catena-Poly[[diaqua­zinc(II)]-μ-l-cystein­ato(2−)-κ4 S:S,N,O-[di-μ-sulfido-bis­[oxido­molybdate(V)](Mo—Mo)]-μ-l-cysteinato(2−)-κ4 S,N,O:S]

Takashi Shibahara; Shinobu Ogasahara; Genta Sakane

doi:10.1107/S1600536808007757

. 2008 Apr 2;64(Pt 5):m605–m606. doi: 10.1107/S1600536808007757

catena-Poly[[diaquazinc(II)]-μ-l-cysteinato(2−)-κ⁴ S:S,N,O-[di-μ-sulfido-bis[oxidomolybdate(V)](Mo—Mo)]-μ-l-cysteinato(2−)-κ⁴ S,N,O:S]

Takashi Shibahara ^a,^*, Shinobu Ogasahara ^a, Genta Sakane ^a

PMCID: PMC2961258 PMID: 21202165

Abstract

The title compound, [Mo₂Zn(C₃H₅NO₂S)₂O₂S₂(H₂O)₂], forms a one-dimensional chain. The cysteine S atom of the dinuclear molybdenum complex anion coordinates to the zinc ion, which has a tetrahedral environment by the additional coordination of two water molecules. The one-dimensional chains are connected to each other by hydrogen bonds. The Zn—S(cysteine) distances [2.3599 (6) and 2.3072 (6) Å] are close to the value in ZnS (2.35 Å). The distances and angles within the complex are very close to those reported for the sodium and potassium di-μ-sulfide species.

Related literature

For related literature, see: Brown & Jeffreys (1973 ▶); Hong et al. (1983 ▶); Kay & Mitchell (1970 ▶); Knox & Prout (1969 ▶); Shibahara et al. (1987 ▶); Lee et al. (1989 ▶); Liu & Williams (1981 ▶); Xing et al. (1998 ▶).

Experimental

Crystal data

[Mo₂Zn(C₃H₅NO₂S)₂O₂S₂(H₂O)₂]
M _r = 627.69
Monoclinic,
a = 8.6881 (11) Å
b = 10.3529 (8) Å
c = 9.8686 (11) Å
β = 108.2022 (14)°
V = 843.23 (16) Å³
Z = 2
Mo Kα radiation
μ = 3.40 mm⁻¹
T = 93.1 K
0.35 × 0.30 × 0.10 mm

Data collection

Rigaku Mercury diffractometer
Absorption correction: multi-scan (Jacobson, 1998 ▶) T _min = 0.382, T _max = 0.727
9357 measured reflections
4556 independent reflections
4549 reflections with F ² > 2σ(F ²)
R _int = 0.019

Refinement

R[F ² > 2σ(F ²)] = 0.019
wR(F ²) = 0.049
S = 1.02
4556 reflections
209 parameters
15 restraints
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.47 e Å⁻³
Δρ_min = −0.94 e Å⁻³
Absolute structure: Flack (1983 ▶), with 2010 Friedel pairs
Flack parameter: 0.002 (7)

Data collection: CrystalClear (Rigaku, 1999 ▶); cell refinement: CrystalClear; data reduction: CrystalStructure (Rigaku, 2007 ▶); program(s) used to solve structure: SIR97 (Altomare et al., 1999 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: CrystalStructure; software used to prepare material for publication: CrystalStructure.

Supplementary Material

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536808007757/wk2080sup1.cif

e-64-0m605-sup1.cif^{(18.5KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536808007757/wk2080Isup2.hkl

e-64-0m605-Isup2.hkl^{(223.2KB, hkl)}

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

Table 1. Selected geometric parameters (Å, °).

Mo1—S1	2.3201 (6)
Mo1—S2	2.3378 (6)
Mo1—S3	2.5572 (6)
Mo1—Mo2	2.8354 (3)
Mo2—S2	2.3276 (6)
Mo2—S1	2.3368 (6)
Mo2—S4	2.5428 (6)
Zn1—O8	2.0052 (17)
Zn1—O7	2.0275 (19)
Zn1—S4ⁱ	2.3072 (6)
Zn1—S3	2.3599 (6)

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O8—Zn1—O7	96.70 (7)
O8—Zn1—S4ⁱ	129.42 (5)
O7—Zn1—S4ⁱ	107.94 (6)
O8—Zn1—S3	93.73 (5)
O7—Zn1—S3	104.55 (6)
S4ⁱ—Zn1—S3	120.25 (2)

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Symmetry code: (i) Inline graphic .

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

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O7—H11⋯O3ⁱⁱ	0.84	2.03	2.832 (2)	161
O8—H13⋯O5ⁱⁱ	0.84	1.77	2.604 (2)	171
O8—H14⋯O4ⁱ	0.84	2.00	2.789 (2)	158

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

Acknowledgments

This work was partly supported by a Special Grant for Cooperative Research administered by the Japan Private School Promotion Foundation.

supplementary crystallographic information

Comment

Molybdenum and L-cysteine are important components of many enzymes. X-ray structures of sulfur/oxygen-bridged dinuclear molybdenum complexes with L-cysteine ligands: Na₂[Mo₂(µ-S)₂O₂(cys)₂].4H₂O (Brown & Jeffreys, 1973; Hong et al., 1983); K₂[Mo₂S₂O₂(cys)₂].4H₂O.CH₃OH (Xing et al., 1998), Ca[Mo₂(µ-S)(µ-O)O₂(cys)₂].3H₂O (Shibahara et al., 1987), and Na₂[Mo₂O₄(cys)₂].5H₂O (Knox & Prout, 1969; Kay & Mitchell, 1970; Liu & Williams, 1981), have been reported, where alkaline or alkaline earth metals are counter cations, and the existence of metal-oxygen (cysteine oxygen) bonds has been reported. Seeking another crystal structure type, we used Zn²⁺ion, as the counter ion. The present structural study of the complex compound Zn[Mo₂O₂S₂(cys)₂].2H₂O (I) reveals the existence of Zn—S(cysteine sulfur) bonds, which result in polymerization; this type of Zn—S bond has been found in zinc finger proteins. The asymmetric unit of I is shown in Fig. 1 and a view of part of a one-dimensional polymeric chain of I is shown in Fig. 2. The zinc ion bridges the molybdenum complex anions: the coordination of the cysteine sulfur in the complex anion to the zinc ion results in the formation of one dimensional chains, where the zinc forms a tetrahedral structure by the additional coordination of two water molecules. The one dimensional chains are connected to each other by hydrogen bonds. Intra-chain hydrogen bonds also exist. The dimensions of the molybdenum complex and of the zinc tetrahedron are listed in Table 1, and the hydrogen bonds are listed in Table 2. The Zn—S(cysteine) distances (2.3599 (6), 2.3072 (6) Å) are close to that in ZnS (2.35 Å). The distances and angles within the complex are very close to those reported in the sodium and potassium salts in the di-µ-sulfide species.

Experimental

The title compound was prepared by the addition of ZnCl₂ to a diluted aqueous solution of Na₂[Mo₂O₂S₂(cys)₂].4H₂O. A crystal suitable for single-crystal X-ray diffraction was selected directly from the prepared sample.