Synthesis and Spectral Properties of 2,7-di-tert-butyl-4,9-bis(arylethynyl)-and 4,10-bis(arylethynyl)pyrenes

Formylation of 2,7-di- tert-butylpyrene with dichloromethyl methyl ether in the presense of AlCl 3 afforded a mixture of 2,7-di- tert-butylpyrene-4,9-biscarbaldehyde and 4,10-biscarbaldehyde in the ratio of 75:25, from which the corresponding bis(arylethynyl)pyrenes were obtained by the Wittig reaction with aryl methyl phosphonium ylides followed by bromination and dehydrobromination.