Ab initio molecular dynamics study of the keto-enol tautomerism of acetone in solution

被引:68
作者
Cucinotta, Clotilde S. [1 ]
Ruini, Alice
Catellani, Alessandra
Stirling, Andras
机构
[1] CNR, INFM, Natl Ctr NanoStruct & Biosyst Surfaces S3, I-00185 Rome, Italy
[2] Univ Modena, Dipartimento Fis, I-41100 Modena, Italy
[3] CNR, IMEM, I-43010 Parma, Italy
[4] Chem Res Ctr, Dept Theoret Chem, H-1525 Budapest, Hungary
关键词
ab initio calculations; metadynamics; molecular dynamics; reaction mechanisms; tautomerism;
D O I
10.1002/cphc.200600007
中图分类号
O64 [物理化学(理论化学)、化学物理学];
学科分类号
070304 ; 081704 ;
摘要
We have studied the keto-enol interconversion of acetone to understand the mechanism of tautomerism relevant to numerous organic and biochemical processes. Applying the ab initio metadynamics method, we simulated the keto-enol isomerism both in the gas phase and in the presence of water. For the gas-phase intramolecular mechanism we show that no other hydrogen-tronsfer reactions can compete with the simple keto-enol tautomerism. We obtain an intermolecular mechanism and remarkable participation of water when acetone is solvated by neutral water. The simulations reveal that C deprotonation is the kinetic bottleneck of the keto-enol transformation, in agreement with experimental observations. The most interesting finding is the formation of short H-bonded chains of water molecules that provide the route for proton transfer from the carbon to the oxygen atom of acetone. The mechanistic picture that emerged from the present study involves proton migration and emphasizes the importance of active solvent participation in tautomeric interconversion.
引用
收藏
页码:1229 / 1234
页数:6
相关论文
共 49 条
[41]   Coordination numbers as reaction coordinates in constrained molecular dynamics [J].
Sprik, M .
FARADAY DISCUSSIONS, 1998, 110 :437-445
[42]   Free energy from constrained molecular dynamics [J].
Sprik, M ;
Ciccotti, G .
JOURNAL OF CHEMICAL PHYSICS, 1998, 109 (18) :7737-7744
[43]   β-Lactone synthesis from epoxide and CO:: Reaction mechanism revisited [J].
Stirling, A ;
Iannuzzi, M ;
Parrinello, M ;
Molnar, F ;
Bernhart, V ;
Luinstra, GA .
ORGANOMETALLICS, 2005, 24 (10) :2533-2537
[44]   Azulene-to-naphthalene rearrangement: The Car-Parrinello metadynamics method explores various mechanisms [J].
Stirling, A ;
Iannuzzi, M ;
Laio, A ;
Parrinello, M .
CHEMPHYSCHEM, 2004, 5 (10) :1558-1568
[45]   Polysiloxanes: Ab initio force field and structural, conformational and thermophysical properties [J].
Sun, H ;
Rigby, D .
SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY, 1997, 53 (08) :1301-1323
[46]   BASE-CATALYZED HALOGENATION OF ACETONE [J].
TAPUHI, E ;
JENCKS, WP .
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 1982, 104 (21) :5758-5765
[47]   NON-PHYSICAL SAMPLING DISTRIBUTIONS IN MONTE-CARLO FREE-ENERGY ESTIMATION - UMBRELLA SAMPLING [J].
TORRIE, GM ;
VALLEAU, JP .
JOURNAL OF COMPUTATIONAL PHYSICS, 1977, 23 (02) :187-199
[48]   UNSTABLE ENOLS IN THE GAS-PHASE - PREPARATION, IONIZATION ENERGIES, AND HEATS OF FORMATION OF (E)-2-BUTEN-2-OL AND (Z)-2-BUTEN-2-OL, 2-METHYL-1-PROPEN-1-OL, AND 3-METHYL-2-BUTEN-2-OL [J].
TURECEK, F ;
BRABEC, L ;
KORVOLA, J .
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 1988, 110 (24) :7984-7990
[49]   Structure and dynamics of nonaqueous mixtures of dipolar liquids. II. Molecular dynamics simulations [J].
Venables, DS ;
Schmuttenmaer, CA .
JOURNAL OF CHEMICAL PHYSICS, 2000, 113 (08) :3249-3260