The preparation, characterization, and crystal and molecular structure of oxobis(ethan-1,2-dithiolato-S,µS′)technetium(V)oxo(ethan- 1,2-dithiolato-S,S′)technetium(V) [(TcO)2(SCH2CH2S)3]. A Tc(V) compound containing metal—sulfur—metal bridges

1985 ◽  
Vol 63 (2) ◽  
pp. 319-323 ◽  
Author(s):  
A. Davison ◽  
B. V. DePamphilis ◽  
R. Faggiani ◽  
A. G. Jones ◽  
C. J. L. Lock ◽  
...  

As a result of an investigation undertaken to evaluate the acetamidomethyl group (—CH2NHCOCH3) as a water-solubilizing protecting group for thiolate ligands, a new type of oxotechnetium(V) complex was prepared. The compound oxobis(ethan-1,2-dithiolato-S,µS′)technetium(V)oxo(ethan-1,2-dithiolato-S,S′)technetium(V), [(TcO)2(SCH2CH2S)3], 1, was synthesized by the reaction of [TcOCl4]− with either an excess of bis(acetamidomethyl)ethanedithiol or 1.5 equiv. of ethanedithiol. The complex was characterized by field desorption mass spectrometry (m/e = 505(8), 507(2.8)) and its structure determined by single crystal X-ray diffraction. 1 has a monoclinic space group P21/c with cell dimensions a = 8.833(2) Å, b = 15,034(3) Å, c = 11.350(2) Å, and β = 108.17(1)°, and has four formula units in the unit cell. Data were collected with the use of MoKα radiation and a Nicolet P3 diffractometer. The crystal structure was determined by standard methods and refined to R1 = 0.0366 and R2 = 0.0455 on the basis of 3312 independent reflections. The compound contains two technetium atoms. Two sulphur atoms of one square pyramidal TcOS4 core are bonded to another TcOS2 unit forming two square pyramids sharing an edge with an angle of 106.0(1) between the basal planes. TheTc—Tc distance is 3.654(1) Å. There are four distinct types of Tc—S bonds (range 2.256(2)—2.418(2) Å) and the Tc—O distances (1.66 Å) are normal.

1977 ◽  
Vol 55 (1) ◽  
pp. 111-114 ◽  
Author(s):  
Lillian Y. Y. Chan ◽  
E. E. Isaacs ◽  
W. A. G. Graham

Reaction of [n-Bu4N]2[Re4(CO)16] with AgBF4 in acetonitrile affords the compound [(CH3CN)3Re(CO)3][BF4]. The latter crystallizes in monoclinic space group P21/c with unit cell dimensions a = 11.021(5) Å, b = 11.136(5) Å, c = 12.980(6) Å, β = 96.906(25)°, and four molecules per unit cell. Data were collected by counter methods and the structure was refined using least-squares procedures to give R = 0.041. The rhenium cation is approximately octahedrally coordinated by six facially arranged ligands. The mean rhenium–nitrogen distance is 2.13 Å, and the mean rhenium–nitrogen–carbon angle in the coordinated acetonitrile is 174.7°.


1987 ◽  
Vol 65 (2) ◽  
pp. 261-270 ◽  
Author(s):  
R. A. Bell ◽  
B. E. Brown ◽  
M. Duarte ◽  
H. E. Howard-Lock ◽  
C. J. L. Lock

1,1,3,3-Tetracyanopropane, 1, was prepared in low yields by a literature method with 2,2,4,4,6-pentacyanocyclohexenamine, 2, as a major by-product. The products were examined by X-ray crystallography. 1 has an orthorhombic space group, Pbcn (No. 60) with cell dimensions, a = 7.158(2), b = 10.510(3), c = 9.733(2) Å and has four formula units in the unit cell. 2 has a monoclinic cell, P21/c (No. 14) with cell dimensions a = 14.368(3), b = 6.626(1), c = 12.300(2) Å, β = 115.60(1)° and has 4 formula units in the unit cell. Data were collected with use of MoKα radiation and a Nicolet P3 diffractometer. The crystal structures were determined by standard methods and refined to Rw = 0.037 (1) and Rw = 0.040 (2) on the basis of 782 and 2108 unique reflections. Bond lengths and angles in the two compounds are normal. 2 has what has been considered to be the less likely tautomeric structure. Both compounds were examined by 1H, 13C nmr, vibrational spectroscopy, and mass spectroscopy. For 2 there was no evidence of the alternative tautomeric structure. New methods were developed for the preparation of both compounds and the mechanism of the original reaction rationalized.


