Reactions of (η5-C9H7)Rh(η2-C2H4)2 with quinones: molecular structure of [(η5-C9H7)Rh(2,3,5,6-C6O2(CH3)4)]

1999 ◽  
Vol 77 (2) ◽  
pp. 199-204
Author(s):  
Stephen A Westcott ◽  
Nicholas J Taylor ◽  
Todd B Marder
Keyword(s):  
Molecular Structure ◽  
Least Squares ◽  
Ground State ◽  
Slip Parameter ◽  
X Ray Diffraction ◽  
X Ray ◽  
A Value ◽  
Hinge Angle

Reactions of (η5-C9H7)Rh(η2-C2H4)2 (1) with quinones were investigated. Substitution of the labile ethylene ligands was observed upon addition of either duroquinone (2,3,5,6-tetramethyl-1,4-benzoquinone) or 1,4-benzoquinone to complex 1. The molecular structure of neutral (η5-C9H7)Rh(2,3,5,6-C6O2(CH3)4) (3), determined by X-ray diffraction, shows that the duroquinone ligand lies in a plane nearly parallel to the indenyl group. The carbonyl moieties of duroquinone lie in a plane incorporating Rh, C2, and the midpoint between C3a and C7a of the indenyl ring. The slip parameter (Δ= d(average Rh-C3a,7a) -d(average Rh-C1,3)) was calculated to be 0.112(2) Å; whereas a value of ca. 0.05 Å had been obtained previously from film data. Values for the hinge angle (HA = angle between normals to the least-squares planes defined by C1, C2, C3 and C1, C7a, C3a, C3) and fold angle (FA = angle between normals to the least-squares planes defined by C1, C2, C3 and C3a, C4, C5, C7, C7a) are 7.2° and 4.0°, respectively.Key words: indenyl, rhodium, quinones, ring-slippage, ground-state distortion.

The crystal structure of dibutyl-bis(pentamethylenedithiocarbamato)tin(IV)

1986 ◽  
Vol 51 (11) ◽  
pp. 2521-2527 ◽  
Author(s):  
Jan Lokaj ◽  
Eleonóra Kellö ◽  
Viktor Kettmann ◽  
Viktor Vrábel ◽  
Vladimír Rattay
Keyword(s):  
Molecular Structure ◽  
Crystal Structure ◽  
Least Squares ◽  
Coordination Polyhedron ◽  
Crystal And Molecular Structure ◽  
Distorted Octahedron ◽  
Monoclinic Space Group ◽  
X Ray Diffraction ◽  
Space Group ◽  
X Ray

The crystal and molecular structure of SnBu2(pmdtc)2 has been solved by X-ray diffraction methods and refined by a block-diagonal least-squares procedure to R = 0.083 for 895 observed reflections. Monoclinic, space group C2, a = 19.893(6), b = 7.773(8), c = 12.947(8) . 10-10 m, β = 129.07(5)°, Z = 2, C20H38N2S4Sn. Measured and calculated densities are Dm = 1.38(2), Dc = 1.36 Mg m-3. Sn atom, placed on the twofold axes, is coordinated with four S atoms in the distances Sn-S 2.966(6) and 2.476(3) . 10-10 m. Coordination polyhedron is a strongly distorted octahedron. Ligand S2CN is planar.

scholarly journals The reaction of 3,5-diphenyl-1,2-dithiolium-4-olate with aniline: the crystal structure of 1-phenylimino-2-phenylamino-3-phenylindene

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
Keyword(s):  
Molecular Structure ◽  
Crystal Structure ◽  
Single Crystal ◽  
Least Squares ◽  
Direct Methods ◽  
Monoclinic Space Group ◽  
X Ray Diffraction ◽  
X Ray ◽  
Cell Dimensions ◽  
Unit Cell Dimensions

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.

