IR SPECTRA AND STRUCTURE OF CHROMENOPIRIDINE AND PYRIDO[1,2-a]PYRIMIDINE SYSTEMS
Irina V.Peretokina, Lev M. Babkov, Anna A. Mecheryakova, Vitaly V. Sorokin; Saratov State Univetsity, Saratov, Russia
Abstract
Тhe aim of our work was to interpret the IR spectrum of a mixture of amino-imino tautomers such as 5-amino-2,4-diimino-3-(pyridine-2-yl)-2,3,4,10 b-tetrahydro-1H-chromeno[3,4-c]pyridine-1-carbonitrile and 4-amino-2,5-diimino-3-(pyridine-2-yl)-2,3,5,10 b-tetrahydro-1-chromeno[3,4-c]pyridine-1-carbonitrile, a mixture of 5-amino-2,4-diimino-3-(pyridine-2-yl)-2,3,4,10 b-tetrahydro-1H-chromeno[3,4-c]pyridine-1-carbonitrile and 4-amino-2,5-diimino-3-(pyridine-2-yl)-2,3,5,10 b-tetrahydro-1-chromeno[3,4-c]pyridine-1-carbonitrile, mixtures of 2-(2-methylphenyl(pyridine-2-ilamino)methyl-malonitriles and their non-cyclized forms of 4-amino-2-(2-methylphenyl)-6H-pyrido[1,2-a]pyrimidine-3-carbinitriles, a mixture of 2-(4-amino-1-cyano-5-imino-1,3,5,10b-tetrahydro-2H- chromeno[3,4-c]pyridine-2-ylidene)-2-cyanoacetamide and 2-cyano-2-(4,5-diamino-1-cyano-1,10b-dihydro-2H-chromene[3,4-c]pyridine-2-ylidene)acetamide and a mixture of 2-cyano-2-(4,5-diamino-9-bromo-1-cyano-1,10b- dihydro-2H-chromeno[3,4-c]pyridine-2-ylidene)acetamide and 2-(5-amino-9-bromo-1- cyano-4-imino-1,3,4,10b-tetrahydro-2H-chromeno[3,4-c]pyridine-2-ylidene)- 2- cyanacetamide.
IR spectrum of the mixture was measured at room temperature with Fourier transform infrared spectrometer Shimadzu IR in the spectral range 400-3700 cm-1. Density functional theory B3LYP/6-31G (d) method and the software package GAUSSIAN 03 were used for modeling the structure and IR spectra in harmonic approximation. The structures of molecules were established.The minimum potential energies, the optimal geometries, the force constants, the dipole moments, the frequencies and forms of normal vibrations and their intensities in the IR spectrum were calculated. A detailed assignment of the vibrational spectra was made. Differences in the geometric structures were established. The differences between calculated IR spectra appear in several regions. Computer simulation of the isolated molecule and Interpretation of the IR spectrum of the mixtures were held using the results of simulation
The presence of molecule in the samples was established. Experimental IR spectra are superposition of spectra of isolated molecules.
Speaker
Irina Peretokina
Saratov State University
Russia
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