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Bifunctional organic ligands are very popular for the design of coordination polymers because they allow the formation of a great diversity of structures. In the title coordination polymer, the new bifunctional inversion‐symmetric ligand 2,5‐bis(1H‐1,2,4‐triazol‐1‐yl)terephthalic acid (abbreviated as H2bttpa) links CdII cations, giving rise to the three‐dimensional CdII coordination polymer catena‐poly[diaqua[μ4‐2,5‐bis(1H‐1,2,4‐triazol‐1‐yl)terephthalato‐κ4O1:O4:N4:N4′]cadmium(II)], [Cd(C12H6N6O4)(H2O)2]n or [Cd(bttpa)(H2O)2]n. The asymmetric unit consists of half a CdII cation, half a bttpa2− ligand and one coordinated water molecule. The CdII cation is located on a twofold axis and is hexacoordinated in a distorted octahedral environment of four O and two N atoms. Four different bttpa2− ligands contribute to this coordination, with two carboxylate O atoms in trans positions and two triazole N atoms in cis positions. Two aqua ligands in cis positions complete the coordination sphere. The fully deprotonated bttpa2− ligand sits about a crystallographic centre of inversion and links two CdII cations to form a chain in a μ2‐terephthalato‐κ2O1:O4 bridge. This chain extends in the other two directions via the triazole heterocycles, producing a three‐dimensional framework. O—H…O hydrogen bonds and weak C—H…N interactions stabilize the three‐dimensional crystal structure. The FT–IR spectrum, X‐ray powder pattern, thermogravimetric behaviour and solid‐state photoluminescence of the title polymer have been investigated. The photoluminescence is enhanced and red‐shifted with respect to the uncoordinated ligand. [ABSTRACT FROM AUTHOR]

A new coordination polymer (CP), namely, poly[[diaquatris[μ2‐1,4‐bis(1H‐imidazol‐1‐yl)benzene]bis[μ6‐4‐(2,4‐dicarboxylatophenoxy)phthalato]tetracobalt(II)] hexahydrate], {[Co4(C16H6O9)2(C12H10N4)3(H2O)2]·6H2O}n, has been synthesized by solvothermal reaction. The CP was fully characterized by IR spectroscopy, elemental analysis, thermogravimetric analysis, and powder and single‐crystal X‐ray diffraction. It presents a three‐dimensional (3D) structure based on tetranuclear CoII secondary building units (SBUs) with a tfz‐d net and point symbol (43)2(46·618·84). The 4‐(2,4‐dicarboxyphenoxy)phthalic acid (H4dcppa) ligands are completely deprotonated and link {Co4(COO)4}4− SBUs into two‐dimensional (2D) layers. Furthermore, adjacent layers are connected by 1,4‐bis(1H‐imidazol‐1‐yl)benzene (bib) ligands, giving rise to a 3D supramolecular architecture. Interestingly, there are numerous elliptical cavities in the CP where isolated unique discrete hexameric water clusters have been observed. The results of thermogravimetric and magnetic analyses are described in detail. [ABSTRACT FROM AUTHOR]

Six two‐dimensional (2D) coordination polymers (CPs), namely, poly[{μ5‐3,3‐[(5‐carboxylato‐1,3‐phenylene)bis(oxy)]dibenzoato‐κ6O1:O1′:O3,O3′:O5:O5′}bis(N,N‐dimethylformamide‐κO)lanthanide(III)], [Ln(C21H11O8)(C3H7NO)2]n, with lanthanide/Ln = cerium/Ce for CP1, praseodymium/Pr for CP2, neodymium/Nd for CP3, samarium/Sm for CP4, europium/Eu for CP5 and gadolinium/Gd for CP6, have been prepared by solvothermal methods using the ligand 3,3′‐[(5‐carboxy‐1,3‐phenylene)bis(oxy)]dibenzoic acid (H3cpboda) in the presence of Ln(NO3)3. The complexes were characterized by single‐crystal X‐ray and powder diffraction, IR spectroscopy, elemental analysis and thermogravimetric analysis (TGA). All the structures of this family of lanthanide CPs are isomorphous with the triclinic space group P and reveal that they have the same 2D network based on binuclear LnIII units, which are further extended via interlayer C—H...π interactions into a three‐dimensional supramolecular structure. The carboxylate groups of the cpboda3− ligands link adjacent LnIII ions and form binuclear [Ln2(RCOO)4] secondary building units (SBUs), in which each binuclear LnIII SBU contains four carboxylate groups from different cpboda3− ligands. Moreover, with the increase of the rare‐earth Ln atomic radius, the dihedral angles between the aromatic rings gradually increase. Magnetically, CP6 shows weak antiferromagnetic coupling between the GdIII ions. The solid‐state luminescence properties of CP2, CP5 and CP6 were examined at ambient temperature and CP5 exhibits characteristic red emission bands derived from the Eu3+ ion (CIE 0.53, 0.31), with luminescence quantum yields of 22%. Therefore, CP5 should be regarded as a potential optical material. [ABSTRACT FROM AUTHOR]

