Measurement of first hyperpolarizabilities by hyper-Rayleigh scattering

Abstract

The origin of spurious and irreproducible signals in the measurement of the hyper-Rayleigh scattering (HRS) of solutions is investigated. A new cell design, coupled with continuous solution filtration through a 20 nm filter, is shown to improve the reproducibility of the measurement to ±5%. A transverse cell dimension of ∼2 mm reduces absorption of the second harmonic. A simple monochromaticity test is used to identify luminescence, and we recommend that it is made routinely. Scattering from the [Ru(bipy)3]2+ cation, attributed to HRS by Zyss et al. [Chem. Phys. Lett. 206, 409 (1993)], appears to be largely due to two-photon excited luminescence. The reliability of calibration procedures is examined, and some revised hyperpolarizabilities are reported.

Calcite microcrystals in the pineal gland of the human brain: First physical and chemical studies

“…It was necessary to separate SHG at 532 nm from spurious background interference due to instrument noise, luminescence, or thermally excited processes. This was achieved by inserting a 540 nm band pass filter that could be tilted about an axis to allow passage of specific wavelength bands in the range 520-540 nm as has been described by Morrison et al [1996].…”

Efficient, Reversible Redox-Switching of Molecular First Hyperpolarizabilities in Ruthenium(II) Complexes Possessing Large Quadratic Optical Nonlinearities

“…All samples were passed through a 0.45 mm filter and were checked for fluorescence by using interference filters as described elsewhere. [11,15] absorptions results in marked attenuation of the quadratic NLO responses, corresponding to a very effective switching of b. The complete reversibility of the Ru III/II redox couples of these complexes shown by cyclic voltammetric studies, [13b,c] together with the reversibility of the MLCT bleaching suggests that the b switching should also be reversible.…”

“…However, although it has been reported that such octupolar complexes exhibit extremely large b values, [9b] it now appears that these claims were exaggerated. [11] Furthermore, only modest b changes occur upon oxidation of [Ru II (bpy) 3 ] 2 .…”

Synthesis and non-linear optical properties of (alkyne)dicobalt octacarbonyl complexes and their substitution derivatives

“…The hyperpolarizability values of all complexes were determined in chloroform at 1064 nm fundamental wavelength using p-nitroaniline in chloroform as an external standard (Table 1) [7]. The hyperpolarizability values increase in the order 2 B/3 B/6 B/7B/8.…”

“…Geometry optimization and energy calculation were carried out by the density functional (B3-LYP) method using the 3-21G* basis set. The dipole moment and hyperpolarizability were calculated by the five-point finite difference method [7,8], which employs the results from 13 SCF calculations with the STO3G basis set on the optimized structure. Numerical calculations have been performed with the program JAGUAR 4.0 [8].…”