First bent form for the hydroxo-bridged cis-diammineplatinum(II) dimer [Pt2(NH3)4(μ-OH)2](ClO4)2

2004 ◽  
Vol 60 (3) ◽  
pp. 255-262 ◽  
Author(s):  
Ken Sakai ◽  
Yosuke Konno ◽  
Noboru Takayama ◽  
Satoru Takahashi

The third crystal structure containing the hydroxo-bridged cis-diammineplatinum(II) dimer has been determined for a perchlorate salt of the complex, [Pt2(NH3)4(μ-OH)2](ClO4)2. However, the dinuclear cations in the nitrate and the carbonate salts, [Pt2(NH3)4(μ-OH)2](NO3)2 [Faggiani, Lippert, Lock & Rosenberg (1977). J. Am. Chem. Soc. 99, 777–781] and [Pt2(NH3)4(μ-OH)2](CO3)·H2O [Lippert, Lock, Rosenberg & Zvagulis (1978). Inorg. Chem. 17, 2971−2975], were reported to possess a nearly planar geometry. The cation in the title perchlorate salt has been found to possess an exceptional bent form in which two Pt coordination planes within the dimer are tilted at an angle of 151.7 (1)° to one another. The diplatinum entity has a syn orientation with regard to the conformation of two hydroxo bridges, in part due to the one-dimensional hydrogen-bonding network achieved in the crystal structure. DFT MO investigations have also been carried out to reveal that the planar-bent selection could be induced by the anti–syn selection at the H(hydroxo) atoms. Comparison has also been made between the geometrical features of the three salts from the viewpoint of the orientation of H(hydroxo) atoms.

Author(s):  
Chia-Hwa Lee ◽  
Gene-Hsiang Lee

In the title compound, C8H8N6, two imidazolyl groups are separated by a zigzag –CH=N—N=CH– linkage. An inversion center is located at the mid-point of the N—N single bond and the complete molecule is generated by symmetry. In the crystal, each molecule forms four N—H...N hydrogen bonds with two neighbouring molecules to constitute a one-dimensional ladder-like structure propagating along thea-axis direction.


2021 ◽  
Vol 22 (4) ◽  
pp. 2030
Author(s):  
Hela Ferjani ◽  
Hammouda Chebbi ◽  
Mohammed Fettouhi

The new organic–inorganic compound (C6H9N2)2BiCl5 (I) has been grown by the solvent evaporation method. The one-dimensional (1D) structure of the allylimidazolium chlorobismuthate (I) has been determined by single crystal X-ray diffraction. It crystallizes in the centrosymmetric space group C2/c and consists of 1-allylimidazolium cations and (1D) chains of the anion BiCl52−, built up of corner-sharing [BiCl63−] octahedra which are interconnected by means of hydrogen bonding contacts N/C–H⋯Cl. The intermolecular interactions were quantified using Hirshfeld surface analysis and the enrichment ratio established that the most important role in the stability of the crystal structure was provided by hydrogen bonding and H···H interactions. The highest value of E was calculated for the contact N⋯C (6.87) followed by C⋯C (2.85) and Bi⋯Cl (2.43). These contacts were favored and made the main contribution to the crystal packing. The vibrational modes were identified and assigned by infrared and Raman spectroscopy. The optical band gap (Eg = 3.26 eV) was calculated from the diffuse reflectance spectrum and showed that we can consider the material as a semiconductor. The density functional theory (DFT) has been used to determine the calculated gap, which was about 3.73 eV, and to explain the electronic structure of the title compound, its optical properties, and the stability of the organic part by the calculation of HOMO and LUMO energy and the Fukui indices.


2012 ◽  
Vol 68 (9) ◽  
pp. m265-m268 ◽  
Author(s):  
Kai-Long Zhong ◽  
Ming-Yi Qian

The title compound, {[Co(H2O)6][Co(SO4)(C10H8N2)(H2O)3][Co(SO4)2(C10H8N2)(H2O)2]}n, contains three crystallographically unique CoIIcentres, all of which are in six-coordinated environments. One CoIIcentre is coordinated by two bridging 4,4′-bipyridine (4,4′-bipy) ligands, one sulfate ion and three aqua ligands. The second CoIIcentre is surrounded by two N atoms of two 4,4′-bipy ligands and four O atoms,i.e.two O atoms from two monodentate sulfate ions and two from water molecules. The third CoIIcentre forms part of a hexaaquacobalt(II) ion. In the crystal structure, there are two different one-dimensional chains, one being anionic and the other neutral, and adjacent chains are arranged in a cross-like fashion around the mid-point of the 4,4′-bipy ligands. The structure features O—H...O hydrogen-bonding interactions between sulfate anions and water molecules, resulting in a three-dimensional supramolecular network.