Three novel coordination polymers (CPs), namely poly[[di‐μ‐aqua‐bis{μ4‐3,3′‐[(5‐carboxylato‐1,3‐phenylene)bis(oxy)]dibenzoato‐κ5O1:O1′,O3:O5:O5′}bis(1,10‐phenanthroline‐κ2N,N′)trinickel(II)] dimethylformamide 1.5‐solvate trihydrate], {[Ni3(C21H11O8)2(C12H8N2)2(H2O)2]·1.5C3H7NO·3H2O}n, (I), poly[[di‐μ‐aqua‐bis{μ4‐3,3′‐[(5‐carboxylato‐1,3‐phenylene)bis(oxy)]dibenzoato‐κ5O1:O1′,O3:O5:O5′}bis(1,10‐phenanthroline‐κ2N,N′)tricobalt(II)] diethylamine disolvate tetrahydrate], {[Co3(C21H11O8)2(C12H8N2)2(H2O)2]·2C2H7N·4H2O}n, (II), and catena‐poly[[aqua(1,10‐phenanthroline‐κ2N,N′)zinc(II)]‐μ‐5‐(3‐carboxyphenoxy)‐3,3′‐oxydibenzoato‐κ2O1:O3], [Zn(C21H12O8)(C12H8N2)(H2O)]n, (III), have been synthesized by the reaction of different metal ions (Ni2+, Co2+ and Zn2+), 3,3′‐[(5‐carboxy‐1,3‐phenylbis(oxy)]dibenzoic acid (H3cpboda) and 1,10‐phenanthroline (phen) under solvothermal conditions. All the CPs were characterized by elemental analysis, single‐crystal and powder X‐ray diffraction, FT–IR spectroscopy and thermogravimetric analysis. Complexes (I) and (II) have isomorphous structures, featuring similar linear trinuclear structural units, in which the central NiII/CoII atom is located on an inversion centre with a slightly distorted octahedral [NiO6]/[CoO6] geometry. This comprises four carboxylate O‐atom donors from two cpboda3− ligands and two O‐atom donors from bridging water molecules. The terminal NiII/CoII groups are each connected to the central NiII/CoII cation through two μ1,3‐carboxylate groups from two cpboda3− ligands and one water bridge, giving rise to linear trinuclear [M3(μ2‐H2O)2(RCOO)4] (M = Ni2+/Co2+) secondary building units (SBUs) and the SBUs develop two‐dimensional‐networks parallel to the (100) plane via cpboda3− ligands with new (32·4)2(32·83·9)2(34·42.82·94·103) topological structures. Zinc complex (III) displays one‐dimensional coordination chains and the five‐coordinated Zn atom forms a distorted square‐pyramidal [ZnO3N2] geometry, which is completed by two carboxylate O‐atom donors from two distinct Hcpboda2− ligands, one O atom from H2O and two N atoms from a chelating phen ligand. Magnetically, CP (I) shows weak ferromagnetic interactions involving the carboxylate groups, and bridging water molecules between the nickel(II) ions, and CP (II) shows antiferromagnetic interactions between the Co2+ ions. The solid‐state luminescence properties of CP (III) were examined at ambient temperature and the luminescence sensing of Cr2O72−/CrO42− anions in aqueous solution for (III) has also been investigated. [ABSTRACT FROM AUTHOR]

