Predicting nonlinear optical properties of delocalized charge states in polyenylic chromophores and dendrimers

摘要

Over the past several years there has been continuing interest in the design fo highly conjugated monomers, oligomers and polymers for a variety of photonics applications dependent on a nonlinear response to intense laser radiation. Materials design criteria for these various applications depend on accurate structure-property relationships, and while these relationships can best be determined experimentally, computational approaches that can accurately predict trends in series are extremely useful in establishing target molecules having the desired photonic properties. We have recently reviewed the relationship between incorporatio of polaronic or bipolaronic charge states in oligometric or polymeric conjugation sequences~1 and enhanced thrid-order optical nonlinearity, particularly for finite-length polyenes. In this presentation we will focus on how these charge states can be stabilized by electron donating substituents in dithienylpolyenes, and in model dendrimers base don bis-(diphenylamino)stilbene repeat units, and illustrate why these criteria are important for the design of new optical limiting chromophores.