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Novel half-sandwich ruthenium complexes termed [(p-cymene)RuClL] were synthesized by chelating arylhydrazone ligands with [(p-cymene)RuCl2]2 and were then fully characterized using different spectroscopic and analytical techniques. The crystal structure of complex 4 indicated that the hydrazone ligands bonded to the ruthenium ion in a bidentate manner through the imine nitrogen and imidazolate oxygen, exhibiting a pseudo-octahedral geometry centered by the ruthenium atom. The as-fabricated air and moisture stable half-sandwich ruthenium complexes demonstrated excellent catalytic activity towards the N-alkylation of hydrazides under mild conditions. Under the catalysis of ruthenium complexes, acyl hydrazides were reacted with different types of alcohols in a one-pot reaction, resulting in N-alkylation hydrazides with different substituents. This catalyst exhibited characteristics such as high catalytic efficiency, broad substrate scope, and mild reaction conditions, indicating that it has great potential for industrial applications. [ABSTRACT FROM AUTHOR]

C24H30O7, orthorhombic, P212121 (no. 19), a = 11.4194(5) Å, b = 13.4657(6) Å, c = 14.7549(7) Å, V = 2268.86(18) Å3, Z = 4, Rgt(F) = 0.0535, wRref(F2) = 0.1239, T = 273(2) K. [ABSTRACT FROM AUTHOR]

Vaccinia mature virus requires A26 envelope protein to mediate acid-dependent endocytosis into HeLa cells in which we hypothesized that A26 protein functions as an acid-sensitive membrane fusion suppressor. Here, we provide evidence showing that N-terminal domain (aa1-75) of A26 protein is an acid-sensitive region that regulates membrane fusion. Crystal structure of A26 protein revealed that His48 and His53 are in close contact with Lys47, Arg57, His314 and Arg312, suggesting that at low pH these His-cation pairs could initiate conformational changes through protonation of His48 and His53 and subsequent electrostatic repulsion. All the A26 mutant mature viruses that interrupted His-cation pair interactions of His48 and His 53 indeed have lost virion infectivity. Isolation of revertant viruses revealed that second site mutations caused frame shifts and premature termination of A26 protein such that reverent viruses regained cell entry through plasma membrane fusion. Together, we conclude that viral A26 protein functions as an acid-sensitive fusion suppressor during vaccinia mature virus endocytosis. [ABSTRACT FROM AUTHOR]

A new electron transfer type photoactive host–guest supramolecule was constructed by introducing (CH3)2NH2+ cations to the MOF framework. The resulting compound 1 exhibits reversible photochromic property without using photochromic components, resulting from photoinduced electron-transfer between the electron-rich anionic framework and the electron-deficient guest ions. In addition, a photoluminescence “on/off switch” occurs during the coloration–decoloration process. The raw materials are non-poisonous and harmless, hence compound 1 may be more cost-effective, clean, and harmless to the heath than existing photochromic materials. [ABSTRACT FROM AUTHOR]

Three novel coordination polymers, namely, [Zn 2 (betc)(L 1 )H(H 2 O)]·2H 2 O ( 1 ), [Zn 2 (btec)(L 2 ) 2 ] ( 2 ) and [Zn 5 (btec) 2 (L 3 ) 1.5 (OH) 2 ]·2H 2 O ( 3 ) (L 1 = 3,5-di(1H-imidazol-1-yl)benzoate, L 2 = 1,3-bis((1H-1,2,4-triazol-1-yl)methyl)benzene and L 3 = 1,3-di(1H-1,2,4-triazol-1-yl)propane), have been hydrothermally synthesized. Compound 1 shows a three dimensional (3D) framework with fsc-3,5-P4/mbm topology. Compound 2 reveals a 3D pillar-layered framework with the presence of 3-fold left- and right-handed helical chains. Compound 3 also exhibits a 3D framework based on 1D zinc chains. In addition, the luminescent properties for 1 – 3 have also been investigated. [ABSTRACT FROM AUTHOR]

Dragon grouper nervous necrosis virus (DGNNV), a member of the genus Betanodavirus, causes high mortality of larvae and juveniles of the grouper fish Epinephelus lanceolatus. Currently, there is no reported crystal structure of a fish nodavirus. The DGNNV virion capsid is derived from a single open reading frame that encodes a 338-amino-acid protein of approximately 37 kDa. The capsid protein of DGNNV was expressed to form virus-like particles (VLPs) in Escherichia coli. The VLP shape is T = 3 quasi-symmetric with a diameter of ∼38 nm in cryo-electron microscopy images and is highly similar to the native virion. In this report, crystals of DGNNV VLPs were grown to a size of 0.27 mm within two weeks by the hanging-drop vapour-diffusion method at 283 K and diffracted X-rays to ∼7.5 Å resolution. In-house X-ray diffraction data of the DGNNV VLP crystals showed that the crystals belonged to space group R32, with unit-cell parameters a = b = 353.00, c = 800.40 Å, α = β = 90, γ = 120°. 23 268 unique reflections were acquired with an overall Rmerge of 18.2% and a completeness of 93.2%. Self-rotation function maps confirmed the fivefold, threefold and twofold symmetries of the icosahedron of DGNNV VLPs. [ABSTRACT FROM AUTHOR]

