نتایج جستجو برای: π electron delocalization

تعداد نتایج: 340883  

2010
Yan-Ping Huo Li-Hua Zhou

The title compound, C(10)H(6)ClF(3)N(2)O(2), was synthesized by coupling 4-dimethyl-amino-1,1,1-trifluoro-but-3-en-2-one with 4-chloro-benzene-diazo-nium chloride. It crystallizes with two mol-ecules in the asymmetric unit, which form two similar centrosymmetric dimers via hydrogen bonds. Extensive electron delocalization and intra-molecular N-H⋯O hydrogen bonds are responsible for a planar con...

Journal: :The Journal of chemical physics 2014
Sandra Rodríguez González Belén Nieto-Ortega Rafael C González Cano Vega Lloveras Juan J Novoa Fernando Mota José Vidal-Gancedo Concepció Rovira Jaume Veciana Elena del Corro Mercedes Taravillo Valentín G Baonza Juan T López Navarrete Juan Casado

We present a complete Raman spectroscopic study in two structurally well-defined diradical species of different lengths incorporating oligo p-phenylene vinylene bridges between two polychlorinated triphenylmethyl radical units, a disposition that allows sizeable conjugation between the two radicals through and with the bridge. The spectroscopic data are interpreted and supported by quantum chem...

2015
Juan J Torres-Vega Alejandro Vásquez-Espinal Lina Ruiz María A Fernández-Herrera Luis Alvarez-Thon Gabriel Merino William Tiznado

The electron delocalization of benzene (C6H6) and hexafluorobenzene (C6F6) was analyzed in terms of the induced magnetic field, nucleus-independent chemical shift (NICS), and ring current strength (RCS). The computed out-of-plane component of the induced magnetic field at a distance (r) greater than or equal to 1.0 Å above the ring center correlates well (R (2)>0.99) with the RCS value. Accordi...

Journal: :journal of physical & theoretical chemistry 2015
pouya karimi

stability of the π-π stacking interactions in the ben||substituted-coronene and hfben||substituted-coronene complexes was studied using the computational quantum chemistry methods (where ben and hfben are benzene and hexaflourobenzene, || denotes π-π stacking interaction, substituted-coronene is coronene molecule which substituted with four x groups, and x= nh2, ch3, oh, h, f, cf3, cn and no). ...

2009
Liang-You Xia Wen-Long Wang Shan-Heng Wang Yan-Lan Huang Shang Shan

In the mol-ecular structure of the title compound, C(15)H(15)NO(3), the two benzene rings are twisted with respect to each other, making a dihedral angle of 75.11 (10)°. In the amide fragment, the C=O and C-N bond distances are 1.248 (3) and 1.321 (3) Å, respectively, indicating electron delocalization. A partially ovelapped arrangement between parallel hydroxy-methoxy-benzene rings is observed...

2017
Yu Xiong Bo Wu Xiaoyan Zheng Zheng Zhao Ping Deng Ming Lin Benzhong Tang Beng S. Ong

A novel, star-shaped electron acceptor, DMTPA-PDI3, derived from a planar dimethylmethylene-bridged triphenylamine core with three acetylene-linked perylene diimide (PDI) units is developed as a nonfullerene acceptor for organic solar cells (OSCs). DMTPA-PDI3 manifests significantly reduced intramolecular twisting, enabling sufficient system-wide π-electron delocalization leading to broadened s...

2008
Wei Wang

In the title compound, C(9)H(12)Cl(2)N(4), the piperidine ring adopts a chair conformation. The electron delocalization of the molecule is indicated by the similar C⋯N distances within the triazine ring and by the double-bond character of the C=N triazine-piperidine connectivity. Weak intra-molecular C-H⋯N hydrogen bonds link the two rings within the mol-ecule, which exhibits a pseudo-mirror pl...

2011
Ewa D. Raczyńska Tomasz M. Stępniewski Katarzyna Kolczyńska

Quantum-chemical calculations were performed for all possible isomers of neutral aniline and its redox forms, and intramolecular proton-transfer (prototropy) accompanied by π-electron delocalization was analyzed. One-electron oxidation (PhNH(2) - e → [PhNH(2)](+•)) has no important effect on tautomeric preferences. The enamine tautomer is preferred for oxidized aniline similarly as for the neut...

Journal: :Angewandte Chemie 2016
Nathaniel J Schuster Daniel W Paley Steffen Jockusch Fay Ng Michael L Steigerwald Colin Nuckolls

We report two new helicenes derived from the double fusion of an acene with two perylene diimide (PDI) subunits. These PDI-helicene homologs exhibit very different structural and electronic properties, despite differing by only a single ring in the link between the PDI units. The shorter inter-PDI link brings the two PDI subunits closer together, and this results in the collision of their respe...

Journal: :The Journal of organic chemistry 2011
Amit Choudhary Kimberli J Kamer Ronald T Raines

Stereoelectronic effects modulate molecular structure, reactivity, and conformation. We find that the interaction between the ester and carboxyl moieties of aspirin has a previously unappreciated quantum mechanical character that arises from the delocalization of an electron pair (n) of a donor group into the antibonding orbital (π*) of an acceptor group. This interaction affects the physicoche...

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