title: Triazolate-based 3D frameworks and a 2D layer with centrosymmetric Cu(II)7, Cu(II)5, Cu(II)4 clusters and tunable interlayer/interchain compactness: hydrothermal syntheses, crystal structures and magnetic properties.
abstract: Four 1,2,3-triazolate-based coordination polymers (CPs) with varied dimensionality, different nuclearity numbers and core topologies, [Cu4(μ-OH)(μ3-OH)(ta)2(btec)]n (1), {[Cu6(μ3-OH)2(ta)8(tp)]·2.5H2O}n (2), {[Cu5(μ3-OH)2(ta)4(ip)2]·2H2O}n (3) and {[Cu5(μ-OH)2(μ3-OH)2(ta)2(pa)2]·2H2O}n (4) (ta = 1,2,3-triazolate, btec = 1,2,4,5-benzenetetracarboxylate, tp = terephthalate, ip = isophthalate and pa = phthalate), were hydrothermally synthesized by varying the numbers and positions of the carboxylate group appended on the phenyl tether, and structurally and magnetically characterized. The former three entities are three-dimensional (3D) robust frameworks with a (4(4)·6(2))(4(11)·6(5))2(4(13)·6(10)·8(5)) topological net containing centrosymmetric Cu(II)7 clusters, square-planar Cu(II)1 cores and tetratopic btec(4-) linkers for 1, a pillared-layered structure consisting of Cu(II)5 + Cu(II)1-based coplanar layers and ditopic tp(2-) pillars for 2 as well as a microporous architecture derived from Cu(II)5 clusters and directional ip(2-) connectors for 3. In contrast, complex exhibits an undulated two-dimensional (2D) layer with alternating Cu(II)4 + Cu(II)1 chains interconnected by anionic pa(2-) connectors. Crystallographically, the increment of the local nuclearity from Cu(II)4 up to Cu(II)7 in 1-4 benefits greatly from the synergistic co-coordination of the hydroxyl group and the coplanar ta(-) ligand towards the metal ion, and the interlayer/interchain compactness is significantly tuned by the position isomerism of the dicarboxylate moieties. Due to the antiferromagnetic coupling in the local clusters and the asymmetric superexchange by μ3-ta(-) mediator, these complexes 4 exhibit different spin ground states (paramagnetic S = 1 and 1/2, ferrimagnetic S = 1/2 as well as spin canting) at low temperatures, which are informative for polynuclear-based magnetic materials.
authors.affiliation: College of Chemistry, Key Laboratory of Inorganic-Organic Hybrid Functional Material Chemistry, Ministry of Education, Tianjin Key Laboratory of Structure and Performance for Functional Molecules, Tianjin Normal University, Tianjin 300387, P. R. China. encui_yang@163.com xiaojun_zhao15@163.com.
authors.forename: Yuan-Yuan
authors.initials: YY
authors.lastname: Zhang
authors.forename: Hong
authors.initials: H
authors.lastname: Zhao
authors.forename: En-Cui
authors.initials: EC
authors.lastname: Yang
authors.forename: Zhong-Yi
authors.initials: ZY
authors.lastname: Liu
authors.forename: Qiu
authors.initials: Q
authors.lastname: Shang
authors.forename: Xiao-Jun
authors.initials: XJ
authors.lastname: Zhao