Preparation of bifluorenes via the synthesis and thermal decomposition of fluorenyltitanium(IV) trichlorides. Molecular and crystal structure of 9,9'-bis(trimethylsilyl)-bi-9,9'-fluorene

Article abstract of DOI:10.1016/S0040-4020(98)01208-3

The reaction of 9-substituted trimethyltinfluorenes with TiCl₄ in hexanes at -40°C leads to unstable fluorenyltitanium(IV) trichlorides which thermal radical decomposition gives quantitatively TiCl₃ and corresponding bifluorenes: (C₁₃H₉)₂ (3a), (9-EtC₁₃H₈)₂ (3b) and (9- SiMe₃C₁₃H₈)₂ (3c). Crystals of 3c are monoclinic (space group P 2₁/n), a = 15.059 A, b = 10.254 A, c = 18.172 A, β = 109.20 deg. IIIc dissociates at 100°C to give two radicals which initiate effectively radical polymerizations of methyl methacrylate and styrene.