The Structure of Monomeric Octahedral d2-Rhenium(V) Monooxo Complexes $\left[ {{\mathbf{ReO}}\left( {{\mathbf{L}}_{{{\mathbf{tri}}}}^{m}} \right)\left( {{\mathbf{L}}_{{{\mathbf{bi}}}}^{n}} \right)} \right],$$\left[ {{\mathbf{ReO}}\left( {{\mathbf{L}}_{{{\mathbf{tri}}}}^{m}} \right){\mathbf{C}}{{{\mathbf{l}}}_{{\mathbf{2}}}}} \right]$ with Oxygen Atoms of Tridentate Chelating (O,S,O and S,O,S) Ligands

Abstract

The structural features of eleven mononuclear octahedral d²-Re(V) monooxo complexes with tridentate chelating (O,S,O and S,O,S) ligands, $\left[ {{\text{ReO}}\left( {\text{L}_{\text{tri}}^{m}} \right)\left( {\text{L}_{\text{bi}}^{n}} \right)} \right],$$\left[ {{\text{ReO}}\left( {\text{L}_{\text{tri}}^{m}} \right){\text{C}}{{{\text{l}}}_{{\text{2}}}}} \right]$, are discussed. The ${\text{Re-O}}{{\left( {\text{L}_{\text{tri}}^{m}} \right)}_{{trans}}}$ bond lengths (except for two cases) were shown to be similar to (or somewhat shorter than), the Re–O(L)_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 ${\text{Re-O}}{{\left( {\text{L}_{\text{tri}}^{m}} \right)}_{{trans}}}$ bonds are, on average, 0.093 Å longer than the Re–O(ST) bonds, which is consistent with the structural requirements of the trans-effect of a multiply bonded oxo ligand.