Zirconium Alkyl Thiolate Complexes:  Synthesis and Reactivity. Molecular Structures of [Zr(η⁵-C₅H₅)₂(η²-C₆H₇N₂S)(Me)] and [Zr(η⁵-C₅H₅)₂(η¹-C₆H₇N₂S)(η²-CH₃CNXylyl)] (Xylyl = 2,6-Dimethylphenyl)

Abstract

The thiolate−alkylzirconocene complex Cp 2 ZrMe(SR) ( 2 ) (Cp = η 5 -C 5 H 5; SR = 4,6-dimethylpyrimidine-2-thiolate) can be prepared by reacting the corresponding dialkylmetallocene complex Cp 2 ZrMe 2 ( 1 ) with 1 equiv of 4,6-dimethyl-2-mercaptopyrimidine. X-ray structure analysis of complex 2 revealed that the thiolate group is bonded in an η 2 fashion through the sulfur and one of the nitrogen atoms. Complex 2 reacts with 2,6-dimethylphenyl isocyanide (CNXylyl) to yield the corresponding iminoacyl derivative, Cp 2 Zr(η 2 -MeCNXylyl)(SR) ( 4 ). The molecular structure of 4 shows that the thiolate group is η 1 -bonded while the iminoacyl group behaves as a bidentate ligand. Reaction of compound 2 with different acidic reagents gives formation of methane and different zirconium complexes. Reaction with HSR renders Cp 2 Zr(SR) 2 ( 3 ) and with (NHEt 3 )(BPh 4 ) the cationic complex [Cp 2 Zr(SR)][BPh 4 ] ( 5 ). An hydride thiolate complex, Cp* 2 ZrH(SR) (Cp* = η 5 -C 5 Me 5 ) ( 6 ) can also be prepared by reaction of “Cp* 2 Zr” with HSR by an oxidative addition reaction.