Highly efficient supramolecular self-assembly with octupolar symmetry for quadratic nonlinear optics

Summary form only given. 3-D octupolar molecules and molecular arrangements represent the right match between nonlinear tensorial properties and stereochemistry, especially in the realm of organometallics. Moreover, the 3-D character of octupolar nonlinear molecules are expected to be particularly suitable for the formation of supramolecular dendrons. As the ruthenium-tris-bipyridine building blocks of various organometallic dendrimers may display large octupolar /spl beta//sub J=3/ hyperpolarizabilities, an octupolar spontaneous supramolecular order would be of great interest for nanoscale quadratic NLO. We have synthesized various dendrimer-like oligomers containing N (N = 1, 2, 3 and 7) monomeric ruthenium tris-bipyridine derivatives. A linear ruthenium-tris-bipyridine sidechain-functionalized oligointide (N = 14) is also synthesized and investigated for comparison. The quadratic NLO hyperpolarizabilities of these supramolecules were characterized by harmonic light scattering in order to rule out 2-photon fluorescence contributions to the harmonic signal.