Synthesis of diphenyl-(2-thienyl)phosphine, its chalcogenide derivatives and a series of novel complexes of lanthanide nitrates and triflates

A novel synthesis of diphenyl(2-thienyl)phosphine, along with its' oxide, sulfide and selenide derivatives, is reported here. These phosphines have been characterized by NMR, IR, MS and X-Ray crystallography. The phosphine oxide derivative was reacted with a selection of lanthanide( iii ) nitrates and triflates, LnX 3 , to give the resultant metal-ligand complexes. These complexes have also been characterized by NMR, IR, MS and X-Ray crystallography. Single crystal X-Ray diffraction data shows a difference in metal-ligand complex stoichiometry and stereochemistry depending on the counteranion (nitrate vs. triflate). The [Ln(Ar 3 P&z.dbd;O) 3 (NO 3 ) 3 ] ligand-nitrate complexes are nine-coordinate to the metal in the solid state (bidentate nitrate), featuring a 1 : 3 lanthanide-ligand ratio and bear an overall octahedral arrangement of the six, coordinated ligands. Our [Ln(Ar 3 P&z.dbd;O) 3 (NO 3 ) 3 ] ligand-nitrate complexes gave three examples of fac -stereochemistry, where mer -stereochemistry is almost universally observed in the literature of highly related [Ln(Ar 3 P&z.dbd;O) 3 (NO 3 ) 3 ] complexes. For the Tb complexes, two different arrangements of the ligands around the metal were observed in the solid state for [Tb(Ar 3 P&z.dbd;O) 3 (NO 3 ) 3 ] and [Tb(Ar 3 P&z.dbd;O) 4 (OTf) 2 ] [OTf]. [Tb(Ar 3 P&z.dbd;O) 3 (NO 3 ) 3 ] is strictly nine-coordinate, ligand mer -stereochemistry in the solid state, and [Tb(Ar 3 P&z.dbd;O) 4 (OTf) 2 ] [OTf] is strictly octahedral, six-coordinate, with a square-planar stereochemical arrangement of the phosphine oxide ligands around the metal. Three and four-coordinate, pseudo-octahedral lanthanide complexes of novel aryl phosphine oxide ligands are structurally reported.