Kinetic Isotope Effects on Dehalogenations at an Aromatic Carbon

被引:37
作者
Dybala-Defratyka, Agnieszka [1 ]
Szatkowski, Lukasz [1 ]
Kaminski, Rafal [1 ]
Wujec, Monika [2 ]
Siwek, Agata [2 ]
Paneth, Piotr [1 ]
机构
[1] Tech Univ Lodz, Inst Appl Radiat Chem, PL-90924 Lodz, Poland
[2] Med Univ, Fac Pharm, Dept Organ Chem, PL-20081 Lublin, Poland
关键词
D O I
10.1021/es800276y
中图分类号
X [环境科学、安全科学];
学科分类号
08 ; 0830 ;
摘要
In order to interpret the observed isotopic fractionation it is necessary to understand its relationship with the isotope effect(s) on steps that occur during the conversion of the initial reactant to the final product. We examine this relationship from the biochemical point of view and elaborate on the consequences of the assumptions that it is based on. We illustrate the discrepancies between theoretical and experimental interpretation of kinetic isotope effects on examples of dehalogenation reactions that occur at an aromatic carbon atom. The examples include 4-chlorobenzoyl-CoA dehalogenase-catalyzed conversion of 4-chlorobenzoyl-CoA to 4-hydroxybenzoyl-CoA, dehaloperoxidase-catalyzed conversion of 2,4,6-trichlorophenol to 2,6-dichloroquinone, and spontaneous hydrolysis of atrazine at pH 12. For this latter reaction we have measured the chlorine kinetic isotope effect and estimated its value theoretically at the DFT level of theory. Results of chlorine kinetic isotope effects suggest that the studied dechlorination reactions proceed in a single step with significant weakening of the carbon-chlorine bond in the transition state.
引用
收藏
页码:7744 / 7750
页数:7
相关论文
共 59 条
[1]   ISOEFF98. A program for studies of isotope effects using Hessian modifications [J].
Anisimov, V ;
Paneth, P .
JOURNAL OF MATHEMATICAL CHEMISTRY, 1999, 26 (1-3) :75-86
[2]   DENSITY-FUNCTIONAL EXCHANGE-ENERGY APPROXIMATION WITH CORRECT ASYMPTOTIC-BEHAVIOR [J].
BECKE, AD .
PHYSICAL REVIEW A, 1988, 38 (06) :3098-3100
[3]   Quantitative evaluation of carbon isotopic fractionation during reversed-phase high-performance liquid chromatography [J].
Caimi, RJ ;
Brenna, JT .
JOURNAL OF CHROMATOGRAPHY A, 1997, 757 (1-2) :307-310
[4]   Evidence for direct attack by hydroxide in phosphodiester hydrolysis [J].
Cassano, AG ;
Anderson, VE ;
Harris, ME .
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 2002, 124 (37) :10964-10965
[5]   EFFICIENT DIFFUSE FUNCTION-AUGMENTED BASIS SETS FOR ANION CALCULATIONS. III. THE 3-21+G BASIS SET FOR FIRST-ROW ELEMENTS, LI-F [J].
CLARK, T ;
CHANDRASEKHAR, J ;
SPITZNAGEL, GW ;
SCHLEYER, PV .
JOURNAL OF COMPUTATIONAL CHEMISTRY, 1983, 4 (03) :294-301
[6]   SELF-CONSISTENT MOLECULAR-ORBITAL METHODS .9. EXTENDED GAUSSIAN-TYPE BASIS FOR MOLECULAR-ORBITAL STUDIES OF ORGANIC MOLECULES [J].
DITCHFIELD, R ;
HEHRE, WJ ;
POPLE, JA .
JOURNAL OF CHEMICAL PHYSICS, 1971, 54 (02) :724-+
[7]   A new interpretation of chlorine leaving group kinetic isotope effects; A theoretical approach [J].
Dybala-Defratyka, A ;
Rostkowski, M ;
Matsson, O ;
Westaway, KC ;
Paneth, P .
JOURNAL OF ORGANIC CHEMISTRY, 2004, 69 (15) :4900-4905
[8]  
DYBALADEFRATYKA A, 2008, QUANTUM TUN IN PRESS
[9]  
DYBALADEFRATYKA A, 2006, ROYAL SOC CHEM SPECI, V303, P163
[10]  
EISNER M, 2005, ENVIRON SCI TECHNOL, V39, P6896