Structural Studies of Technetium Complexes. X. The Crystal-Structure of Tetraphenylarsonium Hexakis(Isothiocyanato)Technetate(IV)-Dichloromethane (1/1)

1987 ◽  
Vol 40 (1) ◽  
pp. 27 ◽  
Author(s):  
GA Williams ◽  
J Bonnyman ◽  
J Baldas
Keyword(s):  
Crystal Structure ◽  
Structural Studies ◽  
X Ray Diffraction ◽  
Octahedral Structure ◽  
Crystal Lattices ◽  
Full Matrix ◽  
X Ray ◽  
C And N ◽  
R Value ◽  
A Site

The crystal structure of [AsPh4]2 [ Tc (NCS)6].CH2Cl2 has been determined by single-crystal X-ray diffraction methods at 23 � 1�C . Crystals are tetragonal, space group I4/m, with a 11.523(5), c 22.43(2) �, and Z 2. Diffraction data from two different crystals were analysed and in both cases disorder was present in the crystal lattices. Full-matrix least-squares refinement gave a final R value of 0.073 for 1188m independent reflections. The [TC(NCS)6]2- anion has an octahedral structure with the technetium(1V) atom situated on a site of 4/m symmetry. The Tc -N bond lengths are 2.00(1) and 2.01(1) Ǻ with N- Tc -N angles of exactly 90�. Two of the Tc -NCS groups are constrained by the crystal symmetry to be perfectly linear, while for the remaining four Tc -NCS groupings the Tc -N-C and N-C-S angles are 175.9(9)� and 175.3(10)� respectively.

Structural Studies of Technetium Complexes. XI. The Crystal Structure of Bis(tetraphenylarsonium) Bis(1,2-dicyanoethenedithiolato)nitridotechnetate(V)

1989 ◽  
Vol 42 (6) ◽  
pp. 875 ◽  
Author(s):  
GA Williams ◽  
J Baldas
Keyword(s):  
Crystal Structure ◽  
Monoclinic Space Group ◽  
Coordination Geometry ◽  
Structural Studies ◽  
X Ray Diffraction ◽  
Apical Position ◽  
Full Matrix ◽  
X Ray ◽  
R Value ◽  
Centrosymmetric Structure

The crystal structure of [AsPh4]2 [ TcN(mnt)2] ( mnt = 1,2-dicyanoethenedithiolate) has been determined by single-crystal X-ray diffraction methods at 21 � 1 C. Crystals are monoclinic, space group Pn , with a 11 369(2), b 15.530(2), c 14.421(3) � , P 97.58(2)�, and Z 2. Full-matrix least-squares refinement gave a final R value of 0.057 for 4232 independent reflections. The technetium atom in the [TcN( mnt )2]2- anion has square-pyramidal coordination geometry with the nitrido ligand in the apical position, Tc =N 1.59(1) � , and four Tc -S bonds with distances varying between 2.367(4) and 2.419(4) �. The Tc =N core is disordered about a pseudo-inversion centre, but unequal occupancies of the disordered sites preclude a centrosymmetric structure.

Structural studies of Technetium Complexes. VIII. The Crystal Structure of Tetraphenylarsonium Tetrabromonitridotechnetate(VI)

1985 ◽  
Vol 38 (1) ◽  
pp. 215 ◽  
Author(s):  
J Baldas ◽  
J Bonnyman ◽  
GA Williams
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Least Squares ◽  
Bond Distance ◽  
Structural Studies ◽  
X Ray Diffraction ◽  
Full Matrix ◽  
X Ray ◽  
Bond Angles ◽  
R Value

The crystal structure of [AsPh4] [TcNBr4] has been determined by single- crystal X-ray diffraction methods at 20�1°C. Crystals are tetragonal, space group P4/n, with a 12.875(2), c 7.992(1)Ǻ, and Z 2. Full-matrix least-squares refinement gave a final R value of 0.039 for 1263 independent reflections. The compound is isostructural with the series [AsPh4] [MNBr4] (M = Mo, Ru , Re or Os) and [AsPh4] [MNCl4](M = Mo, Tc , Ru, Re or Os), and with [AsPh4] [OsNI4] and [AsPh4]- [MOCl4](M = Mo or Re). The [TcNBr4]- anion in [AsPh4] [TcNBr4] possesses C4v symmetry with Br- Tc -Br bond angles of 87.08(1) and 153.91(4)°, and N= Tc -Br bond angles of 103.04(2)°. The Tc≡N bond distance is 1.596(6)Ǻ, and the Tc - Br distances are 2.4816(5)Ǻ.

