| abstract |
The present invention relates to salts of 1,9-diarylheptamethine. The salts include non-carbonated carboxonium salts, non-carbonated hemicarboxonium salts and streptocyanins. The carboxonium salts can be prepared by reacting an aryl ketone with a bisaldehyde in the presence of a strong acid. They allow the hemicarboxonium salts and streptocyanins to be obtained by reaction with the appropriate nitrogen compounds. Streptocyanins are useful as biological markers. |