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Four new complexes based on the 4-(4-carboxyphenyl)-1,2,4-triazole (Hcpt) ligand, {[Co(cpt) 2 (H 2 O) 4 ]·H 2 O}( 1 ), {[Cr(cpt) 2 (H 2 O) 4 ]·10H 2 O}( 2 ), {[Fe(cpt) 2 (H 2 O) 4 ]·10H 2 O}( 3 ), {[Zn(cpt) 2 (H 2 O) 2 ]}( 4 ) have been synthesized and characterized by elemental analysis, single crystal X-ray diffraction and TGA. For complexes 1 , 2 , and 3 , they almost have the same coordination mode that only one nitrogen atom of triazole are involved in the coordination, while in the complex 4 , only the group COO − participates in the coordination. In the crystal structure of 1 , each structural unit[Co(cpt) 2 (H 2 O) 4 ] is linked to another by hydrogen bonding formed by the lattice water molecules, thus forming a one-dimensional chain structure; In the crystal structure of 2 or 3, each structural unit[Cr(cpt) 2 (H 2 O) 4 ] or [Fe(cpt) 2 (H 2 O) 4 ] forms a two-dimensional layered structure by intermolecular hydrogen bonds from the coordinated water molecule and the group COO − . The results of thermogravimetric analysis show that the loss of lattice water and coordinated water molecules in 1 , 2 and 3 is below 120 °C, while the loss of coordinated water molecules in 4 is in the temperature range of 190–260 °C. Hirshfeld surface shows that the N H⋯O hydrogen bonding interaction plays a significant role towards the conformation of the basic structure of these complexes. [ABSTRACT FROM AUTHOR]

The novel cesium chloride–lactose complex (CsCl·C 12 H 22 O 10 (Cs-Lac), cesium chloride- d -arabinose and l -arabinose complexes (CsCl·C 5 H 10 O 5 , Cs-D-Ara and Cs-L-Ara) have been synthesized and characterized using X-ray diffraction, FTIR, FIR, THz and Raman spectroscopies. Cs + is 9-coordinated to two chloride ions and seven hydroxyl groups from five lactose molecules in Cs-Lac. In the structures of CsCl- d -arabinose and CsCl- l -arabinose complexes, two kinds of Cs + ions coexist in the structures. Cs1 is 10-coordinated with two chloride ions and eight hydroxyl groups from five arabinose molecule; Cs2 is 9-coordinated to three chloride ions and six hydroxyl groups from five arabinose molecules. Two coordination modes of arabinose coexist in the structures. α- d -arabinopyranose and α- l -arabinopyranose appear in the structures of Cs-D-Ara and Cs-L-Ara complexes. FTIR and Raman results indicate variations of hydrogen bonds and the conformation of the ligands after complexation. FIR and THz spectra also confirm the formation of Cs-complexes. Crystal structure, FTIR, FIR, THz and Raman spectra provide detailed information on the structure and coordination of hydroxyl groups to metal ions in the cesium chloride–lactose, cesium chloride-D- and l -arabinose complexes. [ABSTRACT FROM AUTHOR]

The coordination structures formed by calcium complexes with nicotinamide (na), isonicotinamide (ina) and picolinamide (pa) and praseodymium bromide-na are reported. The structures of CaCl 2 ·(C 6 H 6 N 2 O) 2 ·2H 2 O (Ca-na), CaCl 2 ·(C 6 H 6 N 2 O) 2 ·4H 2 O (Ca-ina), CaCl 2 ·(C 6 H 6 N 2 O) 2 ·5H 2 O (Ca-pa) and PrBr 3 ·(C 6 H 6 N 2 O) 2 ·6H 2 O (PrBr-na) in the solid state have been characterized by X-ray single crystal diffraction, FTIR, FIR, THz and Raman spectroscopies. Carbonyl oxygen of nicotinamide is coordinated to Ca 2+ , but it is O-monodentate (carbonyl oxygen) and N,O-bidentate ligand (pyridyl nitrogen and carbonyl oxygen) for Pr 3+ to form a chain structure in PrBr-na. For isonicotinamide, only carbonyl oxygen atom is coordinated to Ca 2+ . Pyridyl nitrogen and carbonyl oxygen of picolinamide are coordinated to Ca 2+ to form a five-membered ring structure. The crystal structure and spectroscopic results indicate the differences of the coordination of Ca and Pr ions, the changes of hydrogen bonds and conformation of the ligands induced by complexation. Unlike transition metal ions, Sr 2+ or lanthanide ions, Ca 2+ is inclined to coordinate to carbonyl oxygen atoms of the ligands. [ABSTRACT FROM AUTHOR]

