Reactivity of Sodium Hexaethyl-2,4-dicarba-nido-hexaborate(1-)

1999 ◽  
Vol 64 (6) ◽  
pp. 977-985 ◽  
Author(s):  
Bernd Wrackmeyer ◽  
Hans-Jörg Schanz ◽  
Wolfgang Milius ◽  
Catherine McCammon
Keyword(s):  
Mössbauer Spectroscopy ◽  
Nmr Spectroscopy ◽  
Structural Analysis ◽  
Hydrogen Atom ◽  
Mossbauer Spectroscopy ◽  
Sandwich Complex ◽  
X Ray ◽  
Bromo Derivative ◽  
Boron Tribromide ◽  
C Nmr

Sodium hexaethyl-2,4-dicarba-nido-hexaborate(1-) (6), available from hexaethyl-2,4-dicarba- nido-hexaborane(8) (4) by deprotonation, reacts with deuterated methanol, CD3OD, to give back 4 without H/D exchange of the B-H-B hydrogen atom. The reaction of 6 with diethylboron chloride, Et2BCl, affords hexaethyl-2,4-dicarba-closo-hexaborane(6) (7), the first example of a peralkylated carborane of this type. In contrast, the reaction of 6 with boron tribromide, BBr3, leads mainly to 2,3,4,5,6,7-hexaethyl-2,4-dicarba-closo-heptaborane(7) (8), together with the corresponding 1-bromo derivative (9) and the closo-carborane 7 as side products. The reaction of two equivalents of 6 with FeCl2 gives the air-stable sandwich complex bis[hexaethyl-2,4-dicarba-nido-hexaborate(1-)]iron 10 which was characterised by X-ray structural analysis. All products were characterised by 1H, 11B and 13C NMR spectroscopy, and 57Fe Mössbauer spectroscopy was used to study 10.

X-ray Diffraction,7Li MAS NMR Spectroscopy, and119Sn Mössbauer Spectroscopy Study of SnSb-Based Electrode Materials

2002 ◽  
Vol 14 (7) ◽  
pp. 2962-2968 ◽  
Author(s):  
Francisco J. Fernández-Madrigal ◽  
Pedro Lavela ◽  
Carlos Pérez Vicente ◽  
José L. Tirado ◽  
Jean Claude Jumas ◽  
...  
Keyword(s):  
Mössbauer Spectroscopy ◽  
Nmr Spectroscopy ◽  
Electrode Materials ◽  
Mossbauer Spectroscopy ◽  
Mas Nmr ◽  
Spectroscopy Study ◽  
X Ray Diffraction ◽  
X Ray ◽  
Mößbauer Spectroscopy

Stereoselective Synthesis and Single Crystal X-Ray Structures of Some Sterically Congested Electron-poor N-Vinyl Pyrazole Derivatives

2008 ◽  
Vol 63 (1) ◽  
pp. 65-70 ◽  
Author(s):  
Nader Noshiranzadeh ◽  
Ali Ramazani ◽  
Amir Tofangchi Mahyaria ◽  
Katarzyna Ślepokurab ◽  
Tadeusz Lisb
Keyword(s):  
Nmr Spectroscopy ◽  
Structural Analysis ◽  
Single Crystal ◽  
Structure Determination ◽  
Stereoselective Synthesis ◽  
Pyrazole Derivatives ◽  
One Pot ◽  
X Ray ◽  
One Pot Synthesis ◽  
C Nmr

A one-pot synthesis of sterically congested electron-poor N-vinyl pyrazoles in fairly good yields by the reaction of ethyl 3-phenyl-2-propynoate, pyrazoles and triphenylphosphine is reported. The structures of these compounds were confirmed by IR, 1H, and 13C NMR spectroscopy, and single crystal X-ray structure determination. The structural analysis of the products indicated that the reaction is completely regio- and stereoselective.

Regio- And Stereoselective Addition Of Imides To Ethyl 3-Phenyl-2- Propynoate In The Presence Of Triphenylphosphine. Single Crystal X-Ray Structure Of Ethyl (Z)-2-(1,3-Dioxo-1,3,3A,4,7,7A-Hexahydro-2H-Isoindol- 2-Yl)-3-Phenyl-2-Propenoate

2007 ◽  
Vol 62 (6) ◽  
pp. 829-834 ◽  
Author(s):  
Amir Tofangchi Mahyaria ◽  
Nahid Shajari ◽  
Ali Reza Kazemizadeh ◽  
Katarzyna Ślepokura ◽  
Tadeusz Lis ◽  
...  
Keyword(s):  
Nmr Spectroscopy ◽  
Structural Analysis ◽  
Single Crystal ◽  
Structure Determination ◽  
One Pot ◽  
X Ray ◽  
One Pot Synthesis ◽  
Stereoselective Addition ◽  
High Yields ◽  
C Nmr

A one-pot synthesis of sterically congested N-vinyl imides in fairly high yields by the reaction of ethyl 3-phenyl-2-propynoate, imides and triphenylphosphine is reported. The structures of these compounds were confirmed by IR, 1H, and 13C NMR spectroscopy, and by a single crystal X-ray structure determination. The structural analysis of the products indicated that the reaction is regioand stereoselective

scholarly journals Synthesis And Single Crystal X-Ray Structure Of 2-(1,3,4-Oxadiazol- 2-yl)Aniline

