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.
Laboratoire de chimie organique (UMR CNRS 7611), Institut de chimie moléculaire (FR 2769), Université Pierre et Marie Curie-Paris 6, case 181, 4 place Jussieu, F-75252 Paris cedex 05, France.