Two new supramolecular compounds, [Zn2(L)3(4,4′-bpy)(OH)]n(1) and [Cd(L)2(2,2′-bpy)(H2O)]·2H2O (2) (HL = 2-(4-isopropylbenzoyl)benzoic acid, 4,4′-bpy = 4,4′-bipyridine, 2,2′-bpy = 2,2′-bipyridine), have been hydrothermally synthesized and characterized by elemental analysis, infra-red spectroscopy, thermal gravimetric analyzes, and single-crystal X-ray diffraction.1exhibits 1-D chain and2is 0-D mononuclear. They are both linked into 2-D supramolecular layers by non-covalent interactions. Luminescence properties were also investigated. [ABSTRACT FROM AUTHOR]

C24H30O7, orthorhombic, P212121 (no. 19), a = 11.4194(5) Å, b = 13.4657(6) Å, c = 14.7549(7) Å, V = 2268.86(18) Å3, Z = 4, Rgt(F) = 0.0535, wRref(F2) = 0.1239, T = 273(2) K. [ABSTRACT FROM AUTHOR]

Three new coordination polymers, namely, [Zn(o-bbtz)(nip)] n ( 1 ), [Zn(m-bbtz)(nip)] n ( 2 ), {[Cu(o-bbtz)(nip)]·H 2 O} n ( 3 ), have been successfully synthesized under solventthermal conditions and characterized by single-crystal X-ray diffraction, elemental analysis, IR spectra and thermogravimetric analysis. Both complexes 1 and 2 exhibit 2D layer structure with (4,4) network, which are further connected by π ⋯ π interactions to generate a 3D supramolecular structure. Complex 3 shows a three-dimensional (3D) supramolecular network based on the π ⋯ π interactions and hydrogen bonds. The luminescent properties of 1 and 2 have also been investigated. [ABSTRACT FROM AUTHOR]

Six new coordination polymers, [CdCl 2 (bbim)] n ( 1 ), [ZnCl 2 (bbbm)] n ( 2 ), [ZnCl(HCOO)(bbbm)] n ( 3 ), [Cd(PhCOO) 2 (bbim)] n ( 4 ), [Cd(PhCOO) 2 (bbbm)] n ( 5 ), and {[Zn(ip-OH)(bbim)]·DMF} n ( 6 ) [bbim = 1,1′-(1,4-butanediyl)bis(2-methylbenzimidazole), bbbm = 1,1′-(1,4-butanediyl)bis(benzimidazole), H 2 ip-OH = 5-hydroxylisophthalic acid], have been prepared and characterized by elemental analysis, infrared spectra and X-ray single-crystal diffraction. Complexes 1 – 5 have one-dimensional (1D) chain structures. Complexes 1 , 3 and 4 possess similar 1D meso-helical chain structures, which are extended into 2D or 3D supramolecular network through intermolecular hydrogen-bonding, C–H⋯ π and π ⋯ π interactions. Complexes 2 and 5 exhibit similar 1D infinite helical chains. The 1D chains further form a three-dimensional (3D) supramolecular structure through intermolecular hydrogen-bonding and π ⋯ π interactions in 2 , but form a 2D supramolecular layer via C–H⋯ π interactions in 5 . Complex 6 possesses a 2D 4 4 -sql network. Furthermore, luminescent properties and thermal stabilities of 1 – 6 were also investigated. [ABSTRACT FROM AUTHOR]

Abstract: Two novel inorganic–organic hybrid compounds based on α-Keggin {PMo12O40} (PMo12) clusters, [CuI(bim)2]2{[CuII(bim)2]2[PMoVI 9MoV 3O40]} (1) and [CuI(mim)2]4[PMoVI 11MoVO40]·H2O (2) (bim=benzimidazole, mim=2-methylimidazole), have been hydrothermally synthesized and characterized by single crystal X-ray diffraction, IR spectrum, PXRD, elemental and TG analyses. Single crystal X-ray diffraction analyses reveal that both the two three-dimension (3D) supramolecular structures include left- and right-handed helical chains formed by modified polyoxometalate (POM) clusters via hydrogen bonds. 1 is an unusual bicapped Keggin compound with two Cu atoms as caps connecting with the POM via four bridging oxygen atoms, respectively. 2 is a tetrasupporting compound based on PMo12 cluster modified by four [CuI(mim)2]+ fragments. Photocatalytic activities of the two compounds have also been investigated in this paper. [Copyright &y& Elsevier]

