Concise multigram-scale synthesis of push-pull tricyanofuran-based hemicyanines with giant second-order nonlinearity: an alternative for electro-optic materials.

Highly stable and highly soluble push-pull heptamethine hemicyanines based on the tricyanofuran electron-accepting group can be prepared on a 15 g scale. The compounds display giant second-order nonlinear figure of merit, µß of up to 31,000×10(-48) esu, and lead to a poled material with a second-order nonlinear response, r33 of 90 pm V(-1) at 1.06 µm.