Search results for " table"

Controlling the position of anions relative to a pentafluorophenyl groupw

2012

The position of an anion above an electron-deficient arene can be controlled by the geometry of appended directing groups. Here a series of ammonium substituted pentafluorophenyl derivatives is investigated. The presented results are one step on the way to find the ideal structural features for an effective and superior receptor for anion–π studies.

Deduction of the oxidation degree of the group A15 elements at the phthalocyanines on the basis of the Q band

2017

Electron Crystallography on Polymorphs

2006

Structure analysis via electron diffraction in combination with x-ray powder diffraction and simulation methods has been performed on single crystals of small organic molecules which form polymorphs. For two different examples of pigments and non-linear optical active material data collection, cell parameter and space group determination, structure analysis and refinement are discussed.

Guest-Host Systems of 1,3,5-Tristyrylbenzenes

2003

(E,E,E)-1,3,5-Tris(3,4,5-trimethoxystyryl)benzene (1a) forms monoclinic crystals of the space group P21/c. Incorporation of three transoid diacetyl guest molecules between the three arms leads to triclinic crystals of the space group P1. The styryl groups, originally present in a nonsymmetrical conformation, are simultaneously transformed to a C3 arrangement. (E,E,E)-1,3,5-Tris- (3,4,5-tripropoxystyryl)benzene (1b) forms monoclinic crystals of the space group P21/c. The C3 arrangement of the styryl groups is present in the first, the unsymmetrical arrangement in the second modification. Incorporation of two acetone guests in the largest and the middle-sized angle space between the styryl ar…

ChemInform Abstract: New Polymorph of InVO4: A High-Pressure Structure with Six-Coordinated Vanadium.

2014

High-pressure XRD and Raman spectroscopy on orthorhombic InVO4 (space group Cmcm, Z = 4) reveal the existence of a new wolframite-type polymorph of InVO4 near 7 GPa.

Modal Analysis of a Reinforced Concrete Frame in Various States of Damage

2005

The purpose of this paper is to report selected results of an experiment in which two, natural size r/c frames were put on shaking table and subjected to a sequence of seismic excitations with increasing intensity interlaced with low level, diagnostic tests. The shaking table experiment aimed at working out new methodology for monitoring vibrations of r/c structures to assess their state. Characteristic decrease of natural frequencies and increase of structural damping was observed and analyzed in detail. It was interesting to note 20 per cent drop in natural frequencies prior to visual detection of any cracks.

Preparation and crystal structure of the oxalato-bridged CrIII–AgItwo-dimensional compound {Ag3(H2O)[Cr(dpa)(ox)2]3}n·2nH2O (dpa = 2,2′-dipyridylamin…

2004

The reaction of the mononuclear complex [Cr(dpa)(ox)2]− (dpa = 2,2-dipyridylamine) with Ag+ in aqueous solution affords the two-dimensional compound {Ag3(H2O)[Cr(dpa)(ox)2]3}n·2nH2O (1) whose structure has been determined by single-crystal X-ray diffraction. Six crystallographically independent metal atoms (three chromium and three silver atoms) occur in 1. The three [Cr(dpa)(ox)2]− units in 1 act as ligands towards the silver atoms through the two oxalate groups. Each oxalate group acts as bridging ligand adopting five coordination modes: bis-bidentate, bis-bidentate/monodentate (outer), bis-bidentate/monodentate (inner), bidentate/bis-monodentate (outer) and bidentate/monodentate (outer).…

(2-Chlorobenzyl)tris(2-pyridinethiolato)tin(IV).

2000

In the title compound, (2-chlorobenzyl)tris(pyridine-2-thiolato)-kappa(2)N,S;kappa2N,S;kappaS-tin(IV), [Sn(C7H6Cl)(C5H4NS)3], two of the three pyridine-2-thiolato ligands (SPy) are bidentate and one is monodentate. The bonding C atom of the 2-chlorobenzyl group, the S atom of the monodentate SPy and the S and N atoms of the two bidentate SPy ligands form a distorted octahedron around the Sn atom. The three S atoms and the N atom of one of the bidentate SPy ligands occupy the equatorial positions, while the N atom of the second bidentate SPy ligand and the C(CH2) atom are axial. The axial N-Sn-C angle of 157.9 (1) degree demonstrates the heavy distortion of the octahedron.

A feasibility study of table salt production from seawater reverse osmosis brine

2022

Chiral α-P,N Ligands From a Diastereoselective Ph2PH Addition to (η6-Benzaldimine)tricarbonylchromium Complexes

1999

International audience; Chiral α-aminophosphane (α-P–C–N) ligands have been prepared by reversible addition of Ph2PH to tricarbonylchromium benzaldimine complexes (CO)3Cr[η6-o-C6H4(Y)(CH=NR)] (with Y, R = CH3, CH3 or CH2COOCH3; CH3O, CH3 or p-CH3OC6H4; Cl, C6H5), with complete diastereoselectivity. These complexes are stabilized in solution by electron-withdrawing group(s) on the imine.