Electro-optic and spectroscopic properties of push-pull-chromophores with non-aromatic π-bridges

- Choice of bridge/substitution pattern allows targeting specific spectral features.
- Fulvalenoid bridges (e.g., [5.6.5]-fulvalene) produce large hyperpolarizabilities.
- Hyperpolarizability trends follow either polarizability or dipole, but not both.
- Zwitter-ionic mesomers rationalize results.