Structural and Vibrational study of the 2-(2’-furyl)-1H-imidazole

A. E. LEDESMA; S. A. BRANDÁN; J. ZINCZUK; O. E. PIRO; J. J. LÓPEZ GONZÁLEZ; A. BEN ALTABEF

Córdoba, Argentina

Congreso; 9a Conferencia Latinoamericana de Físico-Química Orgánica; 2007

 The 2-(2’-furyl)-1H-imidazole has been synthesized by catalytic hydrogenation of the 2-(2’-furyl)-4,5-1H-dihydroimidazole. The crystalline structure was determined by diffraction X Ray method. The molecules of the compound have an polymeric arrangement and are connected among them by N-H... N bonds. Moreover, they present two conformations with the same occupancy as the one observed in the Figure. The infrared and Raman spectra were registered in solid state, and the RMN 1H, 13C, COSY spectra were registered in a DMSO-D6 solution. The corresponding geometries for both conformations were calculated using the Gaussian 03 [1] program at theory level B3LYP with the 6-31G*, 6-31G**, 6-311G* y 6-311G** basis sets. Theses results have a very good agreement with the crystallographic data. The vibrational frequencies were calculated at those theory levels too. The force constants were calculated for each conformer using the Pulay et al. [2] methodology from the Scaling Quantum Mechanic Force Field (SQM). The assignation of the observed bands in the vibrational spectra was performed. Furthermore, the analysis of the Natural Bond Orbitals (NBO) [3] was carried out to study the charge transference interactions between the furan and imidazole rings for two conformers.        Referencias: [1] Programa Gaussian 03, GAUSSIAN, Inc. Pittsburgh, PAA, USA, 2003. [2] G. Fogarasi, X. Zhou, P. W. Taylor and P. Pulay, J. Am. Chem. Soc., 1992, 105, 7037. [3] E. D. Gledening, J. K. Badenhoop, A. D. Reed, J. E. Carpenter, F. F. Weinhold, NBO 3.1; Theoretical Chemistry Institute, University of Wisconsin; Madison, WI, 1998   Acknowlegments: Consejo de Investigaciones de la Universidad Nacional de Tucumán (CIUNT) and Consejo de Investigaciones Científicas y Técnicas (CONICET).