The breadth of scientific and technological interests in the general topic of photochemistry is truly enormous and includes, for example, such diverse areas as microelectronics, atmospheric chemistry, organic synthesis, non-conventional photoimaging, photosynthesis, solar energy conversion, polymer technologies, and spectroscopy. This Specialist Periodical Report on Photochemistry aims to provide an annual review of photo-induced processes that have relevance to the above wide-ranging academic and commercial disciplines, and interests in chemistry, physics, biology and technology. In order to provide easy access to this vast and varied literature, each volume of Photochemistry comprises sections concerned with photophysical processes in condensed phases, organic aspects which are sub-divided by chromophore type, polymer photochemistry, and photochemical aspects of solar energy conversion. Volume 34 covers literature published from July 2001 to June 2002. Specialist Periodical Reports provide systematic and detailed review coverage in major areas of chemical research. Compiled by teams of leading authorities in the relevant subject areas, the series creates a unique service for the active research chemist, with regular, in-depth accounts of progress in particular fields of chemistry. Subject coverage within different volumes of a given title is similar and publication is on an annual or biennial basis.
Photochemistry Volume 10
A Review of the Literature Published Between July 1977 and June 1978
By D. Bryce-SmithThe Royal Society of Chemistry
Copyright © 1979 The Chemistry Society
All rights reserved.
ISBN: 978-0-85186-590-4Contents
Introduction and Review of the Year By D. Bryce-Smith, xvii,
Part I Physical Aspects of Photochemistry D. Bryce-Smith, xvii,
Chapter 1 Developments in instrumentation and Techniques By M. A. West, 3,
Chapter 2 Photophysical Processes in Condensed Phaess By R. 6. Cundall and M. W. Jones, 117,
Chapter 3 Gas-phase Photoprocesses By D. Phillips, 171,
Part II Photochemistry of Inorganic and Organometallic Compounds,
Chapter 1 Photochemistry of Transition-metal Complexes By A. Cox, 223,
Chapter 2 The Photochemistry of Transition-metal Organometallic Compounds, Carbonyls, and Low-oxidation-state Complexes By J. M. Kelly, 246,
Chapter 3 Photochemistry of Compounds of the Main Group Elements By J. M. Kelly, 270,
Part III Organic Aspects of Photochemistry,
Chapter 1 Photolysis of Carbonyl Compounds By W. M. Horspool, 281,
Chapter 2 Enone Cycloadditions and Rearrangements : Photoreactions of Cyclohexadienones and Quinones By W. M. Horspool, 298,
Chapter 3 Photochemistry of Olefins, Acetylenes, and Related Compounds By W. M. Horspool, 357,
Chapter 4 Photochemistry of Aromatic Compounds By A. Gilbert, 395,
Chapter 5 Photo-reduction and -oxidation By H. A. J. Carless, 456,
Chapter 6 Photoreactions of Compounds containing Heteroatoms other than Oxygen By S. T. Reid, 488,
Chapter 7 Photoelimination By S. T. Reid, 534,
Part IV Polymer Photochemistry By N. S. Allen and (the late) J. F. McKellar, 565,
1 Introduction, 565,
2 Photopolymerization, 565,
3 Optical and Luminescence Properties of Polymers, 572,
4 Photochemical Processes in Polymeric Materials, 580,
5 Photostabilization Processes in Polymeric Materials, 590,
6 Photochemistry of Dyes and Pigments, 593,
7 Appendix: Review of Patent Literature, 596,
Part V Photochemical Aspects of Solar Energy Conversion By M. 0. Archer, 613,
1 Photochemistry, 613,
2 Photoelectrochemistry at Semiconductor Electrodes, 615,
3 Photoelectrochemistry at Metal Electrodes, 624,
4 Photosynthesis, 625,
5 Photovoltaic Cells, 625,
Part VI Chemical Aspects of Photobiology By G. Beddard, 633,
1 Introduction, 633,
2 Photosynthesis, 633,
3 Chlorophyll Protein Complexes, 640,
4 Fluorescence from Photosynthetic Systems, 641,
5 Orientation of Chl in the Membrane, 645,
6 Fluorescence from Photosynthetic Bacteria, 646,
7 Photosynthetic Accessory Pigments, 647,
8 Photosynthetic Bacteria, 650,
9 Photosystem I, 658,
10 Photosystem II, 660,
11 Bacteriorhodopsin, 663,
12 Visual Photoreceptors, 668,
Author Index, 671,
CHAPTER 1
Part I
PHYSICAL ASPECTS OF PHOTOCHEMISTRY
1
Developments in Instrumentation and Techniques
BY M. A. WEST
1 Introduction
Instrumentation and techniques in photochemistry have probably advanced more in the last two years than over any other comparable period. Developments published during the period July 1976 to June 1978 are covered in this Report and papers cited are designed to be representative of the mass of literature covering photochemistry and related subjects, though not comprehensive. It has often been said that advances in photochemical techniques would have been impossible without parallel advances in electro-optics and electronics. The developments in lasers, without doubt the physical photochemists most useful and applicable excitation source, have enabled unprecedented advances to be made in many areas. For example, in high resolution spectroscopy, i.r. diode lasers now offer spectral resolution of 10-4cm-1; fast pulsed techniques now employ tunable picosecond dye lasers for both transient absorption and emission measurements; and selective photochemistry enables high power tunable lasers to be employed effectively for isotope separation and preparative photochemistry.
