Isomorphic complexes formed by recrystallisation of M(II)Pc (M(II) = Mg, Mn and Zn) in liquid 2-amino-3-picoline

Three isomorphic, Mg, Mn and Zn phthalocyaninato complexes monoaxially ligated by 2-amino-3-picoline (2A3P) are obtained. They crystallise with 2A3P molecule as solvent molecule in the centrosymmetric space group P21/c of monoclinic system. The central M(II) atom in these complexes, M(II)Pc(2A3P), is coordinated by four isoindole N atoms of Pc macrocycle in equatorial position, and by ring N atom of 2A3P molecule in an axial position. The M(II) due to the interaction with an axial 2A3P molecule is significantly displaced from the plane defined by four isoindole N atoms of Pc macrocycle toward the ring N atom of 2A3P molecule. The stability of these complexes in solid was analysed by thermogravimetric measurements. The Mg and Zn complexes in solution are stable under air condition, while the Mn complex is moderately stable in solution and after several days transforms into μ-oxo manganese(III) phthalocyanine complex. The magnetic susceptibility of the MnPc(2A3P) × 2A3P complex shows the Curie–Weiss behaviour in the temperature range of 300–75 K. The calculated μeff indicates on high-spin complex. Below 75 K, the μeff drastically lowered to the value of ∼3.62 μB indicating the intermediate-spin complex. In addition, the co-crystals of 2:1 composition of 2A3P:1,2-dicyanobenzene were isolated during the preparation of the MgPc(2A3P) × 2A3P.