2018 ◽  
Vol 284 ◽  
pp. 1230-1234
Author(s):  
Mikhail V. Maisuradze ◽  
Alexandra A. Kuklina

The simplified algorithm of the numerical solution of the differential diffusion equation is presented. The solution is based on the one-dimensional diffusion model with the third kind boundary conditions and the finite difference method. The proposed approach allows for the quick and precise assessment of the carburizing process parameters – temperature and time.


2019 ◽  
Vol 83 (03) ◽  
pp. 459-463 ◽  
Author(s):  
Stuart J. Mills ◽  
Owen P. Missen ◽  
Georges Favreau

AbstractThe crystal structure of Ni-rich gordaite–thérèsemagnanite has been determined from a sample collected at pillar 80 in the North mine, Cap Garonne, Var, France. The structure was refined to R1 = 0.0693 for 935 reflections with I > 2σ(I). The mineral is isostructural with gordaite, forming a layered structure with an extensive hydrogen-bonding network. The possible polytypic relationship between gordaite, thérèsemagnanite and guarinoite is also discussed. The guarinoite formula (Zn,Co,Ni)6(SO4)(OH,Cl)10·5H2O is also likely to be incorrect and is more likely to be Na(Zn,Co)4(SO4)(OH)6Cl·5–6H2O, meaning that guarinoite is equivalent to Co-rich gordaite-2H and would not be a distinct mineral species.


2014 ◽  
Vol 70 (7) ◽  
pp. 668-671 ◽  
Author(s):  
Zhi-Hui Zhang ◽  
Jin-Long Wang ◽  
Ning Gao ◽  
Ming-Yang He

The novel title organic salt, 4C5H7N2+·C24H8O84−·8H2O, was obtained from the reaction of perylene-3,4,9,10-tetracarboxylic acid (H4ptca) with 4-aminopyridine (4-ap). The asymmetric unit contains half a perylene-3,4,9,10-tetracarboxylate (ptca4−) anion with twofold symmetry, two 4-aminopyridinium (4-Hap+) cations and four water molecules. Strong N—H...O hydrogen bonds connect each ptca4−anion with four 4-Hap+cations to form a one-dimensional linear chain along the [010] direction, decorated by additional 4-Hap+cations attached by weak N—H...O hydrogen bonds to the ptca4−anions. Intermolecular O—H...O interactions of water molecules with ptca4−and 4-Hap+ions complete the three-dimensional hydrogen-bonding network. From the viewpoint of topology, each ptca4−anion acts as a 16-connected node by hydrogen bonding to six 4-Hap+cations and ten water molecules to yield a highly connected hydrogen-bonding framework. π–π interactions between 4-Hap+cations, and between 4-Hap+cations and ptca4−anions, further stabilize the three-dimensional hydrogen-bonding network.


Author(s):  
Hansu Im ◽  
Jineun Kim ◽  
Changeun Sim ◽  
Tae Ho Kim

The title compound, (systematic name:N,N′-dibenzyl-3,3′-dimethoxy-1,1′-biphenyl-4,4′-diamine), C28H28N2O2, was synthesized by the reduction of a Schiff base preparedviaa condensation reaction betweeno-dianisidine and benzaldehyde under acidic conditions. The molecule lies on a crystallographic inversion centre so that the asymmetric unit contains one half-molecule. The biphenyl moiety compound is essentially planar. Two intramolecular N—H...O hydrogen bonds occur. The dihedral angle between the terminal phenyl and phenylene rings of a benzidine unit is 48.68 (6)°. The methylene C atom of the benzyl group is disordered over two sets of sites, with occupancy ratio 0.779 (18):0.221 (18). In the crystal, molecules are connected by hydrogen bonding betweeno-dianisidine O atoms and H atoms of the terminal benzyl groups, forming a one-dimensional ladder-like structure. In the data from DFT calculations, the central biphenyl showed a twisted conformation.


Energies ◽  
2020 ◽  
Vol 13 (22) ◽  
pp. 5863
Author(s):  
Massimo Cardone ◽  
Bonaventura Gargiulo

This paper presents a virtual model of a scroll compressor developed on the one-dimensional analysis software Simcenter Amesim®. The model is semi-empirical: it needs some physical details of the modelled machine (e.g., the cubic capacity), but, on the other hand, it does not require the geometrical features of the spirals, so it needs experimental data to calibrate it. The model also requires rotational speed and the outlet temperature as boundary conditions. The model predicts the power consumption and the mass flow rate and considers leakages and mechanical losses. After the model presentation, this paper describes the test bench and the obtained data used to calibrate and validate the model. At last, the calibration process is described, and the results are discussed. The calculated values fit the experimental data also in extrapolation, despite the model is simple and performs calculations within 7 s. Due to these characteristics, the model is suitable for being used in a larger model as a sub-component.


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