Synthesis of dimanganese complexes containing mixed bridging phosphido ligands; crystal structures of [Mn 2(μ-PPh 2){μ-PPhMN(CO) 5}(CO) 8] and [MN 2(μ-PPhH) (μ-PPhCOMe) (CO) 8

Abstract

The synthesis of a number of dimanganese complexes each containing two different bridging phosphido ligands is reported. The complex Mn 2(μ-PPh 2)(μ-PPhH)(CO) 8 ( 1) is prepared by the reaction of [Mn 2(CO) 10] firstly with PPh 2H followed by reaction with PPhH 2 in decalin. The reaction of 1 with CCl 4 gives Mn 2(μ-PPh 2)(μ-PPhCl)(CO) 8 ( 2) and deprotonation of 1 with n-BuLi followed by reaction of the deprotonated species with RX (X  halide) or [Mn(CO) 5 Br] gives the complexes [Mn 2(μ-PPh 2)(μ-PPhR)(CO) 8 (R  Me( 3a),Et( 3b , CH 2COMe( 3c) or CO 2Et( 3d) and [Mn(μ-PPh 2){μ-PPhMn(CO) 5}(CO 5(CO) 8] ( 4). The deprotonation of [Mn 2(μ-PPhH) 2(Co) 8] with one equivalent of n-BuLi and subsequent reaction with McCOCI gives [Mn 2(μ-PPhH)(μ-PPhCOMe)(CO) 8] ( 5) which exists in solution as a mixture of isomers. The structures of [Mn 2(μ-PPh 2){μ-PPhMn(CO) 5}(CO) 8] ( 4) and of trans-Mn 2(μ-PPhH)(μ-PPhCOMe)(CO) 8] ( 5) have been determined by single-crystal X-ray studies. All the complexes have been characterized spectroscopically and by elemental analysis.