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POMs-based coordination polymers are promising materials for their potential application in the fields of proton conduction, catalysis and magnetism. Three new coordination polymers namely, {[Co 2 (bib) 3 (H 2 O) 2 (H 4 W 12 O 40)]·7H 2 O} n (1), {[Zn 3 (bib) 8 (H 3 ZnW 12 O 40) 2 ]·12H 2 O} n (2) and {[Ag 5 (bib) 5 (H 3 W 12 O 40)]·5H 2 O} n (3) were synthesized under hydrothermal conditions based on linear nitrogen heterocyclic ligand 1,4-bis(1-imidazolyl)benzene (bib). In compound 1 , CoII ions are linked with [H 4 W 12 O 40 ]4– anions to form a planar network and can be simplified as kgd topology, which are further linked with bib ligands to form a 3D framework. Zn2 ions of compound 2 alternately connect with bib ligands and [H 3 ZnW 12 O 40 ]3– anions to form 1D chain structure, while Zn1 ion forms isolated unit with three bib ligands and one [H 3 ZnW 12 O 40 ]3– anion, and a 3D framework is finally constructed through π ... π stacking interactions. In compound 3 , the 3D structure is constructed from a number of 1D chains formed by AgI ions and bib ligands in different directions through π ... π stacking interaction and Ag⋯O weak connection. The proton conductivity of 1 – 3 are 2.03 ​× ​10−5, 1.04 ​× ​10−6 and 1.87 ​× ​10−4 ​S ​cm−1 at 98% RH and 358 ​K, respectively. In addition, compounds 1 – 3 exhibit photocatalytic degradation capacity towards RhB and compound 1 displays antiferromagnetic behavior. Three Keggin POM-based coordination polymers have been prepared under hydrothermal condition and characterized by single-crystal X-ray diffraction, IR, XRD and TGA. The highest proton conductivity of 3 is up to 1.87 ​× ​10−4 ​S ​cm−1 at 358 ​K and 98% RH. [Display omitted] • Three Keggin POM-based coordination polymers have been prepared under hydrothermal condition. • Their structures were characterized by single-crystal X-ray diffraction, IR, XRD and TGA. • The highest proton conductivity of 3 is up to 1.87 ​× ​10−4 ​S ​cm−1 at 358 ​K and relative humidity of 98% RH. [ABSTRACT FROM AUTHOR]

Abstract: Two new coordination polymers, [Ag(tza)]∞ (1) (Htza=tetrazole-1-acetic acid) and [Cu(tza)2]∞ (2) have been prepared at room temperature and characterized by X-ray crystallography, IR, UV–vis, fluorescence spectra and magnetism analysis. Compound 1 exhibits extended helical chains through bridging ligand tza. The Ag ctions between the adjacent chains form a 3-D framework featuring the extended tza-connected Ag chains that obviously affect the photoluminescent property. Compound 2 features undulated layered structure with hourglass-shaped [Cu4(tza)4] as subunits with the weak ferromagnetic interactions between Cu(II) ions, which are further stabilized by inter-lamellar Ch name="rad" /> n bonds in the resulting 3-D supramolecular framework. [Copyright &y& Elsevier]

It still remains a tremendous challenge in exploring high efficient electrocatalysts for hydrogen evolution reaction (HER). Herein, reaction of Co2+ ions and 3-(pyrid-4′-yl)-5 -(4″- carbonylphenyl) -1,2,4-triazolyl (H 2 Pycz) in a mixed solvent system has obtained a new 3D metal organic framework (MOF) formulated as Co 2 (Hpycz) 4 ·H 2 O (1). Compound 1 shows a 3D 8-fold interpenetrating 66- dia topological network with antiferromagnetic interactions between the Co(II) ions. The obtained Co-MOF exhibits a good HER performance: it displays a low onset potential of 101 mV, a small Tafel slope of 121 mV dec−1, exchange current density of 1.62 × 10−4 A cm−2 and long term stability of at least 72 h. This work may enrich the new candidates of MOFs materials for HER application. Herein, reaction of Co2+ ions and 3-(pyrid-4′-yl)-5-(4″-carbonylphenyl)-1,2,4-triazolyl (H 2 Pycz) in a mixed solvent system has obtained a new 3D metal organic framework (MOF) formulated as Co 2 (Hpycz) 4 ·H 2 O (1). Compound 1 shows a 3D 8-fold interpenetrating 66- dia topological network with antiferromagnetic interactions between the Co(II) ions. The obtained Co-MOF exhibits a good HER performance: it displays a low onset potential of 101 mV, a small Tafel slope of 121 mV dec−1, exchange current density of 1.62 × 10−4 A cm−2 and long term stability of at least 72 h. Image 1 [ABSTRACT FROM AUTHOR]

Two new Co(II) coordination polymers(CPs), namely [Co 2 (bpe) 2 (Hbppc)] n ( 1 ) and [Co 3 (μ 3 -OH)(bppc)(bpm)(H 2 O)]·3H 2 O ( 2 ) (H 5 bppc=biphenyl-2,4,6,3′,5′-pentacarboxylic acid, bpe=1,2-bis(4-pyridyl)ethene, bpm=bis(4-pyridyl)amine), have been obtained and characterized by elemental analysis, single-crystal X-ray diffraction, powder X-ray diffraction (PXRD), IR spectra and thermogravimetric analysis (TGA). 1 shows a binodal (4,6)-connected fsc net with a (4 4 ·6 10 ·8)(4 4 ·6 2 ) topology, while 2 shows a binodal (5,7)-connected 3D network based on trinuclear [Co 3 (μ 3 -OH)] 5+ units with unusual (3.4 6 .5 2 .6)(3 2 .4 6 .5 7 .6 5 .7) topology. Variable-temperature magnetic susceptibility measurements reveals that complex 1 shows ferromagnetic interactions between the adjacent Co(II) ions, whereas 2 is a antiferromagnetic system. [ABSTRACT FROM AUTHOR]