C-ansa-zirconocene complexes with O/S donor ligands: Novel homoleptic six coordinate 4-mercaptophenolate complex of Zr(IV)

New C-ansa-zirconocene complexes containing methoxythiophenolate and mercaptophenolate ligands have been synthesized and characterized. The reaction of (HSC6H4-n-OMe) (n = 2, 3 or 4) with [Zr{(t-Bu)HC(η5-C5Me4)(η5-C5H4)}Me2] (1) led to the formation of monosubstituted complexes [Zr{(t-Bu)HC(η5-C5Me4)(η5-C5H4)}Me(κ,S-SC6H4-n-OMe)] (n = 2 (2); n = 3 (3)) and the disubstituted complex [Zr{(t-Bu)HC(η5-C5Me4)(η5-C5H4)}(κ,S-SC6H4-4-OMe)2] (4). The complexes [Zr{(R)HC(η5-C5Me4)(η5-C5H4)}(κ,O-OC6H4-4-SH)2] (R = t-Bu (6); R = CH2CHCH2 (7)) and [Zr(η5-C5H4)2(OC6H4-n-SH)2] (n = 3 (9); n = 4 (10)) have been synthesized using the corresponding dimethyl zirconocene and mercaptophenol. However, the reaction of [Zr{(t-Bu)HC(η5-C5Me4)(η5-C5H4)}Cl2] (11) with 4-mercaptophenol in the presence of NEt3 led to the formation of the first example of a homoleptic six-coordinate mercaptophenolate complex of zirconium, namely [HNEt3]2[Zr(κ,O-OC6H4-4-SH)6] (12). Complex 12 can be obtained in higher yield by the reaction of ZrCl4 with six equivalents of 4-mercaptophenol and NEt3. The reaction of 12 with [Zr(η5-C5H4)2Cl2] gave the unexpected disubstituted complex [Zr(η5-C5H4)2(OC6H4-4-SH)2] (10). The molecular structures of 4 and 12 have been determined by single-crystal X-ray diffraction studies.