Modeling of the Diels–Alder reaction enantioselectivity by quantum mechanics and molecular mechanics
作者:Alexey A. Zeifman、Viktor S. Stroylov、Ilya Yu. Titov、Fedor N. Novikov、Oleg V. Stroganov、Igor V. Svitanko、Ghermes G. Chilov
DOI:10.1016/j.mencom.2015.07.012
日期:2015.7
The enantioselectivity of the Diels-Alder reaction between (E)-3-(4-nitropheny1)-.1-(pyridin-3-yl)prop-2-en-1-one and cyclopenta1,3-diene in the chiral ionic liquids 3-butyl-1-methylimidazolium (S)-camphorsulfonate and (S)-1-methyl-3-(pyrrolidin-2-ylmethyl)imidazolium tosylate or upon chiral promotion with chiral oxazaborolidine was modeled by molecular and quantum mechanics and then experimentally studied; computations were in good agreement with the experimental data, resulting in no stereoselectivity with a chiral ionic liquid used as a co-solvent and prominent stereoselectivity upon chiral promotion.
Role of direction of charge transfer on the nonlinear optical behavior of pyridine substituted chalcone derivatives
作者:Anthoni Praveen Menezes、A. Jayarama
DOI:10.1016/j.molstruc.2014.06.095
日期:2014.10
High quality single crystals of an efficient novel nonlinear optical (NLO) chalcone derivative 3-(4-nitro-phenyl)-1-(pyridine-3-yl) prop-2-en-1-one (4NP3AP) that are transparent in the entire visible and infrared region are grown by the slow evaporation solution growth method at ambient temperature. The single crystal XRD studies reveal that the crystal belongs to monoclinic system with the noncentrosymmetric space group P2(1). The presence of functional groups in the compound is confirmed by different spectroscopic techniques. The surface morphology of the crystal is studied by scanning electron microscopy. The second harmonic generation (SHG) efficiency of 4NP3AP determined by Perry and Kurtz method is 56% that of potassium dihydrogen phosphate (KDP) single crystals. The static and frequency dependent molecular hyperpolarizabilities were computed using MOPAC 2012. Thermal analysis confirms that the crystal is thermally stable up to 177 C. The origin of nonlinearity and the role of charge transfer direction on the nonlinearity of the chalcone have been discussed in detail. (C) 2014 Elsevier B.V. All rights reserved.
BADRAN, M. M.;EL-MELIGIE, S.;EL-ANSARI, A. K., REV. ROUM. CHIM., 34,(1989) N1-12, C. 2093-2099