Dra. Gerli-Candia, Lorena

Nonsteroidal anti-inflammatory drugs (NSAIDs) are among the most frequently prescribed drugs and have multiple therapeutic uses. These drugs are predominantly used for the treatment of musculoskeletal diseases because of their analgesic, antipyretic, and antiplatelet activities. Oxicams constitute an interesting class of organic compounds and have been investigated in the search for new analgesic and anti-inflammatory drugs. In the present work, a theoretical investigation of the molecular structure and spectroscopic properties of a series of five oxicams in different solvents was performed using density functional theory (DFT) methods. The geometric optimizations of the oxicams were carried out using the M06 density functional and the CBSB7 basis set. The infrared data were all obtained at the same theoretical level. The UV-Vis absorption and NMR data of some oxicams were calculated using the DFT and CBSB3 basis sets. The analysis of structural parameters, particularly the bond length and spectroscopic data, indicated that interactions occurred between the hydrogen bond types for 4-meloxicam, isoxicam, and normeloxicam. Stereoelectronic interactions caused by the substitution of alkyl groups caused the bond lengths to elongate. Similarly, the substitution of heteroatoms, such as nitrogen, sulfur, or oxygen, increased the bond lengths and angular stresses.

In this paper, theoretical study using density functional theory (DFT) method (B3LYP level with 6-31G(d,p)) of four novel low band gap acceptor–donor organic materials based on thiophene and phenyl and linked to cyanoacrylic acid as acceptor group are investigated. Different electron side groups were introduced to investigate their effects on the electronic structure; the HOMO, LUMO, gap energy, ionization potentials, electron affinities and open circuit voltage (Voc) of these compounds have been calculated and reported in this paper. The electronic absorption and emission spectra of these dyes are studied by time-dependent density functional theory calculations. A systematic theoretical study of such compound has not been reported as we know. Thus, our aim is first, to explore their electronic and spectroscopic properties on the basis of the DFT quantum chemical calculations. We think that the presented study of structural, electronic and optical properties for these compounds could help in designing more efficient functional photovoltaic organic materials.