Synthesis and spectroscopic properties of meso-substituted quinoxalinoporphyrins

Abstract

A simple and efficient synthetic protocol for the construction of novel meso-substituted quinoxalinoporphyrins has been developed. The reaction of 5-(3,4-diaminophenyl)-10,15,20-triphenylporphyrin with aromatic or aliphatic α-diones afforded the corresponding new quinoxalinoporphyrins in 78–92% yields. Further, this methodology was found to be applicable to obtain β,β′-meso-phenyl-fused quinoxalinodiporphyrins for the first time from porphyrin-2,3-diones in 65–70% yields. All the prepared products were characterized on the basis of spectral and analytical data. The preliminary photophysical studies showed a significant intramolecular energy transfer in the case of newly synthesized quinoxalinoporphyrin dyads.