ert Punjab to go by experts panel's recommendation on ending lockdown: CM By www.newkerala.com Published On :: Sat, 25 Apr 2020 08:23:01 +0530 Full Article
ert Montek Ahluwalia to head expert group for post-COVID-19 revival in Punjab By www.newkerala.com Published On :: Mon, 27 Apr 2020 07:12:02 +0530 Full Article
ert Two hostels of Panjab University to be converted into quarantine centres By www.newkerala.com Published On :: Wed, 29 Apr 2020 15:31:02 +0530 Full Article
ert Living in uncertain times By www.thehindu.com Published On :: Sat, 09 May 2020 16:58:00 +0530 The only thing to do is follow the instructions put out by the government and look after the safety of yourself and the family Full Article Open Page
ert Five killed as truck carrying migrant workers overturns in Madhya Pradesh By www.thehindu.com Published On :: Sun, 10 May 2020 11:21:20 +0530 They were atop a heap of mangoes on the Agra-bound vehicle coming from Hyderabad. Full Article Other States
ert Alert train driver averts accident near Pune, saves 20 migrants’ lives By timesofindia.indiatimes.com Published On :: Sun, 10 May 2020 04:59:00 IST An alert loco driver of a goods train saved the lives of at least 20 migrant workers by applying the emergency brakes and halting the train just 100 metres away from them near Pune on Friday evening. The migrants were walking on the tracks between the Uruli and Loni stations. The incident happened barely 14 hrs after 16 migrants were killed on Aurangabad tracks. Full Article
ert Rashtriya Chemicals & Fertilisers records 35 per cent hike in sale of ‘Suphala’ fertilisers By www.thehindubusinessline.com Published On :: Sun, 10 May 2020 10:24:24 +0530 A PIB press statement said that Rashtriya Chemicals & Fertilisers Ltd (RCF) has registered a hike of 35.47 per cent in the sale of fertilisers und Full Article Companies
ert No player makes a debut at the age of 30, BCCI doesn't entertain such players: Irfan Pathan By www.dnaindia.com Published On :: Sun, 10 May 2020 03:14:00 GMT Pathan's statement came during an Instagram Live session with Suresh Raina. Full Article Sports Cricket
ert Inside Track: Kishor’s expertise By indianexpress.com Published On :: Sat, 09 May 2020 18:46:34 +0000 Full Article Columns Opinion
ert Coherence properties of the high-energy fourth-generation X-ray synchrotron sources By scripts.iucr.org Published On :: 2019-11-01 An analysis of the coherence properties of the fourth-generation high-energy storage rings with emittance values of 10 pm rad is performed. It is presently expected that a storage ring with these low emittance values will reach diffraction limit at hard X-rays. Simulations of coherence properties were performed with the XRT software and an analytical approach for different photon energies from 500 eV to 50 keV. It was demonstrated that a minimum photon emittance (diffraction limit) reached at such storage rings is λ/2π. Using mode decomposition it is shown that, for the parameters of the storage ring considered in this work, the diffraction limit will be reached for soft X-ray energies of 500 eV. About ten modes will contribute to the radiation field at 12 keV photon energy and even more modes give a contribution at higher photon energies. Energy spread effects of the electron beam in a low-emittance storage ring were analysed in detail. Simulations were performed at different relative energy spread values from zero to 2 × 10−3. A decrease of the degree of coherence with an increase of the relative energy spread value was observed. This analysis shows that, to reach the diffraction limit for high photon energies, electron beam emittance should go down to 1 pm rad and below. Full Article text
ert Expert confirms true impact of earthquakes in Devon and Cornwall - Devon Live By www.devonlive.com Published On :: Sat, 07 Dec 2019 08:00:00 GMT Expert confirms true impact of earthquakes in Devon and Cornwall Devon Live Full Article
ert Compasses at Greenwich Are About to Do Something Not Observed in Over 300 Years - ScienceAlert By www.sciencealert.com Published On :: Mon, 02 Sep 2019 07:00:00 GMT Compasses at Greenwich Are About to Do Something Not Observed in Over 300 Years ScienceAlert Full Article
ert UK sees notable reduction in seismic noise caused by human activity – experts - Aberdeen Evening Express By www.eveningexpress.co.uk Published On :: Fri, 24 Apr 2020 07:00:00 GMT UK sees notable reduction in seismic noise caused by human activity – experts Aberdeen Evening Express Full Article
ert N-(tert-Butyl)-2-(2-nitrophenyl)imidazo[1,2-a]pyridin-3-amine By scripts.iucr.org Published On :: 2019-11-12 In the title compound, C17H18N4O2, the dihedral angle between the pyridine and benzene rings is 55.68 (11)°. In the crystal, N—H⋯N hydrogen bonds link the molecules into [010] chains. Full Article text
