Spin crossover in[Co(pytpy)2]2+complexes modified by organosulfonate anions
Two mononuclear cobalt(Ⅱ)complexes,[Co(pytpy)2](2-NH2-1-NS)2·MeOH·H2O(1)and[Co(pytpy)2](4-NH2-1-NS)2·H2O(2),where pytpy=4'-(4-pyridyl)-2,2':6',2"-terpyridine,2-NH2-1-NS-=2-amino-1-naphthalenesulfonate,and 4-NH2-1-NS-=4-amino-1-naphthalenesulfonate,were synthesized and characterized structurally and magnetical-ly.Single-crystal X-ray analysis reveals that both complexes consist of the[Co(pytpy)2]2+cations,organosulfonate anions,and crystallized solvent molecules.The difference between the two anions is the relative position of the sulfo-nate and amino groups.Interestingly,the 2-NH2-1-NS-anion with the sulfonate and amino group in adjacent posi-tions,forms hydrogen bonds with the[Co(pytpy)2]2+cation and solvent molecules,while the 4-NH2-1-NS-anion,with the sulfonate and amino groups in para positions,forms a 2D layer structure through hydrogen bonding.Magnetic measurements revealed significant differences in their magnetic properties:while complex 1 exhibits a reversible and gradual spin crossover behavior,complex 2 remains in the high-spin state.CCDC:2270460,1;2270462,2.
spin crossoverCo(Ⅱ)complexorganosulfonate anionhydrogen bond
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