Synthesis and structure of three isomeric cluster complexes (μ-H)Os3{μ-O2CC5H4Mn(CO)3} (PPh3)2(CO)8

The reaction of (mu-H)Os-3{mu-O2CC5H4Mn(CO)(3)}(CO)(10) with PPh3 in the presence of Me3NO gave mono-and disubstituted heterometallic complexes (mu-H)Os-3{mu- O2CC5H4Mn(CO)(3)} (PPh3)(CO)(9) and (mu-H)Os-3{mu-O2CC5H4Mn(CO)(3)}(PPh3)(2)(CO)(8). Crystal structure determination was performed for three isomeric cluster complexes (mu-H)Os-3{mu-O2CC5H4Mn(CO)(3)} (PPh3)(2)(CO)(8), which are both geometrical and conformational isomers differing in color. The geometrical isomerism is due to the attachment of the PPh3 group at different vertices of the Os-3 triangle relative to the O2CC5H4Mn(CO)(3) bridging ligand. The conformational isomerism implies that the molecules have the same arrangement of ligands and differ only in values of bond angles between the planar fragments of the clusters.