Femtochemistry is the
sciencethat studies chemical reactions on extremely short timescales, approximately 10–15 seconds (one femtosecond, hence the name).
1999, Ahmed H. Zewailreceived the Nobel Prize in Chemistryfor his pioneering work in this field.
Zewail’s technique uses flashes of
laserlight that last for a few femtoseconds. Femtochemistry is the area of physical chemistrythat addresses the short time period in which chemical reactions take place and investigates why some reactions occur but not others. Zewail’s picture-taking technique made possible these investigations. One of the first major discoveries of femtochemistry was to reveal details about the intermediate products that form during chemical reactions, which cannot be deduced from observing the starting and end products. Many publications have discussed the possibility of controlling chemical reactions by this method, but this remains controversial.
The simplest approach and still one of the most common techniques is known as pump-probe spectroscopy. In this method, two or more optical pulses with variable time delay between them are used to investigate the processes happening during a chemical reaction. The first pulse (pump) initiates the reaction, by breaking a bond or exciting one of the reactants. The second pulse (probe) is then used to interrogate the progress of the reaction a certain period of time after initiation. As the reaction progresses, the response of the reacting system to the probe pulse will change. By continually scanning the time delay between pump and probe pulses and observing the response, workers can follow the progress of the reaction in real time.
* [http://nobelprize.org/chemistry/laureates/1999/press.html The 1999 Nobel Prize in Chemistry] , article on "nobelprize.org"
* [http://uf.catalog.fcla.edu/uf.jsp?Ntt=corneliu%20manescu&I=0&N=20&S=JK19HT6CPPU3D7U4N4MFYNC6XYK6LDYB53K6VILHSBAUFDC3AD&Ntk=Author&V=D&Nty=1 Controlling and probing atoms and molecules with ultrafast laser pulses] , PhD Thesis
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См. также в других словарях:
femtochemistry — femtochemija statusas T sritis chemija apibrėžtis Chemijos skyrius, taikantis femtosekundinius (10⁻¹⁵ s) lazerio impulsus. atitikmenys: angl. femtochemistry rus. фемтохимия … Chemijos terminų aiškinamasis žodynas
femtochemistry — noun the study of chemical reactions on a very short time scale, often using pulsed lasers … Wiktionary
femtochemistry — noun the branch of chemistry that studies elementary (often very fast) chemical reactions as they occur; the experimental methods are often based on the use of femtosecond laser pulses • Hypernyms: ↑chemistry, ↑chemical science … Useful english dictionary
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