Raman and infrared spectra, crystal structure and DFT calculations of novel N-benzyl-4-(3-benzylcarbamoyl-propyldisulfanyl)-butyramide: [C6H5CH2NHC(O)(CH2)(4)S](2)

摘要

N-Benzyl-4-(3-benzylcarbamoyl-propyldisulfanyl)-butyramide (BBCPB, C22H28N2O2S2) has been synthesized and a single crystal of the title compound was obtained. Moreover, the Raman (100-3,500 cm(-1)) and infrared (200-4,000 cm(-1)) spectra of the solid sample were recorded and the structure of BBCPB was characterized by single-crystal X-ray diffraction. The C=O and N-H moieties of two symmetrically independent molecules in the unit cell interact via intermolecular hydrogen bonds (C=O center dot center dot center dot N-H)], whereas the benzene rings are oriented diagonally in opposite directions. The unit cell parameters are: a = 5.4500 (3) a", b = 8.6362 (4) a", and c = 23.4738 (14) a". The molecular geometry and the vibrational frequencies of an isolated molecule was optimized using Density Functional Theory with the methods of B3LYP and B3PW91 utilizing the 6-31G(d) basis set. The computed bond lengths were found to be in excellent agreement with X-ray values (R (2) = of 0.96-0.97), whereas the bond angles were less congruent with the B3LYP and B3PW91 methods (R (2) = 0.58-0.74). These deviations are attributed to the absence of intermolecular interaction for the predicted values of an isolated molecule of BBCPB. Aided by normal coordinate analysis, all observed infrared and Raman bands are assigned to their corresponding fundamentals in agreement with B3LYP/6-31G(d) and B3PW91/6-31G(d) predicted wavenumbers. The results presented here are compared with similar molecules whenever appropriate.