Experimental and theoretical determination of the first-order hyperpolarizability of photo- and acidochromic indolino[2,1-b]oxazolidines

We report first-order hyperpolarizability studies of a new series of photo- and acidochromic compounds based on the 10-(2-arylethenyl)indolino[2,1-b]oxazolidine unit combined with various styrylic residues, through polarized hyper-Rayleigh scattering measurements and quantum chemical calculations. The reversible photo- and acido-induced oxazolinic ring opening is accompanied by a major change in the conjugation of the π electrons and therefore NLO-phores are generated. Structure–property relationships concerning intrinsic molecular non-linearity of these multiaddressable molecular switches are presented.