Abstract The preparation is described of two novel classes of bridged cyanines: zwitterionic bis-4-pyridyl and cationic bis-dimethylanilino and bis-methylcarbazolyl derivatives 5 and 11. In these compounds an uneven number of carbon atoms of the methine chain forms part of a five-or six-membered ring. The visible absorption is discussed.
![2,5-bis[(4-dimethylaminophenyl)methylidene]cyclopentan-1-one Structure](https://image.chemsrc.com/caspic/094/19226-99-4.png)