Theoretical and Experimental Spectroscopic Analysis of Cyano-Substituted Styrylpyridine Compounds

International Journal of Molecular Sciences

Maria Eugenia Castro²  Maria Judith Percino²  Victor M. Chapela²  Margarita Ceron²  Guillermo Soriano-Moro²  Jorge Lopez-Cruz¹ 

[1] Theoretical Chemistry Laboratory, Investigation Center, Department of Physical Chemistry, Faculty of Chemical Sciences, Autonomous University of Puebla, 105I, San Claudio y 22 Sur, University City, Puebla City, Pue.-72570, Mexico; E-Mail:;Chemistry Center, Institute of Sciences, Autonomous University of Puebla, Complex of Sciences, ICUAP, 103H, 22 Sur y San Claudio, University City, Puebla City, Pue.-72570, Mexico; E-Mails:

关键词: styrylpyridine compounds;    DFT calculations;    IR spectroscopy;    UV-Vis spectroscopy;    NMR spectroscopy;   

DOI  :  10.3390/ijms14024005

来源: mdpi

【 摘 要 】

A combined theoretical and experimental study on the structure, infrared, UV-Vis and ¹H NMR data of trans-2-(m-cyanostyryl)pyridine, trans-2-[3-methyl-(m-cyanostyryl)] pyridine and trans-4-(m-cyanostyryl)pyridine is presented. The synthesis was carried out with an efficient Knoevenagel condensation using green chemistry conditions. Theoretical geometry optimizations and their IR spectra were carried out using the Density Functional Theory (DFT) in both gas and solution phases. For theoretical UV-Vis and ¹H NMR spectra, the Time-Dependent DFT (TD-DFT) and the Gauge-Including Atomic Orbital (GIAO) methods were used, respectively. The theoretical characterization matched the experimental measurements, showing a good correlation. The effect of cyano- and methyl-substituents, as well as of the N-atom position in the pyridine ring on the UV-Vis, IR and NMR spectra, was evaluated. The UV-Vis results showed no significant effect due to electron-withdrawing cyano- and electron-donating methyl-substituents. The N-atom position, however, caused a slight change in the maximum absorption wavelengths. The IR normal modes were assigned for the cyano- and methyl-groups. ¹H NMR spectra showed the typical doublet signals due to protons in the trans position of a double bond. The theoretical characterization was visibly useful to assign accurately the signals in IR and ¹H NMR spectra, as well as to identify the most probable conformation that could be present in the formation of the styrylpyridine-like compounds.

【 授权许可】

CC BY   
© 2013 by the authors; licensee Molecular Diversity Preservation International, Basel, Switzerland.