A mixed phosphine sulfide/selenide structure as an instructional example for how to evaluate the quality of a model.

This paper compares variations on a structure model derived from an X-ray diffraction data set from a solid solution of chalcogenide derivatives of cis-1,2-bis-(di-phenyl-phosphan-yl)ethyl-ene, namely, 1,2-(ethene-1,2-di-yl)bis-(di-phenyl-phoshpine sulfide/selenide), C26H22P2S1.13Se0.87. A sequence of processes are presented to ascertain the composition of the crystal, along with strategies for which aspects of the model to inspect to ensure a chemically and crystallographically realistic structure. Criteria include mis-matches between F obs 2 and F calc 2, plots of |F obs| vs |F calc|, residual electron density, checkCIF alerts, pitfalls of the OMIT command used to suppress ill-fitting data, comparative size of displacement ellipsoids, and critical inspection of inter-atomic distances. Since the structure is quite small, solves easily, and presents a number of readily expressible refinement concepts, we feel that it would make a straightforward and concise instructional piece for students learning how to determine if their model provides the best fit for the data and show students how to critically assess their structures.

Crystal structures of (Z)-(ethene-1,2-di-yl)bis-(di-phenyl-phosphine sulfide) and its complex with PtII dichloride.

The crystal structures of (Z)-(ethene-1,2-di-yl)bis-(di-phenyl-phosphine sulfide), C26H22P2S2 (I), along with its complex with PtII dichloride, di-chlorido[(Z)-(ethene-1,2-di-yl)bis-(di-phenyl-phosphine sulfide)-κ2 S,S']platinum(II), [PtCl2(C26H22P2S2)] (II), are described here. Compound I features P=S bond lengths of 1.9571 (15) and 1.9529 (15) Å, with a torsion angle of 166.24 (7)° between the two phosphine sulfide groups. The crystal of compound I features both intra-molecular C-H⋯S hydrogen bonds and π-π inter-actions. Mol-ecules of compound I are held together with inter-molecular π-π and C-H⋯π inter-actions to form chains that run parallel to the z-axis. The inter-molecular C-H⋯π inter-action has a H⋯Cg distance of 2.63 Å, a D⋯Cg distance of 3.573 (5) Šand a D-H⋯Cg angle of 171° (where Cg refers to the centroid of one of the phenyl rings). These chains are linked by relatively long C-H⋯S hydrogen bonds with D⋯A distances of 3.367 (4) and 3.394 (4) Šwith D-H⋯A angles of 113 and 115°. Compound II features Pt-Cl and Pt-S bond lengths of 2.3226 (19) and 2.2712 (19) Å, with a P=S bond length of 2.012 (3) Å. The PtII center adopts a square-planar geometry, with Cl-Pt-Cl and S-Pt-S bond angles of 90.34 (10) and 97.19 (10)°, respectively. Mol-ecules of compound II are linked in the crystal by inter-molecular C-H⋯Cl and C-H⋯S hydrogen bonds.

Crystal structure of chlorido-[diphen-yl(thio-phen-2-yl)phosphine-κP]gold(I).

The crystal structure of the title compound, [AuCl(C16H13PS)], is reported. The mol-ecular structure features a nearly linear arrangement of the chloride and phosphino ligands around the gold(I) center, with a P-Au-Cl bond angle of 179.42 (9)°. The Au-P and Au-Cl bond lengths are 2.226 (2) and 2.287 (2) Å, respectively. The geometry of the groups bonded to the phospho-rus atom of the ligand is a slightly distorted tetra-hedron. The phenyl and thienyl rings of the ligand are extensively disordered, with the thienyl refined over all three possible positions on the phospho-rus atom. The relative occupancy ratio between these positions was found to be 0.406 (3):0.406 (2):0.188 (2). One of the major thienyl ring positions with the relative occupancy of 0.406 was modeled as two rotational isomers around the C-P bond with a relative occupancy ratio of 0.278 (3):0.128 (3). Inter-molecular C-H⋯π inter-actions present in the crystal lattice link mol-ecules of the title compound together to form a complex three-dimensional network.

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.