Fe–5Cr–1.5B–0.45C alloys exhibit excellent balance of hardness and toughness. The hard phase of boron carbide in the Fe–Cr–B–C alloy system of high-boron iron-based alloys plays a key role in various properties of the system. Therefore, in this study, several typical hard phase morphological and crystalline structures are analyzed in detail. Use of first-principle methods for calculating the thermodynamic and mechanical properties of the hard phase in Fe–5Cr–1.5B–0.45C alloys shows that the incorporation of alloying elements can further improve the properties of the alloys and the improvement of hardness can enhance the wear resistance properties. We investigate several typical hard phase morphological and crystalline structures in Fe–5Cr–1.5B–0.45C alloys, and calculate the thermodynamic and mechanical properties. It shows that the incorporation of alloying elements can reduce the enthalpies of formation of Fe2B compounds,and further improve the hardness and the wear resistance properties of the alloys. Image 1 • Typical morphology of the hard phase are lamellar, cluster, rod or lath and granular. • Thermodynamic and mechanical properties of various hard phases were calculated using of first-principle methods. • Orthorhombic structure Fe 3 (B, C) with the C or B element dissolved is comparatively formed easily. • Mo reduce the enthalpies of formation of Fe 2 B compounds, increase the hardness of Fe 2 B and Fe 3 C. • The incorporation of alloying elements can further improve its hardness and wear resistance. [ABSTRACT FROM AUTHOR]

Ultrathin c -Si solar cells (≤50 μm) are believed to be applied in military, aerospace and other special circumstances in the future due to their flexibility and high specific power density, and thus has attracted a great deal of research interest. However, until now, lacking fabrication means of high-quality ultrathin c -Si materials accompanied with their inefficient absorption of near-infrared light greatly limits their further application. In this work, we present a simple and novel method to realize rapid thinning and texturing of bulk c -Si at room temperature by varying the ρ ([HF]/([HF] + [H 2 O 2 ])) values during the one-step Cu-assisted chemical etching process, followed by a systematic investigation of the formation mechanism of the surface structures. It is found that the sizes of surface structures accompanied with the etching rate increase with increasing the ρ values from 40% to 95% during the double sided etching process, and a high etching rate of 29.6 µm/min is obtained under the ρ value of 95%. For rapid thinning and efficient absorption of near-infrared light, 45 µm c -Si solar cell with asymmetric front and back light trapping structures is rapidly fabricated by directly immersing as-sawn bulk c -Si substrate into the thinning (ρ = 95%) and texturing (ρ = 60%) solution successively for only a few minutes. A high short-current density (Jsc) (36.12 mA/cm 2 ) and energy-conversion efficiency (17.3%) are achieved, which are 1.09 mA/cm 2 and 0.4% higher respectively than that in 45 µm c -Si with flat back surface. Based on the absorption spectra, it is demonstrated that the 45 µm c -Si cell with our asymmetric structures yields a high theoretical Jsc of 42.47 mA/cm 2 , which nearly approaches the Yablonovitch limit of 42.56 mA/cm 2 . All the findings offer additional insight into the structure formation mechanism and pave a rapid and novel way for exploration of next-generation flexible photovoltaics. [ABSTRACT FROM AUTHOR]

Two iso-structural two-dimensional (2D) porous coordination polymers, which formulated as [Fe(1,3-di(4-pyridyl)propane) 2 (NCX) 2 ] 2 (X = S [ 1 ], Se [ 2 ]) and featured 2-fold interpenetration, have been synthesised and characterized. Crystal structure, Hirshfeld surfaces analysis and magnetic properties of them were described. The basic-unit of 1 and 2 was the 2D rhombic grids [2 × (4, 4)] network, and the intermolecular interactions in the crystals were dominated by C–H…π, H–H and C–H…S (Se) contacts. The stronger ligand field strength of SeCN − than that of SCN − resulted to different magnetic properties: compound 1 shows paramagnetic property while 2 display displays an incomplete SCO transition approximately 30% conversion of high-spin (HS) to low-spin iron(II) sites with transition temperature of 100 K. [ABSTRACT FROM AUTHOR]