ISSN:0038-7010    

DOI:10.1080/00387017508067327

出版商:Taylor & Francis Group    

年代:1975

数据来源: Taylor

摘要:

Among the many different applications to which lasers have been put, one of the more intriguing is their potential use in photochemistry - particularly, in inducing specific reaction pathways that are not accessible from conventional broad-band excitation. One of the first of such experiments was an attempt to use a ruby laser to carry out laser-flash photolysis of Br2, analogous to Porter's work on I2. Since the optical energy of the laser radiation (14,400 cm−l) was less than the Br2dissociation energy, direct photodissociation was not possible; instead, excited Br2* (3πlu) molecules were produced, which were dissociated in subsequent collisions. The Br atoms formed in this way subsequently added to halogenated olefins such as C4F8and C4F7Cl.1The first actual laser flash-photolysis experiment, carried out in Porter's laboratory, used a Q-switched ruby laser to photodissociate dihydrophthalocyanine vapor at ca. 400°C; a multi-photon process is likely to be involved in this case.2As high-power infrared lasers became available, these were used to effect the decomposition of monia, ethyl chloride, and other molecules absorbing at 10.6 μm.3,4It seems clear, in retrospect, that all these reactions were essentially a laser-induced pyrolysis.

ISSN:0038-7010    

DOI:10.1080/00387017508067328

出版商:Taylor & Francis Group    

年代:1975

数据来源: Taylor

摘要:

Results of an experimental study the reaction between electron-excited I2-molecules and an olefine (2-hexene) are given. It is shown that the reaction proceed with excited I2-molecules directly and it is highly selective. Selectivity of the reaction hes been studied primarily on the basis of binding of ortho-I2molecules. Laser separation of ortho-I2and para-I2molecules has been accomplished in the paper.

ISSN:0038-7010    

DOI:10.1080/00387017508067329

出版商:Taylor & Francis Group    

年代:1975

数据来源: Taylor

摘要:

Studies on the structures and dynamic behaviors of electron donor-acceptor(EDA) systems in the excited state (such as exciplexes and excited EDA complexes which are stable also in the ground state) are important for understanding primary processes of some photochemical and photobiological reactions, especially photo-oxidationreduction reactions.

ISSN:0038-7010    

DOI:10.1080/00387017508067330

出版商:Taylor & Francis Group    

年代:1975

数据来源: Taylor

摘要:

The development of the laser some twelve years ago has resulted in the creation and/or the resuscitation of a number of experimental disciplines involving measurements of energy transfer, chemical reaction rates, high resolution spectroscopy as well as nonlinear effects. In the last three years more and more work involving the use of lasers has been reported on in the literature and a number of excellent review articles has been published dealing with many specific experimental and theoretical subfields(1)The audience tuned to laser and laser related research has steadily expanded to include widely varying disciplines ranging from Engineers to Chemists and from Artists to Meteorologists and is reflected in a variety of professional publications tailored for more or less specific audiences; but even a brief survey of the most widely read physical chemistry journals will convince anyone that one of the most extensive applications of the laser has been in the field of energy transfer studies. The study of energy transfer between the various internal modes and translation has been a topic of fundamental research for a number of decades, yet the detailed probing and “preparation” of well defined vibrational, rotational or electronically excited species have always been at best difficult. The availability of a monochromatic, high power, short pulse duration, and almost tunable sources was a boon to chemists, since the new research tool offered the intriguing possibility of measuring the rate constants for processes taking place between molecules “prepared” in well defined quantum states. As a field within a field, the specific application of vibrational excitation of molecules and the subsequent measurement of the various relaxation rates has received the most attention; partly due, no doubt, to the properties of the molecular lasers available in the infrared region and partly due to the significance of vibrational excitation on the rate and mechanism of chemical reactions.

ISSN:0038-7010    

DOI:10.1080/00387017508067331

出版商:Taylor & Francis Group    

年代:1975

数据来源: Taylor

摘要:

A method is described for generating stabilized, intensity-limited pulsetrains from a mode-locked Nd:glass laser with internal second-harmonic generation.

ISSN:0038-7010    

DOI:10.1080/00387017508067332

出版商:Taylor & Francis Group    

年代:1975

数据来源: Taylor

摘要:

From a re-examination of the Einstein coefficients in terms of current theory the common assumption that population inversion cannot be maintained in a two level system by optical pumping is shown to be erroneous. The nonisotropy of the radiative ensemble in an optical resonant cavity, absent from the original derivation by Einstein, is shown to be of decisive importance.

ISSN:0038-7010    

DOI:10.1080/00387017508067333

出版商:Taylor & Francis Group    

年代:1975

数据来源: Taylor

摘要:

This is a scanned image of the original Editorial Board page(s) for this issue.

ISSN:0038-7010    

DOI:10.1080/00387017508067326

出版商:Taylor & Francis Group    

年代:1975

数据来源: Taylor