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

Abstract

The reaction of 9-substituted trimethyltinfluorenes with TiCl 4 in hexanes at −40°C leads to unstable fluorenyltitanium(IV) trichlorides which thermal radical decomposition gives quantitatively TiCl 3 and corresponding bifluorenes: (C 13H 9) 2 ( 3a), (9-EtC 13H 8) 2 ( 3b) and (9-SiMe 3C 13H 8) 2 ( 3c). Crystals of 3c are monoclinic (space group P 2 1/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.