ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

X-ray molecular structure and theoretical study of 1,4-bis[2-cyano-2-(o-pyridyl)ethenyl]benzene

M. Judith Percino, Maria Eugenia Castro, Margarita Ceron, Guillermo Soriano-Moro, Victor M. Chapela, and Francisco J. Melendez

Polymers Laboratory, Chemistry Center, Institute of Sciences, Autonomous University of Puebla, Complex of Sciences, ICUAP, 103H, Puebla, Mexico

E-mail: judith.percino@correo.buap.mx

Abstract: The structural characterisation of the molecule 1,4-bis[2-cyano-2-(o-pyridyl)ethenyl] benzene obtained through Knoevenagel condensation is reported. The single crystals, as light brown rods, were cultured from a chloroform solution using a slow evaporation method at ambient temperature. The compound crystallised in the monoclinic system belonging to the C2/c space group with a = 26.4556(9) Å, b = 3.73562(10) Å, c = 18.4230(6) Å, β = 109.841(4)° and the asymmetric unit comprising Z = 4. The structure is ordered and the molecules of the title compound exhibited a lattice with water molecules located at sites of inversion and two-fold axial symmetries. Thus, only halves of the molecules are symmetrically independent. The lattice is reported and contrasted with X-ray single-crystal diffraction and theoretical calculations of 1,4-bis(1-cyano-2-phenylethenyl)benzene. By using density functional theory (DFT) and second order Moller-Plesset (MP2) theoretical calculations, the ground state geometry in the whole molecule at the B3LYP/6-31+G(d,p), and MP2/6-31+G(d,p) theory levels, respectively, were optimised. The DFT calculations showed a quasi-planar structure of the molecule, whereas the wave function-based MP2 method afforded a non-planar optimised structure with significant torsion angles between the pyridine and phenyl rings.

Keywords: cyano-substituted acrylonitrile compound – X-ray structure – molecular structure – DFT and MP2 calculations

Full paper is available at www.springerlink.com.

DOI: 10.2478/s11696-013-0434-5

Chemical Papers 68 (2) 272–282 (2014)