Crystal and Molecular Structure of Dithiocyanato(triphenylarsine)mercury(II)

1975 ◽  
Vol 53 (22) ◽  
pp. 3383-3387 ◽  
Author(s):  
Joseph Hubert ◽  
André L. Beauchamp ◽  
Roland Rivest
Keyword(s):  
Molecular Structure ◽  
Least Squares ◽  
Coordination Number ◽  
Diffraction Data ◽  
Crystal And Molecular Structure ◽  
Heavy Atom ◽  
Monoclinic Space Group ◽  
X Ray Diffraction ◽  
X Ray ◽  
Heavy Atom Method

The crystal and molecular structure of dithiocyanato(triphenylarsine)mercury(II) has been determined from X-ray diffraction data. The crystals are monoclinic, space group P21/c, with a = 10.290(7), b = 21.199(23), c = 10.719(7) Å, β = 112.00(2)°, and Z = 4. The structure has been solved by the heavy-atom method and refined by block-diagonal least-squares calculations. The agreement factor R obtained for 2607 'observed' reflections is 0.030. The crystal consists of single molecules. The 'characteristic' coordination number of mercury is three, with two sulfur and one arsenic atoms at the apexes of a triangle. The nitrogen atoms of the thiocyanate groups are at 2.67 and 2.74 Å from the adjoining mercury atoms and therefore link the different molecules together.

The crystal and molecular structure of a platinum-silatrane complex

1977 ◽  
Vol 30 (5) ◽  
pp. 1007 ◽  
Author(s):  
GR Scollary
Keyword(s):  
Molecular Structure ◽  
Structural Analysis ◽  
Least Squares ◽  
Crystal And Molecular Structure ◽  
Monoclinic Space Group ◽  
X Ray Diffraction ◽  
Full Matrix ◽  
Space Group ◽  
X Ray

A structural analysis of the platinum-silatrane complex, PtCl [Si(OCH2CH2)3N] [PMe2Ph]2, has been carried out by X-ray diffraction. Crystals are monoclinic, space group P21/c, a 6.630(4), b 17.465(6), c 22.297(6) Ǻ, β 97.4(2)�, Z 4. The structure has been refined by a full- matrix least-squares procedure to R 0.048 for 2165 reflections. Basic geometries are square (platinum), tetrahedral (silicon) and trigonal (nitrogen). Within the silatrane ligand, the Si-N non-bonding distance is 2.89(1) Ǻ.

scholarly journals Approaches to the synthesis of triterpenoids. IV. The ABC + E ring approach to the pentacyclic triterpene skeleton. Synthesis of a pentacyclic compound suitable for triterpene synthesis

1978 ◽  
Vol 56 (16) ◽  
pp. 2139-2149 ◽  
Author(s):  
John W. Apsimon ◽  
Satyanand Badripersaud ◽  
John W. Hooper ◽  
Richard Pike ◽  
George I. Birnbaum ◽  
...  
Keyword(s):  
Molecular Structure ◽  
Least Squares ◽  
Direct Methods ◽  
Unit Cell ◽  
Monoclinic Space Group ◽  
X Ray Diffraction ◽  
Pentacyclic Triterpene ◽  
X Ray ◽  
R Value ◽  
Triterpene Synthesis

Studies on the ABC + E ring construction of the pentacyclic triterpene skeleton are described. Acid-catalysed cyclisation of the mixture of diastereoisomers 11 led to preferential cyclisation of one isomer to 10-methoxy-2,2,4aβ,6aβ, 12bβ -pentamethyl-1,2,3,4,4a,5,6,6a, 6bα,7,8,12b,13,14-tetradecahydro-1-picenone (12). An X-ray analysis was performed on this compound which crystallizes in the monoclinic space group P2/c. There are four molecules in the unit cell which has dimensions a = 6.456(2), b = 42.518(6), c = 8.519(2) Å, β = 100.92(3)°. The structure was solved by direct methods and refined by block-diagonal least-squares to a final R value of 0.042 for all 3234 observed reflections. The molecular structure found by X-ray diffraction confirms the stereochemical reasoning used in the synthetic steps.