ert 6,6'-[(3,3'-Di-tert-butyl-5,5'-dimethoxy-1,1'-biphenyl-2,2'-diyl)bis(oxy)]bis(dibenzo[d,f][1,3,2]dioxaphosphepine) benzene monosolvate By scripts.iucr.org Published On :: 2019-12-10 The crystal structure of the benzene monosolvate of the well known organic diphosphite ligand BIPHEPHOS, C46H44O8P2·C6H6, is reported for the first time. Single crystals of BIPHEPHOS were obtained from a benzene solution after layering with n-heptane at room temperature. One specific property of this type of diphosphite structure is the twisting of the biphenyl units. In the crystal, C—H⋯π contacts and π–π stacking interactions [centroid-to-centroid distance = 3.8941 (15) Å] are observed. Full Article text
ert 2-[4,5-Bis(4-bromophenyl)-1-(4-tert-butylphenyl)-1H-imidazol-2-yl]-4,6-dichlorophenol By scripts.iucr.org Published On :: 2019-12-24 In the title compound, C31H24Br2Cl2N2O, the dihedral angles subtended by the tert-butyl-phenyl, 4,6-dichlorophenol and 4-bromophenyl (×2) rings are 70.7 (3), 8.1 (3), 28.1 (3) and 84.2 (3)°, respectively. The orientations of the pendant rings may be related to intramolecular O—H⋯N and C—H⋯π interactions. One of the tert-butyl methyl groups is disordered over two sets of sites in a 0.54 (3):0.46 (3) ratio. In the crystal, a weak C—H⋯π interaction generates inversion dimers. Full Article text
ert 6-[(tert-Butyldimethylsilyl)oxy]-3-ethenyl-7-methoxy-4-[(trimethylsilyl)ethynyl]naphtho[2,3-c]furan-1(3H)-one By scripts.iucr.org Published On :: 2020-02-21 The tricyclic core in the title compound, C26H34O4Si2, shows disorder of the furan ring and deviates slightly from planarity, with the largest displacement from the least-squares plane [0.166 (2) Å] for the major disordered part of the methine C atom. To this C atom the likewise disordered vinyl group is attached, lying nearly perpendicular to the tricyclic core. In the crystal, mutual C—H⋯π interactions between the methine group of the furan ring and the central ring of the tricyclic core of an adjacent molecule lead to inversion-related dimers. Full Article text
ert Tris(4,4'-di-tert-butyl-2,2'-bipyridine)(trans-4-tert-butylcyclohexanolato)deca-μ-oxido-heptaoxidoheptavanadium acetonitrile monosolvate including another unknown solvent molecule By scripts.iucr.org Published On :: 2020-04-07 The title heptanuclear alkoxido(oxido)vanadium(V) oxide cluster complex, [V7(C10H19O)O17(C18H24N2)3]·CH3CN, was obtained by the reaction of [V8O20(C18H24N2)4] with 4-tert-butylcyclohexanol (mixture of cis and trans) in a mixed CHCl3/CH3CN solvent. The complex has a V7O18N6 core with approximately Cs symmetry, which is composed of two VO4 tetrahedra, two VO6 octahedra and three VO4N2 octahedra. In the crystal, these complexes are linked together by weak intermolecular C—H⋯O hydrogen bonds between the 4,4'-di-tert-butyl-2,2'-bipyridine ligand and the V7O18N6 core, forming a one-dimensional network along the c-axis direction. Besides the complex, the asymmetric unit contains one CH3CN solvent molecule. The contribution of other disordered solvent molecules to the scattering was removed using the SQUEEZE option in PLATON [Spek (2015). Acta Cryst. C71, 9–18]. The unknown solvent molecules are not considered in the chemical formula and other crystal data. Full Article text
ert Crystal structure of 5-(4-tert-butoxyphenyl)-3-(4-n-octyloxyphenyl)-4,5-dihydroisoxazole By scripts.iucr.org Published On :: 2019-05-24 The molecule of the title compound, C27H37NO3, was prepared by [3 + 2] 1,3-dipolar cycloaddition of 4-n-octylphenylnitrile oxide and 4-tert-butoxystyrene, the latter compound being a very useful intermediate to the synthesis of liquid-crystalline materials. In the molecule, the benzene rings of the n-octyloxyphenyl and tert-butoxyphenyl groups form dihedral angles of 2.83 (7) and 85.49 (3)°, respectively, with the mean plane of the isoxazoline ring. In the crystal, molecules are linked by weak C—H⋯O hydrogen interactions into chains running parallel to the b axis. Full Article text
ert Crystal structure, synthesis and thermal properties of tetrakis(4-benzoylpyridine-κN)bis(isothiocyanato-κN)iron(II) By scripts.iucr.org Published On :: 2019-05-31 The asymmetric unit of the title compound, [Fe(NCS)2(C12H9NO)4], consists of an FeII ion that is located on a centre of inversion, as well as two 4-benzoylpyridine ligands and one thiocyanate anion in general positions. The FeII ions are coordinated by two N-terminal-bonded thiocyanate anions and four 4-benzoylpyridine ligands into discrete complexes with a slightly distorted octahedral geometry. These complexes are further linked by weak C—H⋯O hydrogen bonds into chains running along the c-axis direction. Upon heating, this complex loses half of the 4-benzoylpyridine ligands and transforms into a compound with the composition Fe(NCS)2(4-benzoylpyridine)2, that might be isotypic to the corresponding MnII compound and for which the structure is unknown. Full Article text
