μ2-Oxalato-bis­[triphen­yl(thio­urea-κS)tin(IV)]

Yaya Sow; Libasse Diop; Kieran C Molloy; Gabrielle Kociok-Kohn

doi:10.1107/S1600536812040706

. 2012 Oct 6;68(Pt 11):m1337. doi: 10.1107/S1600536812040706

μ₂-Oxalato-bis[triphenyl(thiourea-κS)tin(IV)]

Yaya Sow ^a,^*, Libasse Diop ^a, Kieran C Molloy ^b, Gabrielle Kociok-Kohn ^b

PMCID: PMC3515101 PMID: 23284328

Abstract

The asymmetric unit of the binuclear title compound, [Sn₂(C₂O₄)(C₆H₅)₆(CH₄N₂S)₂], consists of one half of the organotin(IV) molecule. The remainder is generated by a twofold rotation axis passing through the mid-point of the oxalate C—C bond. The Sn^IV atom exhibits a distorted trigonal–bipyramidal coordination environment with the phenyl groups in equatorial positions and the thiourea and the monodentately bridging oxalate anion in axial positions. The molecules are linked through N—H⋯O hydrogen bonds involving the amino group of the thiourea ligand and the uncoordinating oxalate O atoms, forming layers parallel to (001). Weak C—H⋯O interactions are also present.

Related literature

For background to organotin(IV) chemistry, see: Evans & Karpel (1985 ▶); Gielen et al. (1995 ▶). For triphenyltin(IV)-containing compounds and their biological activity, see: Kamruddin et al. (1996 ▶). For related compounds, see: Diallo et al. (2009 ▶); Diasse-Sarr et al. (1997 ▶); Diop et al. (1997 ▶, 1999 ▶, 2003 ▶); Tiekink (1992 ▶).

Experimental

Crystal data

[Sn₂(C₂O₄)(C₆H₅)₆(CH₄N₂S)₂]
M _r = 940.24
Monoclinic,
a = 12.9161 (2) Å
b = 13.9870 (2) Å
c = 21.8215 (3) Å
β = 99.238 (1)°
V = 3891.09 (10) Å³
Z = 4
Mo Kα radiation
μ = 1.44 mm⁻¹
T = 150 K
0.30 × 0.30 × 0.20 mm

Data collection

Nonius KappaCCD diffractometer
Absorption correction: multi-scan (SORTAV; Blessing, 1995 ▶) T _min = 0.659, T _max = 0.747
31403 measured reflections
4472 independent reflections
3665 reflections with I > 2σ(I)
R _int = 0.057

Refinement

R[F ² > 2σ(F ²)] = 0.030
wR(F ²) = 0.066
S = 1.09
4472 reflections
251 parameters
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 1.34 e Å⁻³
Δρ_min = −1.11 e Å⁻³

Data collection: COLLECT (Nonius, 1999 ▶); cell refinement: DENZO and SCALEPACK (Otwinowski & Minor, 1997 ▶); data reduction: DENZO and SCALEPACK; program(s) used to solve structure: SIR97 (Altomare et al., 1999 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: ORTEP-3 (Farrugia, 1997 ▶); software used to prepare material for publication: WinGX (Farrugia,1999 ▶).

Supplementary Material

Click here for additional data file.^{(18.6KB, cif)}

Crystal structure: contains datablock(s) I, New_Global_Publ_Block. DOI: 10.1107/S1600536812040706/wm2662sup1.cif

e-68-m1337-sup1.cif^{(18.6KB, cif)}

Click here for additional data file.^{(214.7KB, hkl)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536812040706/wm2662Isup2.hkl

e-68-m1337-Isup2.hkl^{(214.7KB, 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
N1—H1A⋯O2ⁱ	0.81 (4)	2.06 (4)	2.824 (3)	157 (4)
N2—H2A⋯O2ⁱⁱ	0.86 (4)	2.14 (4)	2.970 (3)	164 (3)
C6—H6⋯O1	0.95	2.44	2.957 (3)	114
C18—H18⋯O2	0.95	2.39	3.234 (3)	147

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

supplementary crystallographic information

Comment

Interest in organotin (IV) chemistry remains high because of several applications found in molecules belonging to this family (Evans & Karpel, 1985; Gielen et al., 1995), specifically triphenyltin(IV)-residue containing compounds for which biological activity has been reported (Kamruddin et al., 1996). Our specific interest lies also in the coordinating behavior of oxy-anions to these organometallic centers; we have previously published several crystal structures dealing with such systems (Diallo et al., 2009; Diasse-Sarr et al., 1997; Diop et al., 1997). Moreover, we have reported spectroscopic data (Diop et al., 1999) and the crystal structure of [Sn₂(C₂O₄)(C₆H₅)₆] which exhibits tetrahedrally coordinate tin atoms (Diop et al., 2003). Here we report a study of the interactions between this species and thiourea, which has yielded the title compound, [Sn₂(C₂O₄)(C₆H₅)₆(CH₄N₂S)₂].

The molecule of the title compound has site symmetry 2 with the twofold rotation axcis passing through the mid-point of the central oxalate C—C bond. The Sn(IV) atom is five-coordinate by one oxygen atom of the oxalate anion, a sulfur atom of the thiourea ligand [Sn—O 2.2471 (17), Sn—S 2.6945 (7) Å] which are in apical positions and to three phenyl groups [Sn—C 2.146 (2), 2.139 (2), 2.139 (2) Å] occupying the equatorial positions of the trigonal bipyramid (Fig. 1). The Sn—S bond length is longer than the Sn—S bond length [2.573 (1) Å] found, for example, in {^t(C₄H₉)₂Sn[S₂CN(CH₃)₂]₂} which contains a trigonal bipyramidally coordinate tin(IV) atom (Tiekink, 1992). The angle S—Sn—O [175.97 (5)°] deviates slightly from linearity. The sum of the C—Sn—C angles (359.96°) indicates a nearly perfectly planar Sn(C₆H₅)₃ residue consistent with the near linearity of the axial substituents. The Sn—O bond length is remarkably long when compared with the Sn—O distance [2.111 (1) Å] in the tetrahedrally coordinate tin(IV) atom in [Sn₂(C₂O₄)(C₆H₅)₆] (Diop et al., 2003). The addition of SC(NH₂)₂ apparently has caused a change in the coordination from tetrahedral to trigonal-bipyramidal along with a Sn—O bond length increase. The two C—O bond length of the oxalate anion are slightly different because the O atom of the C19—O1 bond [1.269 (3) Å] is also involved in bonding to the Sn(IV) atom, whereas the O atom of the C19—O2 bond [1.243 (3) Å] is involved in hydrogen bonding with the amino group. These interactions lead to the formation of layers parallel to (001) (Figs. 2,3). Weak C—H···O hydrogen bonding is also observed.

Experimental

All chemicals were purchased from Aldrich or Merck and used without any further purification. [Sn₂(C₂O₄)(C₆H₅)₆] has been obtained on allowing Sn(C₆H₅)₃OH to react with oxalic acid in a 2:1 ratio in ethanol. A white powder is collected after slow evaporation. When [Sn₂(C₂O₄)(C₆H₅)₆] is mixed with SC(NH₂)₂ in a 1:2 ratio, both as ethanolic solutions, a colorless solution is obtained which gives crystals of [Sn₂(C₂O₄)(C₆H₅)₆(CH₄N₂S)₂] suitable for X-ray work, after a slow solvent evaporation.