The reader is referred to two particular issues of Physics Today which include introductory review articles in i.r.-laser-induced-unimolecular reactions (by N. Bloembergen and E. Yablonovitch), rare-gas halide lasers (J. J. Ewing), and sub-picosecond spectroscopy (E. P. Ippen and C. V. Shank); also physics and photochemistry (V. S. Letokhov), high-resolution spectroscopy of atoms, molecules (T. W. Hansch), and coherent Raman spectroscopy (M. D. Levenson). A compilation of papers reviewing the state-of-the-art of lasers in chemistry included sections on laser Raman and other scattering, pollution and combustion, atomic and molecular spectroscopy, isotope separation and selective excitation, fast pulsed techniques, and developments in lasers and laser techniques.
Although little information appears in the open literature on laser separation of uranium isotopes, there is no doubt that this photochemical process will have a significant impact on fuel processing costs if it can be made economically viable. Equally important in the energy context, of course, is the separation of deuterium for production of heavy water, and there are many laboratory examples (see Laser Focus, July 1978, p. 22) of laser-induced enrichment of this particular isotope.
Apart from advances in laser applications, the reader will notice that great strides have been made in photoacoustic spectroscopy and the applications of vidicon detectors: cf. Vols. 6 and 8. The thermal lens effect offers a new way of determining weak absorption and the quantum yield of fluorescence. Several methods have also appeared for high sensitivity atomic detection at levels of 1 atom cm-3.
2 Plasma Sources
Despite the advances in reducing the wavelength of lasers in the vacuum-u.v., electric discharge and microwave-powered lamps still offer the most useful continuous sources for photochemical applications. For example, a miniature cold-cathode discharge source using flowing neon with emission lines at 73.6 and 74.4 nm maintained its flux to ca. [+ or -] 2% with continuous use over 6 months. A commercially available d.c.-excited cold-cathode design of housing provided Lyman-α radiation of high spectral purity by using uranium hydride in a sealed tube as the source of molecular hydrogen. A flowing hollow-cathode lamp produced intense ion resonance radiation (from Ca, Ba, Zn, Mg, Sr, Yb, or Eu) at ca. 1 mW into 4π/25 steradians. Sulphur hexafluoride at 8 K has been photolysed with a microwave-excited argon discharge in a windowless vacuum-u.v. photolysis lamp with principal lines at 105 and 107 nm. The emission spectra of a similarly excited bromine lamp (used for the gas-phase photolysis of pent-1-ene) and a krypton supersonic jet excited by an electron beam have also been published.
Experiments have shown that the coaxial orifice discharge tube is an effective windowless resonance lamp for argon and neon photolysis of matrix-isolated molecules such as CCl4. A current-regulated power supply for cold cathode discharge lamps has maintained a current deviation of < [+ or -]0.08% with hydrogen.
A vacuum-u.v. and soft X-ray radiation source has been proposed, which was based on spontaneous anti-Stokes scattering from an atomic population stored in a metastable level. The brightness of this source was predicted to be higher than any...
