cm051589+_si_001.cif (19.23 kB)
Second-Harmonic Generation within the P212121 Space Group, in a Series of Chiral (Salicylaldiminato)tin Schiff Base Complexes
dataset
posted on 2006-03-07, 00:00 authored by José María Rivera, Horacio Reyes, Armando Cortés, Rosa Santillan, Pascal G. Lacroix, Christine Lepetit, Keitaro Nakatani, Norberto FarfánA series of 10 (2−11) new chiral (salicylaldiminato)tin Schiff base complexes obtained from the Schiff
base condensation of 4-(diethylamino)salicylaldehyde and various amino acids, in the presence of
diphenyltin oxide, is reported together with the parent achiral (1) derivative. Compounds 2−7 crystallize
in the P212121 orthorhombic space group, and their quadratic nonlinear optical properties are investigated.
At the molecular level, the derivatives possess similar electronic spectra (λmax ≈ 395 nm), and hence
molecular hyperpolarizabilities (β), in relation to the same π-conjugated “push−pull” electronic structure.
In the solid state, they exhibit efficiencies in second-harmonic generation (SHG) up to 8 times that of
urea. The SHG intensities of chromophores 2−6 appear largely correlated with a simple “degree of
chirality” (dχ) parameter, defined from the molecular geometries. The intriguing issue of a possible
quantification of chirality by means of SHG measurement is addressed.