Molecular structure and vibrational and chemical shift assignments of 3,5-bis-(4-methylbenzoyl)-2,6-bis(4-methylphenyl)-4H-pyran-4-one: A combined experimental and theoretical analysis

The molecular geometry, vibrational frequencies, gauge-including atomic orbital (GIAO) H-1 and C-13 chemical shift values of 3,5-bis-(4-methylbenzoyl)-2,6-bis(4-methylphenyl)-4H-pyran-4-one in the ground state have been calculated by using the Hartree-Fock (HF) and density functional method (DFT/B3LYP) with 6-31G(d) basis set. And this structure has been confirmed by IR, C-13 and H-1 spectroscopy. The results of the optimized molecular structure are presented and compared with the experimental X-ray diffraction. The computed vibrational frequencies are used to determine the types of molecular motions associated with each of the experimental bands observed. Also, calculated C-13 and H-1 chemical shift values are compared with the experimental ones. The data of the title compound display significant molecular structure. Moreover, its IR and NMR spectroscopic analysis provide the basis for future design of efficient materials having the pyran core. (C) 2010 Elsevier B.V. All rights reserved.