Ligand substitution in [Fe2(CO)6(NO)(µ-PPh2)] and the isomerism of [Fe2(CO)4(PMe3)2(NO)(µ-PPh2)]
Abstract
Treatment of [NEt4][Fe2(CO)6(µ-CO)(µ-PPh2)] with NO+BF4– provided [Fe2(CO)6(NO)(µ-PPh2)]1. Several phosphide-bridged diiron complexes, [Fe2(CO)5(PR3)(NO)(µ-PPh2)](R = Me 2, OMe 3 or Ph 4), [Fe2(CO)4L2(NO)(µ-PPh2)][L = PMe35, PEt36, PPh37, P(C6H4OMe-p)38, P(OMe)39, P(OEt)310, P(OPh)311, ½Ph2PCH2PPh212, ½Ph2PP(CH2)3PPh213 or ½(η5-C5H4PPh2)2Fe 14] and [Fe2(CO)3{P(OMe)3}3(NO)(µ-PPh2)]15, have been derived from ligand substitution in 1. These complexes exhibit structural versatility. Interconversion between two isomers of 5, 5b and 5c, has been established by variable-temperature 31P-{H} NMR, two-dimensional exchange spectroscopy and single-crystal structure determination.