Se Atoms (se + atom)

Distribution by Scientific Domains


Selected Abstracts


Solvothermal Synthesis, Crystal Structures, and Properties of New Selenidoantimonates [Ln(en)4(SbSe4)] (Ln = La, Nd) and [Sm(en)4]SbSe4·0.5en: The First Example of an SbSe43, Anion Acting as a Ligand to a Lanthanide Complex

EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 14 2006
Ding-Xian Jia
Abstract Three new lanthanide selenidoantimonates [Ln(en)4(SbSe4)] [Ln = La (1), Nd (2)] and [Sm(en)4]SbSe4·0.5en (3) (en = ethylenediamine) were first synthesized by treating LnCl3, Sb, and Se in a stoichiometric ratio with en under mild solvothermal conditions. Compounds 1 and 2 are isostructural. The Ln3+ ion has a nine-coordinate environment involving eight N atoms from four en ligands and one Se atom from the SbSe43, anion forming a distorted bicapped pentagonal bipyramid. [La(en)4(SbSe4)] and [Nd(en)4(SbSe4)] are the first examples of solvothermally synthesized selenidoantimonates with an SbSe43, anion acting as a ligand in a lanthanide complex. The crystal structure of 3 contains an isolated bicapped trigonal-prismatic coordinated [Sm(en)4]3+ cation, a tetrahedral SbSe43, anion, and half a free en molecule in its asymmetric unit. The bandgaps of 2.22 eV for 1, 2.33 eV for 2, and 2.54 eV for 3 have been derived from optical absorption spectra. Compound 1 loses the en ligands in one step, whereas compound 2 loses them in two steps. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006) [source]


Monoclinic Cu3(SeO3)2Cl2: an oxo­halide with an unusual CuO4Cl trigonal,bipyramidal coordination

ACTA CRYSTALLOGRAPHICA SECTION C, Issue 1 2007
Helmuth Berger
In single crystals of a new monoclinic (C2/m) form of tricopper(II) diselenium(IV) dichloride hexa­oxide, Cu3(SeO3)2Cl2, the Se atom is in the 4i position, while the two Cu atoms are in 2a and 4i positions. The structure is based on layers of CuO4Cl trigonal bipyramids, CuO4 square planes and SeO3E tetra­hedra. The Cu polyhedra are connected by edge- and corner-sharing to form [010] chains and these chains are bridged by the Se atoms to form (001) layers. The compound is isostructural with Cu3(TeO3)2Br2. [source]


Facile Controlled Synthesis and Spectroscopy of CdS1,xSex Alloy and (CdS)1,x@(CdSe)x Core,Shell Nanotetrapods

ADVANCED FUNCTIONAL MATERIALS, Issue 24 2009
Mee Rahn Kim
Abstract Nanotetrapods of alloy CdS1,xSex and core,shell (CdS)1,x@(CdSe)x are fabricated easily in water using ethylenediamine as a solvent-coordinating molecular template, and then their optical properties are investigated using diverse static and time-resolved spectroscopic methods. The arms of the alloy nanotetrapods have single-crystalline structures of CdS1,xSex without showing staking faults, while the arms of the core,shell nanotetrapods display polycrystalline shell structures of CdSe. The optical properties of CdS1,xSex, where Se atoms are isolated in the CdS lattice, are very different from those of (CdS)1,x@(CdSe)x, where banded CdSe passivates the CdS core. Compared with pure CdS nanotetrapods, the photoluminescence of CdS0.9Se0.1 shifts to the red by 40,nm, whereas that of (CdS)0.9@(CdSe)0.1 does so only by 5,nm. Although the mean luminescence lifetime of alloy CdS1,xSex is shorter than that of pure CdS, it is still much longer than that of core-shell (CdS)1,x@(CdSe)x. [source]


Ag2.54Tl2Mo12Se15: a new structure type containing Mo6 and Mo9 clusters

ACTA CRYSTALLOGRAPHICA SECTION C, Issue 6 2010
P. Gougeon
The novel structure-type Ag2.54Tl2Mo12Se15 (silver thallium molybdenum selenide) is built up of Mo6Sei8Sea6 and Mo9Sei11Sea6 cluster units in a 1:2 ratio, which are three-dimensionally connected to form the Mo,Se network. The Ag and Tl cations are distributed in several voids within the cluster network. Three of the seven independent Se atoms and one Tl atom lie on sites with 3.. symmetry (Wyckoff sites 2c or 2d). [source]


