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Abstract: Four triazole-bridging coordination complexes, [Zn4(ptr)2(SO4)3(μ 3-OH)2(H2O)4] n (1), [Hg(CN)2(ptr)] n (2), [Hg(Cl)2(ptr)] n (3), and [Cu2(μ 2-ptr)2(μ 2-F)2] n (SiF6) n ·2nH2O (4), were synthesized with (m-phenol)-1,2,4-triazole (ptr). Compounds 1–4 with extended structures of 4-substituted 1,2,4-triazole are rarely reported. The layered structure of 1 can be regarded as constructed from the 2-D inorganic backbone of SO4 2−(2) anions bridging [Zn4(μ 3-OH)2(H2O)2]6− subunits with the ptr ligands anchoring to both sides of backbone. Compounds 2 and 3 are the first mercury(II) complexes with 4-substituted 1,2,4-triazole, which feature the ptr ligand acting as a bidentate ligand bridging the Hg(II) atoms to form arciform –Hg–ptr–Hg–ptr chains. The structure of 4 is constructed from the F atoms bridging Cu atoms in symmetrical μ 2-coordination mode to form a zigzag cationic chain with each ptr ligand bridging a pair of Cu atom on the both sides, resulting in a nonplanar 5-membered [Cu2N2F] ring. Fluorescent properties of 1–4 were characterized and the magnetic property of 4 shows antiferromagnetic interaction between the copper(II) ions. [Copyright &y& Elsevier]

Abstract: The reactions of two kinds of substituted 1,2,4-triazoles with BiI3 yielded three inorganic–organic hybrids: [HL1]4[Bi6I22]·[L1]4·4H2O (1) (L1=3-(1,2,4-triazole-4-yl)-1H-1,2,4-triazole); [HL2]4[Bi6I22]·6H2O (2); [HL2]2[Bi2I8]·[L2]2 (3) (L2=(m-phenol)-1,2,4-triazole). Both 1 and 2 have polynuclear anions of [Bi6I22]4– to build up the inorganic layers and substituted 1,2,4-triazoles as the organic layers. Hybrid 3 consists of two BiI5 square pyramids as inorganic layers. There exist hydrogen bondings and I⋯I interactions in the structures of 1, 2 and 3. Optical absorption spectra of 1, 2 and 3 reveal the presence of sharp optical gaps of 1.77, 1.77 and 2.07eV, respectively, suggesting that these materials behave as semiconductors. [Copyright &y& Elsevier]

Abstract The appearance of the nitrogen-rich energetic MOFs provides another opportunity for the new-generation of high energetic explosives. In this work, an insensitive energetic nitrogen-rich ligand, 3-amino-1, 2, 4-triazole (Hatz) was imported into the system of transition-metal azides via the coordination polymerization strategy in the hope to prepare mixed-ligand nitrogen-rich high energetic MOF materials with low sensitivity and finally a solvent-free 3D energetic compacted metal-organic framework (MOF), Cd 3 (atz) 4 (N 3 ) 2 ( 1 ) was successfully isolated under hydrothermal conditions. Compound 1 was characterized by single crystal X-ray diffraction, IR spectroscopy, elemental analysis (EA), different scanning calorimetry (DSC), and thermogravimetry analysis (TGA). Topological analysis shows that the 3D framework of 1 can be abstracted into a ten-connected topological network. The volatile azido ion can be viewed as a counter anion to be stabilized in a 3D framework as the connection of Cd(II) ions with two independent atz− ligands still remains a 3D framework. Compound 1 has a high calculated density ( ρ ) of 2.517 g cm−3. The standard molar enthalpy of formation ( Δ f H o ) of 1 was calculated to be 1330.10 kJ mol−1, which is higher than those of most of the previously 3D energetic MOFs. Sensitivity tests demonstrate that 1 is insensitive to external mechanical stimuli. TGA demonstrates that 1 has an excellent thermostability which can be stable up to 372 °C. Compound 1 can be served as a high-energy-density material with a favorable level of safety due to its excellent energetic performances, low sensitivities and excellent thermostability. Graphical abstract Importing an insensitive energetic nitrogen-rich ligand, 3-amino-1, 2, 4-triazole (Hatz) into the system of transition-metal azides via the coordination polymerization strategy, a N-rich high energetic MOF material with low sensitivity, Cd 3 (atz) 4 (N 3 ) 2 was isolated. This compound has a high calculated density ( ρ ) of 2.517 g cm−3. The standard molar enthalpy of formation ( Δ f H o ) of this compound was calculated to be 1330.10 kJ mol−1, which is higher than those of most of the previously 3D energetic MOFs. fx1 Highlights • A nitrogen-rich high energetic 3D MOF, Cd 3 (atz) 4 (N 3 ) 2 , was successfully synthesized. • This MOF has a high calculated density of 2.517 g·cm−3 and can be stable up to 372 °C. • The volatile azido contained 3D MOF has a very high calculated molar enthalpy of formation of 1330.10 kJ·mol−1. [ABSTRACT FROM AUTHOR]

Self-assembly reaction of Pb(NO 3 ) 2 with thiophene-2, 5-dicarboxylic acid (H 2 TDC) led to an acentric three-dimensional (3D) metal-organic framework under solvothermal conditions, namely, Pb(TDC) ( 1 ). The 3D framework of 1 is a pillared-layer structure with the I 2 O 1 type which is composed of a 2D inorganic Pb–O–Pb substructural layer and two independent μ 6 -TDC 2- anions pillars. This 3D framework shows a six-connected pcu topological net according to the topological analysis. Compound 1 crystallizes in an acentric space group and displays potential ferroelectric property which could be due to the swing of the thiophene rings. The remnant polarization ( P r ), coercive field ( E c ) and saturation spontaneous polarization ( P s ) of 1 are ca. 0.034 μC cm −2 , 15.7 kV cm −1 and 0.0997 μC cm −2 , respectively. Among the H 2 TDC-based MOFs, the present compound is the first example which shows ferroelectric property. In addition, 1 also exhibits photoluminescent property which can be attributed to ligand-to-metal charge transfer. [ABSTRACT FROM AUTHOR]