Crystal Structure of Tetraethylammonium Bromopentacarbonyltungstate(0)

1995 ◽  
Vol 48 (5) ◽  
pp. 1045 ◽  
Author(s):  
T Whyte ◽  
GA Williams
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Least Squares ◽  
X Ray Diffraction ◽  
Full Matrix ◽  
Space Group ◽  
X Ray ◽  
Bond Lengths ◽  
R Value

The crystal structure of tetraethylammonium bromopentacarbonyltungstate (0), [NEt4] [W(CO)5Br], has been determined by single-crystal X-ray diffraction methods at 22�1°C. Crystals are tetragonal, space group P4/n, with a 9.206(2), c 10.484(2) Ǻ, and Z 2. Full-matrix least-squares refinement gave a final R value of 0.034 for 820 independent reflections. The [W(CO)5Br]- anion possesses exact C4v symmetry, with bond lengths W-Br 2.736(1), W-COtrans 1.93(1) and W-COcis 2.034(6) Ǻ.

Structural studies of technetium complexes. III. The crystal structure of Tris[2-aminobenzenethiolato(2 - )-S, N]technetium(VI) : a trigonal-prismatictechnetium geometry

1982 ◽  
Vol 35 (12) ◽  
pp. 2413 ◽  
Author(s):  
J Baldas ◽  
J Boas ◽  
J Bonnyman ◽  
MF Mackay ◽  
GA Williams
Keyword(s):  
Crystal Structure ◽  
Hydrochloric Acid ◽  
Acid Solution ◽  
Room Temperature ◽  
Structural Studies ◽  
X Ray Diffraction ◽  
Orthorhombic Space Group ◽  
Full Matrix ◽  
X Ray ◽  
Trigonal Prismatic

Tris[2-aminobenzenethiolato(2–)-S,N]technetium(VI), Tc(NHC6H4S)3, has been prepared by the reaction of ammonium pertechnetate with 2-aminobenzenethiol in 0.1 M hydrochloric acid solution at room temperature. The crystal structure of Tc(NHC6H4S)3 has been determined by single-crystal X-ray diffraction methods at 17�C. Crystals are orthorhombic, space group P212121, with a 10.696(2), b 11.363(1), c l5.220(2) �, and Z 4. Automatic diffractometry has provided significant Bragg intensities for 1413 independent reflections, and the structure of the correct enantiomorph has been refined by full-matrix least-squares methods to R 0.044. The compound, which is isostructural with the molybdenum analogue, consists of discrete molecules of Tc(NHC6H4S)3. The environment about the technetium atom closely approximates a trigonal-prismatic geometry. This is the first example where this geometry has been established with technetium. Differences in detail between the structures of TC(NHC6H4S)3 and its molybdenum analogue are discussed. In particular the S3N3 coordination polyhedron in TC(NHC6H4S)3is contracted and the distortions from ideal trigonal-prismatic geometry are less than in the molybdenum analogue.

Preparation and Structure of Dibromobis(N,N-diethyldithiocarbamato)-thionitrosyltechnetium(III)

1991 ◽  
Vol 44 (8) ◽  
pp. 1125 ◽  
Author(s):  
J Baldas ◽  
SF Colmanet ◽  
GA Williams
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Title Compound ◽  
Coordination Geometry ◽  
X Ray Diffraction ◽  
Orthorhombic Space Group ◽  
Full Matrix ◽  
X Ray ◽  
Trans Influence ◽  
R Value

