TETRAMETHYL(2-METHYLTHIOETHYL) CYCLOPENTADIENYL COMPLEXES OF ZIRCONIUM(IV) - SYNTHESIS, CRYSTAL-STRUCTURE, AND DYNAMIC BEHAVIOR IN SOLUTIONS

Chelating sulfur-containing cyclopentadienyl ligand tetramethyl(2-meth ylthioethyl)cyclopentadiene (1), was synthesized for the first time. I ts sodium (2a) and lithium (2b) derivatives were isolated in the cryst alline state. Starting from compound 1 some novel Zr-IV complexes were prepared: ethylthioethyl)cyclopentadienyl]trichlorozirconium (3), met hylthioethyl)cyclopentadienyl]dichlorozirconium (4), and [pentamethylc yclopentadienyl] methylthioethyl)cyclopentadienyl]dichlorozirconium (5 ). The crystal structures of 3 and 5 were determined by X-ray diffract ion analysis. The dynamic behavior of complex 3 in various solvents wa s investigated by H-1 and C-13 NMR spectroscopy. The S-->Zr coordinati on bond was shown to exist in complex 3 both in the crystalline state and in solution. No coordination of this type was found in compounds 4 and 5.