Ambident σ- and π-donor ability of a neutral 10π-aromatic phosphoniobenzophospholideElectronic supplementary information (ESI) available: analytical and spectroscopic data for 2-4. See http://www.rsc.org/suppdata/cc/b0/b005130f/

Abstract

1-Triphenylphosphoniobenzo[c]phospholide 2 which is accessible via NaBH₄ reduction of 1,3-bis(triphenylphosphonio)benzophospholide 1 displays an ambident coordination ability similar to a phosphinine; this is shown by its reactions with (cyclooctene)Cr(CO)₅ and (naphthalene)Cr(CO)₃ which gave (σ(P)-2)Cr(CO)₅ and (η⁵-2)Cr(CO)₃, the first π-complex of a 10π-aromatic phosphorus heterocycle with a d-block metal.