Bis(η-cyclopentadienyl)-molybdenum (and -tungsten or -titanium) complexes with chelate imidazole derivatives and related ligands

Abstract

The new compounds [M(η-C₅H₅)₂(HL–L′)][PF₆]₂. [Mo(η-C₅H₅)₂(L–L′)][PF₆](M = Mo or W), [Ti(η-C₅H₅)₂-(HL–L′)][PF₆][HL–L′= 2-(2′-pyridyl)imidazoline, 2-(2′-pyridyl)imidazole, 2-(2′-pyridyl)benzimidazole, or 8-aminoquinoline], and [M(η-C₅H₅)₂(HL–L′)][PF₆] and [M(η-C₅H₅)₂(L–L′)](M = Mo or W)[H₂L–L′= 2-(2′-hydroxyphenyl)imidazoline or 2-(2′-hydroxyphenyl)benzimidazole] have been prepared. The acid-ionisation constants of the co-ordinated ligands have been measured for the molybdenum and tungsten complexes. Some of the deprotonated complexes have been methylated, and dicationic titanium complexes [Ti(η-C₅H₅)₂-(L–L)][PF₆]₂(L–L = 1,10-phenanthroline or 2,2′-bipyridyl) have also been prepared.