No abstract

A novel [(1,3-benzoxazol-2-yl)-(5-chloro-1,3-benzoxazol-2yl)]amine (L) (1) compound was synthesized. The molecule has a nitrogen atom between 1,3-benzoxazol-2-yl and 5-chloro-1,3-benzoxazol-2-yl groups. For compound 1 there are twelve possible conformers and tautomers. Ab initio calculations were performed in order to investigate the more stable structures. Three crystals of compound Materials and Methods: All chemicals were reagent grade: methanol (J. T. Baker), 2-amino-5-chloro-benzoxazole (Aldrich); NaOH, CS 2 , CH 3 I, DMF, THF, Co(CH 3 CO 2 ) 2 ·4H 2 O, and Ni(CH 3 CO 2 ) 2 ·4H 2 O. They were used without further purification. Melting points were determined with an Electrothermal 9100 apparatus. FAB mass spectra were obtained with a Jeol model SX-102 spectrometer. Elemental analyses were carried out with a Fisions Instruments EA-1108. An FT IR spectrometer (Perkin-Elmer Model 1605) was used for obtaining IR spectra of solid samples in KBr pellets (4000-400 cm -1 ). The UV/ Vis/NIR spectra (diffuse reflectance) were recorded with a Varian Cary 5E spectrophotometer. NMR spectra were recorded with a VARIAN model Unity Inova (300 and 400 MHz) or a Bruker-Avance-DPX 300 by using [D 6 ]DMSO or CDCl 3 as solvent. Magnetic susceptibility measurements were performed on pulverized samples at room temperature with a Johnson Matthey DG8 5HJ balance. X-ray single crystal data for 1a, 1b, and1c were collected with a KAPPA-CCD area detector diffractometer. The crystal structures were determined and refined with the SHELXS97 and Crystals programs. [18,19] Ab initio cal-[(1,3-Benzoxazol-2-yl)-(5-chloro-1,3-benzoxazol-2-yl)]amine culations were performed in order to obtain the minimum energy structure for the twelve tautomers and conformers of compound 1 using the Gaussian 98 package. [20] Geometries were checked to be the minimal by means of the frequency analysis.