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Planar Configuration (planar + configuration)

Distribution by Scientific Domains
Chemistry80%

Selected Abstracts

Recent advances in planar tetracoordinate carbon chemistry

JOURNAL OF COMPUTATIONAL CHEMISTRY, Issue 1 2007
Gabriel Merino
Abstract We summarize our contributions on the quest of new planar tetracoordinate carbon entities (new carbon molecules with exotic chemical structures and strange bonding schemes). We give special emphasis on the rationalization why in this type of molecules the planar configuration is favored over the tetrahedral one. We will concentrate on the latter and will show that molecules containing planar tetracoordinate carbons have a stabilizing system of delocalized , electrons, which shows similar properties as , systems in aromatic molecules. © 2006 Wiley Periodicals, Inc. J Comput Chem 28: 362,372, 2007 [source]

rac -5-Diphenylacetyl-2,2,4-trimethyl-2,3,4,5-tetrahydro-1,5-benzothiazepine and rac -5-formyl-2,2,4-trimethyl-2,3,4,5-tetrahydro-1,5-benzothiazepine

ACTA CRYSTALLOGRAPHICA SECTION C, Issue 11 2009
Thanikasalam Kanagasabapathy
rac -5-Diphenylacetyl-2,2,4-trimethyl-2,3,4,5-tetrahydro-1,5-benzothiazepine, C26H27NOS, (I), and rac -5-formyl-2,2,4-trimethyl-2,3,4,5-tetrahydro-1,5-benzothiazepine, C13H17NOS, (II), are both characterized by a planar configuration around the heterocyclic N atom. In contrast with the chair conformation of the parent benzothiazepine, which has no substituents at the heterocyclic N atom, the seven-membered ring adopts a boat conformation in (I) and a conformation intermediate between boat and twist-boat in (II). The molecules lack a symmetry plane, indicating distortions from the perfect boat or twist-boat conformations. The supramolecular architectures are significantly different, depending in (I) on C,H...O interactions and intermolecular S...S contacts, and in (II) on a single aromatic ,,, stacking interaction. [source]

(E)- N -[(Benzo­[b]­thio­phen-3-yl)­methyl­ene]- N,-(2,5-di­chloro­phenyl)­hydrazine

ACTA CRYSTALLOGRAPHICA SECTION C, Issue 8 2004
Vijayakumar N. Sonar
The title compound, C15H10Cl2N2S, crystallizes in the centrosymmetric space group P21/c with one mol­ecule in the asymmetric unit. The mol­ecule assumes an approximately planar configuration and has an E geometry about the azomethine C=N double bond. The crystal structure is stabilized by extensive hydrogen bonding. [source]

Chiral ureas with two electronegative substituents at 1-N: An unusual case of coexisting pyramidal and almost planar 1-N atoms in the same crystal,

CHIRALITY, Issue 7 2009
Oleg V. Shishkin
Abstract XRD studies of structure of N -acetoxy- N -methoxyurea and N,N -bis(methoxycarbonyl)- N -methoxyimide have revealed that in N -methoxy- N -X-ureas (X = OAc, Cl, OMe, N+C5H5) the additional shortening of NOMe bond took place, which arising from an nO(Me) -,*NX anomeric orbital interaction. XRD studies of N -chloro- N -ethoxyurea crystal have revealed the presence of two kinds of anomeric nitrogen configuration in the ONCl group in the form of a pyramidal configuration and a planar configuration for same 1-N nitrogen atom. XRD studies of N -4-chlorobenzoyloxy- N -ethoxyurea have revealed that the degree of pyramidality of the 1-N nitrogen in N -aroyloxy- N -alkoxyureas is tuned by orientation of benzoyl group with respect to the NO bond, which in turn depends of size of N -alkoxy group. Chirality, 2009. © 2008 Wiley-Liss, Inc. [source]

The Electrophoretic Deposition of Lanthanum Manganite Powders for a Cathode-Supported Solid Oxide Fuel Cell in Planar and Tubular Configurations

INTERNATIONAL JOURNAL OF APPLIED CERAMIC TECHNOLOGY, Issue 6 2008
Ivana Krklju
The purpose of this research was to obtain porous, high-quality cathodes for solid oxide fuel cells in both planar and tubular shapes. To accomplish this, cathodic electrophoretic deposition of the LaMnO3 powder (synthesized by the modified sol,gel method proposed by Pechini) was performed. The optimal sintering temperatures were 1200°C and 1300°C for the tubular and planar configurations, respectively. Single-phase deposits with about 40% porosity were obtained in both configurations. The cathode quality was confirmed by depositing an electrolyte layer of YSZ. After the cosintering of both layers, an extremely dense electrolyte layer was obtained, and the cathode layer retained its high porosity. [source]