The synthesis and spectroscopic characterization of (+)-demethoxyaspidospermine: Density functional theory calculations of the structural, electronic, and non-linear optic and spectroscopic properties

Abstract

(+)-Demethoxyaspidospermine was synthesized via the acylation of aspidospermidine with acetic anhydride, and the structure was determined by elemental analysis and Fourier-transform infrared and nuclear magnetic resonance spectroscopic tools and was supported by the simulated spectroscopic studies. Next, the stable geometries obtained by the conformational analysis performed at the B3LYP/6-31G(d, p) level were used for further investigations carried out in B3LYP and M06-2X functionals, and Hartree–Fock (HF) method, employed by the 6-311++G(d, p) basis set. Also, the natural bond orbital analysis revealed that the most contribution to the lowering of the stabilization energy came from n → π* and π → π* interactions. Moreover, the non-linear optic analysis has shown that the title compound can be a useful agent in the optoelectronic devices because of the optical properties. Also, the chemical reactivity tendency for nucleophilic or electrophilic attack reactions on the compound was evaluated by frontier molecular orbital analysis, and the reactive sites of the compound was shown by highest molecular orbital and lowest unoccupied orbital amplitudes and molecular electrostatic potential diagrams.