SYNTHESIS AND CRYSTAL-STRUCTURE OF THALLIUM(III) BICYCLIC PHTHALOCYANINE

A new synthesis of thallium bicyclic phthalocyanine {14,28-[3-(3-isoindolylimino)- 1,1' isoindolediylidenodiaminothallium(III), C48H24N13Tl = TlPcc} has been performed from thallium and 1,2-dicyanobenzene under a low nitrogen pressure at 210 degrees C. The green complex compound of TlPcc crystallizes in the triclinic system, space group P $(1) over bar$$, with z = 2 in a unit cell of dimensions: a = 11.677(2), b = 12.391(3), c = 16.047(3) Angstrom, alpha = 75.65(3), beta = 86.44(3), gamma = 65.33(3)degrees, V = 2041.8(9)Angstrom(3). The structure was solved and refined on F to R = 0.0628, wR = 0.0820 and S = 0.77 for 3524 independent reflection with 4 less than or equal to 2 Theta less than or equal to 50 degrees (Mo K alpha radiation) and 656 refined parameters. The crystal contains separate molecules of TlPcc. The bicyclic phthalocyaninato macrocyclic hexadendate ligand is composed of six isoindole units forming a distorted trigonal prism with its six N-donor atoms. The central place of the macrocyclic ligand is occupied by the thallium cation. The Tl-N distances range from 2.238(14) to 2.310(13) Angstrom. The conjugation in the inner 16-membered ring is interrupted by the two sp(3)-hybridized C atoms. The details of the crystal structure are compared and discussed in relation to the structure of other phthalocyanines known in the literature.