The title compound, [Tc (NS)(S2CNEt2)2Br2], has been prepared by the reaction of [ TcN (S2CNEt2)2] with SOBr2, and its crystal structure has been determined by single-crystal X-ray diffraction methods at 23�1°C. Crystals are orthorhombic, space group Pnma , with a 14.864(7), b 15.857(7), c 8.938(4)Ǻ, and Z 4. Full-matrix least-squares refinement gave a final R value of 0.047 for 1685 independent reflections. The technetium atom is seven-coordinate with a distorted pentagonal- bipyramidal coordination geometry. The thionitrosyl ligand and a bromo ligand occupy the axial positions, with the thionitrosyl group exerting a small trans influence with Tc-Brtrans 2.595(1) and Tc-Brcis 2.564(1)Ǻ. The coordination of the thionitrosyl group is essentially linear with Tc -N=S 177.2(7)°, Tc -N 1.754(9), and N=S 1.504(9)Ǻ.

scholarly journals Crystal Structure Refinements of Four Monazite Samples from Different Localities

Minerals ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1028 ◽  
Author(s):  
M. Mashrur Zaman ◽  
Sytle M. Antao
Keyword(s):  
Crystal Structure ◽  
Electron Probe ◽  
Unit Cell Volume ◽  
Unit Cell ◽  
X Ray Diffraction ◽  
Unit Cell Parameters ◽  
X Ray ◽  
Cell Parameters ◽  
Large Unit Cell ◽  
A Site

This study investigates the crystal chemistry of monazite (APO4, where A = Lanthanides = Ln, as well as Y, Th, U, Ca, and Pb) based on four samples from different localities using single-crystal X-ray diffraction and electron-probe microanalysis. The crystal structure of all four samples are well refined, as indicated by their refinement statistics. Relatively large unit-cell parameters (a = 6.7640(5), b = 6.9850(4), c = 6.4500(3) Å, β = 103.584(2)°, and V = 296.22(3) Å3) are obtained for a detrital monazite-Ce from Cox’s Bazar, Bangladesh. Sm-rich monazite from Gunnison County, Colorado, USA, has smaller unit-cell parameters (a = 6.7010(4), b = 6.9080(4), c = 6.4300(4) Å, β = 103.817(3)°, and V = 289.04(3) Å3). The a, b, and c unit-cell parameters vary linearly with the unit-cell volume, V. The change in the a parameter is large (0.2 Å) and is related to the type of cations occupying the A site. The average <A-O> distances vary linearly with V, whereas the average <P-O> distances are nearly constant because the PO4 group is a rigid tetrahedron.

Study of thermal properties of Ga0.5In1.5Se3 by differential scanning calorimetry

2021 ◽  
pp. 2150407
Author(s):  
S. I. Ibrahimova
Keyword(s):  
Crystal Structure ◽  
Differential Scanning Calorimetry ◽  
Thermal Properties ◽  
Thermal Effects ◽  
Room Temperature ◽  
Structural Studies ◽  
X Ray Diffraction ◽  
Hexagonal Symmetry ◽  
Scanning Calorimetry ◽  
X Ray

The crystal structure and thermal properties of the [Formula: see text] compound have been investigated. Structural studies were performed by X-ray diffraction at room temperature. The crystal structure of this compound was found to correspond to the hexagonal symmetry of the space group P61. Thermal properties were studied using a differential scanning calorimetry (DSC). It was found in the temperature range [Formula: see text] that thermal effects occur at temperatures [Formula: see text] and [Formula: see text]. The thermodynamic parameters of these effects are calculated.

Crystal structure of Tetracyclo[5,3,1,12,6,04,9]dodecane (iceane)

1977 ◽  
Vol 30 (8) ◽  
pp. 1837 ◽  
Author(s):  
DPG Hamon ◽  
CL Raston ◽  
GF Taylor ◽  
JN Varghese ◽  
AH White
Keyword(s):  
Crystal Structure ◽  
Rigid Body ◽  
Least Squares ◽  
Title Compound ◽  
Molecular Geometry ◽  
Thermal Motion ◽  
X Ray Diffraction ◽  
Full Matrix ◽  
X Ray ◽  
Hexagonal Close Packed

The crystal structure of the title compound, C12H18, has been determined at 295 K by X-ray diffraction and refined by full-matrix least squares to a residual of 0.049 for 216 ?observed? reflections; molecular geometry has been corrected for the effects of thermal motion using a rigid body approximation. Crystals are hexagonal, P63/m, a = 6.582(1), c = 11.843(3) Ǻ, Z = 2, the molecules occupying a hexagonal close- packed array.