A new cobalt(II) coordination polymer (CP), poly[[bis[μ6‐4‐(4‐carboxylatophenoxy)benzene‐1,3‐dicarboxylato‐κ6O1:O1:O3:O3′:O4:O4′]bis(1,10‐phenanthroline‐κ2N,N′)tricobalt(II)] 0.72‐hydrate], {[Co3(C15H7O7)2(C12H8N2)2]·0.72H2O}n, (I), is constructed from CoII ions and 4‐(4‐carboxyphenoxy)isophthalate (cpoia3−) and 1,10‐phenanthroline (phen) ligands. Based on centrosymmetric trinuclear [Co3(phen)2(COO)6] secondary building units (SBUs), the structure of (I) is a three‐dimensional CP with a (3,6)‐connected net and point symbol (42.6)2(44.62.87.102). The positions of four [Co3(phen)2(COO)6] SBUs and four cpoia3− ligands reproduce a Chinese‐knot‐shaped arrangement along the ab plane. (I) has been characterized by single‐crystal X‐ray diffraction, IR spectroscopy, powder X‐ray diffraction (PXRD) and thermostability analysis. It shows a good thermal stability from room temperature to 673 K. In addition, the temperature dependence of the magnetic properties was measured. [ABSTRACT FROM AUTHOR]

The design and synthesis of coordination polymers (CPs) have attracted much interest due to the intriguing diversity of their architectures and topologies. The functional solid catena‐poly[μ2‐aqua‐triaqua{μ4‐5‐[4‐carboxyphenoxy)methyl]benzene‐1,3‐dicarboxylato}{μ3‐5‐[4‐carboxyphenoxy)methyl]benzene‐1,3‐dicarboxylato}dicobalt(II)], [Co2(C16H10O7)2(H2O)4]n or [Co2(HL)2(μ2‐H2O)(H2O)3]n, was synthesized successfully by self‐assembly of CoII ions with 5‐[(4‐carboxyphenoxy)methyl]isophthalic acid (H3L). The title compound was obtained under hydrothermal conditions and exhibits a twofold interpenetrated three‐dimensional skeleton with hms 3,5‐conn topology according to the cluster representation for valence‐bonded metal–organic frameworks (MOFs). It has been characterized by single‐crystal X‐ray diffraction, IR spectroscopy, powder X‐ray diffraction (PXRD), thermogravimetric analysis and susceptibility measurements. The antiferromagnetic coupling between adjacent CoII centres occurs via superexchange through the ligands. [ABSTRACT FROM AUTHOR]

Coordination polymers (CPs) built by coordination bonds between metal ions/clusters and multidentate organic ligands exhibit fascinating structural topologies and potential applications as functional solid materials. The title coordination polymer, poly[diaquabis(μ4-biphenyl-3,4′,5-tricarboxylato-κ4 O3: O3′: O4′: O5)tris[μ2-1,4-bis(1 H-imidazol-1-yl)benzene-κ2 N3: N3′]dicopper(II)dicopper(I)], [CuII2CuI2(C15H7O6)2(C12H10N4)3(H2O)2] n, was crystallized from a mixture of biphenyl-3,4′,5-tricarboxylic acid (H3bpt), 1,4-bis(1 H-imidazol-1-yl)benzene (1,4-bib) and copper(II) chloride in a water-CH3CN mixture under solvothermal reaction conditions. The asymmetric unit consists of two crystallographically independent Cu atoms, one of which is CuII, while the other has been reduced to the CuI ion. The CuII centre is pentacoordinated by three O atoms from three bpt3− ligands, one N atom from a 1,4-bib ligand and one O atom from a coordinated water molecule, and the coordination geometry can be described as distorted trigonal bipyramidal. The CuI atom exhibits a T-shaped geometry (CuN2O) coordinated by one O atom from a bpt3− ligand and two N atoms from two 1,4-bib ligands. The CuII atoms are extended by bpt3− and 1,4-bib linkers to generate a two-dimensional network, while the CuI atoms are linked by 1,4-bib ligands, forming one-dimensional chains along the [20] direction. In addition, the completely deprotonated μ4-η1:η1:η1:η1 bpt3− ligands bridge one CuI and three CuII cations along the a (or [100]) direction to form a three-dimensional framework with a (103)2(10)2(42.6.102.12)2(42.6.82.10)2(8) topology via a 2,2,3,4,4-connected net. An investigation of the magnetic properties indicated a very weak ferromagnetic behaviour. [ABSTRACT FROM AUTHOR]

