Effect of Branching on Two-Photon Absorption in Triphenylbenzene Derivatives

The photophysical and linear and nonlinear spectral properties of octupolar compounds with a triphenylbenzene core are investigated and compared with properties of corresponding dipolar branches. A correlation is found between the solvatochromic behavior and the two‐photon absorption cross section. Moreover, the nature of the core is found to be responsible for the nature of the coupling between branches; in the studied case only (weak) electrostatic interactions are effective, while other cores, like the triphenylamine moiety, are able to promote coherent coupling between the branches, leading to strongly nonadditive properties. Core control: The photophysical spectral properties of octupolar compounds with a triphenylbenzene core are compared with properties of corresponding dipolar branches. The figure shows the correlation between the solvatochromic fluorescence behavior and the two‐photon absorption cross section, ascribed to the intramolecular charge‐transfer character of the transitions.