ert Crystal structure and electrical resistance property of Rb0.21(H2O)yWS2 By scripts.iucr.org Published On :: 2019-06-11 Rb0.21(H2O)yWS2, rubidium hydrate dithiotungstate, is a new quasi two-dimensional sulfide. Its crystal structure consists of ordered WS2 layers, separated by disordered Rb+ ions and water molecules. All atomic sites are located on mirror planes. The WS2 layers are composed of edge-sharing [WS6] octahedra and extend parallel to (001). The presence of structural water was revealed by thermogravimetry, but the position and exact amount could not be determined in the present study. The temperature dependence of the electrical resistance indicates that Rb0.21(H2O)yWS2 is semiconducting between 80–300 K. Full Article text
ert (3,5-Dimethyladamantan-1-yl)ammonium methanesulfonate (memantinium mesylate): synthesis, structure and solid-state properties By scripts.iucr.org Published On :: 2019-07-26 The asymmetric unit of the title compound, C12H22N+·CH3O3S−, consists of three (3,5-dimethyladamantan-1-yl)ammonium cations, C12H22N+, and three methanesulfonate anions, CH3O3S−. In the crystal, the cations and anions associate via N—H⋯O hydrogen bonds into layers, parallel to the (001) plane, which include large supramolecular hydrogen-bonded rings. Full Article text
ert Crystal structure and magnetic properties of bis[butyltris(1H-pyrazol-1-yl)borato]iron(II) By scripts.iucr.org Published On :: 2019-08-20 The asymmetric unit of the title compound, [Fe(C13H18BN6)2], contains two half independent complex molecules. In each complex, the FeII atom is located on an inversion center and is surrounded by two scorpionate ligand butyltris(1H-pyrazol-1-yl)borate molecules that coordinate to the iron(II) ion through the N atoms of the pyrazole groups. The two independent complex molecules differ essentially in the conformation of the butyl substituents. In the crystal, the complex molecules are linked by a series of C—H⋯π interactions, which generate a supramolecular three-dimensional structure. At 120 K, the average Fe—N bond distance is 1.969 Å, indicating the low-spin state of the iron(II) atom, which does not change upon heating, as demonstrated by high-temperature magnetic susceptibility measurements. Full Article text
ert Synthesis and crystal structure of tert-butyl 1-(2-iodobenzoyl)cyclopent-3-ene-1-carboxylate By scripts.iucr.org Published On :: 2019-08-30 1-(2-Iodobenzoyl)-cyclopent-3-ene-1-carboxylates are novel substrates to construct bicyclo[3.2.1]octanes with antibacterial and antithrombotic activities. In this context, tert-butyl 1-(2-iodobenzoyl)-cyclopent-3-ene-1-carboxylate, C17H19IO3, was synthesized and structurally characterized. The 2-iodobenzoyl group is attached to the tertiary C atom of the cyclopent-3-ene ring. The dihedral angle between the benzene ring and the mean plane of the envelope-type cyclopent-3-ene ring is 26.0 (3)°. In the crystal, pairs of C-H⋯O hydrogen bonds link the molecules to form inversion dimers. Full Article text
ert Crystal structure of 4-bromo-N-[(3,6-di-tert-butyl-9H-carbazol-1-yl)methylidene]aniline By scripts.iucr.org Published On :: 2019-09-10 In the title compound, C27H29BrN2, the carbazole ring system is essentially planar, with an r.m.s. deviation of 0.0781 (16) Å. An intramolecular N—H⋯N hydrogen bond forms an S(6) ring motif. One of the tert-butyl substituents shows rotational disorder over two sites with occupancies of 0.592 (3) and 0.408 (3). In the crystal, two molecules are associated into an inversion dimer through a pair of C—H⋯π interactions. The dimers are further linked by another pair of C—H⋯π interactions, forming a ribbon along the c-axis direction. A C—H⋯π interaction involving the minor disordered component and the carbazole ring system links the ribbons, generating a network sheet parallel to (100). Full Article text
ert Crystal structure and Hirshfeld surface analysis of 5-(3,5-di-tert-butyl-4-hydroxyphenyl)-3-phenyl-4,5-dihydro-1H-pyrazole-1-carboxamide By scripts.iucr.org Published On :: 2019-09-12 In the title compound, C24H31N3O2, the mean plane of the central pyrazole ring [r.m.s. deviation = 0.095 Å] makes dihedral angles of 11.93 (9) and 84.53 (8)°, respectively, with the phenyl and benzene rings. There is a short intramolecular N—H⋯N contact, which generates an S(5) ring motif. In the crystal, pairs of N—H⋯O hydrogen bonds link inversion-related molecules into dimers, generating an R22(8) ring motif. The Hirshfeld surface analysis indicates that the most significant contribution involves H⋯H contacts of 68.6% Full Article text
