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A novel stilbene-based salicylhydrazone compound {systematic name: (E)-4,4′-(ethene-1,2-diyl)bis[(N′E)-N′-(2-hydroxybenzylidene)benzohydrazide] dimethyl sulfoxide disolvate, C30H24N4O4·2C2H6OS or L·2DMSO} was synthesized and characterized by single-crystal X-ray diffraction, powder X-ray diffraction and luminescence spectroscopy. The title compound crystallizes in the monoclinic space group P21/c, with half a symmetry-independent L molecule and one dimethyl sulfoxide (DMSO) solvent molecule in the asymmetric unit. The L molecule adopts an almost planar structure, with a small dihedral angle between the planes of the stilbene and salicylhydrazone groups. There are multiple π–π stacking interactions between adjacent L molecules. The DMSO solvent molecules act as proton donors and acceptors, forming hydrogen bonds of various strengths with the L molecules. In addition, the geometry optimization of a single molecule of L and its luminescence properties either in solution, as a solvated solid or as a desolvated solid were studied. The compound shows an aggregation-induced emission (AIE) effect and exhibits switchable luminescence colouration in the solid state by the simple removal or re-addition of the DMSO solvent.

In this article, two new types of three-fold Ti(O,C) twins were observed, and the crystallographic relationships of the twins have been analyzed in depth. The difference in the intersection angles of primary twin boundaries derives from different crystallographic operations forming the face-centered cubic Ti(O,C) twins: two consecutive rotations of 70.5° counter-clockwise or clockwise around the [011] axis. Using double and triple Thompson tetrahedrons, the ambiguity of a three-fold twin in TEM observation is clarified by the analysis of the common [011] axis. These findings might bring about substantial insights to the crystallographic understanding of three-fold twins.

An organic material single crystal of [BzIQl][PIC] ([BzIQl]+ = benzylisoquinolinium; [PIC]− = picrate) has been grown by slow evaporation solution growth technique. Single crystal XRD studies reveal the crystal belongs to monoclinic system with C2/c. The two neighboring [PIC]− anions form a dimer through π⋯π interaction, while the cations stack to a columnar structure through C-H⋯π and π⋯π interactions. The anions (A) and cations (C) are arranged into a columnar structure in a ⋯AA-CC-AA-CC⋯sequence through C-H⋯O hydrogen bonds. The cations and anions are linked through electrostatic and other hydrogen bonding interactions form 3D network. The power XRD measurements substantiate the quality of the crystal. The presence of functional groups of the organic material was confirmed by FT-IR and FT-Raman analysis and theoretical studies. Differential thermal analysis (DTA) carried out on the grown crystal indicates that the material is stable up to 224.9 °C. Additionally, the organic material shows three main emission peaks about 385, 467 and 538 nm upon excitation at 241 nm in solid state at room temperature.

A novel glycoluril scaffold 1, namely 1,6-(1,2-xylylene)-3,4-(1,3-dimetheneyl-hexahydropyrimidine)tetrahydroimidazo[4,5-d]imidazole-2,5(1H,3H)-dione, was synthesized by the Mannich reaction of 1,6-(1,2-xylylene)tetrahydroimidazo[4,5-d]imidazole-2,5(1H,3H)-dione 5 with propanediamine and paraformaldehyde. The yielded product 1 was confirmed with IR, NMR, EI-MS. X-ray crystallographic technique was also conducted and the result showed the crystal belongs to monoclinic system, space group P21/c with unit cell parameters a = 10.6892(11) A, b = 12.1226(9) A, c = 13.7822(13) A, α = 90°, β = 112.620(4)°,γ = 90°, V = 1648.5(3) A3, Z = 4, Dc = 1.428, Mr = 354.41, μ = 0.098 mm−1, F(000) = 752, R1 = 0.0522 and wR2 = 0.1138. A novel molecular scaffold, containing a heterocyclic ring instead of an aromatic ring, was synthesized by the Mannich reaction based on glycoluril.