scholarly journals Synthesis, Crystal Structure and DFT Studies of 4-(2-(4,5-Dimethyl-2-(3,4,5-trimethoxyphenyl)-1H-imidazol-1-yl)ethyl)morpholine

2021 ◽  
Vol 33 (3) ◽  
pp. 611-616
Author(s):  
A. Prabhakaran ◽  
M. Arockia Doss ◽  
E. Dhineshkumar ◽  
R. Rajkumar
Keyword(s):  
Molecular Structure ◽  
Crystal Structure ◽  
Ground State ◽  
Molecular Electrostatic Potential ◽  
Molecular Geometry ◽  
Dft Studies ◽  
X Ray Diffraction ◽  
Frontier Orbitals ◽  
One Pot ◽  
X Ray

The title compound 4-(2-(4,5-dimethyl-2-(3,4,5-trimethoxyphenyl)-1H-imidazol-1-yl)morpholine (DMTPM) was synthesized using a one-pot multicomponent approach. The molecular structure of the compound was charcterized with 1H & 13C NMR, HR-MS and single-crystal X-ray diffraction. In the ground-state, DMTPM molecular geometry was determined using the DFT based on B3LYP/6-31G(d,p) and compared to the experimental results. In addition, molecular electrostatic potential (MEP) map and molecular frontier orbitals (MFO) were performed and the results obtained were compatible with the electronic properties.

Crystal and molecular structure of Octacarbonylbis(diphenylarsino)-methanedimanganese(0)

1983 ◽  
Vol 36 (4) ◽  
pp. 683 ◽  
Author(s):  
BF Hoskins ◽  
RJ Steen
Keyword(s):  
Molecular Structure ◽  
Crystal Structure ◽  
Least Squares ◽  
Crystal And Molecular Structure ◽  
Parent Compound ◽  
Three Dimensional ◽  
X Ray Diffraction ◽  
Triclinic Space Group ◽  
Fourier Methods ◽  
X Ray

The crystal structure of the complex Mn2(CO)8(dam) (dam = Ph2AsCH2AsPh2) has been determined by three-dimensional X-ray diffraction methods. The crystals are triclinic, space group P1, with a 11.191(1), b 16.498(5), c 9.455(1) �, a 93.64(2), β 109.08(2), γ 89.36(2)� and contain two discrete, binuclear molecules of Mn2(CO)8(dam) per unit cell. The structure, solved by direct and Fourier methods, was refined by a least-squares procedure to R and Rw of 0.065 and 0.082 respectively for 1907 independent, statistically significant reflections collected by counter methods. The feature of particular interest in this compound is the accommodation of the bridging bidentate dam ligand [As.. .As separation 3.242(2) �] across a shorter Mn�-Mn� bond [2.962(3) �] which constrains the molecule so that a much less staggered configuration of the two manganese coordination octahedra is observed relative to the parent compound Mn2(CO)10, the rotation of the two equatorial planes in the former being 30�.

Studies of β-Diketone Complexes of Rhenium. VI. The Crystal and Molecular Structure of cis-Dichloropentane-2,4-dionato-trans-bis(triphenylphosphine)rhenium(III)

1974 ◽  
Vol 52 (9) ◽  
pp. 1704-1708 ◽  
Author(s):  
I. D. Brown ◽  
C. J. L. Lock ◽  
Che'ng Wan
Keyword(s):  
Molecular Structure ◽  
Single Crystal ◽  
Least Squares ◽  
Crystal And Molecular Structure ◽  
Unit Cell ◽  
X Ray Diffraction ◽  
Rhenium Atom ◽  
Full Matrix ◽  
X Ray ◽  
Nearest Neighbours

