Syntheses, crystal structures and magnetic properties of trinuclear and [3 × 1 + 1 × 2] pentanuclear complexes derived from a compartmental ligand: Role of solvent on nuclearity and number of components

Reaction of [CuIIL⊂(H2O)] (H2L = N,N′-ethylenebis(3-ethoxysalicylaldimine)) with nickel(II) perchlorate in 1:1 ratio in acetone produces the trinuclear compound [(CuIIL)2NiII(H2O)2](ClO4)2 (1). On the other hand, on changing the solvent from acetone to methanol, reaction of the same reactants in same ratio produces the pentametallic compound [(CuIIL)2NiII(H2O)2](ClO4)2·2[CuIIL⊂(H2O)]·2MeOH (2A), which loses solvated methanol molecules immediately after its isolation to form [(CuIIL)2NiII(H2O)2](ClO4)2·2[CuIIL⊂(H2O)] (2B). Clearly, formation of 1 versus 2A and 2B is solvent dependent. Crystal structures of 1 and 2A have been determined. Interestingly, compound 2A is a [3 × 1 + 1 × 2] cocrystal. The cryomagnetic profiles of 1 and 2B indicate that the two pairs of copper(II)···nickel(II) ions in the trinuclear cores in both the complexes are coupled by almost identical moderate antiferromagnetic interaction (J = −22.8 cm−1 for 1 and −26.0 cm−1 for 2B).