Reaction of tin(iv) phthalocyanine dichloride with decamethylmetallocenes (M = CrII and CoII). Strong magnetic coupling of spins in (Cp*2Co+){SnIVCl2(Pc˙3−)}˙−·2C6H4Cl2†
Abstract
The reaction of tin(IV) phthalocyanine dichloride {SnIVCl2(Pc2−)} with decamethylmetallocenes (Cp*2M, M = Co, Cr) has been studied. Decamethylcobaltocene reduces SnIVCl2(Pc2−) to form the (Cp*2Co+){SnIVCl2(Pc˙3−)}˙−·2C6H4Cl2 (1) complex. The negative charge of {SnIVCl2(Pc˙3−)}˙− is delocalized over the Pc macrocycle providing the alternation of the C–N(imine) bonds, the appearance of new bands in the NIR range and a strong blue shift of both the Soret and Q-bands in the spectrum of 1. The magnetic moment of 1 is equal to 1.68μB at 300 K, indicating the contribution of one S = 1/2 spin of the Pc˙3− macrocycles. These macrocycles form closely packed double stacks in 1 with effective π–π interactions providing strong antiferromagnetic coupling of spins at a Weiss temperature of −80 K. Decamethylchromocene initially also reduces SnIVCl2(Pc2−) to form the [(Cp*2Cr+){SnVICl2(Pc˙3−)}˙− complex but further reaction between the ions is observed. This reaction is accompanied by the substitution of one Cp* ligand of Cp*2Cr by chloride anions originating from {SnIVCl2(Pc˙3−)}˙− to form the complex {(Cp*CrCl2)(SnIV(μ-Cl)(Pc2−))}·C6H4Cl2 (2) in which the (Cp*CrCl2) and {SnIV(Pc2−)} species are bonded through the μ-bridged Cl− anion. According to the DFT calculations, this reaction proceeds via an intermediate [(Cp*2CrCl)(SnClPc)] complex.