The structure and thermal expansion of the astronomical molecule propionitrile have been determined from 100 to 150 K using synchrotron powder X-ray diffraction. This temperature range correlates with the conditions of Titan's lower stratosphere, and near surface, where propionitrile is thought to accumulate and condense into pure and mixed-nitrile phases. Propionitrile was determined to crystallize in space group, Pnma (No. 62), with unit cell a = 7.56183 (16) Å, b = 6.59134 (14) Å, c = 7.23629 (14), volume = 360.675 (13) Å3 at 100 K. The thermal expansion was found to be highly anisotropic with an eightfold increase in expansion between the c and b axes. These data will prove crucial in the computational modelling of propionitrile–ice systems in outer Solar System environments, allowing us to simulate and assign vibrational peaks in the infrared spectra for future use in planetary astronomy.
1,2-bis[10,15-di(3,5-di-tert-butyl)phenylporphyrinatonickel(II)-5-yl]diazene was synthesised via copper-catalyzed coupling of aminated nickel(II) 5,10-diarylporphyrin ("corner porphyrin") and its X-ray crystal structure was determined. Two different crystals yielded different structures, one with the free meso-positions in a trans-like orientation, and the other with a cis-like disposition. The free meso-positions of the obtained dimer have been further functionalized while the synthesis of a zinc analog has so far been unsuccessful. The X-ray crystal structure of the dinitro derivative of the dinickel(II) azoporphyrin was determined, and the structure showed a cis-like disposition of the nitro groups.
Abstract Monomerie diiodides of 2,4,6-tri(tert-butyl)phenyl = (s-Mes), 2,4,6-triisopropylphenyl = (Trip)-and 2,4-di-tert-butyl-6-methylphenyl = (DBMP)-gallium and -indium were prepared by the reaction of the lithiated aryls with MI3 (M = Ga, In) in hexane/Et2O. s-MesInI2 (1), s-Mes2InI (2), s-MesGaI2 (3), s-Mes2GaI (4), Trip2InI (5) and (DBMP)2InI (6) were obtained and characterized by their mass and NMR spectra (1H, 13C), and/or by elemental analyses. An X-ray crystal structure analysis was carried out for 1.
Based on single crystal X-ray diffraction data the crystal structure of tricarbonyl(2,6-dwmbutyl- pyridine)chromium(0) has been determined at 200 K: space group P 21/n, Z = 4, lattice constants a = 680.6(5), b - 1383.3(10), c = 1763.0(16) pm, β = 96.53(8)°, refinement to Rw - 0.048 for 1672 independent reflections with FO > 2 σ. The chromium atom is η6π6- bonded to the essentially planar pyridine ring (Cr-C: 219-222 pm, Cr-N: 221 pm). The CO ligands show “eclipsed” orientation with respect to the 2, 4 and 6 position of the pyridine ring. Two CO groups fit into the gaps formed by two methyl groups of the tert-butyl substituents in 2 and 6 position, respectively. The results are discussed in context with related arene and λ3-phosphorine complexes
Tetranuclear hetero-metal MnIII2NiII2 complexes, [Mn2Ni2(L)4(OAc)2] (1) and [Mn2Ni2(L)4(NO3)2] (2) [H2L = N-(2-hydroxymethylphenyl)-5,6-benzosalicylideneimine], have been synthesized and characterized by X-ray crystal structure analyses, infrared spectra, and elemental analyses. The structure analyses revealed that the complexes have a defective double-cubane metal core connected by μ3-alkoxo bridges. Complexes consist of two bis-μ-alkoxo bridged MnIIINiII heteronuclear units making a dimer-of-dimers structure. The double-cubane cores are significantly distorted due to an effect of syn–syn mode acetato or nitrato bridges. Magnetic measurements indicate that weak antiferromagnetic interactions (Mn-Ni = −0.66 ~ −4.19 cm–1) are dominant in the hetero-metal core.
Crystal structure of propionitrile (CH3CH2CN) determined using synchrotron powder X-ray diffraction