A new Gd3+ coordination polymer (CP), namely, poly[diaqua[μ4‐1′‐carboxy‐3,3′‐(diazene‐1,2‐diyl)dibenzene‐1,2,2′‐tricarboxylato]gadolinium(III)], [Gd(C16H7N2O8)(H2O)2]n, (I), has been synthesized hydrothermally from Gd(NO3)3·6H2O and azobenzene‐2,2′,3,3′‐tetracarboxylic acid (H4abtc). The target solid has been characterized by single‐crystal and powder X‐ray diffraction, elemental analysis, IR spectroscopy and susceptibility measurements. CP (I) crystallizes in the monoclinic space group C2/c. The structure features a 4‐connected topology in which Gd3+ ions are connected by carboxylate groups into a linear chain along the monoclinic symmetry direction. Adjacent one‐dimensional aggregates are bridged by Habtc3− ligands to form a two‐dimensional CP in the (10) plane. A very short hydrogen bond [O...O = 2.4393 (4) Å] links neighbouring layers into a three‐dimensional network. A magnetic study revealed antiferromagnetic Gd...Gd coupling within the chain direction. CP (I) displays a significant magnetocaloric effect (MCE), with a maximum −ΔSm of 27.26 J kg−1 K−1 for ΔH = 7 T at 3.0 K. As the MCE in (I) exceeds that of the commercial magnetic refrigerant GGG (Gd3Ga5O12, −ΔSm = 24 J kg−1 K−1, ΔH = 30 kG), CP (I) can be regarded as a potential cryogenic material for low‐temperature magnetic refrigeration. [ABSTRACT FROM AUTHOR]

A new mononuclear europium complex incorporating the (+)‐di‐p‐toluoyl‐d‐tartaric acid (d‐H2DTTA) ligand, namely, catena‐poly[tris{μ2‐3‐carboxy‐2,3‐bis[(4‐methylphenyl)carbonyloxy]propanoato}tris(methanol)europium(III)], [Eu(C20H17O8)3(CH3OH)3]n, (I), has been synthesized and characterized by IR spectroscopy, elemental analysis, powder X‐ray diffraction and single‐crystal X‐ray diffraction analysis. The structure analysis indicates that complex (I) crystallizes in the trigonal space group R3 and exhibits an infinite one‐dimensional chain structure, in which the Eu3+ ion is surrounded by six O atoms from six d‐HDTTA− ligands and three O atoms from three coordinated methanol molecules, thus forming a tricapped trigonal prism geometry. The d‐H2DTTA ligand is partially deprotonated and adopts a μ1,6‐coordination mode via two carboxylate groups to link adjacent Eu3+ ions, affording an infinite one‐dimensional propeller‐shaped coordination polymer chain along the c axis, with an Eu...Eu distance of 7.622 (1) Å. Moreover, C—H...π interactions lead to the formation of helical chains running along the c axis and the whole structure displays a snowflake pattern in the ab plane. The circular dichroism spectrum confirms the chirality of complex (I). The solid‐state photoluminescence properties were also investigated at room temperature and (I) exhibits characteristic red emission bands derived from the Eu3+ ion (CIE 0.63, 0.32), with a reasonably long lifetime of 0.394 ms, indicating effective energy transfer from the ligand to the metal centre. In addition, a magnetic investigation reveals single‐ion magnetic behaviour. The spin‐orbit coupling parameter (λ) between the ground and excited states is fitted to be 360 (2) cm−1 through Zeeman perturbation. Therefore, complex (I) may be regarded as a chiral optical‐magneto bifunctional material. [ABSTRACT FROM AUTHOR]