Synthesis of novel covalently linked dimeric phthalocyanines

We report the syntheses of the dimeric homonuclear Pcs 9a and 9b and of the dimeric heteronuclear Pc 9c, starting from the unsymmetrical phthalocyanines 7a and 7b, each containing a phenolic OH group in one of its substituents. Compounds 9a and 9b were obtained by single-step alkylations of 7a and 7b with 1,6-dibromohexane or, in better yields, by coupling of Pcs 7a and 7b with the bromoalkyl-derivatized Pcs 8a and 8b, while 9c was prepared by treatment of 8a with Pc-Ni complex 7b. The dimeric Pcs 9a-9c show strong cofacial intramolecular association in solution. ((C) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007).