Density Functional Theory and Experimental Study

Comprehensive theoretical and experimental studies of a natural product 8- hydroxyisodiospyrin (HDO) and Diospyrin (DO) have been carried out. A proper computational model was developed based on correlation of experimental and theoretical data for obtaining the electronic spectroscopic and thermodynamic parameters of HDO and DO. First of all the exact structure of HDO and DO are confirmed from the nice validation of theory and experiment prior to determination of its electroactive nature. Hybrid density functional theory (DFT) at B3LYP/6-31G* level is employed for all theoretical simulations. The experimental and predicted IR and UVvis spectra [B3LYP/6-31+G (d p) level of theory] have excellent correlation. Intermolecular non-covalent interaction of HDO and DO with different atmospheric gases such as NH3 CO2 CO H2O are investigated through geometrical counterpoise (gCP) and dispersion correction for DFT (DFT-D3) i.e. B3LYP-gCP-D3/6-31G* method. Furthermore the inter-molecular interaction was supported by geometrical parameters electronic properties thermodynamic parameters and charge analysis.