Specific features of the structures of monomeric octahedral d ²-rhenium(V) monooxo complexes with oxygen atoms trans to the oxo ligands: Complexes with monodentate neutral ligands ORtrans (OR = DMF, R'OH, L¹–L³)

Specific features of the structures of ten mononuclear octahedral rhenium(V) oxo complexes (I–X) with the oxygen atoms of the ligands DMF, R'OH (R' = Me, Et, Pr), and Ln (Ln = ON4C6 ∙ C6H10 (n = 1), O–(C6H3MeCH2NH+Et2) (n = 2), O–(NH+C5H4) (n = 3)) trans to the multiply bonded oxo ligands have been considered. The Re–O(OR)trans bonds in complexes I–VII (OR = DMF, R'OH, L1) are elongated owing to the structural manifestation of the trans influence of multiply bonded oxo ligands. The Re–O–(OR) bonds with a negatively charged oxygen atom in three complexes with zwitterionic ligands L2 (in VIII) and L3 (in IX and X) are either comparable with the standard Re–O(ST) bond length (in IX and X) or strongly shortened as compared with Rе–O(ST) (in complex VIII). In the anionic complex [ReO(MeOH)Cl2(L4)]– (XI), the oxygen atom of the monomeric neutral ligand МеOH is unexpectedly cis to the oxo ligand, while the trans position to =O(oxo) is occupied by the acido oxygen atom of the bidentate chelating monodeprotonated 2-(diphenylphosphonyl) benzoate ligand (L4)–.