Flash vacuum pyrolysis study of iron cyclopentadienyl complexes and the crystal structure of O-acetyl- N-(1-ferrocenylpropylidene)hydroxylamine

Abstract

Under flash vacuum pyrolysis (FVP) conditions the acylferrocene FcCOCMe 3 ( 1e) [Fe  (C 5H 5)Fe(C 5H 4)] cracks to provide isobutene, but other acylferrocenes FcCOR (R  H, Me, Et, Me 2CH, Ph or PhCH 2) ( 1a–d, f, g) either were recovered unchanged or underwent total decomposition. The oxime FCCHNOH yielded both FcCN and FcCHO while the oxime acetate yielded FcCHO and acetic acid. Other oximes FcCRNOH were too involatile for FVP while of the oxime acetates FcCR=NOCOCH 3, no pyrolysis was observed when R  Me or Me 2CH, but when R  Et, rearrangement to FcCOEt occurred. The structure of FcC(Et)NOCOCH 3 has been determined by an X-ray diffraction study; the crystals are made up of isolated molecules with no short inter- or intra-molecular contacts.