Organic Second-Order Nonlinear Optical Chromophores Modified by Isolation Groups

Organic second-order nonlinear optical (NLO) chromophores are the main constituent part of nonlinear optical material. Scientists are dedicated to researching on the synthesis of novel chromophores with excellent performance by the facile design and modification of organic second-order NLO chromophores for decades. However, the researches on NLO chromophores in order to achieve the efficient translation of molecular microscopic nonlinearity (hyperpolarizability beta) into macroscopic electro-optic (EO) coefficients r(33) is still a challenging task. In recent years, a large number of essays report the novel NLO chromophores by adding isolation groups which can change the shape of chromophores and decrease the electrostatic interaction aimed to achieve the bigger EO coefficients. In this review, the recent processes of novel NLO chromophores modified by isolation groups are reviewed systematically and comprehensively.