X-ray Structure and Variable Temperature NMR Spectra of [meso-Triarylcorrolato]copper(III)

2003 ◽  
Vol 42 (15) ◽  
pp. 4495-4497 ◽  
Author(s):  
Christian Brückner ◽  
Raymond P. Briñas ◽  
Jeanette A. Krause Bauer
Keyword(s):  
Nmr Spectra ◽  
Variable Temperature ◽  
X Ray ◽  
Variable Temperature Nmr Spectra

Siliciumverbindungen mit starken intramolekularen sterischen Wechselwirkungen, XIV [1] Versuche zur Synthese des Tetra-tert-butylsilans: Tri-tert-butylisopropylsilan und verwandte Verbindungen / Silicon Compounds with Strong Intramolecular Steric Interactions, XIV [1] Attempted Synthesis of Tetra-tert-butylsilane: Tri-tert-butylisopropylsilane and Related Compounds

1983 ◽  
Vol 38 (9) ◽  
pp. 1062-1068 ◽  
Author(s):  
Manfred Weidenbruch ◽  
Hermann Flott ◽  
Bernd Ralle ◽  
Karl Peters ◽  
Hans Georg von Schnering
Keyword(s):  
Nmr Spectra ◽  
Hydrogen Exchange ◽  
Variable Temperature ◽  
Silicon Compounds ◽  
X Ray ◽  
Tert Butyl ◽  
Step Procedure ◽  
Variable Temperature Nmr Spectra ◽  
Related Compounds

AbstractReaction of tri-tert-butyl(dihalomethyl)silanes (halo = chloro, bromo) with organolithium compounds, by lithium/halogen or lithium/hydrogen exchange, leads to the corresponding carbenoids which by lithium halide elimination could give the carbenes (t-C4H9)3SiCX. Further intermolecular or intramolecular reaction of these reactive intermediates provides a variety of crowded molecules including alkyltri-tert-butylsilanes, 1,2-bis(tri-tert-butylsilyl)- substituted ethanes and ethenes and ring substituted 1,2-di-tert-butyl-1-silacyclo-butanes. An X-ray structure determination of (E)-1,2-bis(tri-tert-butylsilyl)-1,2-dichloroethene reveals neither a twisting nor an elongation of the CC double bond, but the C = C-Si bond angles exhibit rather unusual values (up to 137.7°) and the Si-C (sp2) bonds are as long as 195 pm.Tri-tert-butylisopropylsilane was prepared by a two step procedure and characterized by its variable temperature NMR spectra. The attempted synthesis of tetra-tert-butylsilane by reactions of the compound with bromine followed by treatment with methyllithium afforded only tri-tert-butylisopropenylsilane.

Article

1999 ◽  
Vol 77 (5-6) ◽  
pp. 1057-1065
Author(s):  
John T Edward ◽  
Francis L Chubb ◽  
Denis FR Gilson ◽  
Rosemary C Hynes ◽  
Françoise Sauriol ◽  
...  
Keyword(s):  
Nmr Spectra ◽  
Acidic Solution ◽  
Variable Temperature ◽  
X Ray Diffraction ◽  
Nmr Studies ◽  
Cage Compounds ◽  
Amine Nitrogen ◽  
X Ray ◽  
Bridgehead Nitrogen ◽  
C Nmr

Three new cage peroxides, 1,6-diaza-3,4,8,9-tetraoxabicyclo[4.4.2]dodecane (3a),1,6-diaza-3,4,8,9-tetraoxa-11-methylbicyclo[4.4.2]dodecane (3b), and 1,6-diaza-3,4,8,9-tetraoxatricyclo[4.4.2.411,12]hexadecane (4), have been prepared by reaction of 1,2-diaminoethane, 1,2-diaminopropane, and trans-1,2-diaminocyclohexane, respectively, with formaldehyde and hydrogen peroxide in aqueous acidic solution. Their structures have been established by X-ray diffraction, and show the bridgehead nitrogen atoms to be predominantly sp2 hybridized. The structures accord with 1H and 13C NMR spectra. Variable temperature NMR studies show that the diperoxide 3a begins to undergo rapid inversion (on the NMR time scale) at about 303 K; up to 370 K the diperoxides 3b and 4 show no conformational change.Key words: cage compounds, formaldehyde, peroxides, amine nitrogen, hybridization.

scholarly journals Solid-state motion of OTeF5− compounds: detection by 19F NMR and IR spectroscopy and correlation with the X-ray structure of an orthorhombic crystalline modification of [C14H19N2+][OTeF5−] (C14H19N2+ = protonated 1,8-bis(dimethylamino)naphthalene)

1989 ◽  
Vol 67 (11) ◽  
pp. 2023-2029 ◽  
Author(s):  
Patti J. Kellett ◽  
Oren P. Anderson ◽  
Steven H. Strauss ◽  
Kent D. Abney
Keyword(s):  
Solid State ◽  
Nmr Spectra ◽  
Room Temperature ◽  
Variable Temperature ◽  
Structural Parameters ◽  
Crystalline Modification ◽  
X Ray Diffraction ◽  
Orthorhombic Space Group ◽  
X Ray ◽  
Triclinic Modification

