2013. 54, 2
– . 228 – 236
UDC 541.6:546.26:547.17
GAS-PHASE REACTION OF THE ISOBUTENYL ANION WITH N2O FROM
AB INITIO CALCULATIONS
J.X. Liang1, Y.B. Wang1, Z.Y. Geng2, Y.Z. Wang2, Y.C. Wang2
1
College of Chemical Engineering, Northwest University for Nationalities, Lanzhou, Gansu, P. R. China
Gansu Key Laboratory of Polymer Materials, College of Chemistry and Chemical Engineering, Key Laboratory
of Eco-environment-related Polymer Materials; Ministry of Education, Northwest Normal University, Lanzhou,
Gansu, P. R. China
E-mail: wangyb16@yahoo.cn
2
Received November, 23, 2011
Revised — January, 8, 2012
Calculations using conventional ab initio theory are performed to investigate the reaction
mechanism associated with the gas-phase ion/molecule reaction of isobutenyl anion with N2O. <...> As a result, our theoretical findings strongly suggest that the main pathway is the reaction pattern of end-N attack and that the corresponding reaction mechanism basically relates to hydrogen migration, which may yield products cis-CH2(CH3)CCN 2 , trans-CH2(CH3)CCN 2 , and
H2O. <...> Those are in good agreement with the experimental observations. <...> Moreover, based on the
NBO, Activation Strain model and methyl group effect analysis, we also explored the characters of rate-determining step of the main pathway. <...> K e y w o r d s: isobutenyl anion, reaction mechanism, second-order Møller—Plesset perturbation theory (MP2). <...> INTRODUCTION
Carbanion, acting as a sort of valuable electron-rich reagent, plays a central role in organic chemistry because of its widespread synthetic utility [ 1 ]. <...> In many cases, it is a reactive nucleophilic intermediate [ 2—7 ] and is often encountered in organic chemistry, organometallic chemistry, alkyl lithium
chemistry and so on [ 8—14 ]. <...> Previously, substantial efforts were made to gain and
characterize carbanions experimentally [ 12—14 ], including bond strengths, [ 16 ] energies, [ 17 ] and
resonance effects. [ 18 ] Also, the corresponding gas-phase reactions have been studied extensively.
[ 11—13, 19, 20 ] Here, the work of Depuy et al. in 1977 [ 19 ] in which, using a flowing afterglow <...>
GAS-PHASE_REACTION_OF_THE_ISOBUTENYL_ANION_WITH_N2O_FROM_ABINITIO_CALCULATIONS.pdf
2013. 54, 2
-
– -
UDC 541.6:546.26:547.17
GAS-PHASE REACTION OF THE ISOBUTENYL ANION WITH N2O FROM
AB INITIO CALCULATIONS
J.X. Liang1, Y.B. Wang1, Z.Y. Geng2, Y.Z. Wang2, Y.C. Wang2
1College of Chemical Engineering, Northwest University for Nationalities, Lanzhou, Gansu, P. R. China
2Gansu Key Laboratory of Polymer Materials, College of Chemistry and Chemical Engineering, Key Laboratory
of Eco-environment-related Polymer Materials; Ministry of Education, Northwest Normal University, Lanzhou,
Gansu, P. R. China
E-mail: wangyb16@yahoo.cn
Received November, 23, 2011
Revised — January, 8, 2012
Calculations using conventional ab initio theory are performed to investigate the reaction
mechanism associated with the gas-phase ion/molecule reaction of isobutenyl anion with N2O.
As a result, our theoretical findings strongly suggest that the main pathway is the reaction pattern
of end-N attack and that the corresponding reaction mechanism basically relates to hydrogen
migration, which may yield products cis-CH2(CH3)CCN2 , trans-CH2(CH3)CCN2 , and
H2O. Those are in good agreement with the experimental observations. Moreover, based on the
NBO, Activation Strain model and methyl group effect analysis, we also explored the characters
of rate-determining step of the main pathway.
Keywords: isobutenyl anion, reaction mechanism, second-order Møller—Plesset perturbation
theory (MP2).
INTRODUCTION
Carbanion, acting as a sort of valuable electron-rich reagent, plays a central role in organic chemistry
because of its widespread synthetic utility [ 1 ]. In many cases, it is a reactive nucleophilic intermediate
[ 2—7] and is often encountered in organic chemistry, organometallic chemistry, alkyl lithium
chemistry and so on [ 8—14]. Many experiments have demonstrated that the stable carbanions, owing
to charge delocalization, do exist [ 2—15]. However, they have not been successfully isolated, possibly
due to their high reactivities [ 9—11, 14 ]. Previously, substantial efforts were made to gain and
characterize carbanions experimentally [12—14 ], including bond strengths, [ 16 ] energies, [ 17 ] and
resonance effects. [ 18 ] Also, the corresponding gas-phase reactions have been studied extensively.
[ 11—13, 19, 20 ] Here, the work of Depuy et al. in 1977 [ 19 ] in which, using a flowing afterglow
(FA)-selected ion flow tube (SIFT), they investigated in detail the reaction mechanism of different
carbanions with some small molecules, is most representative. Unfortunately, to the best of our knowledge,
no theoretical study has hitherto well explored the reaction mechanism of an isobutenyl anion
with N2O, which was only inferred by Depuy from the experiment [ 20 ], as shown in Scheme 1.
Scheme 1
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© Liang J.X., Wang Y.B., Geng Z.Y., Wang Y.Z., Wang Y.C., 2013
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