Novel organoiron compounds resulting from the attempted syntheses of dibenzofulvalene complexes

Thermal reaction of 2,2'-biindenyl with Fe(CO), generates (eta(4)-2,2'-biindenyl)Fe(CO), and a ferrole isomer of (mu,eta(3):eta(3)-dibenzo[b,e]fulvalene)Fe-2(CO)(6) Reaction of the dianion of dibenzo[b,e]fulvalene with iron carbonyls produced a novel cyclized acyliron complex, whose structure was proven by X-ray crystallography; a mechanism is proposed for its formation. Reaction of the same dianion with (eta(5)-cyclopentadienyl)Fe(CO)(2)Br generated another novel cyclic compound (C18H12)Fe(CO)(2)(C5H4), probably via intramolecular radical attack on the eta(5)-bound cyclopentadienyl ring. Treatment of dibenzo[a,d]fulvalene with Fe-2(CO)(9) generates (eta(2)-dibenzo[a, d]fulvalene) Fe(CO)(4), (mu, eta(2) :eta(2)-dibenzo[a,d]fulvalene)Fe-2(CO)(8), and two compounds with bis(eta(5)) structures. These appear to have CO and Fe(CO), groups inserted into the reactive Fe-Fe bond of (mu,eta(5):eta(5)-dibenzo[a,d]fulvalene)Fe-2(CO)(4) (C) 1999 Elsevier Science S.A. All rights reserved.