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D3h Symmetry (d3h + symmetry)
Selected AbstractsSynthesis, Characterisation and Nonlinear Optical Properties of Two-Dimensional Octupolar Systems Based on Phthalocyanine CompoundsEUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 18 2005Maurizio Quintiliani Abstract Four phthalocyanine-based compounds with pseudo D3h symmetry have been synthesised and fully characterised. Palladium cross-coupling methodologies were employed in order to synthesise 1,3,5-tris[(phthalocyaninyl)ethenyl]benzene (Heck) and 1,3,5-tris[(phthalocyaninyl)ethynyl]benzene (Sonogashira) derivatives. Knoevenagel condensation conditions were then applied to the synthesis of 1,3,5-tris[cyano(phthalocyaninyl)ethenyl]benzene and 2,4,6-tris[(phthalocyaninyl)ethenyl]-1,3,5-triazine. Preliminary second-order nonlinear optical studies, by hyper-Rayleigh scattering measurements, revealed that the compounds containing ethenyl linkers induce a strong octupolar effect while the ethynyl-containing compound does not show any octupolar enhancement. The introduction of a triazine central core does not modify significantly the nonlinear optical behaviour of the compound. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005) [source] Multipole moments and polarizability of molecular systems with D3h symmetry in orbitally degenerate statesINTERNATIONAL JOURNAL OF QUANTUM CHEMISTRY, Issue 6 2006I. Ya. Abstract It was proved, by ab initio studies, that the electronic ground states of the molecules MF3 (MV, Cr, Mn), M3 (MLi, Na, K), and C3H3, with D3h symmetry, have orbital degeneracy. It was shown that in the base functions of these degenerate states, the reduced matrix elements of the in-plane E,-type components of the dipole moment, of the quadrupole moments and of the nontotal symmetric components of the (hyper)polarizability are nonzero. The computed values of the dipole and quadrupole moments of the polarizability and hyperpolarizabilities are comparable to those of the molecular systems of the lower than D3h symmetry. © 2005 Wiley Periodicals, Inc. Int J Quantum Chem, 2006 [source] Analysis and calculation of the 31P and 19F NMR spectra of hexafluorocyclotriphosphazeneMAGNETIC RESONANCE IN CHEMISTRY, Issue 4 2005Libor Kapi Abstract The higher order high-resolution 31P and 19F NMR spectra of hexafluorocyclotriphosphazene (F2PN)3 were measured at 183 K and interpreted using subspectral analysis and iterative fitting computation. (F2PN)3 forms a rigid nine-spin system [A[X]2]3 with D3h symmetry. Two complete and very similar sets of six experimental spin,spin coupling constants, 1J(P,F), 2J(P,P), 2J(F,F), 3J(P,F), 4J(F,F)cis and 4J(F,F)trans, were determined for the first time. Theoretical DFT calculations of chemical shifts and coupling constants were performed to assess their predictive value. The PP/aug-cc-pVDZ treatment rendered the best agreement with experimental data. Copyright © 2005 John Wiley & Sons, Ltd. [source] Density Functional Theory (DFT) studies on the ground state of NO3(2A,2) radical and the first triplet state of NO3+cationCHINESE JOURNAL OF CHEMISTRY, Issue 3 2000Cao Xiao-Yan Abstract Density Functional Theory (DFT) studies on the ground states (2A,2) of NO3 radical and on die ground state (1A,;1) and the first triplet state (3E,) of NO3+ cation provide an unambiguous prediction about their geometrical structure: the ground states of both NO3 radical and NO3+ cation have D3h symmetry and the geometrical configuration of me first triplet state 3E, of NO3+ cation has C2v symmetry. It is shown that as for as the ionization energy calculations on NO3 radical are concerned, the results are only slightly different, no mater that gradient corrections of the exchange-correlation energy are included during self-consistent iterations or they are included as perturbations after the self-consistent iterations. [source] | ||||||||||