Synthesis of PAMAM dendrimer and its derivative PAMOL: Determination of thermophysical properties by DFT

Dendrimer (G-0.5 and G0 PAMAM) and derivative of G-0.5 PAMAM (Hydroxy substituted PAMAM, hereafter called PAMOL) were synthesized using different catalyst such as KF/Al₂O_3, 15-Crown-ether, Aliqate-336, 15-Crown-ether & Aliqate-336, K₂CO_3, and Lipase. Products were characterized by IR, NMR and GCMS analysis. The yield of the product was calculated for each reaction and it was found that lipase from Candida antarctica acts as the best catalyst for the reactions with maximum yield 95% and 78% for PAMAM and PAMOL respectively. The structure of PAMAM and PAMOL were optimized by Density Functional Theory at B3LYP/6-311++ G (d,p) and CAM-B3LYP/6-311++G(d,p) level of theory using Gaussian 09 to check the consistency of the results. The thermodynamic properties of the compounds such as thermal energy, enthalpy and Gibbs free energy were determined and reported. The global reactivity descriptors such as chemical potential (μ), hardness (η) and electrophilicity index (ω) were also calculated to characterize the reactive stability of the molecules.