A theoretical study of photodissociation of 1- bromoacetyl bromide (CH2BrCOBr) at 248nm, and the Franck – Condon simulated absorption and emission spectra of Zinc (II) Salen complexes

• Main Authors: Cheng-Wei Lin, 林丞偉
• Other Authors: Hsiu-Hua Chang
• Format: Others
• Published: 2012
• Online Access: http://ndltd.ncl.edu.tw/handle/98268457125731503268

碩士 === 國立東華大學 === 化學系 === 101 === 1. In this thesis, we predict the dissociation paths of CH2BrCOBr at 248nm on adiabatic ground-state potential energy surface with B3LYP/cc-pVTZ calculations, the optimized geometries and harmonic frequencies for reactant, intermediates, transition states, and dissociation products are obtained; the corresponding CCSD(T)/cc-pVTZ energies are computed with B3LYP/cc-pVTZ zero-point energy corrections. The RRKM rate constant for each step is estimated; the branching ratios for major products are then predicted by solving the rate equations. From the results showed that HBr is the major product, and the Br atom is minor. 2. Attempts to simulate the absorption and emission spectra of Zn (II)-Salen complexes are made. The S0 state is calculated with HF/LanL2DZ level of theory to obtain the optimized geometries, harmonic frequencies, and normal modes; CIS/LanL2DZ is employed to explore low-lying singlet excited states ( Sn ). The Franck-Condon Factors are utilized in simulation of the absorption and emission spectra. The nature of absorption spectrum of Zn (II)-Salen complex, Zn(II)-Salen-R (R=OCH3 or OH), has three clear peaks; it is different from R=NO2 which generates two only. On the other hand, the emission spectrum of Zn (II)-Salen complex, Zn(II)-Salen-R (R=OCH3 or OH), has apparent fluorescence intensity; nevertheless, Zn(II)-Salen-NO2 obtains poor consequence.