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Four new alkali metal boroantimonates, namely, A 2 SbB 3 O 8 (A = Na, K, Rb) and β-RbSbB 2 O 6 , have been synthesized by high-temperature solid-state reactions. Isostructural A 2 SbB 3 O 8 (A = Na, K, Rb) crystallizes in the monoclinic space group P 2 1 / c , with structures featuring a novel 3D anionic framework composed of SbO 6 octahedra and linear B 3 O 8 groups with 1D tunnels of Sb 4 B 4 8-membered-rings (MRs) along the a -axis, which are filled by alkali metal ions. β-RbSbB 2 O 6 crystallizes in the polar space group Cc , revealing novel 3D anionic networks composed of SbO 6 octahedra chains and B 2 O 5 groups with 1D tunnels of Sb 4 B 2 6-MRs along the b -axis and 1D tunnels of Sb 3 B 4 7-MRs along the c -axis. Studies on their optical properties and thermal stability, band structure calculations based on DFT methods and linear optical calculations have also been performed.

Using manganese( II ) acetate tetrahydrate and silver salts as precursors, heterostructured Ag@Ag 1.8 Mn 8 O 16 nanocomposites were obtained by in situ redox reaction at room temperature. The molar ratio of Ag + /Mn 2+ was found to play an essential role in determining their morphology. At a molar ratio of 1?:?200, novel nanorod products with diameters of 10–20 nm and lengths of 280–800 nm were obtained. The nanorods were thermally unstable, with further calcination leading to pure MnO nanorods embedded with Ag as the final product, which was demonstrated by analysis of XRD, TEM, Raman spectroscopy and XPS. TG and TEM analysis were also considered to explore the influence of calcination temperature and the molar ratio on the crystalline structure and the morphology of the synthesized product. The novel nanorod exhibited improved performance in oxygen reduction reaction (ORR), indicating a cost-effective electrocatalyst.

We studied acetonitrile vapour inclusion behaviour for flexible single-crystal hosts [M 2 (bza) 4 (pyz)] n (M = Rh 2+ ( 1 ), Cu 2+ ( 2 ); bza = benzoate , pyz = pyrazine ) by adsorption experiments and single-crystal X-ray analysis of the inclusion state. Independent of metal ions, the flexible single-crystal hosts smoothly and reversibly adsorbed acetonitrile molecules up to ca. 2 molecules per M 2 unit through an adsorption leap, which indicated the change of crystal phase transformations. The results showed that the acetonitrile inclusion crystals were isostructural with including acetonitrile molecules aligned in a head-to-tail fashion in a 1D channel . The acetonitrile molecules were densely included in the channel compared with those in an acetonitrile crystal, indicating that the flexible hosts provide a suitable field for observing the acetonitrile inclusion structure. While the inclusion crystal structure was independent of metal ions, the adsorption behaviour has a difference in the critical pressure and amount of the adsorption leap, depending on the metal ions in the host skeletons.

The solvent free reaction of Zn(OAc) 2 with an imidazole ligand resulted in a 1-dimensional (1D) chain structure with the formula [Zn(Im)(HIm) 2 (OAc)] (Im = imidazolate, HIm = imidazole, OAc = carboxylate) ( 1 ). The results by kinetic experiments suggest that ( 1 ) likely evolves from an unidentified metastable phase. This new 1D chain precursor ( 1 ) is a quaternary system comprising Zn, Im, OAc and HIm. We have used this 1D compound as a single precursor to prepare 3-dimensional (3D) Zn(Im) 2 frameworks. Specifically, two Zn(Im) 2 frameworks with known zni and coi topologies were prepared via thermal-mediated transformation when heated in an open atmosphere and in a closed vessel, respectively. In an open atmosphere, the kinetic experiments confirmed the rapid phase transformation from ( 1 ) to zni without formation of an intermediate phase. In contrast, in the formation process of coi in a closed vessel, phase transformation from ( 1 ) to zni and immediately from zni to coi was observed. Thus, in a closed vessel, the released molecules, HOAc and HIm, were occluded in the framework, which may together exert a cooperative structure-directing effect on the formation of the coi framework. Thus, a single precursor approach was established for the synthesis of ZIFs. The present work represents the first example of transforming a 1D coordination polymer into 3D ZIF framework structures.

An in situ , time-resolved energy dispersive powder X-ray diffraction study of the solvothermal crystallisation of the copper( II ) 4,4′,4″-benzene-1,3,5-triyl-tris(benzoate) metal–organic framework MOF-14 shows how reaction conditions must be carefully chosen to allow successful preparation of the material, since on prolonged heating at ≥120 °C the material irreversibly collapses into Cu 2 O under solvothermal conditions in less than 2 hours. This situation is in contrast to the related Cu( II )-containing metal–organic framework HKUST-1, which shows solvothermal stability over similar temperatures and reaction times. The kinetics of crystallisation of both MOFs are examined using a mathematical model proposed by Gualtieri for zeolite crystallisation : this allows separation of the nucleation and growth regimes to yield two rate constants. Arrhenius analysis gives activation energies that reveal in both cases the crystallisations are nucleation controlled. For MOF-14 we can additionally simulate its decomposition as dissolution of the first-formed interpenetrating structure: this produces a complete picture of the solvothermal stability of MOF-14 as nucleation-growth crystallisation , with some evidence of secondary nucleation, followed by dissolution.

