Theoretical Investigation of Nonlinear Optical Properties of Organicand Transition Metal Hybrid Azobenzene Dendrimers

In this work, we report a theoretical exploration of the responses of organic azobenzene dendrimers. The polarizabilities, the first and second hyperpolarizabilities of the azobenzene monomers （GO）, and the first, second and third generation （G1, G2 and G3, respectively） are investigated by semi-empirical methods. The calculated results show that the nonlinear optical （NLO） properties of these organic dendrimers are mainly determined by the azobenzene chromospheres. Additionally, the values oft and y increase almost in proportion to the number of chromophores. On the other hand, two types of transition metal hybrid azobenzene dendrimers （core-hybrid and branch-end hybrid according to the sites combined with transition metals） are simulated and discussed in detail in the framework of time-dependent density functional theory （TDDFT）. The calculated results reveal that the NLO responses of these metal dendrimers distinctly varied as a result of altering the charge transfer transition scale and the excitation energies.