Synthesis and some spectroscopic properties of tetra-2,3-pyridoporphyrazinatosilicon involving bulky axial ligands

Taro Nonomura, Nagao Kobayashi, Tatsuya Tomura

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9 Citations (Scopus)


Tetra-2,3-pyridoporphyrazinatosilicon (SiPyD) containing bis(tri-n-hexylsiloxy) (1) or bis(n-heptylcarbonyloxy) (2) axial ligands have been prepared and characterized by NMR, IR and electronic absorption spectroscopies and by thermogravimetric analysis (TGA) and differential thermal analysis (DTA). These SiPyDs are soluble in common organic solvents, and face-to-face-type stacking is prevented in solution and films. Accordingly, their NMR spectra could be reasonably assigned. Their electronic absorption spectra in solution appear to the blue and red compared with those of the corresponding Si phthalocyanines (SiPcs) and Si tetrapyrazinoporphyrazines (SiPyZs) respectively. These characteristics are reproduced by molecular orbital calculations in the framework of the Pariser-Parr-Pople approximation. On formation of films, the Q bands shift to the red of those in solution by ca 20 nm, suggesting that other similar tetravalent metallophthalocyanines with two long axial ligands can be used for shifting the Q band to the red. TGA and DTA experiments show that the thermal stability of the macrocycles is markedly influenced by the type of axial ligands. Copyright (C) 2000 John Wiley and Sons, Ltd.

Original languageEnglish
Pages (from-to)538-543
Number of pages6
JournalJournal of Porphyrins and Phthalocyanines
Issue number5
Publication statusPublished - 2000 Aug


  • Axial ligand
  • Phthalocyanine
  • Pyridoporphyrazine
  • Silicon

ASJC Scopus subject areas

  • Chemistry(all)


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