The chemistry of group 4 permethylmetallocene complexes with 2-mercaptoethanol: the molecular structure of Cp 2∗Zr(OCH 2CH 2SH) 2

Abstract

Cp 2 ∗TiCl 2 ( Cp ∗ = pentamethylcyclopentadienyl ) reacts with 1 molar equivalent of 2-mercaptoethanol (HOCH 2CH 2SH) in the presence of NEt 3 to give the monomeric chelate complex Cp 2 ∗Ti(OCH 2CH 2S) ( 1). However, Cp 2 ∗ZrCl 2 reacts with 1 molar equivalent of HOCH 2CH 2SH in the presence of NEt 3 to give the oxygen-bonded monomeric complex Cp 2 ∗ZrCl (OCH 2CH 2SH) ( 2). When Cp 2 ∗Zr(CH 3) 2 reacts with 1 molar equivalent of HOCH 2CH 2SH, the oxygen-bonded complex Cp 2 ∗Zr(CH 3) (OCH 2CH 2SH) ( 3) is obtained first. Complex 3 gradually loses the methane in the solid state or in solution to give the complex Cp 2 ∗Zr(OCH 2CH 2S) ( 4), which has the monomeric chelate structure like the titanium complex 1. Complexes 3 and 4 can be converted to the monochloro complex 2 by the addition of triethylammonium chloride. When Cp 2 ∗Zr(CH 3) 2 is in near HOCH 2CH 2SH, the dialkoxy complex Cp 2 ∗Zr (OCH 2CH 2SH) 2 ( 5) is obtained. Complex 5 crystallizes in the orthorhombic Cmca space group with cell parameters a=17.413 (3) A ̊ , b=17.256 (3) A ̊ , c = 17.332 (3) A ̊ , z = 8, R = 0.041 and R w = 0.053. The molecule possesses a mirror plane that bisects the Cp ∗ rings and the OZrO angle. Two Cp ∗ rings are staggered in conformation and disorders are found for the methylene carbons of the ligand.