Crystal and molecular structure of 3,3-diphenyl-3-phosphoniabicyclo[3.2.1]oct-6-ene bromide monohydrate

The title compound crystallizes in the monoclinic space groupP2₁/n,a=13.429(3),b=18.248(6),c=14.497(4)Å,=90.61(2)°,Z=8, with two independent molecules in the asymmetric unit. The structure was solved by heavy-atom methods, and refined to a finalR value of 0.040. The phosphoranium ring adopts a chair conformation which is substantially flattened at the phosphorus end. The ring conformation and torsion angles are compared with similar compounds.     

Structure oftrans-methyl 2-phenylhexahydro-2H-isoxazolo (2,3-a)-pyridine-3-carboxylate

The title compound, a 1,3-dipolar cycloaddition product, crystallizes in the monoclinic space groupP2₁/c, witha=8.199(3),b=16.908(1),c=10.248(2)Å,=93.58(2)° andZ=4. The structure was solved by direct methods and refined by full matrix least squares methods toR=0.038 for 1687 observed reflections. The stereochemistry of this compound was found to have the ee conformation in the solid state as well as in solution. The piperidine ring in the molecule is in the chair form and the isoxazolidine ring adopts an envelope conformation.     

Crystal and molecular structure of phenylbenzyl-1-(2,2,3-trimethylcyclopropyl)phosphine oxide

The title compound crystallizes in the orthorhombic space groupPna2₁, witha=15.576(2),b=19.134(3),c=5.693(1) Å andz=4. The structure was solved by direct methods, and refined to a finalR value of 0.059. This study confirms both the structure and stereochemistry of the title compound.     

Structure of 5-azauracil (C3H3N3O2) and its hydrolysis product

The title compounds cocrystallize in space groupP¯1:a=8.773(3),b=9.14(3),c=14.062(4) Å, =81.38(7), =71.76(3), =82.96(8)°,U=1055.5 ų,Z=4 (two independent molecules each of azauracil, its hydrolysis product, and water in the asymmetric unit). The structure was solved by direct methods and refined by full-matrix least-squares methods toR=0.059 for 2911 observed reflections. Unusually, the crystal contains both the parent molecule and its hydrolysis product in a hydrogen-bonded complex. The hydrogen bonding results in the formation of essentially planar layers of molecules which are held together by dispersion forces.     

Crystal structure of a pentanuclear gold-silver cluster complex

The title compound, [C₁₆H₃₆N]⁺[C₄₈H₃₀Au₃Ag₂]^–, crystallizes in the triclinic space groupP1^–1, witha=18.199(12),b=19.210(8),c=19.270(9)Å,=71.34(3)°=76.43(4)° =72.95(5)° andZ=4, with two independent molecules in the asymmetric unit. The structure was solved by direct methods and refined by full-matrix least squares methods toR=0.072 for 3739 observed reflections. The metal atoms have a trigonal-bipyramidal arrangement with the three Au atoms forming an equilateral triangle and two Ag atoms occupying apical positions. Each Au atom is -bonded to phenylethynyl ligands in a linear coordination. Each Ag atom is asymmetrically pi-bonded to three alkyne groups. The Au-Au distances lie in the range of 3.934–4.010 A, indicating the lack of Au-Au bond.     

Crystal and molecular structure of 3,3-diphenyl-3-phosphoniabicyclo[3.2.1]octane bromide monohydrate

The title compound crystallizes in the monoclinic space groupP2₁/n, witha=13.316(2),b=18.513(3),c=14.621(4) Å,=90.73(2)°,Z=8, and two independent molecules in the asymmetric unit. The structure was solved by heavy-atom methods and refined to a finalR value of 0.036. The phosphoranium ring adopts a chair conformation, which is substantially flattened at the phosphorus end. The ring conformation and torsion angles are compared with those of similar compounds.     

Crystal and molecular structure of 4-bromo-2,2,3,3-tetramethyl-1-benzyl-1-phenylphosphetanium bromide

The title compound crystallizes in the monoclinic space groupP2₁/n, witha=8.881(1),b=17.718(1),c=13.077(8) Å,=99.17(2)° andZ=4. The structure was solved by the heavy-atom method and refined to a finalR value of 0.059. The four-membered ring is nonplanar, with a puckering angle of 22.0°. The Br and phenyl are in pseudoaxial positions and aretrans to each other in the solid state.     

Tetrahedral complexes of 1,2-dimorpholinoethane and 1,3-dimorpholinopropane: Crystal and molecular structure of dichloro(1,2-dimorpholinoethane)cobalt(II)

The ligands 1,2-dimorpholinoethane (DME) and 1,3-dimorpholinopropane (DMP) have been used to prepare Cu(II), Ni(II), Co(II), Hg(II), Zn(II), and Cd(II) complexes having the general formulationMLX ₂ (L=DME and DMP,X=Cl^–). These complexes exhibit spectral properties indicative of a distorted tetrahedral geometry, with DME or DMP coordinating through two nitrogen atoms and two chloride anions making up the coordination sphere of the central metal atom. This is in contrast to six-coordinated, distorted octahedral geometry exhibited by metal complexes of DME when NO ₂ ^– or NO ₃ ^– were used as counter ions. The tetrahedral geometry was confirmed for [Co(DME)Cl₂] by X-ray structure determination. The structure was solved by the heavy-atom method using CAD4 diffractometer data, and refined to a finalR value of 0.028 for 1097 independent reflections. The morpholine moieties of DME in [Co(DME)Cl₂] are in a chair configuration, forbidding any coordination through ethereal oxygen atoms.     

The structure of 2-phenylperhydro-1,2-oxazolo[3,2-c] [1,4]oxazine

The title compound crystallizes in the monoclinic space group P2₁/n, witha=9.590(6),b=11.574(2),c=9.609(2) Å, =105.72(3)^o andZ=4. The structure was solved by direct methods and refined by full matrix least squares methods toR=0.039 for 1899 observed reflections. The stereochemistry of this 6/5 ring system is found to becis-fused with C(3)–C(4) bond in the axial and N(9)–O(1) bond in equatorial disposition. The six-membered ring in the molecule is in the chair and the five-membered isoxazolidine ring adopts an envelope conformation.