Trends in Optical Nonlinearity and Thermal Stability in Electrooptic Chromophores Based upon the 3-(Dicyanomethylene)-2,3-dihydrobenzothiophene-1, 1-dioxide Acceptor†

A series of new thiophene-bridged chromophores based on the powerful heterocyclic acceptor 3-(dicyanomethylene)-2,3-dihydrobenzothiophene-1,1-dioxide has been synthesized; the dependence of the linear and second-order nonlinear optical properties and thermal stability of these species upon the donor group and the bridging group have been studied. In addition, the synthesis of a related new acceptor, not containing the fused benzene ring, is described and a chromophore based upon this acceptor is studied.