ert Crystal structure and Hirshfeld surface analysis of N-(tert-butyl)-2-(phenylethynyl)imidazo[1,2-a]pyridin-3-amine By scripts.iucr.org Published On :: 2019-09-27 The bicyclic imidazo[1,2-a]pyridine core of the title compound, C19H19N3, is relatively planar with an r.m.s. deviation of 0.040 Å. The phenyl ring is inclined to the mean plane of the imidazo[1,2-a]pyridine unit by 18.2 (1)°. In the crystal, molecules are linked by N—H⋯H hydrogen bonds, forming chains along the c-axis direction. The chains are linked by C—H⋯π interactions, forming slabs parallel to the ac plane. The Hirshfeld surface analysis and fingerprint plots reveal that the crystal structure is dominated by H⋯H (54%) and C⋯H/H⋯C (35.6%) contacts. The crystal studied was refined as an inversion twin Full Article text
ert Crystal structure and luminescence properties of 2-[(2',6'-dimethoxy-2,3'-bipyridin-6-yl)oxy]-9-(pyridin-2-yl)-9H-carbazole By scripts.iucr.org Published On :: 2019-10-22 In the title compound, C29H22N4O3, the carbazole system forms a dihedral angle of 68.45 (3)° with the mean plane of the bipyridine ring system. The bipyridine ring system, with two methoxy substituents, is approximately planar (r.m.s. deviation = 0.0670 Å), with a dihedral angle of 7.91 (13)° between the planes of the two pyridine rings. Intramolecular C—H⋯O/N hydrogen bonds may promote the planarity of the bipyridyl ring system. In the pyridyl-substituted carbazole fragment, the pyridine ring is tilted by 56.65 (4)° with respect to the mean plane of the carbazole system (r.m.s. deviation = 0.0191 Å). In the crystal, adjacent molecules are connected via C—H⋯O/N hydrogen bonds and C—H⋯π interactions, resulting in the formation of a three-dimensional (3D) supramolecular network. In addition, the 3D structure contains intermolecular π–π stacking interactions, with centroid–centroid distances of 3.5634 (12) Å between pyridine rings. The title compound exhibits a high energy gap (3.48 eV) and triplet energy (2.64 eV), indicating that it could be a suitable host material in organic light-emitting diode (OLED) applications. Full Article text
ert Crystal structure, synthesis and thermal properties of bis(acetonitrile-κN)bis(4-benzoylpyridine-κN)bis(isothiocyanato-κN)nickel(II) By scripts.iucr.org Published On :: 2019-10-22 In the crystal structure of the title compound, [Ni(NCS)2(CH3CN)2(C12H9NO)2] or Ni(NCS)2(4-benzoylpyridine)2(acetonitrile)2, the NiII ions are octahedrally coordinated by the N atoms of two thiocyanate anions, two 4-benzoylpyridine ligands and two acetonitrile molecules into discrete complexes that are located on centres of inversion. In the crystal, the discrete complexes are linked by centrosymmetric pairs of weak C—H⋯S hydrogen bonds into chains. Thermogravimetric measurements prove that, upon heating, the title complex loses the two acetonitrile ligands and transforms into a new crystalline modification of the chain compound [Ni(NCS)2(4-benzoylpyridine)2], which is different from that of the corresponding CoII, NiII and CdII coordination polymers reported in the literature. IR spectroscopic investigations indicate the presence of bridging thiocyanate anions but the powder pattern cannot be indexed and, therefore, this structure is unknown. Full Article text
ert Crystal structure and photoluminescence properties of catena-poly[[bis(1-benzyl-1H-imidazole-κN3)cadmium(II)]-di-μ-azido-κ4N1:N3] By scripts.iucr.org Published On :: 2019-10-29 The new title one-dimensional CdII coordination polymer, [Cd(C10H10N2)2(μ1,3-N3)2]n, has been synthesized and structurally characterized by single-crystal X-ray diffraction. The asymmetric unit consists of a CdII ion, one azide and one 1-benzylimidazole (bzi) ligand. The CdII ion is located on an inversion centre and is surrounded in a distorted octahedral coordination sphere by six N atoms from four symmetry-related azide ligands and two symmetry-related bzi ligands. The CdII ions are linked by double azide bridging ligands within a μ1,3-N3 end-to-end (EE) coordination mode, leading to a one-dimensional linear structure extending parallel to [100]. The supramolecular framework is stabilized by the presence of weak C—H⋯N interactions, π–π stacking [centroid-to-centroid distance of 3.832 (2) Å] and C—H⋯π interactions between neighbouring chains. Full Article text