Three new diamond-like compounds with the formula of I2−II−IV−VI4 (I=Cu; II=Mg; IV=Si, Ge; VI=S, Se) have been synthesized via traditional high-temperature solid-state reactions and structurally characterized by single crystal X-ray diffraction analysis. All the three compounds crystallize in the space group Pmn21 in the wurtzite-type superstructure with a=7.563(4), b=6.448(3), c=6.179(3)Å, Z=2 for Cu2MgSiS4 (1); a=7.953(5), b=6.797(4), c=6.507(4)Å, Z=2 for Cu2MgGeS4 (2); a=7.638(4), b=6.515(4), c=6.225(3)Å, Z=2 for Cu2MgSiSe4 (3). All atoms in these compounds are tetrahedrally coordinated. Optical diffuse reflectance UV/Vis/NIR spectra indicate that compounds 1 and 2 have the band gaps of 3.20 and 2.36eV, respectively. Electronic structure calculations using the CASTEP code indicate that they are all direct band gap compounds. [ABSTRACT FROM AUTHOR]

A novel open-framework cadmium selenite bromide, [Cd10(SeO3)8Br4]·HBr·H2O (1), has been obtained by a solid-state reaction at 450°C, and the structure has been determined by single-crystal X-ray diffraction analysis. Compound 1 crystallizes in Pbcm of the orthorhombic system: a=10.882(3), b=16.275(5), c=18.728(6)Å, V=3317(2)Å3, R1/wR2=0.0411/0.0659. Compound 1 is characteristic of a novel 3-D open-framework structure, composing ∞ 2[CdSeO3] layers and the pillars of edge-shared CdO3Br2 square pyramids. The lattice water molecules and the HBr molecules locate in the voids of the framework. Optical absorption spectrum of 1 reveals the presence of an optical gap of 1.65eV. Solid-state photoluminescent study indicates that compound 1 exhibits strong violet emission. TG–DSC measurement shows that compound 1 is thermally stable up to 200°C. [ABSTRACT FROM AUTHOR]

Abstract: A new quaternary supramolecular complex (Hg2As)2 (CdI4) (1) has been prepared by the solid-state reaction and structurally characterized by single crystal X-ray diffraction analysis. Compound 1 crystallizes in the space group P21 of the monoclinic system with two formula units in a cell: a=7.945(4), b=12.934(6), c=8.094(4)Å, β=116.898°(1), V=741.7(6)Å3. The structure of 1 is characterized by a tridymite-like three-dimensional cationic framework, which is composed of mercury and arsenic atoms, with the channels being occupied by discrete CdI4 2− tetrahedral guest-anions. The optical properties were investigated in terms of the diffuse reflectance and Fourier transform infrared spectra. The electronic band structure along with density of states (DOS) calculated by DFT method indicates that the present compound is a semiconductor with a direct band gap, and that the optical absorption is mainly originated from the charge transitions from I-5p and As-4p to Cd-5s and Hg-6s states. [Copyright &y& Elsevier]

Abstract: Two isostructural metal chalcogenides, Hg2Te2Br2 (1) and Hg2Te2I2 (2), were obtained by solid-state reactions and structurally characterized. Compounds 1 and 2 crystallize in the acentric space group P43212 of the tetragonal system with eight formula units in a cell: a=10.2388(9), c=14.480(2)Å, V=1518.0(3)Å3, R 1/wR 2=0.0670/0.1328 for 1 and a=10.711(3), c=15.025(8)Å, V=1724(1)Å3, R 1/wR 2=0.0637/0.1233 for 2. Both compounds are characterized by a three-dimensional (3-D) framework structure, which is composed by interconnected left-handed helices formed by both tetrahedral and trigonal Hg atoms. Optical absorption spectra of 1 and 2 reveal the presence of sharp optical gaps of 2.06 and 1.85eV, respectively, suggesting that both materials are semiconductors. TG-DTA measurements show that both compounds are thermally stable up to 200°C. The composition of both compounds is well confirmed by the semiquantitative microscope analyses. [Copyright &y& Elsevier]

Abstract: Three new zinc coordination polymers [Zn2(btc)2(H2O)2] n ·n[Zn(H2O)6] (1), [Zn3(btc)2(2,2′-bipy)2(H2O)3] n ·2nH2O (2) and [Zn3(btc)2(H2O)6] n ·nH2O (3) (H3btc=1,2,4-benzenetricarboxylic acid, 2,2′-bipy=2,2′-bipyridine) were obtained by the diffusion method and their crystal structures were determined by single-crystal X-ray diffraction. Compounds 1–3 have the similar tetrametallic unit [Zn4(btc)2] SBUs and these SBUs are further connected into stair-like structure, 2-D layer and 3-D framework for 1, 2 and 3, in which the btc3− ligands adopt μ 3, μ 4 and μ 5 coordination modes, respectively. The title compounds show strong blue fluorescence, which may be assigned as π*→n transition of the ligand mixed with the ligand-to-metal change transfer (LMCT), indicating the fluorescence, indicates the title compounds may be good candidates for blue-light photoactive materials. [Copyright &y& Elsevier]