Synthesis and structures of cycloalkylidene-bridged biscyclopentadienyl-tetracarbonyldiiron complexes C(CH2) n [( η 5-C5H4)Fe(CO)]2( μ-CO)2(n = 4, 5 and 6)

Abstract

A series of cycloalkylidene-bridged biscyclopentadienyldiiron complexes, C(CH2) n [(η5-C5H4)Fe(CO)]2(μ-CO)2 (n = 4, 5 and 6) have been synthesized by the reacting C(CH2) n Cp2 (Cp = C5H5) with Fe(CO)5 in refluxing xylene. The molecular structures of C(CH2)5[(η5-C5H4)Fe(CO)]2(μ-CO)2(2) and trans-C(CH2)4[(η5-t-BuC5H3)Fe(CO)]2(μ-CO)2(4t) have been determined by X-ray diffraction. The Fe—Fe bond distance [2.466 A], in (2) is the shortest reported to date for bridged biscyclopentadienyldiiron complexes.