ert (μ-Di-tert-butylsilanediolato)bis[bis(η5-cyclopentadienyl)methylzirconium] By scripts.iucr.org Published On :: 2019-11-08 The reaction of t-Bu2Si(OH)2 with two equivalents of Cp2Zr(CH3)2 produces the title t-Bu2SiO2-siloxide bridged dimer, [Zr2(CH3)2(C5H5)4(C8H18O2Si)] or [Cp2Zr(CH3)]2[μ-t-Bu2SiO2] (1), where one methyl group is retained per zirconium atom. The same product is obtained at room temperature even when equimolar ratios of the silanediol and Cp2Zr(CH3)2 are used. Attempts to thermally eliminate methane and produce a bridging methylene complex resulted in decomposition. The crystal structure of 1 displays typical Zr—CH3 and Zr—O distances but the Si—O distance [1.628 (2) Å] and O—Si—O angle [110.86 (15)°] are among the largest observed in this family of compounds suggesting steric crowding between the t-Bu substituents of the silicon atom and the cyclopentadienyl groups. The silicon atom lies on a crystallographic twofold axis and both Cp rings are disordered over two orientations of equal occupancy. Full Article text
ert checkCIF validation ALERTS: what they mean and how to respond By scripts.iucr.org Published On :: 2020-01-01 Authors of a paper that includes a new crystal-structure determination are expected to not only report the structural results of interest and their interpretation, but are also expected to archive in computer-readable CIF format the experimental data on which the crystal-structure analysis is based. Additionally, an IUCr/checkCIF validation report will be required for the review of a submitted paper. Such a validation report, automatically created from the deposited CIF file, lists as ALERTS not only potential errors or unusual findings, but also suggestions for improvement along with interesting information on the structure at hand. Major ALERTS for issues are expected to have been acted on already before the submission for publication or discussed in the associated paper and/or commented on in the CIF file. In addition, referees, readers and users of the data should be able to make their own judgment and interpretation of the underlying experimental data or perform their own calculations with the archived data. All the above is consistent with the FAIR (findable, accessible, interoperable, and reusable) initiative [Helliwell (2019). Struct. Dyn. 6, 05430]. Validation can also be helpful for less experienced authors in pointing to and avoiding of crystal-structure determination and interpretation pitfalls. The IUCr web-based checkCIF server provides such a validation report, based on data uploaded in CIF format. Alternatively, a locally installable checkCIF version is available to be used iteratively during the structure-determination process. ALERTS come mostly as short single-line messages. There is also a short explanation of the ALERTS available through the IUCr web server or with the locally installed PLATON/checkCIF version. This paper provides additional background information on the checkCIF procedure and additional details for a number of ALERTS along with options for how to act on them. Full Article text
ert Crystal structure, synthesis and thermal properties of bis(4-benzoylpyridine-κN)bis(isothiocyanato-κN)bis(methanol-κN)iron(II) By scripts.iucr.org Published On :: 2020-01-31 In the crystal structure of the title compound, [Fe(NCS)2(C12H9NO)2(CH4O)2], the FeII cations are octahedrally coordinated by two N atoms of 4-benzoylpyridine ligands, two N atoms of two terminal isothiocyanate anions and two methanol molecules into discrete complexes that are located on centres of inversion. These complexes are linked via intermolecular O—H⋯O hydrogen bonds between the methanol O—H H atoms and the carbonyl O atoms of the 4-benzoylpyridine ligands, forming layers parallel to (101). Powder X-ray diffraction proved that a pure sample was obtained but that this compound is unstable and transforms into an unknown crystalline phase within several weeks. However, the solvent molecules can be removed by heating in a thermobalance, which for the aged sample as well as the title compound leads to the formation of a compound with the composition Fe(NCS)2(4-benzoylpyridine)2, which exhibits a powder pattern that is similar to that of Mn(NCS)2(4-benzoylpyridine)2. Full Article text