A compound, obtained in large yields from the reaction of acetylacetone and oxodichloroethoxobis(triphenylphosphine)rhenium(V) in benzene, has been shown by single crystal X-ray diffraction to be cis-dichloropentane-2,4-dionato-trans-bis(triphenylphosphine)rhenium(III). The crystals are monoclinic with a = 13.06(1), b = 18.30(1), c = 16.55(1) Å, and β = 112.7(2)°. The space group is P21/c and there are four molecules per unit cell. A total of 3841 independent reflections, of which 2686 were observed, were examined by film methods, the intensities being measured with a microdensitometer. The structure was refined by full matrix least-squares analysis to an R2 value of 0.068. The ligands are arranged around the rhenium atom in the manner described by the compound name to give a rough octahedron of nearest neighbours and the Re—Cl (2.369 Å av.), Re—O (2.02 Å av.), and Re—P (2.474 Å av.) distances are as expected.

A structural, solvent exchange and spin equilibrium study of (N,N-dimethylformamide)(R,S,R,S)-(1,4,8,11-tetramethyl-l,4,8,11- tetraazacyclotetradecane)nickel(II)

1984 ◽  
Vol 37 (4) ◽  
pp. 713 ◽  
Author(s):  
SF Lincoln ◽  
TW Hambley ◽  
DL Pisaniello ◽  
JH Coates
Keyword(s):  
Molecular Structure ◽  
Solid State ◽  
Least Squares ◽  
Methyl Groups ◽  
Solvent Exchange ◽  
X Ray Diffraction ◽  
X Ray ◽  
Equilibrium Study ◽  
Trigonal Bipyramidal ◽  
Spin Species

The molecular structure of R,S,R,S-[Ni {(-N(Me)(CH2)2N(Me)(CH2)3-)2} (OCHNMe2)](SO3CF3)2 has been determined in the solid state by X-ray diffraction methods. The geometry about nickel(11) is midway between square based pyramidal and trigonal bipyramidal with OCHNMe2 occupying the axial or an equatorial site in these geometries respectively. The nickel(II) is displaced 0.29 � from the least-squares tetraaza plane on the same side as the four methyl groups and OCHNMe2. In OCHNMe2 solution the formation of this five-coordinate high-spin species by coordination of OCHNMe2 by its four-coordinate low-spin precursor is characterized by K(298.2 K) = 10 � 2, ∆H = -12.8 � 2.7 kJ mol-1 and ∆S = -24.1 � 9.O JK-l mol-1 as determined by spectrophotometry. 1H (300 MHz) n.m.r. studies show that kwx(298.2 K) = (1.6 � 0.2) × 107 s-1, ∆H‡ = 27.8 � 0.4 kJ mol-1 and ∆S‡ = -13.O � 2.0 JK-1 mol-1 characterize the exchange of OCHNMe2 on R,S,R,S-[Ni {(-N(Me)(CH2)2N(Me)(CH2)3-)2 }(OCHNMe2)]2+.

The crystal and molecular structure of (±)-('E')-N-Acetylpiperidine-2-carboxylic acid

1980 ◽  
Vol 33 (1) ◽  
pp. 215 ◽  
Author(s):  
ID Rae ◽  
CL Raston ◽  
AH White
Keyword(s):  
Molecular Structure ◽  
Crystal Structure ◽  
Carboxylic Acid ◽  
Single Crystal ◽  
Least Squares ◽  
Crystal And Molecular Structure ◽  
X Ray Diffraction ◽  
Space Group ◽  
X Ray

The crystal structure of N-acetylpiperidine-2-carboxylic acid has been determined by single-crystal X-ray diffraction methods at 295(1) K and refined by least squares to a residual of 0.039 for 846 'observed' reflections. Crystals are orthorhombic, with space group Pbca, a 13.684(6), b 11.602(4), c 11.171(4)Ǻ, Z 8. The ring is a chair structure in which, contrary to an earlier proposal based on 1H n.m.r. studies, there is almost perfect staggering about the C(2)-C(3) bond.

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