Synthesis and crystal structure of novel, soluble titanyl phthalocyanines

Novel titanyl phthalocyanines titanyl-tetrakis-(1,1,4,4-tetramethyl-6,7-tetralino)-porphyrazine (1), titanyl-2,3,9,10,16,17,23,24-octakis(phenylethynyl)-phthalocyanine (2a), titanyl-2,3,9,10,16,17,23,24-octakis((4-tert-butylphenyl)ethynyl)-phthalocyanine (3a), titanyl-(2,3,9,10,16,17,23,24-octakis(phenylethyl))phthalocyanine (2b) and titanyl-(2,3,9,10,16,17,23,24-octakis((4-tert-butylphenyl)ethyl)-phthalocyanine (3b) were prepared by reductive cyclotetramerisation of the respective dinitrile precursors in the presence of a titanium(IV) template. The spectroscopic properties were examined by UV–Vis and IR techniques. Soluble compounds 1, 2b and 3b were characterized by 1H and 13C NMR spectroscopy and show good stability towards thermal degradation. The molecular structure of 1 was determined, thus being one of the few examples of soluble phthalocyanines with a low grade of aggregation characterized by single crystal X-ray diffraction. Compound 1 crystallizes in the triclinic space group P 1 ¯ , and the molecules arrange in a coplanar, slipped-stacked structure.