ert Synthesis, crystal structure, and thermal properties of poly[aqua(μ5-2,5-dicarboxybenzene-1,4-dicarboxylato)strontium] By scripts.iucr.org Published On :: 2020-02-14 A coordination polymer formulated as [Sr(H2BTEC)(H2O)]n (H4BTEC = benzene-1,2,4,5-tetracarboxylic acid, C10H6O8), was synthesized hydrothermally and characterized by single-crystal and powder X-ray diffraction, scanning electron microscopy and thermal analysis. Its crystal structure is made up of a zigzag inorganic chain formed by edge-sharing of [SrO8] polyhedra running along [001]. Adjacent chains are connected to each other via the carboxylate groups of the ligand, resulting in a double-layered network extending parallel to (100). O—H⋯O hydrogen bonds of medium-to-weak strength between the layers consolidate the three-dimensional structure. One of the carboxylic OH functions was found to be disordered over two sets of sites with half-occupancy. Full Article text
ert Structural and luminescent properties of co-crystals of tetraiodoethylene with two azaphenanthrenes By scripts.iucr.org Published On :: 2020-02-25 Two new co-crystals, tetraiodoethylene–phenanthridine (1/2), 0.5C2I4·C13H9N (1) and tetraiodoethylene–benzo[f]quinoline (1/2), 0.5C2I4·C13H9N (2), were obtained from tetraiodoethylene and azaphenanthrenes, and characterized by IR and fluorescence spectroscopy, elemental analysis and X-ray crystallography. In the crystal structures, C—I⋯π and C—I⋯N halogen bonds link the independent molecules into one-dimensional chains and two-dimensional networks with subloops. In addition, the planar azaphenanthrenes lend themselves to π–π stacking and C—H⋯π interactions, leading to a diversity of supramolecular three-dimensional structural motifs being formed by these interactions. Luminescence studies show that co-crystals 1 and 2 exhibit distinctly different luminescence properties in the solid state at room temperature. Full Article text
ert Crystal structure and photoluminescent properties of bis(4'-chloro-2,2':6',2''-terpyridyl)cobalt(II) dichloride tetrahydrate By scripts.iucr.org Published On :: 2020-03-05 In the title hydrated complex, [Co(C15H10ClN3)2]Cl2·4H2O, the complete dication is generated by overline{4} symmetry. The CoN6 moiety shows distortion from regular octahedral geometry with the trans bond angles of two N—Co—N units being 160.62 (9)°. In the crystal, O—H⋯Cl and C—H⋯O interactions link the components into (001) sheets. The title compound exhibits blue-light emission, as indicated by photoluminescence data, and a HOMO–LUMO energy separation of 2.23 eV was obtained from its diffuse reflectance spectrum. Full Article text
ert Crystal structure and DFT computational studies of (E)-2,4-di-tert-butyl-6-{[3-(trifluoromethyl)benzyl]iminomethyl}phenol By scripts.iucr.org Published On :: 2020-04-24 The title compound, C23H28F3NO, is an ortho-hydroxy Schiff base compound, which adopts the enol–imine tautomeric form in the solid state. The molecular structure is not planar and the dihedral angle between the planes of the aromatic rings is 85.52 (10)°. The trifluoromethyl group shows rotational disorder over two sites, with occupancies of 0.798 (6) and 0.202 (6). An intramolecular O—H⋯N hydrogen bonding generates an S(6) ring motif. The crystal structure is consolidated by C—H⋯π interactions. The molecular structure was optimized via density functional theory (DFT) methods with the B3LYP functional and LanL2DZ basis set. The theoretical structure is in good agreement with the experimental data. The frontier orbitals and molecular electrostatic potential map were also examined by DFT computations. Full Article text
ert Symmetry-mode analysis for intuitive observation of structure–property relationships in the lead-free antiferroelectric (1−x)AgNbO3–xLiTaO3 By scripts.iucr.org Published On :: 2019-06-21 Functional materials are of critical importance to electronic and smart devices. A deep understanding of the structure–property relationship is essential for designing new materials. In this work, instead of utilizing conventional atomic coordinates, a symmetry-mode approach is successfully used to conduct structure refinement of the neutron powder diffraction data of (1−x)AgNbO3–xLiTaO3 (0 ≤ x ≤ 0.09) ceramics. This provides rich structural information that not only clarifies the controversial symmetry assigned to pure AgNbO3 but also explains well the detailed structural evolution of (1−x)AgNbO3–xLiTaO3 (0 ≤ x ≤ 0.09) ceramics, and builds a comprehensive and straightforward relationship between structural distortion and electrical properties. It is concluded that there are four relatively large-amplitude major modes that dominate the distorted Pmc21 structure of pure AgNbO3, namely a Λ3 antiferroelectric mode, a T4+ a−a−c0 octahedral tilting mode, an H2 a0a0c+/a0a0c− octahedral tilting mode and a Γ4− ferroelectric mode. The H2 and Λ3 modes become progressively inactive with increasing x and their destabilization is the driving force behind the composition-driven phase transition between the Pmc21 and R3c phases. This structural variation is consistent with the trend observed in the measured temperature-dependent dielectric properties and polarization–electric field (P-E) hysteresis loops. The mode crystallography applied in this study provides a strategy for optimizing related properties by tuning the amplitudes of the corresponding modes in these novel AgNbO3-based (anti)ferroelectric materials. Full Article text
