Uv-VIS Spectroscopy and Its Applications

ISBN-13: 9783642774799 / Angielski / Miękka / 2012 / 244 str.

Heinz-Helmut Perkampus; H. C. Grinter; T. L. Threlfall

Opis

UV-VIS spectroscopy is one of the oldest methods in molecular spectroscopy. The definitive formulation of the Bouguer-Lambert- Beer law in 1852 created the basis for the quantitative evaluation of absorption measurements at an early date. This led firstly to colorimetry, then to photometry and finally to spectrophotometry. This evolution ran parallel with the development of detectors for measuring light intensities, i.e. from the human eye via the photo- element and photocell, to the photomultiplier and from the photo- graphic plate to the present silicon-diode detector both of which allow simultaneous measurement of the complete spectrum. With the development of quantum chemistry, increasing atten- tion was paid to the correlation between light absorption and the structure of matter with the result that in recent decades a number of excellent discussions of the theory of electronic spectroscopy (UV-VIS and luminescence sp, ctroscopy) have been published. Consequently, this extremely ivteresting aspect of molecular spec- troscopy has dominated the teaching of the subject both in my own lectures and those of others. However, it is often overlooked that, in addition to the theory, applications of spectroscopic methods are of particular interest to scientists. For this reason, a lecture series about electronic spectroscopy given in the Institute for Physical Chemistry at the Heinrich-Heine-University in Dusseldorf was supplemented by one about "UV-VIS spectroscopy and its applications." This formed the basis of the present book.

Spis treści

1 Introduction.- 2 Principles.- 2.1 The Bouguer-Lambert-Beer Law and Its Practical Application.- 2.2 Primary Photophysical Processes.- 2.3 Vibrational Structure of Electronic Spectra.- 2.4 Electronic Spectra and Molecular Structure.- References.- 3 Photometers and Spectrophotometers.- 3.1 Photometers.- 3.2 Spectrophotometers.- 3.3 The Stray Light Error.- 3.3.1 General Observations.- 3.3.2 The Stray Light Error of Transmission and Absorbance and Its Measurement.- 3.4 Light Sources for UV-VIS Spectroscopy.- References.- 4 Analytical Applications of UV-VIS Spectroscopy.- 4.1 Photometric Determination of a Single Substance.- 4.1.1 Photometric Determination of Elements by Means of Complexing Agents.- 4.1.2 Photometric Determination of Anions and Ammonia.- 4.1.3 Photometric Water Analyses.- 4.1.4 Photometric Determination of Organic Compounds.- 4.1.5 Enzymatic Analysis and Enzyme Kinetics.- 4.2 Multicomponent Analysis.- 4.2.1 Basic Equations.- 4.2.2 An Example of a Multicomponent Analysis.- 4.3 Identification and Structure Determination.- 4.4 Chemometrics.- References.- 5 Recent Developments in UV-VIS Spectroscopy.- 5.1 Dual-Wavelength Spectroscopy.- 5.2 Derivative Spectroscopy.- 5.3 Reflectance Spectroscopy.- 5.4 Photoacoustic Spectroscopy.- 5.4.1 Principles of PAS.- 5.4.2 PAS Applications.- 5.5 Luminescence-Excitation Spectroscopy.- References.- 6 Investigation of Equilibria.- 6.1 General.- 6.2 Protolytic Equilibria; pK-Values.- 6.3 Complex-Forming Equilibria.- 6.3.1 H-Bond Association.- 6.3.2 EDA Complexes.- 6.3.3 Metal Complexes.- References.- 7 Investigation of the Kinetics of Chemical Reactions.- 7.1 Fundamental Equations of Kinetics.- 7.1.1 Introduction of Absorbance as a Measurement Parameter.- 7.1.2 Classification of Other Types of Reaction.- 7.1.2.1 2nd Order Reactions.- 7.1.2.2 3rd Order Reactions.- 7.1.2.3 Pseudo 1st Order Reactions.- 7.1.2.4 Consecutive Reactions.- 7.1.2.5 Parallel Reactions.- 7.2 The Number of Linearly Independent Partial Reactions.- 7.3 Evaluation of Kinetic Measurements.- 7.4 Examples.- 7.5 Fast Reactions.- 7.5.1 Flow Methods: The Stopped-Flow Technique.- 7.5.2 Spectroscopic Relaxation Techniques.- 7.6 Photoreactions.- 7.7 Spectrometers for Kinetic Measurements.- 7.7.1 Rapid Spectrometers.- 7.7.2 FT-UV Spectrometers.- 7.7.3 Diode Array Spectrometers.- 7.8 Determination of the Spectra of Intermediates.- References.- 8 Evaluation of UV-VIS Spectral Bands.- 8.1 Oscillator Strength and Transition Moment.- 8.2 Band Analysis.- 8.2.1 Gaussian and Lorentzian Functions.- 8.2.2 Application of Derivative Spectra.- 8.3 Vibrational Structure.- References.- Index of Illustrated Absorption Spectra.

O autorze

UV-VIS spectroscopy plays an important role in analytical chemistry and owes widespread application in physical chemistry, physics, and life sciences. The author has created a detailed and comprehensive reference on all important aspects of UV-VIS spectroscopy; it will be an invaluable source of information for specialists and non-specialists.