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In the presence of nitrogen heterocyclic compound 2,5-di(1 H -imidazole-1 -yl)pyridine (2,5-DIP), luminescent chiral synthons (R)-H 3 CTA and (S)–H 3 CTA assembled with Zn2+ ions to obtain enantiomers [Zn((R)-HCTA) (2,5-DIP)] n (HU14 -R ) and [Zn((S)-HCTA) (2,5-DIP)] n (HU14– S )) under hydrothermal condition, respectively. Partially deprotonated (R)-HCTA2- anions were bridged by Zn2+ ions to form small left-handed (R)-HCTA-Zn chain in HU14- R , while (S)-HCTA2- anions and Zn2+ ions were connected together resulting in enantiomeric right-handed chain in HU14– S . Moreover, larger left-handed (R)-HCTA-Zn-2,5-DIP chain and right-handed (S)-HCTA-Zn-2,5-DIP chain were found in HU14 -R and HU14– S , respectively. These helical building blocks were joined together to create a pair of 3D frameworks with dia net, which show strong fluorescent characteristic and circular dichroism response. Further tests proved that HU14 -R and HU14– S have circularly polarized light (CPL) activity and their luminescence anisotropy factors (g 1um) at 358 nm are +0.00346 and −0.00157, respectively. Moreover, as fluorescent probes, they have high stability, reliability and interference detection rate, and detection limits are up to 2.80 × 10−6 M for Cr 2 O 7 2− and 6.19 × 10−6 M for MnO 4 −. [Display omitted] • Chiral synthon with bright fluorescence. • Circular polarization luminescence activity. • High sensitivity and selective recognition for Cr 2 O 7 2− and MnO 4 − ions. [ABSTRACT FROM AUTHOR]

Utilizing the lactic acid derivatives ( R )-4-(1-carboxyethoxy)benzoic acid (denoted: ( R )-H 2 CBA) and ( S )-4-(1-carboxyethoxy)benzoic acid (denoted: ( S )-H 2 CBA)as chiral linkers to self-assemble with 4, 4′-bipyridine (denoted: BIP) and Cd(II) ions, a couple of three-dimensional homochiral coordination polymers, namely [Cd 3 (( R )-CBA) 3 (BIP) 2 (H 2 O)]·xGuest ( 1-D ) and [Cd 3 (( S )-CBA) 3 (BIP) 2 (H 2 O)]·xGuest ( 1-L ), have been synthesized under solvothermal reaction condition. Single crystal X-ray diffraction analysis reveals the two complexes contain single helical chains based on enantiopure ligands and cadmium clusters. Moreover, some physical characteristics such as PXRD, thermal stability, solid-state circular dichroism (CD) and luminescent were also investigated. [ABSTRACT FROM AUTHOR]

Two isostructural polyoxometalate-based inorganic–organic hybrids with 1D helical chain, [CuH 3 L 2 (GeMo 12 O 40 )]·2H 2 O ( 1 ) and [CuH 3 L 2 (SiMo 12 O 40 )]·2H 2 O ( 2 ), where L =2,4,5-tri(4-pyridyl)-imidazole have been synthesized under hydrothermal conditions. It is the first time to use the L ligand to synthesis the Keggin-type polyoxometalate-based inorganic–organic hybrids. The two compounds possess the left- and right-handed helical chains and the POMs as pendants attach in the helical chains through Cu–O bonds. The two compounds have been characterized by elemental analyses, infrared (IR) spectroscopy, powder X-ray diffraction (PXRD), X-ray photoelectron spectra (XPS), thermogravimetric analysis (TGA) and photoluminescent spectroscopy. Moreover, nitrogen adsorption−desorption measurement, electrochemical and photocatalysis properties for degradation of methylene blue (MB) upon a UV irradiation of compound 1 have been examined. [ABSTRACT FROM AUTHOR]

Abstract: A novel uninodal 5-connected metal-organic framework (MOF), [Cd2L2(4,4′-bipy)3/2(H2O)2] n (H2L=m-thioacetatebenzoic acid and 4,4′-bipy=4,4′-bipyridine), was prepared under hydrothermal condition. It features an unusual brick-wall shape layer by 4,4′-bipy, which consists of right- and left-handed helical chains arrayed alternatively and finally expands by L2– to a rare 5-connected nov (44.66) topology network. Photoluminescence study reveals that it displays intense structure-related fluorescent emission bands (λ ex=355nm) at 450nm in the solid state at room temperature. [Copyright &y& Elsevier]

Abstract: Two new vanadium tellurites, Cu(TATP)V2TeO8 (1) and Cu(DPPZ)V2Te2O10 (2), (TATP=1,4,8,9-tetranitrogen-trisphene, DPPZ=dipyridophenazine) have been synthesized under hydrothermal conditions and structurally characterized by elemental analyses, IR, and single-crystal X-ray diffraction. Compound 1 features an interesting two-dimensional layer structure constructed by [V2TeO8] n double-chain-like ribbons linked by [Cu(TATP)]2+ bridges. Compound 2 consists of two types of chiral layers: one left-handed and the other right-handed, which lead to racemic solid-state compound. In each layer, there exist two types of inorganic helical chains (V4Te4O8) n and (Te2O2) n , with same handedness. Two types of helical chains are linked by μ 3(O6) atoms to generate a V/Te/O inorganic anionic layer. The [Cu(DPPZ)]2+ cationic complex fragments are covalently bonded to the layer, projecting below and above the vanadium tellurites layer. [Copyright &y& Elsevier]

