Synthesis and characterization of new dinuclear complexes (CO)5MnRe(CO)3(L) (L= 2,2'-Bipyromidine, 2,3-Bis(2-pyridyl)pyrazine) and trinuclear compounds (CO)5MnRe(CO)3(L)R (R = Re(Br)(CO)3, W(CO)4). Evidence for asymmetric distortion of the bridging 2,2'-