Monoclinic polymorph of trans-tetra­aquabis­[(4-pyridylsulfanyl)­acetato-κN]cobalt(II)

Dušan Mikloš; Jozef Miklovič; Jan Moncol; Peter Segľa; Marian Koman

doi:10.1107/S1600536808023593

. 2008 Jul 31;64(Pt 8):m1089. doi: 10.1107/S1600536808023593

Monoclinic polymorph of trans-tetraaquabis[(4-pyridylsulfanyl)acetato-κN]cobalt(II)

Dušan Mikloš ^a, Jozef Miklovič ^b, Jan Moncol ^a,^*, Peter Segľa ^a, Marian Koman ^a

PMCID: PMC2961997 PMID: 21203067

Abstract

The crystal structure of the title compound, [Co(C₇H₆NO₂S)₂(H₂O)₄], is a polymorph of the structure first reported by Du, Zhao & Wang [(2004). Dalton Trans, pp. 2065–2072]. The asymmetric unit of the title compound contains one half-molecule; the Co^II atom lies on an inversion centre in a distorted octahedral geometry coordinated by two N atoms of the pyridine rings of the 4-pyridylthioacetate anions and four O atoms of water molecules. In the crystal structure, intermolecular O—H⋯O hydrogen bonds link the molecules, forming a three-dimensional network.

Related literature

For related literature, see: Bernstein et al. (1995 ▶); Chiang et al. (1993 ▶); Du et al. (2004 ▶); Du & Li (2006 ▶); Kondo et al. (2002 ▶); For related structures, see: Fang et al. (2004 ▶); Zhang et al. (2004 ▶).

Experimental

Crystal data

[Co(C₇H₆NO₂S)₂(H₂O)₄]
M _r = 467.37
Monoclinic,
a = 12.173 (1) Å
b = 10.479 (1) Å
c = 7.523 (2) Å
β = 106.78 (3)°
V = 918.8 (3) Å³
Z = 2
Mo Kα radiation
μ = 1.21 mm⁻¹
T = 293 (2) K
0.45 × 0.40 × 0.30 mm

Data collection

Siemens P4 diffractometer
Absorption correction: ψ scan (XEMP; Siemens, 1994 ▶) T _min = 0.608, T _max = 0.684
3491 measured reflections
2651 independent reflections
2283 reflections with I > 2σ(I)
R _int = 0.024
3 standard reflections every 97 reflections intensity decay: 2.0%

Refinement

R[F ² > 2σ(F ²)] = 0.032
wR(F ²) = 0.102
S = 1.37
2651 reflections
125 parameters
H-atom parameters constrained
Δρ_max = 0.41 e Å⁻³
Δρ_min = −0.37 e Å⁻³

Data collection: XSCANS (Siemens, 1994 ▶); cell refinement: XSCANS; data reduction: XSCANS; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: ORTEP-3 (Farrugia, 1997 ▶); software used to prepare material for publication: enCIFer (Allen et al. 2004 ▶).

Supplementary Material

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536808023593/ez2135sup1.cif

e-64-m1089-sup1.cif^{(16.6KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536808023593/ez2135Isup2.hkl

e-64-m1089-Isup2.hkl^{(127.6KB, hkl)}

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

Table 1. Hydrogen-bond geometry (Å, °).

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O1W—H1W⋯O1ⁱ	0.82	2.05	2.849 (2)	163
O1W—H2W⋯O1ⁱⁱ	0.82	1.95	2.757 (2)	167
O2W—H3W⋯O2ⁱⁱ	0.82	1.91	2.725 (2)	176
O2W—H4W⋯O2ⁱⁱⁱ	0.82	1.95	2.743 (2)	163

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

Acknowledgments

We thank the Scientific Grant Agency of the Ministry of Education of the Slovak Republic and the Slovak Academy of Sciences (grant Nos. 1/4454/07 and 1/0353/08).

supplementary crystallographic information

Comment

Several transition metal coordination polymers that contain bridging 4-pyridylthioacetate ligands have been reported recently (Chiang et al., 1993; Du et al., 2004; Du & Li, 2006; Kondo et al., 2002). However, if the 4-pyridylthioacetate anions are coordinated only as terminal ligands there is a possibility that they may also be able to participate in a hydrogen-bonding network. As part of our efforts to investigate metal(II) complexes based on pyridyl-carboxylic acids, we report herein the crystal structure of the title compound, (I).

In the molecular structure of (I) (Fig. 1) the Co^II atom lies on an inversion centre and adopts a distorted octahedral coordination geometry with the two N atoms of the pyridine rings of the 4-pyridylthioacetate anions and the four O atoms of the water molecules, where the two symmetry related 4-pyridylthioacetate ligands are in trans positions.

The bond lengths and angles may be compared with the corresponding values in the triclinic polymorph [Co(C₇H₆NO₂S)₂(H₂O)₄] [(II); Du et al., 2004]. In (II), the Co^II atom displays similar distorted octahedral coordination geometry, but the angle between the plane through the pyridine rings and that through the four water O atoms of 87.9° is closer to a right angle than the angle of 77.8° in (I). Correspondingly, the distance between the two planes of pyridine rings in (II) is shorter (0.22 Å) than that (0.80 Å) in (I). On the other hand, complex (I) is isostructural with [Cu(C₇H₆NO₂S)₂(H₂O)₄] [(III); Fang et al., (2004)] and [Ni(C₇H₆NO₂S)₂(H₂O)₄] [(IV); Zhang et al., (2004)].

In the crystal structure, intermolecular O–H···O hydrogen bonds (Table 1) link the molecules to form a three-dimensional network. The molecules of (I) lying in layers parallel to the ac plane are linked by O1W–H2W···O1ⁱⁱ; O2W–H3W···O2ⁱⁱ and O2W–H4W···O2ⁱⁱⁱ [Symmetry codes: (ii) -x + 2, -y + 1, -z + 1; (iii) x - 1, y, z] hydrogen bonds (Fig. 2). The hydrogen bonds between two coordinated water molecules O2W and two carboxylate groups through only one carboxylate O atom (O2) of the carboxylate group create R₄²(8) rings (Bernstein et al., 1995). On the other hand, both O atoms of the two carboxylate groups and two coordinated water molecules create R₄⁴(12) rings (Bernstein et al., 1995) in the triclinic polymorph (II). The hydrogen bonds O1W–H1W···O1ⁱ [Symmetry code: (i) -x + 2, y - 1/2, -z + 1/2] link the layers to form a 3-D hydrogen bonding network (Fig. 3).

Experimental

Well shaped red crystals of (I) suitable for X-ray analysis were prepared in an H-tube. An aqueous solution of the sodium salt of 4-pyridylthioacetic acid, was placed in the first part of the H-tube, and an aqueous solution of Co(II) sulfate in the second part. Crystals formed after two weeks, whereafter they were separated and dried at room temperature (yield 70%). Anal. Calc. for C₁₄H₂₀CoN₂O₈S₂: C, 35.98; H, 4.31; N, 5.99; S, 13.72; Co, 12.61. Found: C, 35.82; H, 4.41; N, 5.90; S, 13.59; Co, 12.75%. Selected IR data (cm^-1): 1570 (versus,br) (ν_a(COO^-) + ν(C=N)), 1376 (versus) (ν_s(COO^-)), 430 (m) (γ(py), pyridine ring out-of-plane bending). Electronic data (cm^-1): 21200, 20300, 9200br.