Femtosecond b-cleavage dynamics: Observation of the diradical intermediate in the nonconcerted reactions of cyclic ethers

نویسندگان

  • A. A. Scala
  • A. H. Zewail
  • Arthur Amos Noyes
چکیده

Femtosecond ~fs! dynamics of reactions of cyclic ethers, symmetric and asymmetric structures, are reported. The diradical intermediates and their b-cleavages, which involve simultaneous C-C, C-H s-bond breakage and C-O, C-C p-bond formation, are observed and studied by fs-resolved mass spectrometry. To compare with experiments, we present density functional theory calculations of the potential energy surface and microcanonical rates and product distributions. © 1998 American Institute of Physics. @S0021-9606~98!02619-1#

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

Direct imaging of transient molecular structures with ultrafast diffraction.

Ultrafast electron diffraction (UED) has been developed to study transient structures in complex chemical reactions initiated with femtosecond laser pulses. This direct imaging of reactions was achieved using our third-generation apparatus equipped with an electron pulse (1.07 +/- 0.27 picoseconds) source, a charge-coupled device camera, and a mass spectrometer. Two prototypical gas-phase react...

متن کامل

CLEAVAGE OF ESTERS AND ETHERS WITH SILICA CHLORIDE

Silica chloride converted benzyl or tert-butyl esters to the corresponding acid chlorides and alkyl chlorides. It also converted benzyl or tert-butyl phenyl ethers to the corresponding allcyl chlorides and phenol

متن کامل

Studies on DNA-cleaving agents: computer modeling analysis of the mechanism of activation and cleavage of dynemicin-oligonucleotide complexes.

Dynemicin A is a recently identified antitumor antibiotic. Upon activation, dynemicin is reported to cause double-stranded cleavage of DNA, putatively through the intermediacy of a diradical. Computer modeling of this activation and cleavage process is described herein as part of an effort to establish a structural hypothesis for this mechanistic sequence and for the design of simple analogues....

متن کامل

Rapid oxidation of alcohols and trimethylsilyl and tetrahydropyranyl ethers with CrO3 in the presence of sulfonic acid functionalized ordered nanoporous Na+-montmorillonite

A mild, efficient and fast method for the oxidation of alcohols and trimethylsilyl and tetrahydropyranyl ethers to their corresponding carbonyl compounds using CrO3 in the presence of sulfonic acid functionalized ordered nanoporous Na+-montmorillonite (SANM) and under solvent-free conditions is reported. All reactions were performed at room temperature in high to excellent...

متن کامل

Double proton transfer dynamics of model DNA base pairs in the condensed phase.

The dynamics of excited-state double proton transfer of model DNA base pairs, 7-azaindole dimers, is reported using femtosecond fluorescence spectroscopy. To elucidate the nature of the transfer in the condensed phase, here we examine variation of solvent polarity and viscosity, solute concentration, and isotopic fractionation. The rate of proton transfer is found to be significantly dependent ...

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:

دوره   شماره 

صفحات  -

تاریخ انتشار 1998