Poly[bis­[μ4-N-(2-hydroxy­imino­propion­yl)-N′-(2-oxidoimino­propion­yl)propane-1,3-diaminato]dimethano­lcalciumdicopper(II)]

Valentina A Kalibabchuk; Natalia I Usenko; Irina A Golenya; Turganbay S Iskenderov; Matti Haukka

doi:10.1107/S1600536809033467

. 2009 Aug 29;65(Pt 9):m1139–m1140. doi: 10.1107/S1600536809033467

Poly[bis[μ₄-N-(2-hydroxyiminopropionyl)-N′-(2-oxidoiminopropionyl)propane-1,3-diaminato]dimethanolcalciumdicopper(II)]

Valentina A Kalibabchuk ^a,^*, Natalia I Usenko ^b, Irina A Golenya ^b, Turganbay S Iskenderov ^c, Matti Haukka ^d

PMCID: PMC2970044 PMID: 21577475

Abstract

In the title compound, [CaCu₂(C₉H₁₃N₄O₄)₂(CH₃OH)₂]_n, the Ca^II atom lies on an inversion center and is situated in a moderately distorted octahedral environment. The Cu^II atom is in a distorted square-pyramidal geometry, defined by four N atoms belonging to the amide and oxime groups of the triply deprotonated residue of N,N′-bis(2-hydroxyiminopropanoyl)propane-1,3-diamine (H₄pap) and one oxime O atom from a neighboring Hpap ligand at the apical site, forming a dimeric [Cu₂(Hpap)₂]²⁻ unit. Each dimeric unit connects four Ca atoms and each Ca atom links four [Cu₂(Hpap)₂]²⁻ units through Ca—O(amide) bonds, leading to a three-dimensional framework. The crystal structure involves intra- and intermolecular O—H⋯O hydrogen bonds.

Related literature

For the coordination chemistry of tetradentate oxime-and-amide open-chain ligands, see: Duda et al. (1997 ▶); Fritsky et al. (1999 ▶). For oximes as efficient metal chelators, see: Gumienna-Kontecka et al. (2000 ▶); Onindo et al. (1995 ▶); Sliva et al. (1997a ▶,b ▶). For the use of oximes in stabilizing high oxidation states of metal ions, see: Fritsky et al. (1998 ▶, 2006 ▶). For related structures, see: Kanderal et al. (2005 ▶); Fritsky (1999 ▶); Fritsky et al. (2000 ▶); Mokhir et al. (2002 ▶); Moroz et al. (2008 ▶); Wörl et al. (2005 ▶).

Experimental

Crystal data

[CaCu₂(C₉H₁₃N₄O₄)₂(CH₄O)₂]
M _r = 713.71
Monoclinic,
a = 10.0554 (4) Å
b = 8.7794 (3) Å
c = 15.4465 (7) Å
β = 97.882 (2)°
V = 1350.74 (9) Å³
Z = 2
Mo Kα radiation
μ = 1.83 mm⁻¹
T = 120 K
0.28 × 0.24 × 0.13 mm

Data collection

Nonius KappaCCD diffractometer
Absorption correction: multi-scan (SADABS; Sheldrick, 1996 ▶) T _min = 0.622, T _max = 0.796
8392 measured reflections
3074 independent reflections
2573 reflections with I > 2σ(I)
R _int = 0.035

Refinement

R[F ² > 2σ(F ²)] = 0.030
wR(F ²) = 0.079
S = 1.04
3074 reflections
192 parameters
H-atom parameters constrained
Δρ_max = 1.11 e Å⁻³
Δρ_min = −0.56 e Å⁻³

Data collection: COLLECT (Nonius, 1998 ▶); cell refinement: DENZO/SCALEPACK (Otwinowski & Minor, 1997 ▶); data reduction: DENZO/SCALEPACK; program(s) used to solve structure: SIR2004 (Burla et al., 2005 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: ORTEP-3 (Farrugia, 1997 ▶); software used to prepare material for publication: SHELXL97.

Supplementary Material

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536809033467/hy2216sup1.cif

e-65-m1139-sup1.cif^{(20.1KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536809033467/hy2216Isup2.hkl

e-65-m1139-Isup2.hkl^{(150.9KB, hkl)}

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

Table 1. Selected bond lengths (Å).

Cu1—N1	1.9751 (18)
Cu1—N2	1.9469 (18)
Cu1—N3	1.9320 (19)
Cu1—N4	1.9650 (18)
Cu1—O2ⁱ	2.4646 (16)
Ca1—O3	2.3134 (16)
Ca1—O4ⁱⁱ	2.2818 (16)
Ca1—O5	2.3811 (16)

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Symmetry codes: (i) Inline graphic ; (ii) .

Table 2. Hydrogen-bond geometry (Å, °).

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O1—H1O⋯O2	0.99	1.65	2.610 (2)	165
O5—H5O⋯O2ⁱⁱⁱ	0.94	1.79	2.681 (2)	159

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Symmetry code: (iii) Inline graphic .

