Experimental and theoretical study of the structure and vibrational spectra of valpromide, C7H15CONH2

NIEVES C. COMELLI; NESTOR E. MASSA; EDUARDO A. CASTRO; LUIS BRUNO BLANCH; ALICIA H. JUBERT

JOURNAL OF RAMAN SPECTROSCOPY

JOHN WILEY & SONS, LTD.

Lugar: THE ATRIUM, SOUTHERN GATE, CHICHESTER P019 8SQ, UK; Año: 2008 vol. 40 p. 6 - 17

0377-0486

In this work,we present results of the conformational and vibrational properties of valpromide(Vpd),an amide with antiepileptic activity, studied by IR and Raman spectroscopy at 300 and 77 K, and 300 K, respectively. Experimental data are compared against ab initio calculations performed at B3LYP level with the inclusion of solvatation effects. Experimental results, reinforced by theoretical calculations, point out that Vpd has three conformers on the potential energy surface, with different structures that can be identified in the C O and NH spectral regions. These conformers are defined by different angular arrays of the dihedral angles formed with the C O, C?N and C?H, C?C of the aliphatic chain bonds. The existence of different conformations and structures are discussed on the basis of results derived from electronic localization function (ELF) and natural orbital bond (NBO) analysis.