Binuclear chromium carbonyl complexes of methylaminobis(difluorophosphine): metal–metal bonds versus four-electron donor bridging carbonyl groups

[MeN(PF2)2]mCr2(CO)n (m = 1, n = 10, 9, 8; m = 2, n = 8, 7, 6; m = 3, n = 6, 5, 4) have been studied theoretically. Low-energy structures with four-electron donor groups and split ligands are found.

Synthesis and coordination chemistry of (PNEt2)2-bridged [2]ferrocenophanes

The trivalent phosphorus-bridged [2]ferrocenophane complex having NEt2 groups on the respective phosphorus centers was prepared, and its reactions as a diphosphine ligand were examined for iron and chromium carbonyl complexes.

Coordination chemistry of 9-sila- and 9-germa-phenanthrenes — unique coordination modes in their metallene complexes

Ligand exchange reactions of 9-sila- and 9-germa-phenathrenes with chromium carbonyl complexes, [Cr(CH3CN)3(CO)3] and [Cr(η6-benzene)(CO)3], were performed. Their reactions with [Cr(CH3CN)3(CO)3] afforded the corresponding η6-complexes, in which Cr(CO)3 moieties coordinated to the C6-rings. However, those with [Cr(η6-benzene)(CO)3] gave unique four-membered complexes bearing semibridging carbonyl ligands. All the structures of novel complexes were determined by NMR and X-ray crystallographic analysis.