An orthorhombic crystalline modification of [(PS)H+][OTeF5−] was studied by single crystal X-ray diffraction ((PS)H+ = protonated 1,8-bis(dimethylamino)naphthalene): orthorhombic, space group Cmcm, a = 8.607(2), b = 14.048(3), c = 13.365(2) Å, Z = 4, T = −130 °C. The structural parameters for the anion and cation in this modification (Mod-B) are very similar to those for the previously reported triclinic modification of this salt (Mod-A). However, variable temperature IR spectra for Mod-B suggest that the OTeF5− anion is exhibiting a two-site O/Fax interchange above −70 °C. Solid-state 19F NMR spectra suggest that this interchange may be as rapid as 104–105 s−1 at room temperature. Keywords: crystal structure of protonated 1,8-bis(dimethylamino)naphthalene)pentafluorotellurate(VI), polymorphism, solid state 19FNMR.

A Structural Study on Indium Tris-thiocarbamates

1994 ◽  
Vol 49 (2) ◽  
pp. 193-198 ◽  
Author(s):  
S. Bhattacharya ◽  
Miss Neena Seth ◽  
V. D. Gupta ◽  
H. Nöth ◽  
M. Thomann
Keyword(s):  
Structural Study ◽  
Nmr Spectra ◽  
Variable Temperature ◽  
Point Group ◽  
Molecular Structures ◽  
X Ray ◽  
H Nmr ◽  
Group D

Indium tris(thiocarbamates) In(S2CNiPr2)3 (1), In(SOCNiPr2)3 (2) and In(S2CNC4H4)3 (3) have been synthesized and characterized. Variable temperature 1H NMR spectra of 1 and 2 are reported. The X-ray molecular structures of 1 and 3 are found to be quite similar; the symmetry of the In(S2C)3 unit in 3 is close to point group D3 with small asymmetry in the In-S bonds.

scholarly journals Synthesis of N,O-Chelating Hydrazidopalladium Complexes from 1,2-Bis(trifluoroacetyl)hydrazine

Inorganics ◽  
2021 ◽  
Vol 9 (10) ◽  
pp. 76
Author(s):  
Yoshihito Kayaki ◽  
Tomohiro Hayakawa ◽  
Takao Ikariya
Keyword(s):  
Crystal Structure ◽  
Structure Determination ◽  
Nmr Spectra ◽  
Structural Changes ◽  
Variable Temperature ◽  
Palladium Complexes ◽  
Electron Donors ◽  
Crystal Structure Determination ◽  
X Ray ◽  
Square Planar

N,O-chelating dicarbonylhydrazido-palladium complexes were synthesized by treatment of 1,2-bis(trifluoroacetyl)hydrazine with a mixture of a Pd(0) source, [Pd(dba)2] (DBA = dibenzylideneacetone), and four-electron donors including 1,3-bis(diphenylphosphino)propane (DPPP), N,N,N’,N’-tetramethylethylenediamine (TMEDA), and two equivalents of triphenylphosphine. The same products from DPPP and TMEDA could be obtained alternatively by using Pd(OAc)2 through deprotonation of the diacylhydrazine. The five-membered chelate structure was confirmed by NMR spectra and X-ray crystal structure determination. The X-ray structures indicate that the products are formally considered as Pd(II) complexes with a hydrazido(2–) ligand. In the case of the triphenylphosphine-coordinated complex, a fluxional behavior in dichloromethane-d2 was observed by variable temperature NMR experiments, possibly due to structural changes between the square planar and pseudo-tetrahedral geometries.

Synthesis and conformational analysis of disaccharide analogues containing disulfide and selenosulfide functionalities in the interglycosidic linkages

2005 ◽  
Vol 83 (6-7) ◽  
pp. 929-936 ◽  
Author(s):  
Nagasree Chakka ◽  
Blair D Johnston ◽  
B Mario Pinto
Keyword(s):  
Nmr Spectra ◽  
Variable Temperature ◽  
Conformational Space ◽  
Molecular Orbital Theory ◽  
Line Broadening ◽  
Orbital Theory ◽  
Synthetic Strategy ◽  
Conformational Preferences ◽  
Variable Temperature Nmr Spectra ◽  
Low Energy Conformations

The synthesis of novel disaccharides containing disulfide (methyl-4-S-(β-D-galactopyranosyl-1'-thio)-4-thio-α-D-glucopyranoside (1)) and selenosulfide (methyl-4-Se-(β-D-galactopyranosyl-1'-thio)-4-seleno-α-D-glucopyranoside (2)) functionalities in the interglycosidic linkages is described. The synthetic strategy relied on the reaction of a β-glycosylthiosulfonate with a carbohydrate thiol or selenol nucleophile. The resulting protected β-dihetero-linked disaccharides were deprotected to give the target compounds. The conformational preferences of these dihetero analogues were inferred from NOESY experiments and line-broadening effects in variable-temperature NMR spectra, and are rationalized in terms of molecular orbital theory. Low-energy conformations of these compounds can populate regions of conformational space not usually occupied by β-linked disaccharides, and offer the possibility for presentation of novel ligand topographies.Key words: disaccharides, disulfides, selenosulfides, interglycosidic linkages, conformations, MO explanation.

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