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

The reaction of (mu-H)Os-3{mu-O2CC5H4Mn(CO)(3)}(CO)(10) with PPh3 in the pr esence 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 di fferent vertices of the Os-3 triangle relative to the O2CC5H4Mn(CO)(3) brid ging ligand. The conformational isomerism implies that the molecules have t he same arrangement of ligands and differ only in values of bond angles bet ween the planar fragments of the clusters.