ChemInform Abstract: Binuclear Copper(I) Complexes Containing Two or Three 2-(Diphenylphosphine)pyridine (dppy) Bridging Ligands: X-Ray Crystal Structure of (Cu2(μ-dppy)3(MeCN))(BF4)2 and Variable-Temperature 1H and 31P-(1H) NMR Studies.

ChemInform ◽  
1989 ◽  
Vol 20 (47) ◽  
Author(s):  
E. LASTRA ◽  
M. P. GAMASA ◽  
J. GIMENO ◽  
M. LANFRANCHI ◽  
A. TIRIPICCHIO
Keyword(s):  
Crystal Structure ◽  
1H Nmr ◽  
Variable Temperature ◽  
Binuclear Copper ◽  
Nmr Studies ◽  
Bridging Ligands ◽  
X Ray

Binuclear copper(I) complexes containing bis(diphenylphosphino)methane bridging ligands. X-ray crystal structure of [Cu2(dppm)2(Py)2(NO3)](NO3) · CH3OH

Polyhedron ◽  
1997 ◽  
Vol 16 (23) ◽  
pp. 4033-4038 ◽  
Author(s):  
Yang Ruina ◽  
Lin Kunhua ◽  
Hou Yimin ◽  
Wang Dongmei ◽  
Jin Douman
Keyword(s):  
Crystal Structure ◽  
Binuclear Copper ◽  
Bridging Ligands ◽  
X Ray

The crystal structure of cis-chlorobis(triethylphosphine)-1,8-naphthyridineplatinum(II) tetrafluoroborate, [PtCl(PEt3)2(naph)]BF4, a complex containing a monodentate 1,8-naphthyridine ligand

1978 ◽  
Vol 56 (4) ◽  
pp. 450-455 ◽  
Author(s):  
Gordon W. Bushnell ◽  
Keith R. Dixon ◽  
Masood A. Khan
Keyword(s):  
Crystal Structure ◽  
Variable Temperature ◽  
X Ray Diffraction ◽  
Nmr Studies ◽  
Interatomic Distances ◽  
X Ray ◽  
Heterocyclic Ligand ◽  
Square Planar ◽  
Cell Dimensions ◽  
R Value

The crystal structure of cis-chlorobis(triethylphosphine)-1,8-naphthyridineplatinum(II) tetrafluoroborate has been determined by single crystal X-ray diffraction and refined to an R-value of 0.063. The cell dimensions are a = 1.4246, b = 1.2676, c = 1.6530 nm, β = 115.66°. The space group is P21/c with 4 molecules per unit cell, and the measured density is 1.665 g cm−3. The structure is essentially a 4-coordinate square planar platinum(II) complex containing monodentate 1,8-naphthyridine. Interatomic distances to platinum are: Pt—Cl, 236.6(4); Pt—P(1), 225.4(4); Pt—P(2), 225.2(4); Pt—N(1), 208.3(11); and Pt—N(2), 304.5(14) pm. The structure is discussed in relation to variable temperature nmr studies of solutions, which indicate fluxional behaviour of the heterocyclic ligand.

Ferrocenyl-penta-(β-naphthyl)benzene — Synthesis, structure, and dynamic behaviour

2003 ◽  
Vol 81 (11) ◽  
pp. 1180-1186 ◽  
Author(s):  
Laura E Harrington ◽  
James F Britten ◽  
Michael J McGlinchey
Keyword(s):  
Crystal Structure ◽  
Carbon Monoxide ◽  
Low Temperature ◽  
Dynamic Behaviour ◽  
Variable Temperature ◽  
Alder Reaction ◽  
Diels Alder ◽  
Nmr Studies ◽  
X Ray ◽  
Diels Alder Reaction

3-Ferrocenyl-2,4,5-tri-(β-naphthyl)cyclopentadienone undergoes a Diels–Alder reaction with di-(β-naphthyl) acetylene to yield, after elimination of carbon monoxide, ferrocenyl-penta-(β-naphthyl)benzene (4). 1H and 13C variable-temperature NMR studies on 4 reveal the existence of multiple diastereoisomers at low temperature. These data are interpreted in terms of slowed rotation of the naphthyl groups, and are supported by the X-ray crystal structure of 4, which exhibits disorder at three of the naphthyl sites.Key words: sterically crowded molecules, hindered rotations, crystallography, NMR.

Reversible Heterolytic Si–H Bond Activation by an Intramolecular Frustrated Lewis Pair

2012 ◽  
Vol 67 (10) ◽  
pp. 987-994 ◽  
Author(s):  
Wanli Nie ◽  
Hendrik F. T. Klare ◽  
Martin Oestreich ◽  
Roland Fröhlich ◽  
Gerald Kehr ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Low Temperature ◽  
Ambient Temperature ◽  
Bond Activation ◽  
Variable Temperature ◽  
Crystal Structure Analysis ◽  
Nmr Studies ◽  
X Ray ◽  
Predominant Species ◽  
Frustrated Lewis Pair

The intramolecular frustrated P/B Lewis pair Mes2PCH2CH2B(C6F5)2 (7) reacts readily with phenylsilane by heterolytic cleavage of the Si-H bond to give the zwitterion [Mes2(PhH2Si)P+CH2CH2B-H(C6F5)2] (8a), which has been fully characterized and its structure confirmed by X-ray crystal structure analysis. Variable-temperature NMR studies revealed that the reaction is reversible. Adduct 8a is the predominant species (ca. 98%) in CD2Cl2 solution at low temperature (193 K), whereas at ambient temperature (299 K) it exists in a ca. 7 : 3 equilibrium with unreacted 7 and PhSiH3. Diphenylsilane reacted similarly with the frustrated Lewis pair 7, however, the equilibrium was found to favor the starting materials in the investigated temperature range.