1994 ◽  
Vol 49 (6) ◽  
pp. 812-820 ◽  
Author(s):  
Mohsen Safarpour Haghighi ◽  
Andreas Franken ◽  
Heiner Homborg

Of the isostructural series of monoclinic (PNP)[Ln(Pc)2]• xH2O compounds (Ln = La ••• Tm) the crystal structures of the complex salts of tervalent La (1), Gd (2) and Tm (3) have been determined by single crystal X-ray diffraction analysis. Unit cell data for 2: space group P21/c; a = 15.172(8), b = 20.826(2), c = 25.876(3) Å, β = 95.19(3)°, V - 8143(4) Å3, Z = 4; 1 and 3 are isostructural with 2. The lanthanide ion occupies the center of a nearly ideal square antiprism, although the two staggered phthalocyanine rings are severely distorted in an unsymmetrical funnel-shaped fashion due to electronic, steric, and packing influences in the crystal lattice. Steric effects dictate also the geometry of the PNP cation, which adopts a hybrid conformation whose structural characteristics are between the common linear and bent conformers with medium short P-N distances (1.562 Å) and large P-N-P angles in the range 165.6° (1) > 158.3° (2) > 156.1° (3). The strong IR bands at ca. 1375 cm-1 assigned to the asym. (P-N) stretch are diagnostic for this hybrid conformation. The presence of water of crystallization in the periphery of the diphthalocyanine anion is confirmed. The shortest contact distance is observed to one of the bridging nitrogen atoms of the Pc2- ligand (3.02 Å) indicating a weak (HO-H•••N) hydrogen bond


1987 ◽  
Vol 65 (12) ◽  
pp. 2830-2833 ◽  
Author(s):  
David M. McKinnon ◽  
Peter D. Clark ◽  
Robert O. Martin ◽  
Louis T. J. Delbaere ◽  
J. Wilson Quail

3,5-Diphenyl-1,2-dithiolium-4-olate (1) reacts with aniline to form 1-phenylimino-2-phenylamino-3-phenylindene (3a). Under suitable conditions, 6-phenylbenzo[b]indeno[1,2-e]-1,2-thiazine is also formed. These structures are confirmed by alternative syntheses. The molecular structure of 3a has been determined by single crystal X-ray diffraction. Compound 3a crystallizes in the monoclinic space group C2/c with unit cell dimensions a = 20.777(3) Å, b = 6.130(3) Å, c = 31.327(3) Å, 3 = 99.59(1)°, and Z = 8. The structure was solved by direct methods and refined by least squares to a final R = 0.055. The molecular structure of 3a shows the three phenyl containing substituents to have the planes of their ring systems tilted between 40° and 60° from the plane of the indene system due to steric repulsions.


1998 ◽  
Vol 547 ◽  
Author(s):  
Brenda R. Cabrera ◽  
Ru-Ji Wang ◽  
Jing Li ◽  
Tan Yuen

AbstractGrowth of [(C10H8N2)2CuBr]Cu3Br4(I) crystals was achieved using the hydrothermal synthesis. Single crystal X-ray diffraction analysis shows that this compound crystallizes in monoclinic system, space group P21/c (no. 14) with four formula units in the unit cell. The cell dimensions are the following: a = 16.769(2) Å, b = 23.873(6) Å, c = 6.523(2) Å, β = 98.37(3)°, V = 2584(1) Å3. The title compound represents a new structure type. It consists of one-dimensional ribbons of 1[(Cu3Br4)] extending along the c-axis and discrete [(C10H8N2)2CuBr]+ complexes. The magnetic susceptibility study indicates a paramagnetic behavior due to the Cu(II) in the complex cations. The effective paramagnetic moment was calculated to be 2.20 μB from fitting the χ(T) data.


1987 ◽  
Vol 40 (6) ◽  
pp. 1131 ◽  
Author(s):  
CHL Kennard ◽  
G Smith ◽  
T Hari

The crystal structure of the herbicide acifluorfen (5-[(2-chloro-4-trifluoromethyl)]phenoxy-2- nitrobenzoic acid] has been determined by X-ray diffraction and refined to a residual of 0.051for 1124 observed reflections. Crystals are monoclinic, space group C2/c with cell dimensions a 26.848(7), b 8 .O29(2), c 19 .Ol4(6) �, ,R l34.72(2)� and Z 8. The molecules form centrosymmetric hydrogen-bonded cyclic dimers [O---0, 2.637(7) �] with the carboxylic acid group and the phenoxy group synclinally related to the first phenyl ring while the nitro substituent isessentially coplanar with the ring.


