Substituted thieno¬3,2-b thiophenes and their use

摘要

Compounds of the formula I in which R is a C1- to C22-alkyl radical, A<1> and A<2> are hydrogen or methyl or A<1> is hydrogen and A<2> is the nitro group, and B is the cyano group, the nitro group or an electron-attracting organic group having a double bond which is in conjugation with the thieno[3,2-b]thiophene ring system, have a high dipole moment and a high polarizability and are suitable for purposes of nonlinear optics. If R in the formula I is a C12- to C22-alkyl radical, monomolecular layers can be applied to a substrate by the Langmuir-Blodgett method. The resulting layer elements are suitable, inter alia, as waveguides.