Gas-phase measurements of the influence of stepwise solvation on the kinetics of nucleophilic displacement reactions with chloromethane and bromomethane at room temperature

1984 ◽  
Vol 106 (12) ◽  
pp. 3447-3452 ◽  
Author(s):  
Diethard K. Bohme ◽  
Asit B. Raksit
Keyword(s):  
Gas Phase ◽  
Room Temperature ◽  
Phase Measurements ◽  
Nucleophilic Displacement ◽  
Displacement Reactions ◽  
Kinetics Of

Gas-phase measurements of the influence of stepwise solvation on the kinetics of SN2 reactions of solvated F− with CH3Cl and CH3Br and of solvated Cl− with CH3Br

1985 ◽  
Vol 63 (11) ◽  
pp. 3007-3011 ◽  
Author(s):  
Diethard K. Bohme ◽  
Asit B. Raksit
Keyword(s):  
Gas Phase ◽  
Room Temperature ◽  
Specific Rate ◽  
Flowing Afterglow ◽  
Phase Measurements ◽  
Sn2 Reactions ◽  
Energy Profiles ◽  
Nucleophilic Displacement ◽  
Displacement Reactions ◽  
Kinetics Of

Flowing afterglow measurements are reported which reveal the influence of stepwise solvation on the nucleophilicity of F− and Cl− in the gas phase at room temperature. The specific rates of nucleophilic displacement reactions with CH3Cl and CH3Br are followed for additions of up to three molecules of solvent for F− solvated with D2O, CH3OH, and C2H5OH and for Cl− solvated with CH3OH, C2H5OH, CH3COCH3, HCOOH, and CH3COOH. The observed precipitous response of the specific rate to solvation is attributed to intermediate features of plausible reaction energy profiles.

Bridging the gap between the gas phase and solution: transition in the kinetics of nucleophilic displacement reactions

1981 ◽  
Vol 103 (4) ◽  
pp. 978-979 ◽  
Author(s):  
Diethard K. Bohme ◽  
Gervase I. Mackay
Keyword(s):  
Gas Phase ◽  
Nucleophilic Displacement ◽  
Displacement Reactions ◽  
Kinetics Of

The gas phase reactivity of the dimethylchloronium ion with alkylbenzenes

1981 ◽  
Vol 59 (15) ◽  
pp. 2412-2416 ◽  
Author(s):  
John A. Stone ◽  
Margaret S. Lin ◽  
Jeffrey Varah
Keyword(s):  
High Pressure ◽  
Gas Phase ◽  
Mass Spectrometer ◽  
Aromatic Hydrocarbons ◽  
Relative Rate ◽  
Ion Source ◽  
Nucleophilic Displacement ◽  
Rate Of Reaction ◽  
Displacement Reactions ◽  
Bonded Complexes

The reactivity of the dimethylchloronium ion with a series of aromatic hydrocarbons has been studied in a high pressure mass spectrometer ion source using the technique of reactant ion monitoring. Benzene is unreactive but all others, from toluene to mesitylene, react by CH3+ transfer to yield σ-bonded complexes. The relative rate of reaction increases with increasing exothermicity in line with current theories of nucleophilic displacement reactions.

Di-imide: Some Physical and Chemical Properties, and the Kinetics and Stoichiometry of the Gas-phase Decomposition

1973 ◽  
Vol 51 (21) ◽  
pp. 3605-3619 ◽  
Author(s):  
C. Willis ◽  
R. A. Back
Keyword(s):  
Gas Phase ◽  
Room Temperature ◽  
Chemical Properties ◽  
Phase Decomposition ◽  
Important Intermediate ◽  
Long Lifetime ◽  
Physical And Chemical ◽  
Text Formation ◽  
Kinetics Of

Preparation of di-imide by passing hydrazine vapor through a microwave discharge yields mixtures with NH3 containing typically about 15% N2H2, estimated from the gases evolved on decomposition. The behavior of the mixture (which melts at −65 °C) on warming from −196 to −30 °C suggests a strong interaction between the components. Measurements of magnetic susceptibility and e.p.r. experiments showed that N2H2 is not strongly paramagnetic, which with other observations points to a singlet rather than a triplet ground-state.Di-imide can be vaporized efficiently, together with NH3, by rapid warming, and the vapor is surprisingly long-lived, with a typical half-life of several minutes at room temperature. The near-u.v. (3200–4400 Å) absorption spectrum of the vapor was photographed; it shows well-defined but diffuse bands, with εmax = 6(± 3) at 3450 Å.Di-imide decomposes at room temperature in two ways:[Formula: see text][Formula: see text]Formation of NH3 was not observed but cannot be ruled out. The decomposition of the vapor is complicated by a sizeable and variable decomposition that occurs rapidly during the vaporization. The stoichiometry of this and the vapor-phase decomposition depends on total pressure and di-imide concentration. The kinetics of the decomposition of the vapor were studied from 22 to 200 °C by following the disappearance of N2H2 by absorption of light at 3450 Å, or the formation of N2H4 by absorption at 2400 Å, and by mass spectrometry. The kinetics are complex and can be either first- or second-order, or mixed, depending on surface conditions. The effect of olefin additives on the decomposition was studied, and is also complex.Mechanisms for the decomposition are discussed, including the possible role of trans-cis isomerization. The relatively long lifetime found for di-imide in the gas phase suggests that it may be an important intermediate in many reactions of hydronitrogen systems.

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