Excited-State Parameters of One Intramolecular Cyclization by TD-DFT, CIS and ZINDO Methods

Abstract

Using a time-dependent-density functional theory (TD-DFT), Configuration Interaction Singles (CIS) and Zerner's Intermediate Neglect of Differential Overlap (ZINDO) methods, we have investigated the UV-Visible spectra of one new intramolecular cyclization at before and after intramolecular attack. All structures were optimized at the B3LYP/6-311++G** level while UV-Visible parameters were calculated via different basis sets; 6-31++G**, 6-31+G* and 6-31G*. In the all compounds, with the presence of donors substituted λ_max values are greater, when acceptors substituted are smaller, in the TD-DFT and CIS methods. In the CIS and TD-DFT methods, after the cyclization oscillator strength is low i.e. possibility of transmission and transmission intensity is low, because between two aromatic rings, carbonyl groups does not exist. The 3D-surfaces diagrams showed changes of the λ_maxand energy gap compared with Hammett Para-effect number in the CIS and TD-DFT methods, clearly. The calculations were performed using GAUSSIAN 09W suite of programs.