Homoleptic octahedral hexakis(trimethylphosphine oxide)lanthanide hexafluorophosphates, [Ln(Me3PO)6][PF6]3:

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, LnX₃, 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(Ar₃PO)₃(NO₃)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(Ar₃PO)₃(NO₃)₃] ligand-nitrate complexes gave three examples of fac-stereochemistry, where mer-stereochemistry is almost universally observed in the literature of highly related [Ln(Ar₃PO)₃(NO₃)₃] complexes. For the Tb complexes, two different arrangements of the ligands around the metal were observed in the solid state for [Tb(Ar₃PO)₃(NO₃)₃] and [Tb(Ar₃PO)₄(OTf)₂] [OTf]. [Tb(Ar₃PO)₃(NO₃)₃] is strictly nine-coordinate, ligand mer-stereochemistry in the solid state, and [Tb(Ar₃PO)₄(OTf)₂] [OTf] is strictly octahedral, six-coordinate, with a square-planar stereochemical arrangement of the phosphine oxide ligands around the metal.

Bis(diphenylphosphino)methane Dioxide Complexes of Lanthanide Trichlorides: Synthesis, Structures and Spectroscopy

Bis(diphenylphosphino)methane dioxide (dppmO2) forms eight-coordinate cations [M(dppmO2)4]Cl3 (M = La, Ce, Pr, Nd, Sm, Eu, Gd) on reaction in a 4:1 molar ratio with the appropriate LnCl3 in ethanol. Similar reaction in a 3:1 ratio produced seven-coordinate [M(dppmO2)3Cl]Cl2 (M = Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb), whilst LuCl3 alone produced six-coordinate [Lu(dppmO2)2Cl2]Cl. The complexes have been characterised by IR, 1H and 31P{1H}-NMR spectroscopy. X-ray structures show that [M(dppmO2)4]Cl3 (M = Ce, Sm, Gd) contain square antiprismatic cations, whilst [M(dppmO2)3Cl]Cl2 (M = Yb, Dy, Lu) have distorted pentagonal bipyramidal structures with apical Cl. The [Lu(dppmO2)2Cl2]Cl has a cis octahedral cation. The structure of [Yb(dppmO2)3(H2O)]Cl3·dppmO2 is also reported. The change in coordination numbers and geometry along the series is driven by the decreasing lanthanide cation radii, but the chloride counter anions also play a role.

A new air- and moisture-stable pentagonal-bipyramidal DyIII single-ion magnet based on the HMPA ligand

A new pentagonal-bipyramidal Dy^III SIM was obtained with HMPA ligand, which is stable to air and moisture and shows slow relaxation of magnetization up to 36 K (1000 Hz) with U_eff of 556 K.

(Penta-fluoro-propionato-κO)tetra-kis-(trimethyl-phosphine oxide-κO)copper(II) penta-fluoro-propionate

The title compound, [Cu(C₃F₅O₂)(C₃H₉OP)₄](C₃F₅O₂), comprises a cationic Cu^II complex and a disordered penta­fluoro­propionate counter-ion. The metal atom has a distorted square-pyramidal coordination environment formed by four O atoms originating from trimethyl­phosphine oxide mol­ecules and the remaining one belonging to the monodentate penta­fluoro­propionate anion, which is situated in the basal plane of the pyramid. The mol­ecules are held together in the crystal by a net of weak C—H⋯O and C—H⋯F hydrogen bonds. The counter anion is disordered over two sets of sites in a 0.629 (5):0.371 (5) ratio.