The microstructures and formation mechanisms of various kinds of Ti(O,C) twins in a Nb–23Ti–15Al alloy have been investigated. The crystallographic features of the twins are systematically characterized using transmission electron microscopy (TEM). Lamellar or corner Ti(O,C) twins consist of coherent {111} twin boundaries (TBs) and incoherent {112} TBs. The three-fold Ti(O,C) twins are newly found, with symmetric Σ9 {114} or asymmetric Σ9 {115}/{111} serving as the secondary TBs. Moreover, slabs on Ti(O,C) TBs showing three-layer periodic contrasts are identified to be the twin overlapping. According to the microstructure characteristics, we propose a new model based on oriented attachment to interpret the formation of Ti(O,C) twins, which involves the contact, rotation, attachment and Ostwald ripening of Ti(O,C) grains. Our results provide new insights on the formation mechanisms of nanotwinned grains.

The water-gas shift reaction is studied using a series of Cu–Fe composite oxide catalysts, which were prepared by co-precipitation, deposition-precipitation, sol–gel, solid state reaction and mechanical mixing method, respectively. Distinct crystal structure and texture of the as-prepared catalysts were formed, and their reduction properties as well as surface basicities were modulated. The CO conversion in the water gas shift reaction is found to be correlation well with the Cu components in the temperature range of 200–350 °C, while the CO conversion is mainly controlled by Fe3O4 sites at temperature above 350 °C. The characterization results demonstrate that the formation of CuFe2O4 is ideal to obtain well dispersed Cu crystals; the weak basic sites are positive to the WGS reaction; and the strong interaction between copper and iron species can result in good Cu dispersion. The catalyst that was fabricated by the co-precipitation method, possesses the largest amount of CuFe2O4 and weak basic sites, as well as highly dispersed Cu crystals, thus showing the best catalytic activity and stability for the WGS reaction in our cases.

Two couples of enantiomerically pure chiral cyano-bridged heterobimetallic one-dimensional (1D) chain complexes: [Mn(( R , R )-Salphen)Fe(Tp)(CN) 3 ] n ( 1 ) and [Mn(( S , S )-Salphen)Te(Tp)(CN) 3 ] n ( 2 ) (Salphen = N , N '-1,2- diphenyl ethylenebis (salicylideneiminato) dianion, Tp = tris(pyrazolyl) hydroborate), [Mn(( R , R )-Salphen)Fe(Tp*) (CN) 3 ·2H 2 O] n ( 3 ) and [Mn(( S , S )-Salphen)Fe(Tp*)(CN) 3 ·2H 2 O] n (4) (Tp* = hydridotris (3,5-dimethylpyrazol- 1-yl) borate), have been successfully synthesized by the reactions of Mn Ⅲ schiff-base complexes with the tricyanometalate building block, [(L Tp )Fe(CN) 3 ] - (L Tp = Tp or Tp*). All complexes are made up of neutral cyano-bridged zigzag double chains with (-Fe-C≡N-Mn-N≡C-) n as the repeating unit. Circular dichroism (CD) spectra confirm the enantiomeric nature of the optically active complexes. Magnetic studies demonstrate that ferromagnetic interactions are operative in these complexes. The ferromagnetic couplings become weak in the chains with the bending of the Mn-N≡C angles.

Herein we report the 1.15 A X-ray crystal structure of a short alpha-helix in which the N-terminal i and i + 4 main chain hydrogen bond is replaced with a carbon-carbon bond. The structure shows that the hydrogen-bond surrogate (HBS) derived alpha-helix truly resembles the structure of canonical alpha-helices and provides unequivocal support for our helix nucleation strategy.

