IN-III-PHTHALOCYANINES - SYNTHESIS, PROPERTIES, AND CRYSTAL-STRUCTURE OF TETRA(N-BUTYL)AMMONIUM-CIS-DI(NITRITO-O,O')PHTHALOCYANINATO(2-)INDATE(III)

[In(Cl)Pc(2-)] reacts with ((n)Bu(4)N)NO2 in acetone yielding green-blue ((n)Bu(4)N)(cis)[In(NO2)(2)Pc(2-)], which crystallizes in the monoclinic space group P2(1)/n (No. 14). Both nitrite anions are coordinated as chelating nitrito-O,O'(NO2) ligands to In-III in cia-geometry. Consequently In-III is octa-coordinated within a distorted ''quadratic'' antiprism and directed towards the Pc(2-)-Ligand. One of the NO2 Ligands has equivalent N-O bonds similar to free nitrite, while the other has asymmetric N-O bonds. Both (In,O,N,O) rings are approximately planar with a dihedral angle of 80 degrees. The Pc(2-) ligand is distorted in an asymmetrically convex manner. Partially overlapping pairs of Pc(2-) ligands related by an inversion center form double layers, which are separated by layers containing the ((n)Bu(4)N)(+) cations. The cyclic voltammogram shows three electrode processes, which are assigned to the redox pairs: Pc(3-)/Pc(2-) (-0.94 V) < In-I/In-III (-0.78 V) < Pc(2-)/Pc(-) (0.64 V). The UV-VIS-NIR spectra and vibrational spectra are discussed.