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Highlights: [•] The first hyperpolarizability of a redox switching RuII/III complex has been investigated. [•] Both TDDFT and SOS methods confirm and explain experimental β contrast. [•] MLCT state dominates RuII β whereas ILCT contribution is negligible. [•] MLCT state disappears and β drops substantially upon oxidation. [•] The depolarization ratio changes little upon oxidation. [Copyright &y& Elsevier]

Abstract: A joint experimental and theoretical study is carried out to investigate the structural and absorption properties of the C212 organic dye adsorbed onto the TiO2 anatase surface. UV–Vis measurements evidence a significant blue shift of the main absorption band of the dye upon absorption, which is well reproduced by theoretical calculations combining tight-binding and time-dependent DFT calculations. The blue shift is substantiated by a loss in the efficiency of the light-induced charge transfer along the anchored dye, which partly originates from the deprotonation of the carboxylic acid function. [Copyright &y& Elsevier]

TDDFT calculations are associated to an extrapolation scheme to predict the optical properties of twelve donor-acceptor copolymers, in which carbazole, benzodithiophene or cyclopentadithiophene donor subunits are combined to benzofurazane, benzothiadiazole or diketopyrrolopyrrole acceptor moieties. Relative excitation energies and absorption strengths are rationalized in terms of geometrical, electronic and optical descriptors. It is shown that the combination of a cyclopentadithiophene with a diketopyrrolopyrrole leads to the lowest excitation energy and highest light absorption efficiency within the series. However, combining cyclopentadithiophene and benzodithiophene subunits appears as more efficient for solar cell applications due to better energy level alignment with respect to PCBM. [ABSTRACT FROM AUTHOR]

Abstract: This theoretical Letter addresses the non-linear optical properties of a series of substituted dimethylaminophenylethylenyl-indolino[2,1-b]oxazolidine derivatives, which were recently shown to behave as multiaddressable NLO switches. The influence of the chemical nature of the substituent on the static and dynamic first hyperpolarizability, as well as of its grafting location, is investigated by using various semi-empirical and high level ab initio schemes. It is found that a para-substitution on the indolinic skeleton with a [(N,N-1,3-dimethylpyrimidine-2,4,6-trione)-5-yl]methylidenyl group should increase by 75% the efficiency of the switches. [Copyright &y& Elsevier]