Theoretical study on the alkaline hydrolysis of methyl thioacetate in aqueous solution.

نویسندگان

  • Chein-Wei Fu
  • Thy-Hou Lin
چکیده

A base-catalyzed hydrolysis reaction of thiolester has been studied in both gas and solution phases using two ab initio quantum mechanics calculations such as Gaussian09 and CPMD. The free-energy surface along the reaction path is also constructed using a configuration sampling technique, namely, the metadynamics method. While there are two different reaction paths obtained for the potential profile of the base-catalyzed hydrolysis reaction for thiolester in the gas phase, a triple-well reaction path is computed for the reaction in the solution phase by two quantum mechanics calculations. Unlike the S(N)2 mechanism (a concerted mechanism) found for the gas-phase reaction, a nucleophilic attack from the hydroxide ion on the carbonyl carbon to yield a tetrahedral intermediate (a stepwise mechanism) is observed for the solution-phase reaction. Moreover, the energy profiles computed by these two theoretical calculations are found to be very comparable with those determined experimentally.

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Recovery of Methyl Acetoacetate from Antibiotic Production Plant\'s Waste Streams (TECHNICAL NOTE)

Chemical recovery of methyl acetoacetate from the amoxicillin plant’s waste stream was investigated. In process of amoxicillin production for activation of amoxicillin molecule, hydrolysis takes place at final stage. As a result methyl acetoacetate is formed. Liquid-liquid extraction was employed for the recovery of methyl acetoacetate from the waste stream. Diluted alkaline solution was used a...

متن کامل

Stability Modification of SPR Silver Nano-Chips by Alkaline Condensation of Aminopropyltriethoxysilane

The Silver SPR chip was modified by alkaline-silane condensation with aminopropyltriethoxysilane (APTES) in NaOH aqueous solution at different times. Silver sputtered slides coated with APTES were immersed in NaOH solution, enabling us to produce silver surfaces homogeneously covered with APTES. The surface properties of grafted APTES on sputtered silver surface as a occasion of time were studi...

متن کامل

Study of the adsorption of methyl orange from aqueous solution using nickel oxide nanoparticles: Equilibrium and Kinetics Studies

Methyl orange is one dye resulted from the textile industry. The aim of this study is to test theadsorption capacity of nickel oxide nanoparticles for removing the methyl orange from aqueoussolution. The parameters studied were the effect of temperature, contact time and initial pH ofsolution. Results indicate that the removal efficiency of nickel oxide nanoparticles increases withincreasing co...

متن کامل

Enzymes-Assisted Generation of Thiols from Thioacetates

Thiols are important constituents of the flavour of many foods and beverages. They were produced efficiently by enzymatic hydrolysis of thioacetates, which are commercially available or easily accessible, by reaction of thioacetic acid with alkenes. Enzymatic reactions were performed in water or phosphate buffer resulting in good overall yields of the target thiols. Introduction Natural flavour...

متن کامل

Alkaline phosphatase mono- and diesterase reactions: comparative transition state analysis.

Enzyme-catalyzed phosphoryl transfer reactions have frequently been suggested to proceed through transition states that are altered from their solution counterparts. Previous work with Escherichia coli alkaline phosphatase (AP), however, suggests that this enzyme catalyzes the hydrolysis of phosphate monoesters through a loose, dissociative transition state, similar to that in solution. AP also...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

عنوان ژورنال:
  • The journal of physical chemistry. A

دوره 115 46  شماره 

صفحات  -

تاریخ انتشار 2011