Temperature-induced structural transformations accompanied by changes in magnetic properties of two copper coordination polymers

Abstract

Two ferromagnetic copper compounds have been synthesized under different temperature, which represented the rare example of structural transformations resulting from the coordination modes of organic ligands supported by magnetic results.

Two temperature-induced 1D CuII chain enantiomeric pairs showing different magnetic properties and nonlinear optical responses

“…50,51 Similar results also were observed in the 1D Cu II chain CPs with carboxylates as the bridging ligands in an eq-ax binding fashion ( J = 0.071 cm −1 ). 52 However, the 1D Cu II chain [Cu (NO 3 ) 2 (bipy)] n (5) was reported to show a weak antiferromagnetic coupling between Cu II ions ( J = −0.11 cm −1 ) due to the presence of a classical Cu 2 O 2 moiety with the Cu-O-Cu angle being 112.41°(>99°), usually resulting in an antiferromagnetic coupling. 44,53 Thus S-1-Cu represents the first example of chiral 1D Cu II chain CPs with an NO 3 − group as a sole bridging ligand, displaying a ferromagnetic coupling.…”

Synthesis, X-ray structures, and magnetic properties of seven polynuclear Cu(ii) complexes containing pyrazole-3,5-dicarboxylate with various ancillary ligands

“…The Cu-L-Cu angle, Cu-L-L-Cu torsion angle, and g approaching 901 lead to ferromagnetic exchange whereas the antiferromagnetic exchange is observed when the Cu-L-Cu angle, Cu-L-L-Cu torsion angle, and g are close to 1801/01. [29][30][31][32][33][34] Pyrazole-3,5-dicarboxylic acid (H 3 pzdc) is a multidentate ligand which exhibits various coordination abilities. H 3 pzdc has six potential coordination sites including four carboxylate oxygen and two pyrazole nitrogen atoms.…”

Amide-Driven Secondary Building Unit Structural Transformations between Zn(II) Coordination Polymers

“…14−16 Their rational design consisting of the judicious selection of metal nodes and organic ligands has led to the formation of the desired secondary building units (SBUs), which are directly related with the properties of the resulting compounds. 17−19 In this context, small changes on the synthetic conditions inter alia starting metal salt 20 or precursor, 21 metal−ligand ratio, 22 temperature, 23 or solvent 24 can lead to the obtention of different CPs. In addition, their possible structural transformations triggered by external stimuli (e.g., solvent, 25 light, 26 heat, 27 or synergic effects 28,29 ) have attracted remarkable attention, paving the way for the obtention of new structures inaccessible through other synthetic methods.…”

“…In this context, small changes on the synthetic conditions inter alia starting metal salt or precursor, metal–ligand ratio, temperature, or solvent can lead to the obtention of different CPs. In addition, their possible structural transformations triggered by external stimuli (e.g., solvent, light, heat, or synergic effects , ) have attracted remarkable attention, paving the way for the obtention of new structures inaccessible through other synthetic methods. − Besides, when these transformations show a reversible behavior, the CPs display promising applications in molecular capture, switches, and so on .…”