Cr1.45Tl1.87Mo15Se19, a monoclinic variant of the hexagonal In3Mo15Se19 type

ACTA CRYSTALLOGRAPHICA SECTION C, Issue 12 2009
P. Gougeon
The monoclinic compound Cr1.45Tl1.87Mo15Se19 (chromium thallium pentadecamolybdenum nonadecaselenide) represents a variant of the hexagonal In3Mo15Se19 structure type. Its crystal structure consists of an equal mixture of Mo6Se8Se6 and Mo9Se11Se6 cluster units. The Mo and Se atoms of the median plane of the Mo9Se11Se6 unit, as well as three Cr ions, lie on sites with m symmetry (Wyckoff site 2e). The fourth Cr ion is in a 2b Wyckoff position with site symmetry. [source]


BaLn2Se4 (Ln = Er, Tm and Yb)

ACTA CRYSTALLOGRAPHICA SECTION C, Issue 9 2009
Daniel E. Bugaris
The compounds BaLn2Se4 (Ln = rare-earth metal = lanthanide = Er, Tm and Yb), namely barium di(erbium/thulium/ytterbium) tetraselenide, crystallize in the orthorhombic space group Pnma in the CaFe2O4 structure type. In this structure type, all atoms possess m symmetry. The Ln atoms are octahedrally coordinated by six Se atoms. A three-dimensional channel structure is formed by the corner- and edge-sharing of these LnSe6 octahedra. The Ba atoms are coordinated to eight Se atoms in a bicapped trigonal,prismatic arrangement, and they occupy the channels of the three-dimensional framework. [source]


Monoclinic Cu3(SeO3)2Cl2: an oxo­halide with an unusual CuO4Cl trigonal,bipyramidal coordination

ACTA CRYSTALLOGRAPHICA SECTION C, Issue 1 2007
Helmuth Berger
In single crystals of a new monoclinic (C2/m) form of tricopper(II) diselenium(IV) dichloride hexa­oxide, Cu3(SeO3)2Cl2, the Se atom is in the 4i position, while the two Cu atoms are in 2a and 4i positions. The structure is based on layers of CuO4Cl trigonal bipyramids, CuO4 square planes and SeO3E tetra­hedra. The Cu polyhedra are connected by edge- and corner-sharing to form [010] chains and these chains are bridged by the Se atoms to form (001) layers. The compound is isostructural with Cu3(TeO3)2Br2. [source]


Structure of the N-terminal fragment of Escherichia coli Lon protease

ACTA CRYSTALLOGRAPHICA SECTION D, Issue 8 2010
Mi Li
The structure of a recombinant construct consisting of residues 1,245 of Escherichia coli Lon protease, the prototypical member of the A-type Lon family, is reported. This construct encompasses all or most of the N-terminal domain of the enzyme. The structure was solved by SeMet SAD to 2.6,Å resolution utilizing trigonal crystals that contained one molecule in the asymmetric unit. The molecule consists of two compact subdomains and a very long C-terminal ,-helix. The structure of the first subdomain (residues 1,117), which consists mostly of ,-strands, is similar to that of the shorter fragment previously expressed and crystallized, whereas the second subdomain is almost entirely helical. The fold and spatial relationship of the two subdomains, with the exception of the C-terminal helix, closely resemble the structure of BPP1347, a 203-amino-acid protein of unknown function from Bordetella parapertussis, and more distantly several other proteins. It was not possible to refine the structure to satisfactory convergence; however, since almost all of the Se atoms could be located on the basis of their anomalous scattering the correctness of the overall structure is not in question. The structure reported here was also compared with the structures of the putative substrate-binding domains of several proteins, showing topological similarities that should help in defining the binding sites used by Lon substrates. [source]


Crystallization and preliminary X-ray studies of the glutaredoxin from poplar in complex with glutathione

ACTA CRYSTALLOGRAPHICA SECTION D, Issue 6 2003
Katia D'Ambrosio
A monocysteinic mutant of poplar glutaredoxin (C30S) has been overproduced and purified. The protein has been crystallized in complex with glutathione using the hanging-drop vapour-diffusion technique in the presence of PEG 4000 as a precipitating agent. A native data set was collected at 1.55,Å resolution. The crystals belong to space group P212121, with unit-cell parameters a = 45.7, b = 49.1, c = 104.8,Å. Isomorphous crystals of a selenomethionine derivative were grown under the same conditions. Three data sets were collected at 1.73,Å using the FIP synchrotron beamline at the ESRF. The positions of the Se atoms were determined and model rebuilding and refinement are in progress. [source]