132584-47-5Relevant academic research and scientific papers
A Copper(II) Tetephthalato Derivative Ordering Ferromagnetically at Tc = 13 K
Bakalbassis, Evangelos,Kahn, Olivier,Bergerat, Pierre,Jeannin, Suzanne,Jeannin, Yves,Dromsee, Yves
, p. 1771 - 1772 (1990)
Magnetic and EPR data concerning the molecular-based compound Cu(ta)(MeOH)*1/2H2O (ta = terephthalato), are consistent with triplet pair states coupling ferromagnetically at the scale of the crystal lattice, with a critical temperature around 13 K.
Weak ferromagnetism in the molecular compound Cu(ta)(3-pic)·H2O (ta = terephthalato, 3-pic = 3-picoline). Crystal structure of Cu(ta)(3-pic)2·0.5(3-pic)·0.5CH3OH
Bakalbassis, Evangelos,Bergerat, Pierre,Kahn, Olivier,Jeannin, Suzanne,Jeannin, Yves,Dromzee, Yves,Guillot, Maurice
, p. 625 - 631 (2008/10/08)
The two compounds Cu(ta)(3-pic)2·0.5(3-pic)·0.5CH3OH (1) and Cu(ta)(3-pic)·H2O (2) have been synthesized, ta standing for terephthalato and 3-pic for 3-picoline. The crystal structure of 1 has been determined. 1 crystallizes in the monoclinic system, space group P21/c, with a = 9.703 (4) A?, b = 13.184 (8) A?, c = 19.825 (4) A?, β = 115.12 (2)°, and Z = 4. The structure consists of Cu(ta) infinite layers, to which the 3-pic molecules are perpendicular, and noncoordinated 3-pic and CH3OH molecules. In the lattice the Cu(ta)(3-pic)2 units are centrosymmetrically related, affording copper(II) pairs with a Cu?Cu separation of 4.414 A?. Those pairs are linked together through terephthalate bridges. 1 spontaneously evolves in air to yield 2. The copper(II) ions in 1 are magnetically isolated. In contrast, the magnetic properties of 2 are quite unusual. Magnetic susceptibility measurements together with EPR spectra and low-field (5 G) and high-field (up to 20 T) magnetization data lead to the following description: 2 consists of antiferromagnetically coupled copper(II) pairs with a singlet-triplet energy gap J ≈ -330 cm-1. In addition, antisymmetric interaction gives rise to a residual magnetic moment in the ground state. The pairs weakly couple through the terephthalate bridges in such a way that the pair magnetic moments align along the same direction. 2 exhibits a weak ferromagnetic transition at Tc = 2.8 K.
