Structure and magnetic field-induced transition in a one-dimensional hybrid inorganic-organic chain system, Co_2(4,4′-bpy)(tfhba) _24,4′-bpy (4,4′-bpy = 4,4′-bipyridine; Tfhba = 2,3,5,6-tetrafluoro-4-hydroxybenzoate)

摘要

Two isostructural hybrid inorganic-organic frameworks, M _2(4,4′-bpy)(tfhba)_24,4′-bpy, (M = Co (1), Zn (2); 4,4′-bpy = 4,4′-bipyridine; tfhba = 2,3,5,6-tetrafluoro-4- hydroxybenzoate) have been synthesized and their structures elucidated using single crystal X-ray diffraction. These materials are the first hybrid structures synthesized using the tfhba ligand. They contain a one-dimensional chain of corner-sharing MO_4N trigonal bipyramids that has not been observed to date for Co~(2+) units. The magnetic properties of 1 have been investigated and indicate ferromagnetic ordering along the chains, with weak antiferromagnetic interactions between them. Overall the system is antiferromagnetic with a Néel temperature of 3 K, but undergoes a field-induced magnetic phase transition at 3 kOe.