ert Synthesis, structure, magnetic and half-metallic properties of Co2−xRuxMnSi (x = 0, 0.25, 0.5, 0.75, 1) compounds By scripts.iucr.org Published On :: 2020-01-01 A series of Co2−xRuxMnSi (x = 0, 0.25, 0.5, 0.75, 1) Heusler compounds were successfully synthesized. The heat-treatment conditions were crucial to make the materials form a single phase with a Heusler structure. With increasing Ru content, the half-metallic gap, lattice parameters and magnetization are continuously adjustable in a wide range. The Co2−xRuxMnSi (x = 0, 0.25) compounds are rigorous half-metals and show a T3 dependence of resistance at low temperature. The Co2−xRuxMnSi (x = 0.5, 0.75, 1) Heusler compounds are the nearly half-metallic materials and show a semiconductive dependence of resistance at low temperature. The experimental magnetization is consistent with that in theory and follows the Slater–Pauling rule. The Curie temperature is higher than 750 K for all Co2−xRuxMnSi Heusler compounds. Full Article text
ert Calcium-ligand variants of the myocilin olfactomedin propeller selected from invertebrate phyla reveal cross-talk with N-terminal blade and surface helices By scripts.iucr.org Published On :: 2019-08-22 Olfactomedins are a family of modular proteins found in multicellular organisms that all contain five-bladed β-propeller olfactomedin (OLF) domains. In support of differential functions for the OLF propeller, the available crystal structures reveal that only some OLF domains harbor an internal calcium-binding site with ligands derived from a triad of residues. For the myocilin OLF domain (myoc-OLF), ablation of the ion-binding site (triad Asp, Asn, Asp) by altering the coordinating residues affects the stability and overall structure, in one case leading to misfolding and glaucoma. Bioinformatics analysis reveals a variety of triads with possible ion-binding characteristics lurking in OLF domains in invertebrate chordates such as Arthropoda (Asp–Glu–Ser), Nematoda (Asp–Asp–His) and Echinodermata (Asp–Glu–Lys). To test ion binding and to extend the observed connection between ion binding and distal structural rearrangements, consensus triads from these phyla were installed in the myoc-OLF. All three protein variants exhibit wild-type-like or better stability, but their calcium-binding properties differ, concomitant with new structural deviations from wild-type myoc-OLF. Taken together, the results indicate that calcium binding is not intrinsically destabilizing to myoc-OLF or required to observe a well ordered side helix, and that ion binding is a differential feature that may underlie the largely elusive biological function of OLF propellers. Full Article text
ert The flavin mononucleotide cofactor in α-hydroxyacid oxidases exerts its electrophilic/nucleophilic duality in control of the substrate-oxidation level By scripts.iucr.org Published On :: 2019-09-24 The Y128F single mutant of p-hydroxymandelate oxidase (Hmo) is capable of oxidizing mandelate to benzoate via a four-electron oxidative decarboxylation reaction. When benzoylformate (the product of the first two-electron oxidation) and hydrogen peroxide (an oxidant) were used as substrates the reaction did not proceed, suggesting that free hydrogen peroxide is not the committed oxidant in the second two-electron oxidation. How the flavin mononucleotide (FMN)-dependent four-electron oxidation reaction takes place remains elusive. Structural and biochemical explorations have shed new light on this issue. 15 high-resolution crystal structures of Hmo and its mutants liganded with or without a substrate reveal that oxidized FMN (FMNox) possesses a previously unknown electrophilic/nucleophilic duality. In the Y128F mutant the active-site perturbation ensemble facilitates the polarization of FMNox to a nucleophilic ylide, which is in a position to act on an α-ketoacid, forming an N5-acyl-FMNred dead-end adduct. In four-electron oxidation, an intramolecular disproportionation reaction via an N5-alkanol-FMNred C'α carbanion intermediate may account for the ThDP/PLP/NADPH-independent oxidative decarboxylation reaction. A synthetic 5-deaza-FMNox cofactor in combination with an α-hydroxyamide or α-ketoamide biochemically and structurally supports the proposed mechanism. Full Article text
