Phthalocyanine Derivatives with Eight Peripheral Long‐Chain n ‐Alkylseleno Substituents

Abstract

4,5-Bis(n-octylseleno)phthalodinitrile and 4,5-bis(n-dodecylseleno)phthalodinitrile were efficiently synthesised from 4,5-dichlorophthalodinitrile and the corresponding selenolate RSeMgBr (prepared in situ from elemental selenium and RMgBr; R = n-octyl, n-dodecyl). Lithium chloride was essential for achieving the substitution of both chloro substituents. The crystal structures of the mono-substitution product 4-chloro-5-n-octylselenophthalodinitrile and both disubstitution products were determined by single-crystal X-ray diffraction, with that of 4,5-bis(n-dodecylseleno)phthalodinitrile exhibiting intermolecular C-H···Se contacts compatible with hydrogen bonds. Cyclotetramerisation of these 4,5-bis(n-alkylseleno)phthalodinitriles under Tomoda conditions afforded the corresponding 2,3,9,10,16,17,23,24-octakis(n-alkylseleno)phthalocyanines PcSeRH2 (R = n-octyl, n-dodecyl). The phthalocyaninatomanganese(III) complexes [MnCl(PcSeR)] were obtained from the cyclotetramerisation in the presence of manganese(II) chloride after aerobic work-up. The use of terbium(III) chloride as metal salt in the cyclotetramerisation furnished the double decker complexes [Tb(PcSeR)2].