Syntheses, structures, and magnetic properties of a series of Mn-containing coordination polymers based on 5-nitro-1,2,3-benzenetricarboxylic acid and different N-donor ligands

A family of coordination polymers assembled with a flexible hexacarboxylate ligand and auxiliary N-donor ligands: syntheses, structures, and physical properties

“…24 Upon cooling, χ m T continuously decreases to reach a minimum of 15.07 cm 3 mol −1 K at 44 K, which is followed by an abrupt increase and then a final decrease to reach 3.48 cm 3 mol −1 K at 2 K. The magnetic susceptibility above 44 K conforms to the Curie-Weiss law with C = 19.97 cm 3 mol −1 K and Θ = −14.15 K. This plot is typical of the presence of antiferromagnetic coupling with the occurrence of a weak spin canting, which would be responsible for the increase in χ m T at low temperatures. 26 Upon cooling, the values of χ m T firstly decrease constantly, next an inflexion at 44 K appears, then reach the highest value of 17.89 cm 3 mol −1 K at 34 K, and finally fall to the value of 4.63 cm 3 mol −1 K at 2 K. The magnetic susceptibility above 46 K conforms to the Curie-Weiss law with C = 11.68 cm 3 mol −1 K and Θ = −13.99 K. For 6, the χ m T value at room temperature is 1.91 cm 3 mol −1 K, which is comparable to the expected χ m T value (1.875 cm 3 mol −1 K) of one magnetism-isolated CoIJII) ion with S = 3/2 and g = 2.0, indicating a little orbital contribution as also found in many other high-spin CoIJII) complexes. For 3, the χ m T value at 300 K (11.00 cm 3 mol −1 K) is slightly lower than the three non-interacting MnIJII) ions (13.13 cm 3 mol −1 K, with S = 1/2 and g = 2.00).…”

“…For 3, the χ m T value at 300 K (11.00 cm 3 mol −1 K) is slightly lower than the three non-interacting MnIJII) ions (13.13 cm 3 mol −1 K, with S = 1/2 and g = 2.00). 26 Upon cooling, the values of χ m T firstly decrease constantly, next an inflexion at 44 K appears, then reach the highest value of 17.89 cm 3 mol −1 K at 34 K, and finally fall to the value of 4.63 cm 3 mol −1 K at 2 K. The magnetic susceptibility above 46 K conforms to the Curie-Weiss law with C = 11.68 cm 3 mol −1 K and Θ = −13.99 K.…”

A thermally stable three-dimensional cobalt(II) coordination polymer based on the V-shaped ligand 4-(4-carboxyphenoxy)isophthalate

“…Lately, a class of semirigid and V-shaped tricarboxylic acid molecules, examples being 5-(4-carboxyphenoxy)isophthalic acid (He et al, 2012), 2-(2,4-dicarboxyphenoxy)benzoic acid (Ning et al, 2016), 3-(4carboxyphenoxy)phthalic acid, 3-(2-carboxyphenoxy)phthalic acid, 4-(2-carboxyphenoxy)phthalic acid, 4-(4-carboxyphenoxy)phthalic acid (Wang et al, 2009), 4-(4-carboxyphenoxy)phthalic acid (Wang et al, 2015) and 4-(4-carboxyphenoxy)phthalic acid (Zhang et al, 2012), have attracted much interest since they may lead to the generation of uncommon network structures with multinuclear clusters as subunits. It is noteworthy that polynuclear clusters as secondary building units (SBUs) in CPs can reduce the interpenetration and serve as high-connected nodes, which can form novel high-connected topological nets due to metal clusters having different sizes ISSN 2053ISSN -2296 # 2018 International Union of Crystallography and connectivities (Niu et al, 2011;Yang et al, 2013). Metalcluster entities as SBUs have been proved to be an effective and powerful synthetic strategy in constructing new CPs and new topologies (Gu et al, 2017;Li et al, 2012).…”

pH‐Controlled topologies of two Co(II) complexes based on 5‐Nitro‐1,2,3‐benzenetricarboxylic acid and 1,6‐Bis(1,2,4‐triazole‐1‐yl)hexane

“…Among aromatic multicarboxylic acid, 5‐nitro‐1,2,3‐benzenetricarboxylic acid (H 3 nbta) has at least three particular structural features: (i) it consists of three carboxylic groups and has a high asymmetry that can result in unusual polymeric species; (ii) it can lead to a great variety of structures by forming short bridges via one carboxylate end or long bridges via benzene rings; (iii) it may provide the potential to construct unpredicatable and interesting structures due to the existence of a noncoordinating electron‐withdrawing nitro‐ group. The MOFs based on H 3 nbta with neutral N‐donor ligands, displaying remarkable functional properties and structural diversity, have been extensively studied by some groups .…”