Phthalocyaninodehydroannulenes

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, but undergoes an irreversible change at 220 degrees C. MALDI-TOF mass spectrometry of the product reveals that the compound undergoes oligomerisation at this temperature.

Synthetic approaches to asymmetric phthalocyanines and their analogues

“…226 Torres' and Cook's research groups utilized Glaser and Eglinton reactions for the preparation of cyclic binuclear and trinuclear diyne-bridged phthalocyanines 68 and 69 (Scheme 24). 224,225,229 In this case, dihalo A 3 B type phthalocyanines 67 with neighboring halogen atoms were coupled with the alkyne fragments using a palladiumcatalyzed reaction. Once transformed into acetylene-containing compounds with terminal C-H bonds, they undergo self-condensation to form cyclic binuclear or trinuclear compounds.…”

Properties of Some Alkyl Substituted Phthalocyanines and Related Macrocycles

“…The latter is illustrated in Figure 14. The dialkynyl substituted Pc, obtained from the corresponding dibromo compound, was oxidatively coupled to form a mixture of the dehydro[12]annulene and dehydro[18]annulene, 15 and 16 , which were separable 76…”

Multinuclear Phthalocyanine‐Fused Molecular Nanoarrays: Synthesis, Spectroscopy, and Semiconducting Property

“…Despite the extremely limited reports on truly conjugated tetrapyrrole‐fused 2D materials at present, the efforts made in this direction have resulted in a series of multinuclear porphyrin/phthalocyanine‐fused molecular arrays with further extended conjugated systems . Due to the easy functionalization and relatively high reactivity of the porphyrin chromophore, multinuclear porphyrin‐fused arrays have usually been prepared by utilizing the so‐called post‐cyclization strategy with various kinds of porphyrin moieties as starting material.…”