Synthesis and Characterization of Manganese(I) Carbonyl Complexes of the Type [(OC)4Mn{μ-P(R)Aryl}]2†

Metalation of secondary phosphanes HPRR' [R = R' = C6H4-4-Me, C6H3-3,5-Me-2 (3), C6H4-4-NMe2 (4); R/R' = Ph/cHex] with Mn-2(CO)(10) in boiling xylene (mixture of isomers), until the evolution of gaseous carbon monoxide ceases, leads to the formation of the dinuclear complexes of the type [(OC)(4)Mn(mu-PRR')](2) [R = R' = C6H4-4-Me (5), C6H3-3,5-Me-2 (6), R/R' = Ph/cHex (7), R = R' = C6H4-4-NMe2 (8)] with poor to moderate yields. These manganese(I) complexes are only sparingly soluble or even nearly insoluble in hydrocarbons at room temperature. Planar four-membered Mn2P2 rings represent the central moiety with four carbonyl ligands at each manganese( I) atom. The steric demand of the P-bound substituents influences the Mn-P bond lengths as well as the P-Mn-P bond angles.