New lamellar oxophosphorus derivatives of nickel(II): x-ray powder diffraction structure determinations and magnetic studies of Ni(HPO3).H2O, NiCl(H2PO2).H2O, and NixCo1-x(HPO3).H2O solid solutions
By cothermolysis of [CpRFe(CO)2]2 [CpR = η5-C5(CH2Ph)5 (Cpbn) (1) and η5-C5Me4C2H4SMe (CpS) (2)] with P4 phosphorus two novel pentaphosphaferrocenes of the formula [CpRFe(η5-P5)] [CpR = CpS (3), Cpbn (4)] have been synthesised and comprehensively characterised. These two products represent the first derivatives of this class of compounds with a functionalised as well as a sterically bulky adjacent cyclopentadienyl ligand. The pentabenzylcyclopentadienyl derivative 4 as well as both of the starting materials [CpRFe(CO)2]2 1 and 2 have been additionally characterised by X-ray diffraction structure determinations. The pentaphosphaferrocene 4 represents in the crystal lattice highly aggregated units via intra- and intermolecular π-stacking interactions of the phenyl rings of the Cpbn ligand.
AbstractIn the interest of obtaining crystalline polydiacetylene with absorption at longer wavelengths, new derivatives of 2,4-hexadiyne with planar, visible absorbing aromatic chromophores have been designed, synthesized, and thermally polymerized. The resulting polymers have a red shifted maximum with absorption extending to the infrared. Their Raman spectra show the usual polydiacetylene ene-yne structure, and X-ray powder diffraction reveals that the new polymers are crystalline.
The use of 1H NMR spectroscopy, in tandem with X-ray crystallography, has cast light on the conformation of the 1,6-disulfide-bridged derivatives of d-gluco-, d-manno-, d-allo-, d-galacto-, and d-talo-pyranose. A similar investigation was performed on the thiosulfinate derived from the d-gluco disulfide. Single-crystal X-ray structure determinations are reported for (1S,5S,6S,7S,8R)-6,7,8-tribenzoyloxy-9-oxa-2,3-dithiabicyclo[3.3.1]nonane, (1S,5S,6S,7R,8R)-6,7,8-tribenzoyloxy-9-oxa-2,3-dithiabicyclo[3.3.1]nonane, and (1S,2S,5S,6S,7S,8R)-6,7,8-triacetoxy-9-oxa-2,3-dithiabicyclo[3.3.1]nonane 2-oxide.
Trimethoprim crystallizes in the triclinic space group P-1 (#2) with a = 10.5085(3), b = 10.5417(2), c = 8.05869(13) Å, α = 101.23371(21), β = 112.1787(3), γ = 112.6321(4)°, V = 743.729 Å3, and Z = 2. A reduced cell search in the Cambridge Structural Database yielded three previous structure determinations, using data collected at 100 K, 173 K, and room temperature. In this work, the sample was ordered from the United States Pharmacopeial Convention (USP) and analyzed as-received. The room temperature (295 K) crystal structure was refined using synchrotron (λ = 0.412826 Å) powder diffraction data and optimized using density functional theory techniques. We found similar hydrogen bonding patterns with the previous determinations. In addition, we identified two C–H⋯O hydrogen bonds, which also contribute to the crystal energy. When comparing the previously reported trimethoprim structure determinations, the unit cell length lattice parameters were found to contract at lower temperatures, particularly 100 K. All structures show reasonable agreement, with unit cell length differences ranging between 0.05 and 0.15 Å. The diffraction data for this study were collected on beamline 11-BM at the Advanced Photon Source, and the powder X-ray diffraction pattern of the compound has been submitted to ICDD® for inclusion in the Powder Diffraction File™ (PDF®).
Powder X-ray diffraction of trimethoprim Form I, C14H18N4O3