Abstract
4-Bromo- and 4,5-dibromo-3,6-dibutoxyphthalonitrile have been prepared and treated with 3,6-didecylphthalonitrile in cross tetramerisation reactions in the presence of nickel acetate to afford monobromo- and dibromo-dibutoxyhexadecylphthalocyaninato nickel(II) complexes. Sonogashira and Stille coupling reactions on these compounds displaced the bromine substituents by ethynyl groups. Oxidative coupling of the monoethynyl derivatised nickel phthalocyanine afforded a butadiynyl-linked dinuclear phthalocyanine. The corresponding coupling reaction of the diethynylated phthalocyanine gave a mixture of phthalocyaninodehydroannulenes. Separation of the mixture yielded the diphthalocyaninodehydro[12]annulene as the major product. Electrospray mass spectrometry provides evidence for its aggregation in solution. The corresponding cyclic trimer, the triphthalocyaninodehydro[18]annulene. has been identified as a minor product. Both compounds show a large splitting of the Q-band absorption in the visible region spectrum, Most of the mononuclear phthalocyanine precursors exhibit discotic liquid crystal behaviour. The diphthalocyaninodehydro[12]annulene also enters a mobile phase on heating, hut undergoes an irreversible change at 220 degreesC. MALDI-TOF mass spectrometry of the product reveals that the compound undergoes oligomerisation at this temperature.
Original language | English |
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Pages (from-to) | 3958-3967 |
Number of pages | 10 |
Journal | Chemistry - A European Journal |
Volume | 6 |
Issue number | 21 |
Publication status | Published - 2000 |