Organic chromophores can be designed to possess highly polarizable, linearly extended pi-electron systems that, in turn, can be tailored to optimize the NLO response, e.g., their molecular hyperpolarizability. For example, dipolar “push-pull” chromophores, coupling electron donor and acceptor components via a conjugated bridge, can exhibit exceptionally large molecular hyperpolarizabilites. Dipolar NLO chromophores require a host matrix that enforces long-range dipolar order in the bulk phase, while octopolar NLO chromophores require media that drive bulk phase octopolar order.
Research to date that has focused on organizing NLO octopoles in the bulk phase has relied upon the synthesis of high generation dendritic octopoles,(Le Bozec et al. 2001) spontaneous organization within an appropriate liquid-crystalline phase,(Hennrich et al. 2006) or all-optical poling;(Nunzi et al. 1994; Fiorini et al. 1995) all of these approaches have met with only limited success. We propose to confer macroscopic order cofactors by leveraging the directed and self assembly capabilities of designed protein-chromophore complexes.