نتایج جستجو برای: π electron delocalization
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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...
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...
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...
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). ...
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...
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...
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...
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...
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...
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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