N-Methyldiethanolamine-Modified Titanium Isopropoxide: X-Ray Crystal Structure of [Ti2(μ2-(OCH2CH2)2NCH3)(μ2-OPri)(OPri)5]

2002 ◽  
Vol 55 (8) ◽  
pp. 513 ◽  
Author(s):  
T. Kemmitt ◽  
N. I. Al-Salim ◽  
G. J. Gainsford
Keyword(s):  
Solid State ◽  
Variable Temperature ◽  
Titanium Isopropoxide ◽  
State Structure ◽  
X Ray ◽  
Coordination Numbers ◽  
X Ray Crystallography ◽  
Exchange Processes ◽  
Amine Function ◽  
Ligands Exchange

A highly fluxional dititanium N-methyldiethoxoamine hexaisopropoxide complex was isolated from reactions of N-methyldiethanolamine with Ti(OPri)4. X-ray crystallography identified the solid state compound as the unsymmetrical complex Ti2(μ2-(OCH2CH2)2NCH3)(μ2-OPri)(OPri)5. In solution, the time-averaged structure was shown by NMR to be symmetrical. The amine function coordinates to both titanium atoms alternately, while the isopropoxide ligands exchange to maintain equal coordination numbers on both titaniums. Variable temperature NMR demonstrates that the exchange processes slow on cooling, and a spectrum consistent with the solid-state structure is apparent at –50�C.

Structural diversity in thallium chemistry: structures of four chlorothallate(III) salts including a novel compound containing three geometrically different anions

1996 ◽  
Vol 74 (8) ◽  
pp. 1490-1502 ◽  
Author(s):  
Margaret Ann James ◽  
Jason A.C. Clyburne ◽  
Anthony Linden ◽  
Bruce D. James ◽  
John Liesegang ◽  
...  
Keyword(s):  
Hydrogen Bonding ◽  
Solid State ◽  
Structural Diversity ◽  
State Structure ◽  
X Ray ◽  
Coordination Numbers ◽  
X Ray Crystallography ◽  
Hydrogen Bonding Networks ◽  
Alkyl Ammonium ◽  
High Coordination

Four new thallium-containing salts with different alkyl ammonium cations have been prepared and characterized by X-ray crystallography: 1: bis(p-toluidinium) pentachlorothallate(III), [CH3C6H4NH3]2 [TlCl5], M = 597.9, monoclinic, P21/c, a = 7.515(2), b = 21.376(6), c = 12.769(2) Å, β = 92.13(2)°, V = 2050(1) Å3, Z = 4, Dcalc = 1.937 Mg m−3, µ = 8.512 mm−1, T = 293(1) K, R = 0.046; 2: 1,5-pentanediammonium pentachlorothallate(III), [NH3(CH2)5NH3] [TlCl5], M = 485.83, orthorhombic, P212121, a = 13.226(2), b = 13.595(2), c = 7.628(2) Å, V = 1371.6(3) Å3, Z = 4, Dcalc = 2.352 Mg m−3, µ = 12.84 mm−1, T = 173(1) K, R = 0.025; 3: pentakis(2-adamantaneammoniumn) bistetrachlorothallate(III) hexachlorothallate(III), [C10H18N]5 [TlCl4]2[TlCl6], M = 1870.75, monoclinic, P21a = 16.466(5), b = 25.985(2), c = 7.724(3) Å, β = 90.14(3)°, V = 3305(2) Å3, Z = 2, Dcalc = 1.880 Mg m−3, µ = 7.978 mm−1, T = 173(1) K, R = 0.056; 4: bis(piperazinium) decachlorodithallate(III) trihydrate, [NH2C4H8NH2]2 [Tl2Cl10]•3H2O, M = 993.62, monoclinic, C2/c, a = 14.154(3), b = 15.445(3), c = 13.228(3) Å, β = 114.44(1)°, V = 2632.7(9) Å3, Z = 4, Dcalc = 2.506 Mg m−3, µ = 13.39 mm−1, T = 173(1) K, R = 0.026. For most of the salts examined, formation of [TlCl5]2− is possible; however, no isolated [TlCl5]2− anions were observed. In most cases, high coordination numbers at thallium were observed (CN = 6), and these can be achieved via formation of anionic chains or through dimerization, giving [Tl2Cl10]4−. Of particular interest is the solid state structure of salt 3 in which there are three geometrically different chlorothallate ions. Extensive hydrogen-bonding networks are observed in each structure. Key words: thallium, thallium(III) chlorides, chlorothallate, hydrogen bonding, alkyl ammonium cations.

