Tricarbonyl Derivatives of Manganese(I) with Diphosphinite Chelating Ligands

Abstract

Reaction of [MnBr(CO)3L] [L = Ph2POCH2CH2OPPh2, L1, {(CH3)2CH}2POCH2CH2OP{CH(CH3)2}2, L2] with AgO3SCF3 and AgO2CCF3 in dichloromethane afforded the new complexes [Mn(O3SCF3)(CO)3L] and [Mn(O2CCF3)(CO)3L], respectively. Substitution of O3SCF3 resulted in the new species [Mn(SCN)(CO)3L], [Mn(NCCH3)(CO)3L](O3SCF3) and, in the case of L2, [Mn(CN)(CO)3L2]. By contrast, any attempt to displace the O2CCF3 ligand in the same way was unsuccessful. After maintaining for some days the complex [Mn(CH3CN)(CO)3L1](O3SCF3) in dichloromethane at room temperature, the new complex [MnCl(CO)3L1] was formed. All the new complexes were characterized by elemental analysis, mass spectrometry and IR and NMR spectroscopies. In the case of [Mn(O3SCF3)(CO)3L1], [Mn(O2CCF3) (CO)3L1], [MnCl(CO)3L1], [Mn(CH3CN) (CO)3L2] (O3SCF3), [Mn(CN)(CO)3L2] and [Mn(O2CCF3)(CO)3L2], together with the previously synthesized complex [MnBr(CO)3L2], suitable crystals for X-ray structural analysis were isolated. In all of them the Mn atom adopts six-coordination by bonding to the three CO ligands, the two P atoms of L and either one C atom (CN), one oxygen atom (O2CCF3, O3SCF3), one N atom (CH3CN, SCN) or the halogen atom (Cl, Br).