Single crystals of Na 5 RE 4 (OH)[SiO 4 ] 4 (RE = Pr, Nd, Sm, Eu, Tb–Yb, Y) were grown using the hydroflux synthetic method. All compositions adopt the tetragonal I space group with lattice parameter ranges of a = 11.5275(4)–12.0588(3) ? and c = 5.3951(4)–5.4846(13) ?. Intense photoluminescent properties were observed for Na 5 Eu 4 (OH)[SiO 4 ] 4 , Na 5 Gd 4 (OH)[SiO 4 ] 4 , and Na 5 Tb 4 (OH)[SiO 4 ] 4 . The magnetic susceptibility was measured for the magnetic rare earth containing compositions, where the terbium analogue displayed antiferromagnetic order at T = 2.8 K.

The effects of the thickness of the large-mismatched amorphous In 0.6 Ga 0.4 As buffer layer on In 0.3 Ga 0.7 As epi-films grown on a GaAs substrate have been systematically investigated. The In 0.3 Ga 0.7 As films with the In 0.6 Ga 0.4 As buffer layer of 0, 1, 2, and 4 nm thickness are grown by low-temperature molecular beam epitaxy (LT-MBE) and are characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM). It is found that the degree of relaxation and the crystallinity of the as-grown In 0.3 Ga 0.7 As films are strongly affected by the thickness of the amorphous In 0.6 Ga 0.4 As buffer layer. The thinner In 0.6 Ga 0.4 As buffer layer is not enough to efficiently release the misfit strain between the In 0.3 Ga 0.7 As epilayer and the GaAs substrate, while the thicker In 0.6 Ga 0.4 As buffer layer is unfavorable to trap the dislocations and prevent them from extending into the In 0.3 Ga 0.7 As epi-films. We have demonstrated that the amorphous In 0.6 Ga 0.4 As buffer layer with a thickness of 2 nm can advantageously prevent threading and misfit dislocations from propagating into the subsequent In 0.3 Ga 0.7 As epilayer and increase the degree of relaxation of the as-grown In 0.3 Ga 0.7 As, ultimately leading to a high-quality In 0.3 Ga 0.7 As film. Our novel buffer layer technology has triggered a simple but effective approach to grow high-crystallinity In 0.3 Ga 0.7 As epitaxial film and is favorable for fabrication of GaAs-based high-efficiency four-junction solar cells.

Single domain relaxor-PT crystals are important from both fundamental and application viewpoints. Compared to domain engineered relaxor-PT crystals, however, single domain crystals are prone to cracking during poling. In this paper, based on the analysis of the cracking phenomenon in [001] poled tetragonal 0.25Pb(In 0.5 Nb 0.5 )O 3 –0.37Pb(Mg 1/3 Nb 2/3 )O 3 –0.38PbTiO 3 (PIN–PMN–PT) crystals, the non-180° ferroelastic domain switching was thought to be the dominant factor for cracking during the poling process. A high temperature poling technique, by which the domain switching can be greatly avoided, was proposed to achieve the single domain relaxor-PT crystals. By this poling approach, a quasi-single domain crystal was obtained without cracks. In addition, compared to room temperature poling, the high temperature poled PIN–PMN–PT crystals showed improved electromechanical properties, i.e. , a low dielectric loss, a low strain–electric field hysteresis and a high mechanical quality factor, demonstrating a beneficial poling approach.

A homochiral 3D diamondoid metal–organic framework [Zn 2 (etza) 4 ] ( 1 , named JUC-81 , JUC = Jilin University, China, Hetza = ethyl 1H-tetrazole-5-acetate ) has been prepared through spontaneous resolution. The bulk crystals have enantiomeric excess observed by vibrational circular dichroism ( VCD ) spectra , and also show second-order nonlinear optical effects and ferroelectric feature.

A novel 3D supermolecular metal–organic framework (LMOF 1 ) {[Cd 1.5 (TCPB)(phen) 2DMF·3.5dioxane·H 2 O]} n (H 3 TCPB = 1,3,5-tris(4-carbonylphenyloxy)benzene and phen = 1,10-phenanthroline monohydrate) was solvothermally synthesized, and after the incorporation of the fluorescent guest molecule rhodamine B (RhB) into the channel of LMOF 1 , the composite RhB@LMOF 1 was successfully prepared. Because the channels of LMOF 1 could restrain the dissociation of the RhB aggregates, RhB@LMOF 1 displayed outstanding stability under varying treatment conditions. The solid-state fluorescence spectrum analysis showed that RhB@LMOF 1 possesses the characteristic emissions of both RhB and LMOF 1 . Subsequently, the luminescence sensing of RhB@LMOF 1 for six types of pesticides was investigated at room temperature. The results demonstrated that RhB@LMOF 1 could sensitively and selectively recognize organophosphorous (OP) pesticides, which is mainly attributed to the synthetic effect of the internal filter effect (IFE) and photo-induced electron transfer (PET).