Synthesis and optical properties of tetrapyrazinoporphyrazines containing asymmetrical alkyl chains and t-butylphenyl groups

Abstract

Tetrapyrazinoporphyrazine magnesium complexes with four long alkyl groups and four 4-tert-butyl phenyl groups at the peripheral positions were synthesized from 2,3-dicyano-5-(4-tert-butylphenyl)-6-alkyl pyrazine derivatives using freshly prepared solutions of magnesium butoxide in n-butanol. The corresponding metal-free derivatives were obtained through treatment with p-toluenesulfonic acid. The resulting chromophores contained alkyl chains substituted at their peripheries and showed good solubility in organic solvents. The fluorescence of the tetrapyrazinoporphyrazine magnesium complexes was greatly influenced by the intermolecular aggregation. Q band spectra of the porphyrazine magnesium complexes in DMF exhibited the characteristic patterns of the monomeric species, with fluorescence maxima at 653–658 nm. These new compounds were characterized using UV-visible spectroscopy, MALDI-TOF-MS and 1H NMR spectroscopy.