Preparation and properties of some rare-earth phthalocyanines

Abstract

The preparations and magnetic and spectral properties of one ytterbium and two gadolinium phthalocyanines are described and comparisons made with previous studies. The susceptibility of all three compounds followed a Curie-Weiss law, with ø small, and the magnetic moments were typical for trivalent rare-earth compounds with little or no coupling between the metal ions. The e.p.r. signals observed were due to the metal ions. Structures proposed are Cl(pc)YbCl,2H₂O (where pc = C₃₂H₁₆N₈) for ytterbium, and (pc)Gd(pc)H and an associated anionic form for gadolinium. Both gadolinium materials are stable under certain solution conditions, although the anionic material tends to decompose and is difficult to obtain from solution. A polymeric form of phthalonitrile (m.p. 306ºC) was isolated during purification. A simple acid-base equilibrium is proposed for the gadolinium compounds but it is complicated by the separation procedures and by the nature and purity of the solvent.