1986 ◽  
Vol 39 (7) ◽  
pp. 1081 ◽  
Author(s):  
AA Diamantis ◽  
JM Frederiksen ◽  
MA Salam ◽  
MR Snow ◽  
ERT Tiekink

The crystal structures of two vanadium(v) complexes, VOL(OCH2CH3)(1) and (VOL)2O (2), where L is the dinegative , tridentate ligand 4- phenylbutane-2,4-dione benzoylhydrazonato (2-), were determined by X-ray diffraction methods. Crystals of (1) are monoclinic, space group P21/n, a 11.064(4), b 7.565(1), c 21.786(5) Ǻ and β 95.93(2)° and Z 4; those of (2) are also monoclinic, C2/ c, with unit cell dimensions a 18.287(3), b 14.991(2), c 11.643(2)Ǻ, β 92.85(2)° for Z 4. The structures were refined by full-matrix least-squares methods to final R 0.036 for 1801 reflections with I ≥ 2.5σ(I) for (1), and R 0.061 for 1272 reflections with I ≥ 2.5σ(I) for (2). The coordination environment of the vanadium atom in both structures is a tetragonal pyramid with the oxo ligand occupying the apical positon.


1992 ◽  
Vol 70 (3) ◽  
pp. 792-801 ◽  
Author(s):  
Jagadese J. Vittal ◽  
Philip A. W. Dean ◽  
Nicholas C. Payne

The structures of three tetramethylammonium salts containing anions of formula [(μ-SePh)6(MSePh)4]2− (M = Zn and Cd) were determined by single crystal X-ray diffraction techniques. The Zn salt crystallizes in different space groups depending upon the solvent combination used in the synthesis. Thus crystals of (Me4N)2[Zn4(SePh)10], 1, grown from a mixture of methanol, acetonitrile, and acetone are triclinic, space group [Formula: see text] with cell dimensions a = 13.214(2), b = 23.859(2), c = 13.072(1) Å, α = 91.134(8), β = 113.350(8), γ = 79.865(9)°, and Z = 2. In the absence of acetone, a solvated crystal (Me4N)2[Zn4(SePh)10]•CH3CN, 2, is formed, which belongs to the monoclinic space group P21/n with a = 14.248(1), b = 39.722(2), c = 13.408(1) Å, β = 97.132(5)°, and Z = 4. The Cd salt (Me4N)2[Cd4(SePh)10], 3, crystallizes in the monoclinic space group P21/c, with a = 20.830(2), b = 14.282(1), c = 25.872(1) Å, β = 99.626(6)°, and Z = 4. These three salts are the first examples of homoleptic, tetranuclear selenolatometal(II) anions with (μ-Se)6M4 cages of adamantane-type stereochemistry. In each case the phenyl substituents of the bridging ligands adopt the configuration [aae, aae, aee, aee], which has the minimum number of two 1,3-axial–axial non-bonding substituent interactions. Keywords: selenolate complexes, synthesis, X-ray crystallography, isomerism, adamantane stereochemistry.


1987 ◽  
Vol 65 (7) ◽  
pp. 1568-1575 ◽  
Author(s):  
R. Faggiani ◽  
H. E. Howard-Lock ◽  
C. J. L. Lock ◽  
M. A. Turner

1-Methylthyminato-N3-triphenylphosphinegold(I) was prepared by reacting chloro(triphenylphosphine)gold(I) with 1-methylthymine in aqueous methanol at pH 11. The product was examined by X-ray crystallography and was found to have the orthorhombic space group C2221 (no. 20) with cell dimensions a = 12.760(7) Å, b = 11.530(2) Å, c = 31.893(5) Å, and eight formula units in the unit cell. Data were collected with use of MoKα radiation and a Syntex P21, diffractometer. The crystal structure was determined by standard methods and refined to R = 0.112 and Rw = 0.076 on the basis of 4760 unique reflections. Bond lengths and bond angles are normal. Packing in the crystal lattice is dominated by the triphenylphosphine rings which arrange roughly as blades of a propellor and are the source of the crystal's chirality. The title and related compounds were also examined by 1H nmr, 13C nmr, and vibrational spectroscopy.


1980 ◽  
Vol 58 (10) ◽  
pp. 1042-1045 ◽  
Author(s):  
R. L. Parkes ◽  
N. C. Payne ◽  
E. O. Sherman

An air-stable, red, crystalline, N-bonded acetonitrile complex of Os(III), OsCl3(NCCH3)(P(C6H5)3)2, has been prepared and characterized by elemental analysis, magnetic susceptibility, and a single crystal X-ray structure determination. Crystals are monoclinic, space group P21/c, cell dimensions a = 10.029(2), b = 15.233(2), c = 25.246(4) Å, β = 113.65(1)°, and Z = 4. Three dimensional X-ray diffraction intensity data were collected on an automatic four circle diffractometer using Cu radiation. Full-matrix least-squares refinement on F converged at R = 0.038 for 4384 unique observations. The Os atom has a slightly distorted octahedral coordination geometry, with trans phosphine ligands, mean Os—P 2.406(2) Å. The acetonitrile ligand is σ-bonded through the N atom, Os—N 2.038(6) Å. The bond trans to the acetonitrile ligand. Os—Cl(1) 2.364(2) Å, is not significantly different from the mean of the cisOs—Cl bonds, 2.361(2) Å.


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