Displacement reactions, gas-phase

Figure 1. Reaction coordinate for the gas-phase displacement reaction X + CHSY -> XCHS + Y and definitions of the quantities in Eqs. 1-3.

These results suggest that the Marcus equations can be applied quite successfully to gas phase displacement reactions, as suggested by Professor Brauman. We are currently generating more cross reactions and intend to test other rate-equilibrium relationships using our data. 

From gas phase displacement reactions, Rudolph and Parry 58> obtained an equilibrium constant for the reaction. 

Since the first report in 1979 of gas-phase displacement reactions of nucleophiles, including halide ions, with acyl halides283 this field has not received great attention. In the original work the mechanistic proposal was advanced that reaction proceeds according to the double-well energy model via ion-dipole complexes as intermediates rather than the classical tetrahedral adduct of solution chemistry283. A claim of further evidence for this... 

Nucleophilicity and leaving group ability 211 Effect of solvation on the gas-phase reaction 212 Mechanism of the gas-phase SN2 reaction 213 Potential energy surfaces for gas-phase SN2 reactions 214 Recent theoretical developments 218 Some examples of gas-phase SN2 reactions involving positive ions 220 Nucleophilic displacement reactions by negative ions in carbonyl systems 222 General features 222... 

Model for nucleophilic displacement reactions at carbonyl centres 227 Gas-phase nucleophilic reactions of carbonyl systems involving positive ions 229... 

The field of gas-phase organic reactions of ionic species has blossomed in the last 15 years to the point where a single review article becomes a formidable task. The scope of the present report covers gas-phase reactions initiated by nucleophilic attack with special emphasis on displacement reactions. This choice was dictated by the analogy with well-known reactions in solution, which may be considered as a classical chapter of physical organic chemistry. 

In the early 1930s, Ingold proposed that nucleophilic displacement reactions be divided into SN1 and SN2 types. Could he have known how broadly these classifications might apply Consider the novel gas-phase displacement by a hydride ion of benzene from a chromium center ... 

Chabinyc, M. L., S. L. Craig, et al. (1998). Gas-phase ionic reactions dynamics and mechanism of nucleophilic displacements. Science 279, 1882. 

These problems can be somewhat overcome by a study of reactions in solution where much greater densities are possible than in the gas phase and fast bimolecular reaction are diffusion limited [1,28,29]. However, since coordinatively unsaturated metal carbonyls have shown a great affinity for coordinating solvent we felt that the appropriate place to begin a study of the spectroscopy and kinetics of these species would be in a phase where there is no solvent the gas phase. In the gas phase, the observed spectrum is expected to be that of the "naked" coordinatively unsaturated species and reactions of these species with added ligands are addition reactions rather than displacement reactions. However, since many of the saturated metal carbonyls have limited vapor pressures, the gas phase places additional constraints on the sensitivity of the transient spectroscopy apparatus. 

Nuclear motion, the principle of least, and the theory of stereoelectronic control, 24, 113 Nucleophiles, partitioning of carbocations between addition and deprotonation. 35, 67 Nucleophilic aromatic photosubstitution, 11,225 Nucleophilic catalysis of ester hydrolysis and related reactions, 5,237 Nucleophilic displacement reactions, gas-phase, 21, 197... 

Gas-phase nucleophilic displacement reactions, 21, 197 Gas-phase pyrolysis of small-ring hydrocarbons, 4, 147 Gas-phase reactions of organic anions, 24, 1... 

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