2-Phenyl­selanyl-3,5-methano-2H-cyclo­penta­[b]­furan-2-one

The title compound, C₁₄H₁₄O₂Se, crystallizes as separate neutral mol­ecules each consisting of one norbornane moiety bridged through aa Se atom to a phenyl group and covalently bonded to both the C and O atoms of a carboxyl­ate group forming a five-membered ring. It is a useful intermediate in the synthesis of larger organometallic complexes. One mol­ecule of the title compound constitutes the asymmetric unit. The packing of mol­ecules in well defined layers results in a number of C—H...Se `agostic' interactions and weak C—H...O=C hydrogen bonds.

()-5-Ethyl-1-methyl-5-phenyl­pyrimidine-2,4,6-trione at 163 K

A low-temperature [163 (2) K] redetermination of the crystal structure of the title compound, C₁₃H₁₄N₂O₃ [originally determined by Bideau, Marly & Housty (1969). C. R. Acad. Sci. Ser. C, 269, 549-551], has been performed. Although no gross strucural differences have been observed, H atoms have been located and the extended structure ex­amined.

Bis­[2,4-bis(2-pyridyl-κN)-6-(4-pyridyl)-1,3,5-triazine-κN³]­ruthenium(II) bis­(hexa­fluoro­phosphate)

The coordination of Ru in the title compound, [Ru(C₁₈H₁₂N₆)₂](PF₆)₂, is octahedral. The coordination sphere is formed by six N atoms from the tridentate sites of two ligands that are meridionally oriented around the Ru^II ion. The locations of the donor atoms deviate substantially from an ideal octahedron. The Ru—N distances are in the range 1.983 (4)–2.111 (4) Å. The Ru atom occupies a special position with twofold rotational symmetry. One of the P atoms occupies a special position with twofold rotational symmetry and the other P atom is located on a special position at a centre of symmetry.