Manganese complexes of phosphino-mu-phosphido ligands

The reaction of the manganese precursors [MnOTf(CO)(3){1,2-(PH2)(2)C6H4}], 5, or [MnOTf(CO)(3){1,2-(PH2)(2)C2H4}], 6, with either the silver complex of 1,3-diallylbenzimidazol-2-ylidiene or the free carbene, resulted in the formation of the new, dimeric phosphino-mu-phosphido manganese species 7 and 8. Complex 7 crystallises in two isomeric forms (cis and trans), depending upon the choice of solvent. The structures of both isomers have been determined by single-crystal X-ray techniques.