Diphenylphosphenium bromide

The structure of the title compound, C₁₂H₁₂P⁺·Br⁻, is composed of discrete cations and anions, which are both located on a crystallographic mirror plane. The angle between the two phenyl rings is 69.18 (11)°. The crystal packing is stabilized by P—H...Br hydrogen bonds.

Di-tert-butyl­phosphine oxide

The title compound, C₈H₁₉OP, is the oxidation product of ^tBu₂PH. The mol­ecule is located on a crystallographic mirror plane. As a result, there is just one half-mol­ecule in the asymmetric unit.

Hexakis(dimethyl sulfoxide)copper(II) bis­(hydrogen sulfate)

The title compound, [Cu(C₂H₆OS)₆](HSO₄)₂, is composed of discrete [Cu(C₂H₆OS)₆]²⁺ cations and HSO₄^- anions. The Cu atom is located on a centre of inversion. Two HSO₄^- anions are connected via hydrogen bonds, forming a centrosymmetric dimer.

The `absolute structure' of di­methyl­di­phenyl­phospho­nium iodide

The structure of the title compound, C₁₄H₁₆P⁺·I^-, has been reported previously by Staples, Carlson, Wang & Fackler [Acta Cryst. (1995), C51, 498-500] in the space group P6₅22 without any information about the determination of the absolute structure. We present here a redetermination of this structure from new intensity data in the space group P6₁22 with the direction of the polar axis unequivocally determined for this particular crystal. Both the cation and anion are located on twofold rotation axes.

cis-trans-Tetra­chloro­bis(dimethyl sulfide-κS)tin

The mol­ecule of the title compound, [SnCl₄(C₂H₆S)₂], is located on a centre of inversion with a half-mol­ecule in the asymmetric unit. The Sn atom shows a quadratic bipyramidal coordination.

μ-1,2-Ethanediylbis(diphenyl­phosphine)-κ²P:P′-bis­{acetato[1,2-ethanediylbis(diphenyl­phosphine)-κ²P,P′]copper(I)} diethyl ether disolvate

The title compound, [Cu₂(C₂H₃O₂)₂(C₂₆H₂₄P₂)₃]·2C₄H₁₀O, crystallizes with one dicopper(I) unit located on a centre of inversion and two diethyl ether mol­ecules in general positions. The Cu atoms exhibit slightly distorted tetra­hedral coordination.

Tetra­kis(trimethyl­sil­yl)methane

The crystal structure of the title compound, C₁₃H₃₆Si₄, originally determined by powder diffraction methods, has been redetermined using single-crystal data. The mol­ecule is located on a threefold rotation axis with the methane C and one of the Si atoms located on this axis. All other atoms occupy general positions.

Methyl­triphenyl­silane

The title compound, C₁₉H₁₈Si, crystallizes with two almost identical mol­ecules in the asymmetric unit, which are related by a non-crystallographic translation. The phenyl rings show a propeller-like conformation, with significant deviation from C₃ symmetry.

1,1,4,7,7-Penta­methyl­diethylenetriammonium bis­(hexa­fluoro­phosphate)

The title compound, C₉H₂₅N₃²⁺·2PF₆^-, consists of discrete hexa­fluoro­phosphate anions and 1,1,4,7,7-penta­methyl­diethylenetriamine cations. The geometric parameters are in the usual ranges. Only one PF₆^- cation forms hydrogen bonds with both NH donors of the cation.