Synthesis, characterization, and reactivity of the first hafnium alkyl complex stabilized by amidate ligands

2005 ◽  
Vol 83 (6-7) ◽  
pp. 1037-1042 ◽  
Author(s):  
Robert K Thomson ◽  
Brian O Patrick ◽  
Laurel L Schafer
Keyword(s):  
Coordination Chemistry ◽  
Solid State ◽  
Key Words ◽  
Low Temperatures ◽  
Variable Temperature ◽  
X Ray ◽  
X Ray Crystallography ◽  
Exchange Processes ◽  
Hydrolysis Of

A photo and thermally stable bis(amidate)–dibenzyl complex of Hf ([DMP(NO)Ph]2Hf(CH2Ph)2(THF) (2a) was formed as a monosolvated THF adduct in near quantitative yield from Hf(CH2Ph)4 and N-2,6-dimethylphenyl(phenyl)amide (1). Isomerization between the THF-bound product and the THF-free product can be observed visually by the conversion from a red-orange product at low temperatures to a pale yellow product at high temperatures. Solid-state crystallographic characterization of the orange product confirmed its constitution as a monosolvated species. Kinetic parameters for the exchange of the THF moiety were determined from variable-temperature NMR experiments. The product of the hydrolysis of the Hf dibenzyl species by water was characterized by X-ray crystallography, and was found to be a rare tetrametallic Hf oxo cluster species (3).Key words: hafnium, protonolysis, amidate, coordination chemistry, organometallic chemistry, exchange processes.

Synthesis and structural characterization of a magnesium phthalocyanine(3–) anion

2012 ◽  
Vol 16 (01) ◽  
pp. 154-162 ◽  
Author(s):  
Edwin W.Y. Wong ◽  
Daniel B. Leznoff
Keyword(s):  
Absorption Spectrum ◽  
Solid State ◽  
Single Crystal ◽  
Structural Characterization ◽  
Heterometallic Complex ◽  
State Structure ◽  
Solid State Structure ◽  
X Ray ◽  
X Ray Crystallography

The reduction of magnesium phthalocyanine (MgPc) with 2.2 equivalents of potassium graphite in 1,2-dimethoxyethane (DME) gives [K2(DME)4]PcMg(OH)(1) in 67% yield. Compound 1 was structurally characterized using single crystal X-ray crystallography and was found to be a monomeric, heterometallic complex consisting of a μ3-OH ligand that bridges a [MgIIPc3-]- anion to two potassium cations solvated by four DME molecules. An absorption spectrum of 1 confirms the Pc ligand is singly reduced and has a 3–charge. The solid-state structure of 1 does not indicate breaking of the aromaticity of the Pc ligand. Compound 1 is only the second Pc3- complex and the first reduced MgPc to be isolated and structurally characterized.

The two solid-state conformations of nefopam methiodide, a quaternary ammonium salt of the analgesic drug

1990 ◽  
Vol 68 (7) ◽  
pp. 1128-1134 ◽  
Author(s):  
Robert Glaser ◽  
André Michel ◽  
Marc Drouin
Keyword(s):  
Solid State ◽  
Ammonium Salt ◽  
Quaternary Ammonium ◽  
Quaternary Ammonium Salt ◽  
State Structure ◽  
X Ray Diffraction ◽  
Analgesic Drug ◽  
X Ray ◽  
Positional Disorder ◽  
X Ray Crystallography

