Metal phthalocyanine (CV+){MCl2Pc}− salts with two chromophores (CV+: Crystal violet, Pc: Phthalocyanine) based on SnIIPc and FeIIIClPc phthalocyanines

Abstract

Interaction of crystal violet (CV+)(Cl−) salt with SnII(Pc2−) or FeIIICl(Pc2−) is accompanied by coordination of two chloride ligands to metal centers and the formation of isostructural (CV+){MCl2Pc}−⋅XC6H4Cl2 complexes (M = SnIV(1) and FeIII(2), X = 0.4 and 0.5, respectively). Coordination of chloride ligands to SnII in 1 is accompanied by charge transfer from metal to Pc2− and finally the formation of the Pc•3− macrocycles without any reductants whereas charge state of FeIII and Pc2− is preserved at the formation of 2. The salts involve two CV+ and Pc chromophores strongly absorbing in the visible and NIR ranges with maxima at 610 and 723, 1013 nm for 1 and 553, 597 and 671 nm for 2. One-dimensional closely packed chains composed of the MCl2Pc− anions are formed both in 1 and 2 with π-π interaction between the phenylene groups of the macrocycles. Magnetic moment of 1 is 1.65 μB at 300 K indicating a contribution from one S = 1/2 spin localized on Pc•3−. These spins are coupled antiferromagnetically with Weiss temperature of −16 K, and deviation from the Curie-Weiss law to the antiferromagnetic side is observed below 80 K. Salt 1 manifests an EPR signal with g = 1.9925 and the linewidth of 33.4 mT at 300 K. This signal narrows and shifts to smaller g-factor with the temperature decrease but this tendency changes to an opposite one below 50 K. Spins in 2 are localized on FeIII and the salt manifests a broad asymmetric EPR signal.