Synthesis, characterization, and fluxional behavior in solution of the salts Et4N+[Me2Ga(N2C5H7)(OCH2CH2X)]M(CO)3− (where N2C5H7 = 3,5-dimethylpyrazolyl, X = NMe2 or SEt, and M = Cr, Mo, or W). X-Ray crystal structure of the W complex with X = NMe2

1990 ◽  
Vol 68 (1) ◽  
pp. 109-114 ◽  
Author(s):  
Kenneth S. Chong ◽  
Steven J. Rettig ◽  
Alan Storr ◽  
James Trotter
Keyword(s):  
Crystal Structure ◽  
Variable Temperature ◽  
Heavy Atom ◽  
Carbonyl Groups ◽  
Nmr Studies ◽  
X Ray ◽  
H Nmr ◽  
Allyl Complex ◽  
Tungsten Complexes ◽  
Infrared Studies

The tricarbonyl anions of Cr, Mo, and W incorporating unsymmetrical tridentate chelating pyrazolyl gallate ligands, [Me2Ga(N2C5H7)(OCH2CH2X)]M(CO)3−, have been isolated as their crystalline Et4N+ salts. 1H nmr and solution infrared studies indicate that the octahedral anions display a facial arrangement of the gallate ligand and the three carbonyl groups. This stereochemistry has been proven definitively for the tungsten complex with X = NMe2 by an X-ray structure determination (see below). Fluxional behavior for the anions in d6-acetone solution has been demonstrated by variable temperature 1H nmr studies and is compared to similar behavior displayed by the neutral molybdenum "allyl" complex, [Me2Ga(N2C3H3)(OCH2CH2NMe2)]Mo(CO)2(η3-C4H7). Crystals of tetraethylammonium [dimethyl(3,5-dimethylpyrazol-1-yl)(2-N,N-dimethylaminoethoxy)gallato-N2,N3,O]tricarbonyltungstate are orthorhombic, a = 11.312(9), b = 33.111(9), c = 7.445(6) Å, Z = 4, space group P212121. The structure was solved by conventional heavy atom methods and was refined by full-matrix least-squares procedures to R = 0.033 and Rw = 0.034 for 2508 reflections with I ≥ 3σ(I). The [Me2Ga(N2C5H7)(OCH2CH2NMe2)]W(CO)3− anion has fac-octahedral coordination geometry with W—O = 2.228(7), W—N(pyrazolyl) = 2.299(8), W—N(amine) = 2.37(1), and W—CO = 1.91 (1)–1.92(1) Å. Keywords: pyrazolyl-gallate complexes, fluxional behavior of Ga–W complexes, crystal structure of Ga–W complex, gallate–tungsten complexes.

scholarly journals Powder study of 3-azabicyclo[3.3.1]nonane-2,4-dione form 2

2006 ◽  
Vol 62 (7) ◽  
pp. o3046-o3048 ◽  
Author(s):  
Ashley T Hulme ◽  
Philippe Fernandes ◽  
Alastair Florence ◽  
Andrea Johnston ◽  
Kenneth Shankland
Keyword(s):  
Crystal Structure ◽  
Simulated Annealing ◽  
Hydrogen Bonds ◽  
Powder Diffraction ◽  
Title Compound ◽  
Variable Temperature ◽  
Polycrystalline Sample ◽  
Asymmetric Unit ◽  
X Ray ◽  
Compound C

A polycrystalline sample of a new polymorph of the title compound, C8H11NO2, was produced during a variable-temperature X-ray powder diffraction study. The crystal structure was solved at 1.67 Å resolution by simulated annealing from laboratory powder data collected at 250 K. Subsequent Rietveld refinement yielded an R wp of 0.070 to 1.54 Å resolution. The structure contains two molecules in the asymmetric unit, which form a C 2 2(8) chain motif via N—H...O hydrogen bonds.

Crystal structure of trans-[W(CO)4(η2-C2H4)2] and IR and 1H NMR studies of the reactions of this and related ethene carbonyl complexes of tungsten(0), [W(CO)n(η2-C2H4)6- n] ( n=3–5)

1999 ◽  
Vol 23 (4) ◽  
pp. 407-416 ◽  
Author(s):  
Teresa Szymańska-Buzar ◽  
Krystyna Kern ◽  
Anthony J. Downs ◽  
Timothy M. Greene ◽  
Leigh J. Morris ◽  
...  
Keyword(s):  
Crystal Structure ◽  
1H Nmr ◽  
Carbonyl Complexes ◽  
Nmr Studies
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