Solid state structures and properties of free-base 5,10,15-triphenylcorrole (TPCor) anions obtained by deprotonation and reduction. Effective magnetic coupling of spins in (Cp*2Cr+)(H+)(H2TPCor˙2−)·C6H4Cl2

Abstract

The reduction of 5,10,15-triphenylcorrole (H₃TPCor) with decamethylchromocene yields (Cp*₂Cr⁺)(H⁺)(H₂TPCor˙²⁻)·C₆H₄Cl₂ (1). It is accompanied by the deprotonation of H₃TPCor and the formation of planar H₂TPCor˙²⁻ radical dianions. Complex 1 manifests a band at about 750 nm observed in the solution spectra of H₂TArylCor˙²⁻ and demonstrates an EPR signal attributed to the reduced corrole macrocycle. The magnetic moment of 1 of 4.10μ_B at 300 K indicates the contribution of Cp*₂Cr⁺ (S = 3/2) and H₂TPCor˙²⁻ (S = 1/2). These paramagnetic species alternate in the π-stacks providing rather effective antiferromagnetic coupling of spins at the Weiss temperature of −31 K. To distinguish the H₂TPC˙²⁻ dianions from the deprotonated H₂TPCor⁻ anions, we also studied the {cryptand[2,2,2](Na⁺)}(H₂TPCor⁻)·0.5C₆H₄Cl₂ (2) salt with deprotonated corrole anions. In this case, a planar macrocycle was formed as well. However, the properties of H₂TPCor⁻ in 2 differ from those of H₂TPCor˙²⁻ in 1.