[Bis­(4-methyl-1,3-thia­zol-2-yl-κN)methane]­tricarbonyl­dichlorido­tungsten(II)

Christoph E Strasser; Stephanie Cronje; Helgard G Raubenheimer

doi:10.1107/S1600536811038104

. 2011 Sep 30;67(Pt 10):m1460. doi: 10.1107/S1600536811038104

[Bis(4-methyl-1,3-thiazol-2-yl-κN)methane]tricarbonyldichloridotungsten(II)

Christoph E Strasser ^a,^*, Stephanie Cronje ^a, Helgard G Raubenheimer ^a

PMCID: PMC3201421 PMID: 22065685

Abstract

The title compound, [WCl₂(C₉H₁₀N₂S₂)(CO)₃], is a heptacoordinate tungsten(II) complex with a capped–octahedral coordination sphere in which one CO ligand caps a face formed by a chloro ligand and the two other carbonyls. The chloro ligands are mutually trans positioned at an angle of 156.98 (7)°. The chelating bis(4-methyl-1,3-thiazol-2-yl)methane ligand coordinates with the imine N atoms. In the crystal, molecules are linked into chains parallel to [201] by weak C—H⋯O contacts between the CH₂ group of the bis(4-methylthiazol-2-yl)methane ligand and the O atom of the capping CO group.

Related literature

For related compounds, see: Baker et al. (1986 ▶); Moss & Smith (1983 ▶); Stiddard (1962 ▶); Szymanska-Buzar (1989 ▶); Tripathi et al. (1976 ▶). For related structures, see: Baker et al. (1996 ▶, 2000 ▶); Drew et al. (1988 ▶, 1995 ▶); Hillhouse et al. (1982 ▶); Shiu et al. (1990 ▶). For the isolation of the title compound, see: Strasser et al. (2009 ▶).

Experimental

Crystal data

[WCl₂(C₉H₁₀N₂S₂)(CO)₃]
M _r = 549.10
Monoclinic,
a = 8.6876 (17) Å
b = 12.912 (2) Å
c = 14.851 (3) Å
β = 105.550 (3)°
V = 1604.9 (5) Å³
Z = 4
Mo Kα radiation
μ = 7.80 mm⁻¹
T = 100 K
0.13 × 0.13 × 0.04 mm

Data collection

Bruker APEX CCD diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2002 ▶) T _min = 0.549, T _max = 0.772
9133 measured reflections
3310 independent reflections
2843 reflections with I > 2σ(I)
R _int = 0.037

Refinement

R[F ² > 2σ(F ²)] = 0.042
wR(F ²) = 0.099
S = 1.07
3310 reflections
201 parameters
H-atom parameters constrained
Δρ_max = 3.92 e Å⁻³
Δρ_min = −2.06 e Å⁻³

Data collection: SMART (Bruker, 2002 ▶); cell refinement: SAINT (Bruker, 2003 ▶); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: X-SEED (Barbour, 2001 ▶; Atwood & Barbour, 2003 ▶); software used to prepare material for publication: X-SEED.

Supplementary Material

Crystal structure: contains datablock(s) I, Global. DOI: 10.1107/S1600536811038104/rk2300sup1.cif

e-67-m1460-sup1.cif^{(19.1KB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536811038104/rk2300Isup2.hkl

e-67-m1460-Isup2.hkl^{(162.4KB, 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
C10—H10A⋯O2ⁱ	0.99	2.38	3.28 (1)	151

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Symmetry code: (i) Inline graphic .

Acknowledgments

We would like to thank the National Research Foundation (NRF) of South Africa for financial support.

supplementary crystallographic information

Comment

Heptacoordinate W(II) complexes are common due to the 18–electron configuration at the metal centre. The title compound, shown in Fig. 1, was obtained through unclear side reactions which involve the formation of bis(4–methyl–1,3–thiazol–2–yl)methane from the anionic (4–methyl–1,3–thiazol–2–yl)carbonyl or activated (4–methyl–1,3–thiazol–2-yl)(trichloromethoxycarbonyl)methylene ligands as well as concomitant oxidation of W(0) to W(II).

