Indenyl-and flourenyl-transition metal complexesss : I. Synthesis, structures, and reactions of ν 5-and ν 6-derivatives of chromium group metals

Abstract

The reaction leading to the ν 5-fluorenyl-and ν-indenyl-tricarbonylmetallate anions, ν 5-C 13H 9(CO) 3Cr - and ν 5-C 9H 7(CO) 3M - where M stands for Cr, Mo, W have been studied. Deprotonation of (ν 6-fluorene)Cr(CO) 3 with t-BuOK seemingly proceeds via the corresponding ν 6-anionic intermediate which is transformed into the ν 5-isomer with a conversion halftime of several minutes. Chromium and molydenum ν 5-anions rearrage on treatment with CH 3COOH to the corresponding ν 6-indene and fluorene complexes. Protonation of ν 5-C 9H 7- (CO) 3W - leads to the stable hyride ν 5-C 9H 7(CO) 3WH. All the anions studied react with Hg(CN) 2 to give symmetric organomercury derivatives containing M–Hg bonds (M=Cr, Mo, W). The reaction of ν 5-C 9H 7(CO) 3Cr - and ν 5-C 13H 9 structure and containing a Cr–CH 3 bond: the product ν 5-C 9H 7(CO) 3CrCH 3 has undergo thermal rearrangement to the ν 6-compounds via transfer of the CH 3 group to the five-membered ring and of the Cr(CO) 3 group to the benzene nucleus. The molybdenum and tungsten anions form stable σ-methyl derivatives in reactions with CH 3I. The possible reversible isomerization processes involving anionic and neutral compounds are considered form mechanic and stereo-chemical points view.