Alpha-helical coiled coils play a crucial role in mediating specific protein-protein interactions. However, the rules and mechanisms that govern helix-helix association in coiled coils remain incompletely understood. Here we have engineered a seven heptad "Phe-zipper" protein (Phe-14) with phenylalanine residues at all 14 hydrophobic a and d positions, and generated a further variant (Phe-14(M)) in which a single core Phe residue is substituted with Met. Phe-14 forms a discrete alpha-helical pentamer in aqueous solution, while Phe-14(M) folds into a tetrameric helical structure. X-ray crystal structures reveal that in both the tetramer and the pentamer the a and d side-chains interlock in a classical knobs-into-holes packing to produce parallel coiled-coil structures enclosing large tubular cavities. However, the presence of the Met residue in the apolar interface of the tetramer markedly alters its local coiled-coil conformation and superhelical geometry. Thus, short-range interactions involving the Met side-chain serve to preferentially select for tetramer formation, either by inhibiting a nucleation step essential for pentamer folding or by abrogating an intermediate required to form the pentamer. Although specific trigger sequences have not been clearly identified in dimeric coiled coils, higher-order coiled coils, as well as other oligomeric multi-protein complexes, may require such sequences to nucleate and direct their assembly.

Two new organic-inorganic molecular solids of tetra(isothiocyanate)cobalt(II) dianion and disubstituted benzyl triphenylphosphinium, [2Cl4FBzTPP]2[Co(NCS)4] (1) and [2Cl4ClBzTPP]2[Co(NCS)4] (2) ([2Cl4FBzTPP](+)=1-(2'-chloro-4'-fluorobenzyltriphenylphosphonium) and [2Cl4ClBzTPP](+)=1-(2',4'-dichlorobenzyltriphenylphosphonium), were synthesized and characterized by elemental analysis, FT-IR, UV-Vis spectra, ESI-MS and single crystal X-ray diffraction method. Compounds 1 and 2 crystallize in the monoclinic Pc and triclinic P-1, respectively. The Co(II) ion of the [Co(NCS)4](2-) anion shows a distorted tetrahedral coordination geometry. The [2Cl4FBzTPP](+) cations containing P(2) atoms in 1 form a column by the Cl⋯π interactions, while the [2Cl4ClBzTPP](+) cations in 2 form two columns by the C-H⋯π and π⋯π interactions. The anion and the cation are linked by C-H⋯S hydrogen bonds and Cl⋯S interactions. Magnetic susceptibility measurement in the temperature range 2-300K shows that both 1 and 2 exhibit a weak antiferromagnetic exchange interaction as the temperature falls, and ultraviolet fluorescence emission in the solid state at room temperature.

A new method was developed for the fabrication of CdS-TiO(2) semiconductor nanoparticles as visible-light-excitable photocatalyst at low temperatures. Nanosized CdS acting as an effective and stable sensitizer was incorporated into TiO(2) by microemulsion-mediated solvothermal hydrolyzation followed by acidic peptization of the precipitate under 70 °C. The new method avoided the calcination or other pyrochemical treatments involved in traditional preparations, and thus eliminated the unwanted agglomeration of nanoparticles or the oxidation of CdS by oxygen. Compared to traditional methods, it was highly simplified, bypassing those miscellaneous steps like filtration, sintering, milling and redispersion in solutions. The crystal structure, configuration, element composition, as well as the light-absorption properties of the obtained CdS-TiO(2) hydrosol were characterized in detail. The hydrosol consisting of uniform and small crystalline particles of about 2 nm in diameter was thermodynamically stable and showed good dispersibility. The photocatalytic activity of the 'coupled' material was confirmed through the photocatalytic degradation of methylene blue (MB) dye under visible light irradiation, and the cooperative photocatalytic mechanism is discussed.

The fully self‐consistent discrete variational method within the local‐spin‐density framework has been employed to obtain the electronic structure and magnetic moments of the Mn‐containing cubic Laves phase pseudobinary compound of YFe2. The calculated results show that the substitution of Mn atoms on Fe sites weakens the ferromagnetism of this compound. The magnetic moments on distinct atomic sites were derived from the calculation. We found that when the Fe atom has one Mn atom in its nearest neighbor sites, its magnetic moment decreases rapidly, while the Mn moment is 0.71μB, parallel to the Fe moment. Based upon our results, the various experimental data have been satisfactorily explained.