Formation of antiferromagnetic heteronuclear thiolate and sulfide bridged complexes

The reaction between the antiferromagnetic complex Cp 2 Cr 2 (μ-SCMe 3 ) 2 (μ-S) ( 1 ) and WI(CO) 4 (NO) ( 2 ) was studied. At 40–50°C the predominant product was the antiferromagnetic adduct Cp 2 Cr 2 (μ-SCMe 3 ) 2 (μ 4 -S)W 2 (μ-I) 2 (CO) 4 (NO) 2 ( 3 ) (CrCr 2.764(4) Å, W ⋯ W 3.559(1) Å, −2J = 338 cm −1 ), in which a sulfur atom bridges all four metal atoms. Further heating of 3 in the presence of an excess of 1 afforded the trinuclear antiferromagnetic cluster Cp 2 Cr 2 (μ 3 -S) 2 (μ-SCMe 3 ) 2 W(SCMe 3 )(NO) ( 7 ) (WCr 3.090(1) Å, CrCr 3.027(1) Å, −2J = 246 cm −1 ) which can also be prepared by direct reaction between 1 and 2 (ratio 3:2) at 80°C in toluene. It is suggested that this process via the formation of an unstable intermediate CpCr(μ-SCMe 3 ) 2 (μ-S)W(CO) 2 (NO). In an attempt to use the trinuclear cluster Fe 3 S 2 (CO) 9 as a metal containing ligand for 2 , the known iron clusters Fe 2 S 2 (CO) 6 and (ON) 4 Fe 4 S 4 were isolated. All products, including the two iron clusters, were characterized by X-ray diffraction studies at −60°C.