylphosphineplatinum(0) quinone complexes. J. Chem. Soc., A. 1971:416–422. doi: 10.1039/j19710000416. [DOI] [Google Scholar]
  81. Dell’Anna M. M., Censi V., Carrozzini B., Caliandro R., Denora N., Franco M., Veclani D., Melchior A., Tolazzi M., Mastrorilli P.. Triphenylphosphane Pt­(II) complexes containing biologically active natural polyphenols: Synthesis, crystal structure, molecular modeling and cytotoxic studies. J. Inorg. Biochem. 2016;163:346–361. doi: 10.1016/j.jinorgbio.2016.08.006. [DOI] [PubMed] [Google Scholar]
  82. Stoll S., Schweiger A.. EasySpin, a comprehensive software package for spectral simulation and analysis in EPR. J. Magn. Reson. 2006;178:42–55. doi: 10.1016/j.jmr.2005.08.013. [DOI] [PubMed] [Google Scholar]
  83. Dolomanov O. V., Bourhis L. J., Gildea R. J., Howard J. A. K., Puschmann H.. OLEX2: a complete structure solution, refinement and analysis program. J. Appl. Crystallogr. 2009;42:339–341. doi: 10.1107/S0021889808042726. [DOI] [Google Scholar]
  84. Sheldrick G. M.. SHELXT - integrated space-group and crystal-structure determination. Acta Crystallogr., Sect. A: Found. Adv. 2015;71:3–8. doi: 10.1107/S2053273314026370. [DOI] [PMC free article] [PubMed] [Google Scholar]
  85. Sheldrick G. M.. A short history of SHELX. Acta Crystallogr., Sect. A: Found. Crystallogr. 2008;64:112–122. doi: 10.1107/S0108767307043930. [DOI] [PubMed] [Google Scholar]

Associated Data

This section collects any data citations, data availability statements, or supplementary materials included in this article.

Supplementary Materials

om5c00441_si_001.pdf (2.1MB, pdf)
om5c00441_si_002.xyz (46.1KB, xyz)

Articles from Organometallics are provided here courtesy of American Chemical Society

RESOURCES