Influence of intermolecular hydrogen bonding on magnetic properties of mononuclear cobalt and nickel pivalates with amidine ligands
摘要:
The magnetic properties of the mononuclear cobalt(ii) amidine complex Co(Me3CCOO)(2){H2N(C5H3N)NH(MeC=NH (1) having a tetrahedral structure and its solvate 1-HOOCCMe3.0.5C(6)H(6) (1a) are substantially different. Complex 1 possesses ferromagnetic properties and exhibits residual magnetization at liquid-helium temperatures, whereas solvate la and the octahedral amidine complex Ni(Me3CCOO)(2)(H2N(C5H3N)NH(MeC=NH}.MeCN (3.MeCN) show antiferromagnetic properties. Apparently, this is associated with the difference in the type of intermolecular nonbonded interactions in the crystals of 1, 1a, and 3 . MeCN, which form channels for spin-spin exchange. The tetrahedral isostructural mononuclear complexes ML2 (M = Co (5), Ni (6), L is N-tosyl-2,5-dimethyl-8-aminoquinoline) were synthesized. These complexes exhibit antiferromagnetic properties.