2007 ◽  
Vol 62 (6) ◽  
pp. 835-840 ◽  
Author(s):  
Ali Souldozi ◽  
Katarzyna Ślepokura ◽  
Tadeusz Lis ◽  
Ali Ramazani
Keyword(s):  
Mass Spectrometry ◽  
Nmr Spectroscopy ◽  
Structural Analysis ◽  
Single Crystal ◽  
Structure Determination ◽  
High Yield ◽  
Aminobenzoic Acid ◽  
Aromatic Rings ◽  
X Ray ◽  
C Nmr

Reaction of 2-aminobenzoic acid with (N-isocyanimino)triphenylphosphorane proceeds smoothly at r. t. to afford 2-(1,3,4-oxadiazol-2-yl)aniline in high yield. The structure of this compound was confirmed by IR, 1H, and 13C NMR spectroscopy, mass spectrometry, and single crystal X-ray structure determination. The X-ray structural analysis of the product indicated that its aromatic rings are approximately co-planar

An unusual reaction of a bridged triterpenoid α-diketone with acetic anhydride

1991 ◽  
Vol 56 (12) ◽  
pp. 2917-2935 ◽  
Author(s):  
Eva Klinotová ◽  
Václav Křeček ◽  
Jiří Klinot ◽  
Miloš Buděšínský ◽  
Jaroslav Podlaha ◽  
...  
Keyword(s):  
Acetic Acid ◽  
Nmr Spectroscopy ◽  
Acetic Anhydride ◽  
Spectral Methods ◽  
X Ray Diffraction ◽  
X Ray ◽  
Mild Conditions ◽  
Condensation Products ◽  
Unsaturated Lactones ◽  
C Nmr

3β-Acetoxy-21,22-dioxo-18α,19βH-ursan-28,20β-olide (IIIa) reacts with acetic anhydride in pyridine under very mild conditions affording β-lactone IVa and γ-lactones Va and VIIa as condensation products. On reaction with pyridine, lactones Va and VIIa undergo elimination of acetic acid to give unsaturated lactones VIIIa and IXa, respectively. Similarly, the condensation of 20β,28-epoxy-21,22-dioxo-18α,19βH-ursan-3β-yl acetate (IIIb) with acetic anhydride leads to β-lactone IVb and γ-lactone Vb; the latter on heating with pyridine affords unsaturated lactone VIIIb and 21-methylene-22-ketone Xb. The structure of the obtained compounds was derived using spectral methods, particularly 1H and 13C NMR spectroscopy; structure of lactone IVa was confirmed by X-ray diffraction.

Nature and mechanism of ilmenite alteration: a Mössbauer and X-ray diffraction study of oxidized ilmenite from the Beja-Acebuches Ophiolite Complex (SE Portugal)

2002 ◽  
Vol 66 (3) ◽  
pp. 421-430 ◽  
Author(s):  
J. C. Waerenborgh ◽  
J. Figueiras ◽  
A. Mateus ◽  
M. Gonçalves
Keyword(s):  
Mössbauer Spectroscopy ◽  
Mossbauer Spectroscopy ◽  
X Ray Diffraction ◽  
Ophiolite Complex ◽  
Cation Site ◽  
X Ray ◽  
Mößbauer Spectroscopy ◽  
Ilmenite Structure ◽  
Optical Evidence ◽  
Excess Fe

AbstractIlmenites from the least-altered rocks of the Beja-Acebuches Ophiolite Complex (SE Portugal), with low Ti values and excess Fe, despite rare optical evidence of hematite exsolution, were studied by 57Fe Mössbauer spectroscopy and X-ray diffraction. According to single-crystal XRD the sequence of alternate layers characteristic of the ideal ilmenite structure is preserved, the excess Fe being accommodated in the Ti layers. No superparamagnetic oxides were detected by 57Fe Mössbauer spectroscopy. The typical spectra of bulk αFe2O3 and of Fe3+-containing ilmenite, in the paramagnetic state above 49 K and magnetically ordered at 6 K, are observed. The average degree of oxidation of the ilmenites, estimated from the chemical analysis assuming ideally stoichiometric full cation site occupancies, is also confirmed by 57Fe Mössbauer data. Since our crystal chemistry study gave no evidence of crypto-exsolution textures within the ilmenite with the observed compositions, fast cooling from magmatic temperatures and decomposition of ilmenite in supergene conditions is suggested.

A Study of Aluminum-Substituted Iron Dextran Complexes by Mössbauer Spectroscopy and X-ray Diffraction

2001 ◽  
Vol 13 (1) ◽  
pp. 136-140 ◽  
Author(s):  
Tianrong Cheng ◽  
Robert Bereman ◽  
Eddy De Grave ◽  
Larry H. Bowen
Keyword(s):  
Mössbauer Spectroscopy ◽  
Mossbauer Spectroscopy ◽  
Iron Dextran ◽  
X Ray Diffraction ◽  
X Ray ◽  
Mößbauer Spectroscopy
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