Synthesis and Structural Studies of Complexes of Bis(pentafluorophenyl)mercury with Di(phosphane oxide) Ligands

The reaction of bis(pentafluorophenyl)mercury with the ligands bis(diphenylphosphano) methane P,P’-dioxide ({Ph₂P(O)}₂CH₂) (1), bis{2-(N,N,N’N’-tetraethyldiaminophosphano) imidazol-1-yl} methane P,P’-dioxide ({2-PO(NEt₂)₂C₃N₂H₂}₂CH₂) (2) and bis (2-diphenylphosphanophenyl) ether P,P’-dioxide ({2-PPh₂(O)C₆H₄}₂O) (3) afforded crystalline σ-donor complexes [{Hg(C₆F₅)₂}₂{Ph₂P(O)}₂CH₂] (1Hg), [Hg(C₆F₅)₂{2-PO(NEt₂)₂C₃N₂H₂}₂CH₂]_n (2Hg) and [Hg(C₆F₅)₂{2-PPh₂(O)C₆H₄}₂O] (3Hg), respectively. The molecular structures of 1Hg, 2Hg and 3Hg show considerable differences. In complex 1Hg, a single bridging bidentate ligand connects two three-coordinate T-shape mercury atoms with a near linear C-Hg-C atom array. Complex 2Hg is a one-dimensional coordination polymer in which adjacent four-coordinate mercury atoms with a linear C-Hg-C atom array are linked by bridging bidentate O,O’- ligands, whilst in complex 3Hg a T-shape three-coordinate mercury atom is ligated by (3) in a monodentate fashion. The Hg-O bond lengths of complexes 1Hg, 2Hg and 3Hg differ substantially (range 2.5373(14)-2.966(3) Å) owing to structural and bonding differences.