Structural Features of Monomeric Octahedral d2-Rhenium(V) Monooxo Complexes with Oxygen Atoms of Tridentate Chelating (O,P,O and O,P,N) Ligands

Abstract

The structural features of eleven mononuclear octahedral d²-Re(V) monooxo complexes with tridentate chelating (O,P,O and O,P,N) ligands, [ReO\(\left( {{\text{L}}_{{{\text{tri}}}}^{m}} \right)\)\(\left( {{\text{L}}_{{{\text{bi}}}}^{n}} \right)\)], [ReO\(\left( {{\text{L}}_{{{\text{tri}}}}^{m}} \right)\)Cl₂], and [ReO\(\left( {{\text{L}}_{{{\text{tri}}}}^{m}} \right)\)-Cl(PPh₃)], are considered. The Re–O\({{\left( {{\text{L}}_{{{\text{tri}}}}^{m}} \right)}_{{trans}}}\) bond lengths are commensurable (or somewhat shorter) with the Re–O\({{\left( {{\text{L}}_{{{\text{tri}}}}^{m}} \right)}_{{cis}}}\) or Re–O(ST) bond lengths, which is indicative of the presence of pseudo-dioxo ReO₂ groups with increased bond orders for both trans-arranged Re–O bonds. In the structures of two compounds, the Re–O\({{\left( {{\text{L}}_{{{\text{bi}}}}^{{\text{2}}}} \right)}_{{trans}}}\) bonds are, on average, 0.094 Å longer than Re–O(ST) and 0.189 Å longer than Re–O\({{\left( {{\text{HL}}_{{{\text{bi}}}}^{{\text{3}}}} \right)}_{{cis}}}\), in accordance with the structural consequences of the trans-effect of a multiply bonded oxo ligand.