Push–pull chromophores comprising benzothiazolium acceptor and thiophene auxiliary donor moieties: Synthesis, structure, linear and quadratic non-linear optical properties

Novel, push–pull chromophores combining a cationic benzothiazolium acceptor moiety and either one or two thiophene rings as a part of the conjugated π-system between the donor and the acceptor moieties have been synthesized and characterized. The chromophores displayed pronounced quadratic NLO activity with their first molecular hyper polarizabilities in agreement with their linear spectral properties.