Complexes of the type [WX₂(CO)₃(L)₂] (X = Cl, Br or I; L = N–donor ligand) have been synthesized by photochemical reaction of e.g. [W(CO)₆], CCl₄ and 2,2'–bipyridine (bipy) to yield [WCl₂(CO)₃(bipy)] (Szymanska-Buzar, 1989), oxidation of [W(CO)₄(L)₂] (Stiddard et al., 1962) or [W(CO)₃(CH₃CN)₃] (Baker et al., 1986) with bromine or iodine or reaction of [WX₃(CO)₄]^- (X = Br or I) with bipy (Moss & Smith, 1983).

This is the first structural determination of a [WX₂(CO)₃(L)₂]–type complex with chloro ligands. Such complexes (X = Cl) with monodentate L = nitriles (Baker et al., 1986) and L = alkylamines (Tripathi et al., 1976) were reported to be highly unstable. It is therefore surprising that for the present compound no decomposition, e.g. decarbonylation (Shiu et al., 1990) was encountered when crystals were briefly exposed to oxygen, room temperature and light during set–up of the X–ray diffraction experiment. The chelating bis(4–methylthiazol–2–yl)methane ligand may exert additional stabilizing properties when compared to the ligands used in the literature.

Crystal and molecular structures of seven–coordinate complexes of the type [WX₂(CO)₃(RCN)₂] (RCN is an organic nitrile) have been reported by Baker et al. (1986, 1996, 2000) and Drew et al. (1988, 1995). The W—N bond distances in these nitrile complexes are shorter than those found in the title compound while other geometrical parameters are similar. The nitrile complexes also exhibit capped–octahedral geometry with trans–disposed iodo ligands. They possess a mirror plane that bisects the molecule while in the title compound the whole molecule is asymmetric; the position of the carbonyl ligands with respect to the bidentate bis(thiazolyl)methane is incompatible with C_s symmetry. Hillhouse et al. (1982) report coordination of a tetraarylphosphazide (PhNNNPPh₃) to a dibromotricarbonyltungsten fragment which is different from the title compound and the structures mentioned here in that it contains a set of cis–bromo ligands, possibly caused by the smaller bite angle of the tetraarylphosphazide (N—W—N angle of 56.7 (2)° as opposed to the N1—W1—N2 angle measuring 83.3 (2)° in the title compound). Finally, a geometrically very similar complex to the one reported here but utilizing a bis(azolyl)methane ligand was prepared by Shiu et al., (1990) [WBr₂(CO)₃(CH₂R₂)] (R = 3,4,5–trimethyl–1H–pyrazol–1–yl–κN²).

The significantly longer W1—Cl2 bond (2.528 (2)Å) in the title compound is adjacent to the capping CO ligand while the W1—Cl1 bond is undisturbed by a capping ligand and measures 2.4708 (17)Å. The same effect is observed to a variable degree in all structures mentioned here for comparison. The individual molecules of the title compound are arranged into chains parallel to the [2 0 1] line by weak C—H···O contacts between the CH₂ group of the bis(4–methylthiazol–2–yl)methane ligand and O2 of the capping CO group.

Experimental

A crystal of the tile compound was isolated when tetramethylammonium pentacarbonyl[(4–methyl–1,3–thiazol–5–yl)carbonyl]tungstate(1-) was treated with bis(trichloromethyl)carbonate and pyridine to obtain the carbyne complex [W(≡CC₄H₄NS)Cl(CO)₂(py)₂] by oxide abstraction (Strasser et al., 2009). Decomposition concomitant with development of a green colour was noticed; the reaction mixture was chromatographed on Florisil at 243 K using CH₂Cl₂/acetonitrile mixtures and an yellow fraction was obtained containing the title compound which was crystallized from CH₂Cl₂/pentane at 253 K.