Synthesis, characterisation and structural investigations of iodine-doped indium(III) and zirconium(IV) diphthalocyanines: [InPc2]I2 and [ZrPc2]I2

Article abstract of DOI:10.1016/S0020-1693(01)00627-2

Crystals of iodine-doped indium(III) and zirconium(IV) diphthalocyanines, [InPc₂]I₂ and [ZrPc₂]I₂, were grown directly in the reaction of In-Tl alloy or zirconium powder with 1,2-dicyanobenzene under a stream of iodine at about 200°C. Both partially oxidised diphthalocyaninato complexes crystallise in the P4/mcc space group of the tetragonal system with one molecule per unit cell. The space group of P4/mcc requires that the central metal ions are disordered in these structures. The crystal structures shown columnar pseudo-one-dimensional stacks of [InPc₂] or [ZrPc₂] units with a non-integral charge and linear chains of symmetrical triiodide I₃^- ions, which were detected by a Raman spectroscopy. The pseudo-one-dimensional aggregates of [InPc₂]^2/3+ or [ZrPc₂]^2/3+ as well as the chains of I₃^- ions are aligned along the [001] direction. The formal oxidation state of the Pc macrorings equals to ? -1.167 and ? -1.667 in indium(III) and zirconium(IV) diphthalocyaninato complexes. The EPR measurement shows a single sharp EPR line at g = 2.0028 and 2.0026 for the indium and zirconium complexes, respectively. The conductivity measurement on polycrystalline samples at room temperature equals 2.7-3.1 × 10^-2 and 5.2-5.5 × 10^-2 Ω^-1 cm^-1 for [InPc₂]I₂ and [ZrPc₂]I₂, respectively. The charge transport proceeds mainly along the pseudo-one-dimensional [MPc₂]^2/3+ aggregates. Both iodine-doped metallodiphthalocyaninato complexes exhibit non-metallic character in conductivity (dσ/dT > 0).