Symmetrical and Nonsymmetrical Chromophores with Tröger’s Base Skeleton: Chiroptical, Linear, and Quadratic Nonlinear Optical Properties—A Joint Theoretical and Experimental Study

We report on the novel chiral push-pull chromophores derived from 6H,12H-5,11-methanodibenzo[b,f][1,5]diazocine (Tröger's base skeleton). The synthesis of symmetrical chromophores featuring two identical acceptors, as well as the synthesis of unsymmetrical chromophores featuring only one acceptor is given. Symmetrical chromophores were prepared in the enantiomerically pure form and their chiroptical properties were investigated. Second-order nonlinear optical (NLO) properties of new chromophores were investigated with the aid of hyper-Rayleigh scattering (HRS). The detailed theoretical analysis of the second-order NLO properties of the chromophores was also undertaken. The joint theoretical and experimental studies of chromophores derived from Tröger's base skeleton, in comparison with benchmark chromophores featuring a dimethylamino group as the donor, provided insight into the relationship between the structure of the new chromophores and their NLO properties.