By using the Z-scan method we studied the third-order nonlinear optical parameters of several aminobenziliden-1,3-indandione (ABI) derivatives that have previously been shown to own second-order nonlinear optical properties. Measurements were carried out using two 1064 nm Nd:YAG lasers with picosecond (ps) and nanosecond (ns) pulse widths, respectively. When ns laser was employed in the Z-scan setup, a strong thermal lensing took place resulting in severe overestimation of optical Kerr coefficients. Due to this reason the ps laser was employed to evaluate correct magnitude of Kerr effect. For investigated organic molecules, experimental results show that two-photon absorption at 1064 nm is in correlation with molar extinction coefficient at 532 nm. Here we demonstrate good linear correlation between values of second-order molecular hyperpolarizability determined experimentally and those obtained by quantum chemical modeling.

No abstract

No abstract

No abstract

Phosphorescent iridium­(III) complexes suffer from a strong aggregation quenching, limiting their use in solution-processed or crystalline organic light-emitting diodes. Here we report how an intramolecular stacking between a flexibly bridged bulky aromatic pendant group and the core of nonionic heteroleptic complex can be exploited to minimize the negative effects of this drawback. The stacked conformation provides a rigid sterical shielding of the polar molecular surface, improving photoluminescence quantum yield of the complex both in solution and crystalline state.

A new indane based electron acceptor fragment has been developed and can be used to acquire NLO active chromophores with controlled stereochemistry.

The nonlinear refractive index dependence on the incident light polarization state have been studied for pure chloroform and chloroform solutions of aminobenziliden-1,3indandione derivatives. Measurements were done with linearly, elliptically and circularly polarized light using an 8 ns and 30 ps pulse duration 1064 nm lasers. This allows us to separate electronic, molecular reorientation and thermo-optical components of the nonlinear refractive index. The refractive index variations with the change of laser pulse repetition rate were employed to identify the presence of the thermo-optical effect. Quantum chemical calculations of linear polarizability were used to estimate the magnitude of molecular reorientation induced refractive index changes for solvents and solutions. Overall, in this paper we have outlined various essential aspects that need to be taken into account to correctly interpret Z-san measurement results for organic solvents and solutions.

No abstract