Abstract: A new three-dimensional (3D) zincophosphite |Co(en)3| [Zn4(HPO3)5(H2PO3)] (1) has been solvothermally synthesized by using a racemic mixture of a chiral cobaltammine complex Co(en)3Cl3 as the structure-directing agent. Single-crystal X-ray diffraction analysis reveals that compound 1 crystallizes in the monoclinic space group P21/c (no. 14) with a=18.6180 (4)Å, b=8.7601(18)Å, c=17.4840(4)Å, β=93.42(3)°, V=2846.4(10)Å3, Z=4 with R 1=0.0530. Its structure is built up from strict alternation of ZnO4 tetrahedra and HPO3 pseudo-tetrahedra, giving rise to a 3D inorganic framework with 4-, 6-, 8-, 10- and 12 MRs, and the metal complex molecules, both the Δ and Λ enantiomers, sit in 10-MRs channels. In addition, it is worth noting that left- and right-handed helical chains exist in the framework, which is induced by chiral metal complex Co(en)3Cl3 template molecules. Further characterization of compound 1 has been performed, including X-ray powder diffraction, ICP, CHN, IR and TG analyses. [Copyright &y& Elsevier]

New coordination polymers [M(Pht)(4-MeIm)2(H2O)]n (M=Co (1), Cu (2); Pht2-=dianion of o-phthalic acid; 4-MeIm=4-methylimidazole) have been synthesized and characterized by IR spectroscopy, X-ray crystallography, thermogravimetric analysis and magnetic measurements. The crystal structures of 1 and 2 are isostructural and consist of [M(4-MeIm)2(H2O)] building units linked in infinite 1D helical chains by 1,6-bridging phthalate ions which also act as chelating ligands through two O atoms from one carboxylate group in the case of 1. In complex 1, each Co(II) atom adopts a distorted octahedral N2O4 geometry being coordinated by two N atoms from two 4-MeIm, three O atoms of two phthalate residues and one O atom of a water molecule, whereas the square-pyramidal N2O3 coordination of the Cu(II) atom in 2 includes two N atoms of N-containing ligands, two O atoms of two carboxylate groups from different Pht, and a water molecule. An additional strong O–H⋯O hydrogen bond between a carboxylate group of the phthalate ligand and a coordinated water molecule join the 1D helical chains to form a 2D network in both compounds. The thermal dependences of the magnetic susceptibilities of the polymeric helical Co(II) chain compound 1 were simulated within the temperature range 20–300 K as a single ion case, whereas for the Cu(II) compound 2, the simulations between 25 and 300 K, were made for a linear chain using the Bonner–Fisher approximation. Modelling the experimental data of compound 1 with MAGPACK resulted in: g=2.6, |D|=62 cm-1. Calculations using the Bonner–Fisher approximation gave the following result for compound 2: g=2.18, J=–0.4 cm-1. [Copyright &y& Elsevier]

An imide-based O-donor ligand, 4-carboxyphenyl-1,3-dioxoisoindoline-5-carboxylic acid (H 2 In-4-ba), and one Zn(II) coordination polymer, [Zn(In-4-ba)(py) 2 ] n (1 , py ​= ​pyridine), have been synthesized. Single-crystal X-ray diffraction indicates that 1 has a quasi-3 1 helical chain structure, which shows one-dimensional to two-dimensional (1D → 2D) extension to be a homochiral layer of consecutively interweaving poly-helices with the same helicity. Coexistence of such homochiral layers in opposite chirality makes individual crystal of 1 to be in a racemic manner. Thermogravimetric (TG) analysis indicated that 1 shows high thermal stability approaching 440 ​°C. Thermal activation of 1 gives a desolvated phase, [Zn(In-4-ba)] n (1′), as supported by TG trace. Of particular note, reversible crystal-to-crystal transformations between solvated 1 and desolvated 1′ have been achieved upon decoordination and recoordination of the py ligands, as evidenced by XRPD patterns, IR spectra, and TG diagrams. The photoluminescence properties of as-synthesized 1 , desolvated 1′ , and resolvated 1′ /py have also been studied. All of them exhibit an emission band centered at 486, 492, and 486 ​nm, respectively, which is originated from the ligand-centered charge transfer. Further, the emission intensity of 1′ is weaker than that of 1 and 1′ /py, implying the influence of coordinated py ligands and/or structure regulation on photoluminescence. A solvated zinc(II) coordination polymer showing quasi-3 1 helical chain structure and its desolvated phase have exhibited reversible crystal-to-crystal transformations upon solvent decoordination and recoordination. [Display omitted] • Zn(II) coordination polymer 1 has a quasi-3 1 helical chain structure. • Zn(II) coordination polymer 1 shows 1D.→ 2D homochiral layer of poly-helices. • Zn(II) coordination polymer 1 is high thermally stable approaching 440 ​°C. • Zn(II) coordination polymer 1 exhibits ligand-centered fluorescence. • Solvent-induced reversible crystal-to-crystal transformations have been achieved. [ABSTRACT FROM AUTHOR]