Octupolar dendrimers with large first hyperpolarizability

A series of 1,3,5-tricyano-2,4,6-tris(styryl)benzene derivatives (1,2) and dendrimers (3) have been synthesized and their first hyperpolarizabilities (beta) were determined. Whereas the lambda(max) values of 1-3 are similar, the oscillator strength increases with the molecular size. For all compounds, the Stokes shifts are significantly larger when NAr2 is used as the donor. The beta(0) values of 1-3 range from 252 to 507 x 10(-30) esu and increases with the number of octupolar units in the molecule. When the octupolar molecules are linked to the 1,3,5-position of the benzene ring by flexible ether linkages, the beta(O) value increases by 1.7 fold. On the other hand, octupolar monodendron based on the nitrogen atom core and 1,3,5-tricyano-2,4,6-tris(p-diarylaminostyryl)benzene moieties at the periphery exhibits beta(O) = 507 x 10(-30) esu, which is one of the largest (O) values reported for the octupolar molecules.