In this work, we report a theoretical exploration of the responses of organic azo- benzene dendrimers. The polarizabilities, the first and second hyperpolarizabilities of the azobenzene monomers (G0), 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 of β and γ 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.
A di-molybdenum carbonyl compound containing thiolate and dithiocarbamate li- gands, [Bu4N][(CO)4Mo(μ-SC6H5)2Mo(C5H10dtc)(CO)2] 1 (C5H10dtc = S2CNC5H10), has been pre- pared by reaction of [Mo2(SC6H5)2(CO)8] with C5H10dtcNa and [NBu4]Br in acetone. It crystallizes in monoclinic, space group P21/n with a = 13.162(3), b = 17.466(2), c = 20.453(4) ?, β = 100.77(1)°, Z = 4, V = 4619(2) ?3, C40H56Mo2N2O6S4, Mr = 980.95, Dc = 1.389 g/cm3, μ = 7.66 cm?1, F(000) = 1988 and R = 0.0746 for 5161 observed reflections with I > 2σ(I). The complex contains a [Mo2S2]2? planar core in which one Mo atom is chelated by a C5H10dtc ligand, leading to different coordination environments of the two Mo atoms. 95Mo NMR measurement indicates that the two Mo atoms are in different oxidation states.
