Structure-Activity Relationship of New Organic NLO Materials Based on Push-Pull Azodyes. 1. Synthesis and molecular properties of the dyes
作者:N. Tirelli、A. Altomare、R. Solaro、F. Ciardelli、U. Meier、Ch. Bosshard、P. G�nter
DOI:10.1002/prac.19983400204
日期:——
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.