Nonlinear optical properties of a new stable ferrocenyl Schiff-base polychlorotriphenylmethyl radical

Here we report the NLO properties of the isomeric trans and cis forms of radical 1. This fact allowed us to prove the feasibility of polychlorotriphenylmettzyl radicals as building blocks with electron acceptor ability for NLO materials. Moreover, by comparing the beta (vec) values obtained for isomers trans-1 and cis-1 with those of related ferrocenyl-based chromophores, we propose that molecular torsions strongly decrease the second-order NLO response.