Formation of “A-frame” dirhenium(I) hexacarbonyl complexes by trans-1,2-bis(diphenylphosphino)ethylene and bis(bidentate) ligands

Complexes 1-4 were synthesized. Despite its rigid backbone and trans-oriented phosphino groups, the 1,2-bis(diphenylphosphino)ethylene ligand adopts a syn conformation with nearly eclipsed P-Re bonds in these complexes. Complex 2 forms dimers in the solid state via S⋯S interactions. The nature of bonding of these interactions was investigated theoretically.201