Three new supramolecular compounds, [Cu( o -HPIDC)(bpy)(H 2 O)]·2H 2 O 1 , [Cu( o -H 2 PIDC)(phen)Cl]·[Cu(phen) 2 Cl]·10H 2 O·Cl 2 and {[Cd( o -H 2 PIDC)(H 2 O) 2 Cl]·H 2 O} 2 3 ( o -H 3 PIDC = 2-(pyridine-2-yl)-1H-imidazole-4,5-dicarboxylic acid, bpy = 2,2'-bipyridine, phen = 1,10-phenanthroline), were hydrothermally synthesized and characterized. In compound 1 , the adjacent two supramolecular layers are constructed from different types of helical chains with the same pitch. In compound 2 , the adjacent 2D water-chloride layers, {[(H 2 O) 10 Cl] − } n , are pillared by [Cu( o -H 2 PIDC)(phen)Cl] units to form the overall 3D supramolecular network with 1D channels through O H⋯O hydrogen bond interactions. In compound 3 , two Cd(II) are linked into a binuclear [Cd 2 ( o -H 2 PIDC) 2 (H 2 O) 4 Cl 2 ] with a ten-membered ring by two o -H 2 PIDC − ligands. The three compounds self-assemble into 3D supramolecular structures via hydrogen bond and π-π stacking interactions. The fluorescence properties of compound 3 was also investigated. [ABSTRACT FROM AUTHOR]

Abstract: Two serious three-dimensional (3D) lanthanide organic frameworks, {[Ln(Hbidc)(ox)1/2(H2O)]·H2O}n [Ln=Pr (1), Nb (2) and Sm (3)] (H3bidc=Benzimidazole-5,6-dicarboxylic acid, H2ox=oxalic acid) and [Ln(Hbidc)(ox)1/2]n [Ln=Eu (4) and Gd (5)], have been synthesized solvothermally under different temperature conditions. Their structures have been characterized by single-crystal X-ray diffraction, elemental analysis, IR spectra and thermogravimetric analysis. Structure analyses reveal that the five compounds exhibit similar 3D network structures that ox2− and Hbidc2− ligands showing the same coordination mode to link metal centers. The difference between the two kinds of compounds is that the coordination and lattice water molecules are absent in 4–5 due to the higher reaction temperature. Additionally, the luminescence properties of compounds 3 and 4 have been investigated in detail. [Copyright &y& Elsevier]

Abstract: A series of lanthanide complexes, [LnL1L2 1/2(H2O)2]n [Ln=La(1), Sm(2), Gd(3), Eu(4), H2L1 =2,4-bis(4-methylbenzoyl)isophthalic acid and H2L2 =2,5-bis(4-methylbenzoyl)terephthalic acid] have been prepared under hydrothermal conditions and characterized by PXRD, IR, elemental analysis and single crystal X-ray diffraction. Complexes 1–4 are isostructural and comprise paddlewheel dinuclear lanthanide secondary building units linked by four carboxylic groups. L1 ligands link the dinuclear lanthanide building blocks to form one-dimensional double-stranded looplike chains. The chains are further connected together to form two-dimensional layers by L2. Furthermore, the luminescent properties of 2 and 4 were also studied. [Copyright &y& Elsevier]

Abstract: Two new coordination polymers, {[Zn3L2.5(μ 3-OH)(H2O)3]·4H2O} n (1) and [Zn2L1.5(μ 3-OH)(4,4′-bpy)0.5] n (2) (H2L=2,5-bis(4-methylbenzoyl)terephthalic acid, 4,4′-bpy=4,4′-bipyridine), have been hydrothermally synthesized and characterized by elemental analysis, IR spectroscopy, TG, PXRD and single crystal X-ray diffraction. Complex 1 possesses a 2D double-layer configuration with 48·62 network constructed with trinuclear zinc(II) clusters and L2− ligands, which extends into a 3D architecture via O–H···O interactions between coordinated water molecules and lattice water molecules. Complex 2 is a uninodal 8-connected 3D framework with a 424·64 network based on tetranuclear zinc(II) clusters as nodes. Moreover, the luminescent properties of complexes 1 and 2 were also investigated. [Copyright &y& Elsevier]

Abstract: Archaeal RadA/Rad51 are close homologues of eukaryal Rad51/DMC1. Such recombinases, as well as their bacterial RecA orthologues, form helical nucleoprotein filaments in which a hallmark strand exchange reaction occurs between homologous DNA substrates. Our recent ATPase and structure studies on RadA recombinase from Methanococcus voltae have suggested that not only magnesium but also potassium ions are absorbed at the ATPase center. Potassium, but not sodium, stimulates the ATP hydrolysis reaction with an apparent dissociation constant of ∼40 mM. The minimal inhibitory effect by 40 mM NaCl further suggests that the protein does not have adequate affinity for sodium. The wild-type protein''s strand exchange activity is also stimulated by potassium with an apparent dissociation constant of ∼35 mM. We made site-directed mutations at the potassium-contacting residues Glu151 and Asp302. The mutant proteins are expectedly defective in promoting ATP hydrolysis. Similar potassium preference in strand exchange is observed for the E151D and E151K proteins. The D302K protein, however, shows comparable strand exchange efficiencies in the presence of either potassium or sodium. Crystallized E151D filaments reveal a potassium-dependent conformational change similar to what has previously been observed with the wild-type protein. We interpret these data as suggesting that both ATP hydrolysis and DNA strand exchange requires accessibility to an “active” conformation similar to the crystallized ATPase-active form in the presence of ATP, Mg2+ and K+. [Copyright &y& Elsevier]