The solid-state structure of nefopam methiodide, a quaternary ammonium salt of nefopam hydrochloride (a non-narcotic analgesic drug), has been determined by single crystal X-ray diffraction analysis. Nefopam methiodide gives crystals belonging to the monoclinic P21/c space group and, at 298 K, a = 10.001(1), b = 9.928(1), c = 17.598(1) Å, β = 94.41(1)°, V = 1742.2(2) Å3, Z = 4, R(F) = 0.086, and Rw(F) = 0.108. Due to disorder, the boat (flattened chair) and twist-chair (flattened chair) conformations of the 2,5-benzoxazocine eight-membered ring were both observed in the crystal with 55:45 occupancy, respectively. Positional disorder was also observed for the iodide counterion, which showed occupancies of 81:9.5:9.5. Keywords: nefopam, analgesic, X-ray crystallography, conformation.

Cyclic Alkyl(aryl)boranes for 1,1-Carboboration of Monoalkynyltin Compounds

2013 ◽  
Vol 68 (5-6) ◽  
pp. 493-502 ◽  
Author(s):  
Bernd Wrackmeyer ◽  
Peter Thoma ◽  
Wolfgang Milius
Keyword(s):  
Solid State ◽  
High Selectivity ◽  
Ring Expansion ◽  
Membered Ring ◽  
Reaction Products ◽  
State Structure ◽  
Alkyl Aryl ◽  
X Ray ◽  
X Ray Crystallography ◽  
Nmr Techniques

Two cyclic alkyl(aryl)boranes, a 1-bora-indane derivative 1, and a tricyclic derivative 4, containing the boron atom in a six-membered ring, were structurally characterized by NMR techniques in solution. The solid-state structure of the 1-bora-indane 1 was determined by X-ray crystallography. The reactivity of these cyclic alkyl(aryl)boranes towards monoalkynyltin compounds, Me3Sn-C≡C-Me and Me3Sn-C C-Fc (Fc=ferrocenyl), was studied using multinuclear magnetic resonance methods (1H, 11B, 13C, 119Sn NMR). Novel alkenylboranes were formed by 1,1-carboboration reactions. This process involves an expansion of both five- and six-membered rings. Insertion into the respective B-C(aryl) bond was preferred with high selectivity. In the case of the six-membered ring in 4, the ring expansion to seven-membered rings proved to be readily reversible, and the thermodynamically stable reaction products were formed by ring contraction and concomitant transfer of the exocyclic B-nPr group

Solid-state structure of NH-pyrazolium hydrochlorides and hydrobromides by X-ray crystallography and CPMAS NMR

1997 ◽  
Vol 415 (1-2) ◽  
pp. 81-92 ◽  
Author(s):  
Concepción Foces-Foces ◽  
Lourdes Infantes ◽  
Rosa Marı́a Claramunt ◽  
Concepción López ◽  
Nadine Jagerovic ◽  
...  
Keyword(s):  
Solid State ◽  
State Structure ◽  
Solid State Structure ◽  
X Ray ◽  
X Ray Crystallography

Self-Assembly of a Charge-Neutral Molecular Square

2004 ◽  
Vol 57 (5) ◽  
pp. 409 ◽  
Author(s):  
Mohammad Akbar Ali ◽  
Paul V. Bernhardt ◽  
Chong Lee Kiem ◽  
Aminul Huq Mirza
Keyword(s):  
Molecular Weight ◽  
Solid State ◽  
Self Assembly ◽  
1H Nmr Spectroscopy ◽  
The Self ◽  
State Structure ◽  
X Ray ◽  
X Ray Crystallography ◽  
A Charge ◽  
Molecular Square

Complexation of cadmium(II) by the ditopic (bis-tridentate) thiocarbazone ligand 1,5-bis(6-methyl-2-pyridyl- methylene)thiocarbonohydrazide, H2L1, results in the self-assembly of a charge-neutral 2 × 2 molecular grid, [Cd4(L1)4], comprising four metals and four ligands in an interlocked cyclic array. The solid-state structure of this tetramer has been established by X-ray crystallography and in solution by 1H NMR spectroscopy. The presence of lower molecular weight oligomers was identified by both NMR and ESI-MS.

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