Synthese und Kristallstruktur von l,13-Bis(8-chinolyl)- 1,4,7,10,13-pentaoxatridecan-diquecksilber(I)-diperchlorat

1991 ◽  
Vol 46 (1) ◽  
pp. 1-4 ◽  
Author(s):  
Klaus Brodersen ◽  
Jörg Zimmerhackl
Keyword(s):  
Crystal Structure ◽  
Aqueous Solution ◽  
X Ray Diffraction ◽  
Triclinic Space Group ◽  
Space Group ◽  
X Ray ◽  
R Value ◽  
Torsional Angles ◽  
L 13 ◽  
Oxygen Atoms

1,13-Bis(8-quinolyl)-1,4,7,10,13-pentaoxatridecane-dimercury(I)-diperchlorate is formed by the reaction of 1,13-bis(8-quinolyl)-1,4,7,10,13-pentaoxatridecane in ethanol with an aqueous solution of dimercury(I)-diperchlorate.It crystallizes in the triclinic space group P Ī with a = 1020.6(2), b = 1200.6(8), c = 1441.1(6) pm , α = 69.60(5)°, β = 83.04(13)°, y = 66.53(4)° and Z = 2. The crystal structure was determined by X -ray diffraction and refined to an R-value o f 0.079. The Hg22+ -ion is coordinated to both nitrogen atoms and four oxygen atoms of one molecule of the ligand. By changing four C - O torsional angles from trans to gauche, the ligand adopts a helical, chiral configuration around the Hg22+-ion. The CIO4--ions are not coordinated to the Hg22+-ion.

Structural studies of technetium complexes. V. The preparation and crystal structure of Dichlorobis(diethyldithiocarbamato)thionitrosyltechnetium(III)

1984 ◽  
Vol 37 (4) ◽  
pp. 751 ◽  
Author(s):  
J Baldas ◽  
J Bonnyman ◽  
MF Mackay ◽  
GA Williams
Keyword(s):  
Crystal Structure ◽  
Positive Charge ◽  
Mirror Plane ◽  
Structural Studies ◽  
Asymmetric Unit ◽  
X Ray Diffraction ◽  
Orthorhombic Space Group ◽  
Data Set ◽  
Coordination Environment ◽  
X Ray

Dichlorobis(diethyldithiocarbamato)thionitrosyltechnetium(III), [Tc(S2CNEt2)2Cl2(NS)], has been prepared by the reaction of [Tc(S2CNEt2)2N] with either disulfur dichloride or thionyl chloride. The crystal structure of [TC(S2CNEt2)2Cl2(NS)] has been determined by single-crystal X-ray diffraction methods at 15�C. Crystals are orthorhombic, space group Pcmn, with a 8.936(1), b 15.681(1), c 28.445(7) �, and Z 8. Automatic diffractometry has provided significant Bragg intensities for 2078 independent reflections, and the structure has been refined by full-matrix least-squares methods to R 0.078. The crystal lattice is disordered across a non-crystallographic mirror plane, the degree of disorder being 4.0(2)% for the crystal described above, and 21.9(7)% for another crystal initially used to obtain an intensity data set. There are two independent molecules of [Tc(S2CNEt2)2Cl2(NS)] in the asymmetric unit, and in each the technetium atom is seven-coordinate with a pentagonal-bipyramidal coordination environment. The Tc=N=S bonding is linear with Tc=N c. 1.75 and N=S c. 1.52 �, which indicates that the thionitrosyl group is a three-electron donor with a formal positive charge. This is only the third crystal structure of a complex containing the thionitrosyl group to be determined, and the first for technetium.

Sign in / Sign up

Export Citation Format

Share Document