Several new push-pull azobenzene dyes were synthesized by diazonium salt coupling of electron-poor anilines with N,N-dialkylanilines. Their dipole moments and first-order hyperpolarizabilities were evaluated respectively from the concentration dependence of the dielectric constant of solutions in apolar solvents and by the electric-field-induced-second-harmonic-generation (EFISH) technique. Investigation of the influence of both nature and steric hindrance of the electron with drawing group allowed to highlight a significant deviation from linearity in the relationship between dipole moments and first-order hyperpolarizabilities. This effect was particularly noticeable when multiple electron withdrawing groups pointing in different directions were present on the same phenyl ring.
Structure-activity relationship of new NLO organic materials based on push-pull azodyes. 1. Synthesis and molecular properties of the dyes
ALTOMARE, ANGELINA;SOLARO, ROBERTO;CIARDELLI, FRANCESCO;
1998-01-01
Abstract
Several new push-pull azobenzene dyes were synthesized by diazonium salt coupling of electron-poor anilines with N,N-dialkylanilines. Their dipole moments and first-order hyperpolarizabilities were evaluated respectively from the concentration dependence of the dielectric constant of solutions in apolar solvents and by the electric-field-induced-second-harmonic-generation (EFISH) technique. Investigation of the influence of both nature and steric hindrance of the electron with drawing group allowed to highlight a significant deviation from linearity in the relationship between dipole moments and first-order hyperpolarizabilities. This effect was particularly noticeable when multiple electron withdrawing groups pointing in different directions were present on the same phenyl ring.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
