Syntheses and characterization of Co (pydc) (H_2O)_2 and Ni(pydc)(H_2O) (pydc = 3,5-pyridinedicarboxylate)

摘要

The hydrothermal reaction of 3,5-pyridinedicarboxylic acid (pydcH_2) and Co(NO_3)_2 or Ni(NO_3)_2 in the presence of 4,4'-bipyridine results in two novel compounds Co(pydc)(H_2O)_2 (1) and Ni(pydc)(H_2O)_ (2). Crystal data: 1, monoclinic, C2/c, 0 = 9.900(2), b = 11.984(2), C = 7.3748(15) A, beta = 105.37(3) deg, V = 843.7(3) A~3, Z = 4; 2, monoclinic, P2_1/c, a=7.7496(6), b = 15.0496(11), c = 6.4224(5) A, beta = 108.437(1) deg, V = 710.59(9) A~3, Z = 4. The structure of 1 is composed of honeycomb layers built up from {CoO_4N} trigonal bipyramids and 3,5-pyridinedicarboxylate bridges. The structure of 2 adopts a three-dimensional framework structure in which the Ni atoms are coordinated by the pydc bridges both within the honeycomb layer and between the layers. The magnetic properties of 1 and 2 have been investigated.