Acknowledgments

The authors thank the Ministry of Education and Science of Ukraine for financial support (grant No. M/263–2008).

supplementary crystallographic information

Comment

N,N'-bis(2-hydroxyiminopropionylpropane)-1,2-diamine and its homologues (Duda et al., 1997; Fritsky et al., 1999), tetradentate oxime-and-amide open-chain ligands, have been intensively studied during the past 15 years as efficient polychelate ligands forming stable complexes with nickel(II) and copper(II) ions. The presence of an additional strong donor amide function in the vicinity of the oxime group results in important increase of chelating efficiency. For example, amide derivatives of 2-hydroxyiminopropanoic acid were shown to act as highly efficient chelators with respect to copper(II), nickel(II) and aluminium(III) ions (Gumienna-Kontecka et al., 2000; Onindo et al., 1995; Sliva et al., 1997a,b). Also, tetradentate oxime-and-amide open-chain ligands possess strong σ-donor capacity and thus have been successfully used for preparation of metal complexes with efficient stabilization of unusually high oxidation states of transition metal ions like Cu^III and Ni^III (Fritsky et al., 1998; Fritsky et al., 2006).

Earlier, the crystal and molecular structures of mononuclear anionic copper(II) complexes with N,N'-bis(2-hydroxyiminopropanoyl)propane-1,3-diamine (H₄pap) of composition [Li(H₂O)₄][Cu(Hpap)].2H₂O (Duda et al., 1997) and PPh₄[Cu(Hpap)].4.5H₂O (Kanderal et al., 2005) have been reported, as well as a series of modular cationic and anionic complex compounds containing [Cu(Hpap)]^- anions (Fritsky et al., 2000). The present report describes the crystal structure of the title compound, a three-dimensional coordination polymer of composition [CaCu₂(Hpap)₂(CH₃OH)₂], featuring copper(II) complex anions connected by calcium ions.

The structure of the title compound is presented in Fig. 1. The ligand in the complex anion is coordinated in a tetradentate fashion forming three condensed chelate rings and being triply deprotonated. In the complex anion the Cu^II atom is situated in a distorted square-pyramidal geometry. The basal plane is defined by four N atoms belonging to the deprotonated amide and oxime groups of the Hpap ligand, which adopt a pseudo-macrocyclic conformation due to the presence of an intramolecular hydrogen bond uniting the cis-oximate O atoms. The apical position is occupied by the oxime O2 atom, and as a result, two neighboring Cu complex anions are united into a centrosymmetric [Cu₂(Hpap)₂]^2- dimer, with a Cu···Cuⁱ [symmetry code: (i) -x, 2-y, -z] separation of 4.164 (1) Å. Each dimeric unit connects four Ca atoms and each Ca links four dimeric [Cu₂(Hpap)₂]^2- units.

The basal plane of the Cu1 atom exhibits tetrahedral distortion with deviations of the N atoms from the mean plane defined by them by 0.025 (1) Å. Cu1 is displaced by 0.255 (1) Å from this plane in the direction of the apical O atom. The observed Cu—N distances (Table 1) are normal for the complexes with N-coordinated amide and oxime groups (Fritsky et al., 1998; Fritsky et al., 2006). A noticeable difference between Cu—N(amide) and Cu—N(oxime) distances is observed. The O1···O2 separation of the intramolecular hydrogen bond is equal to 2.610 (2) Å, which is close to the values reported for the analogous complexes with lithium and tetraphenylphosponium cations. The C═N, C═O, N—O and C—N bond lengths are typical for 2-hydroxyiminopropanoic acid and its amide derivatives (Fritsky, 1999; Mokhir et al., 2002; Moroz et al., 2008).

The Ca^II atom occupies a special position and is situated in moderately distorted octahedral environment (Fig. 1). The Ca—O bond distances are similar to the reported ones for six-coordinate calcium complexes (Wörl et al., 2005). The axial bond length Ca1—O5 [2.381 (1) Å] are somewhat longer than the equatorial ones. The O—Ca—O anlges values are in the range 84.31 (6) to 95.69 (6)°. The coordination geometry of the Ca atom is formed by six O atoms belonging to two methanol molecules and four amide groups. Thus, each Ca atom unites four dimeric Cu complex anionic unit. These Ca—O bonds, together with the intermolecular O—H···O hydrogen bonds between the methanol OH group and oxime O2 atom (Table 2), lead to a three-dimensional framework (Fig. 2).

Experimental

A solution of N,N'-bis(2-hydroxyiminopropanoyl)propane-1,3-diamine (0.244 g, 1 mmol) in 10 ml of methanol was heated to 323 K and added with stirring to a solution of copper(II) chloride dihydrate (0.170 g, 1 mmol) in water (5 ml). Then an aqueous solution of calcium hydrocarbonate (4 ml, 1 M) was added. The obtained mixture was stirred at 323 K for 10 min and then filtered. The filtrate was cooled, filtered and set aside for crystallization at room temperature. The resulting dark-red crystals formed within 12 h were separated by filtration, washed with water and air-dried (yield 78%). N,N'-bis(2-hydroxyiminopropanoyl)propane-1,3-diamine was prepared according to the reported procedure (Duda et al., 1997).