An ab initio and ion cyclotron resonance study of the reactions between alkoxide negative ions and silane systems. Stable adduct formation, and nucleophilic displacement reactions

1981 ◽  
Vol 34 (3) ◽  
pp. 519 ◽  
Author(s):  
G Klass ◽  
VC Trenerry ◽  
JC Sheldon ◽  
JH Bowie
Keyword(s):  
Ab Initio ◽  
Negative Ions ◽  
Ion Cyclotron Resonance ◽  
Trigonal Bipyramidal ◽  
Nucleophilic Displacement ◽  
Stable Adduct ◽  
Displacement Reactions ◽  
Scf Calculations ◽  
Hydrogen Scrambling ◽  
Lcao Mo

Ab initio LCAO-MO-SCF calculations suggest that reaction of HO-(or MeO-) with silane should proceed through a stable trigonal bipyramidal adduct. Reaction of alkoxide anions with a variety of alkylsilanes in an i.c.r. spectrometer leads to (i) nucleophilic displacement reactions, (ii) stable adducts, (iii) decomposing adducts which collapse to tetrahedral anions by elimination of a neutral molecule, and (iv) proton abstraction reactions. The nucleophilic displacement reaction between MeO- and Me3SiR has been used to produce a variety of R- species, including the allyl, propargyl and benzyl anions. The reactions of these ions with methyl nitrite have been used to show that (i) the benzyl anion does not undergo benzylic hydrogen/phenyl hydrogen scrambling prior to reaction, (ii) the allyl anion reacts as a symmetrical species, and (iii) that hydrogen scrambling does not occur in the propargyl anion, and that C3H3- may either react as HC≡C-CH2- or -HC=C=CH2.

Ab Initio LCAO–MO–SCF Calculations on Formic Acid, Formate Ion, and Protonated Formic Acid

1970 ◽  
Vol 52 (4) ◽  
pp. 1784-1789 ◽  
Author(s):  
A. C. Hopkinson ◽  
K. Yates ◽  
I. G. Csizmadia
Keyword(s):  
Formic Acid ◽  
Ab Initio ◽  
Scf Calculations ◽  
Lcao Mo

The Reactions of Alkoxide-Alkanol Negative Ions with Ketene. An ab initio and Ion Cyclotron Resonance Study

1985 ◽  
Vol 38 (3) ◽  
pp. 355 ◽  
Author(s):  
RN Hayes ◽  
JC Sheldon ◽  
JH Bowie
Keyword(s):  
Ab Initio ◽  
Cyclotron Resonance ◽  
Negative Ions ◽  
Ion Cyclotron Resonance ◽  
Reaction Sequence ◽  
Major Pathway ◽  
Stable Species ◽  
Product Ions ◽  
A Minor ◽  
Competing Reactions

Alkanol-alkoxide negative ions [RO----HOR] react with ketene to form stable species H-C≡C-O----HOR. The initial intermediate in the reaction sequence is produced by the formation of a hydrogen bond between the negatively charged oxygen of [RO----HOR] and a hydrogen of ketene. This intermediate decomposes by competing reactions, viz. ( i ) a minor pathway involving direct elimination of ROH, and (ii) a major pathway involving a rearrangement sequence. Intermediates and product ions have been defined by using ab initio calculations at the 4-31G level. The differences between the reactions of [RO----HOR]/ketene and [RO---- HOR]/acetaldehyde systems are discussed.

Electron impact studies. CXVIII. An ion cyclotron resonance study of the reactivity of negative ions derived from ethenetetracarbonitrile. Anionic polymerization in the gas phase

1977 ◽  
Vol 30 (10) ◽  
pp. 2161 ◽  
Author(s):  
JH Bowie
Keyword(s):  
Gas Phase ◽  
Electron Impact ◽  
Anionic Polymerization ◽  
Cyclotron Resonance ◽  
Negative Ions ◽  
Ion Cyclotron Resonance ◽  
Impact Studies ◽  
Stable Adduct ◽  
Ion Cyclotron

.The [M·–l CN·I- species from ethenetetracarbonitrile (tetracyanoethylene) reacts with neutral ethene- tetracarbonitrile to give the stable adduct C11N7-. The decomposing form of this adduct eliminates C2N2 to produce C,9N5- which may react with ethenetetracarbonitrile to yield C15N,9-. Analogous anionic polymerization reactions yield a number of detectable peaks in the i.c.r. spectrum of tetra- cyanoethylene, with the structures of the ions possibly corresponding to a. Diagram Polymerization of this type can also be initiated by other nucleophiles including Cl-, Br-, I- and CF3CO2-.

Photoelectron spectroscopy and ab initio LCAO MO SCF calculations on thiazyl fluoride

1972 ◽  
Vol 14 (4) ◽  
pp. 525-527 ◽  
Author(s):  
R.L. Dekock ◽  
D.R. Lloyd ◽  
A. Breeze ◽  
G.A.D. Collins ◽  
D.W.J. Cruickshank ◽  
...  
Keyword(s):  
Ab Initio ◽  
Photoelectron Spectroscopy ◽  
Scf Calculations ◽  
Lcao Mo

The reactions of [F----HOMe] and [MeCO2----HF] negative ions with acetaldehyde and acetone. An Ion Cyclotron Resonance and ab initio Study

1983 ◽  
Vol 36 (2) ◽  
pp. 289 ◽  
Author(s):  
JC Sheldon ◽  
JH Bowie
Keyword(s):  
Ab Initio Calculations ◽  
Ab Initio ◽  
Cyclotron Resonance ◽  
Methyl Formate ◽  
Negative Ions ◽  
Model System ◽  
Ion Cyclotron Resonance ◽  
Ab Initio Study ◽  
Mechanistic Pathway ◽  
System F

The ion [F-- - -HOMe] may be produced by the reaction of CF3O- with methyl formate, a reaction of a type widely used for the production of 'solvated' negative ions. The possible reaction mechanism for the model system F-/HCO2H has been explored by ab initio calculations. The reactions of acetaldehyde and acetone with [F-- - -HOMe] yield stable [M + F-] ions which are thought to correspond to 'solvated' enolate negative ions. Their formation in terms of a mechanistic pathway, recently proposed to account for the formation of [M + RO-] ions from [RO-- - -HOR]/ > CH-CO- systems, is supported by ab initio calculations.

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