Lambda-type regioregular oligothiophenes: synthesis and second-order NLO properties

J Org Chem. 2007 Jul 20;72(15):5855-8. doi: 10.1021/jo070888a. Epub 2007 Jun 27.

Abstract

The synthesis of a new series of Lambda-type, D-Pi-A regioregular oligothiophenes is described. The simultaneous presence of the chiral centers and the Lambda-type structure disfavored the formation of centro-symmetrical dimeric assemblies. Hence, enhanced first hyperpolarizabilities betaHRS were measured in comparison with those of the corresponding monomers.