ert Volt-per-Ångstrom terahertz fields from X-ray free-electron lasers By scripts.iucr.org Published On :: 2020-04-29 The electron linear accelerators driving modern X-ray free-electron lasers can emit intense, tunable, quasi-monochromatic terahertz (THz) transients with peak electric fields of V Å−1 and peak magnetic fields in excess of 10 T when a purpose-built, compact, superconducting THz undulator is implemented. New research avenues such as X-ray movies of THz-driven mode-selective chemistry come into reach by making dual use of the ultra-short GeV electron bunches, possible by a rather minor extension of the infrastructure. Full Article text
ert Synthesis, crystal structure, polymorphism and microscopic luminescence properties of anthracene derivative compounds By journals.iucr.org Published On :: Crystal structure and microscopic optical properties of anthracene derivative compounds have been investigated by single-crystal synchrotron X-ray diffraction, laser confocal microscopy and fluorescence lifetime imaging microscopy. Full Article text
ert Linux certifications By www.bleepingcomputer.com Published On :: 2019-07-09T19:16:08-05:00 Full Article
ert What are the certificates to do for a cyber security job? By www.bleepingcomputer.com Published On :: 2019-11-29T23:05:02-05:00 Full Article
ert Laboratory tests reveal precise way to measure vertical lift in bumblebees and other small insects and birds By insider.si.edu Published On :: Thu, 28 Jan 2010 20:01:27 +0000 Birds do it. Bees do it. And in a laboratory in northern California, scientists using bumblebees recently figured out the best way to measure it--vertical lift! The post Laboratory tests reveal precise way to measure vertical lift in bumblebees and other small insects and birds appeared first on Smithsonian Insider. Full Article Animals Research News Science & Nature animal flight bees birds insects Tropical Research Institute
ert Smithsonian bat expert Kristofer Helgen answers common questions about bats By insider.si.edu Published On :: Fri, 29 Oct 2010 17:37:23 +0000 To celebrate a cool Halloween creature--bats--we teamed up with the Smithsonian’s Kristofer Helgen, curator of mammals at the National Museum of Natural History. Here, he answers three commonly asked questions about these winged mammals. The post Smithsonian bat expert Kristofer Helgen answers common questions about bats appeared first on Smithsonian Insider. Full Article Animals Q & A Science & Nature bats conservation mammals National Museum of Natural History
ert Harvard-Smithsonian Center for Astrophysics to own and operate ALMA Vertex Prototype Antenna By insider.si.edu Published On :: Tue, 05 Apr 2011 17:56:54 +0000 The Harvard-Smithsonian Center for Astrophysics has been selected by the National Science Foundation as the recipient of a 12-meter (39-foot) radio antenna designed for submillimeter-wavelength astronomy. The ALMA Vertex Prototype Antenna was one of three antennas built as prototypes for the Atacama Large Millimeter Array, a 66-dish radio observatory currently being constructed in Chile. The post Harvard-Smithsonian Center for Astrophysics to own and operate ALMA Vertex Prototype Antenna appeared first on Smithsonian Insider. Full Article Research News Science & Nature Space astronomy biodiversity Center for Astrophysics | Harvard & Smithsonian technology
ert New study reveals desert tortoise is actually two distinct species By insider.si.edu Published On :: Thu, 30 Jun 2011 12:00:27 +0000 A new study shows that the desert tortoise, thought to be a single species for the last 150 years, is in fact two separate and distinct species, based on DNA evidence and biological and geographical distinctions. The post New study reveals desert tortoise is actually two distinct species appeared first on Smithsonian Insider. Full Article Animals Research News Science & Nature biodiversity collections conservation conservation biology endangered species National Museum of Natural History new species reptiles
ert Swift satellite alerts astronomers to cosmic accident in constellation Draco By insider.si.edu Published On :: Wed, 24 Aug 2011 18:03:04 +0000 Two studies appearing in the Aug. 25 issue of the journal Nature provide new insights into a cosmic accident that has been streaming X-rays toward Earth since late March. NASA's Swift satellite first alerted astronomers to intense and unusual high-energy flares from the new source in the constellation Draco. The post Swift satellite alerts astronomers to cosmic accident in constellation Draco appeared first on Smithsonian Insider. Full Article Science & Nature Space astronomy astrophysics Center for Astrophysics | Harvard & Smithsonian Smithsonian Astrophysical Observatory