Spectroscopy historical aspects

One quality control application of near-IR spectroscopy is the nondestructive determination of tablet hardness. Near-IR prediction of tablet hardness has been used and investigated by Drennen for a number of years. In 1991, the first publication of the near-IR technique for this application appeared [26]. Ciurczak and Drennen published similar results in 1992 [60] and Drennen and Lodder in 1993 [61]. Results of a study presented at the 1994 annual meeting of the American Association of Pharmaceutical Scientists were published in a 1995 paper [62]. In that paper, Kirsch and Drennen identified the utility of the technique in the determination of multiple film-coated tablet properties, including tablet hardness. In a review paper regarding the use of near-IR in the analysis of solid dosage forms, Kirsch and Drennen discussed the historical aspects of near-IR prediction of tablet hardness [27]. 

In the preceding Sect. I have tried to illustrate the problems and developments of polymer stereochemistry from both the historical and logical points of view. A clear connection exists between synthetic and stmctural aspects For the solution of problems yet unsolved an interdisciplinary approach is required involving not only polymer chemistry but also spectroscopy, crystallography, statistical thermodynamics, solid state physics, and so on. 

An especially convenient aspect of IR spectroscopy is its practice. A small amount of sample can be pressed between two NaCl or KBr (Table 6.19) disks and the spectrum can be determined without further preparation. A spectrum so obtained is recorded as neat or between salts. If the sample is a solid, it may be mixed in a mortar and pestle with KBr and then pressed into a disk. The salt disk may be placed directly in the IR beam. In neither case is there a concern about solvent peaks. Of course, solvents may be used. Carbon tetrachloride and chloroform are the most commonly used solvents when the compound requires dissolution. Alternately, the sample may be intimately mixed (mulled) with mineral oil (a hydrocarbon oil). The thick slurry may then be smeared on a salt disk and placed in the spectrometer. The brand of mineral oil used historically is Nujol and such slurries are still called Nujol mulls. The transmission characteristics of potential solvents for IR spectroscopy may be found in Table 6.20. 

Why then write another review on the (helium I) photoelectron spectroscopy of silicon compounds At a time of rapidly increasing computer application to various aspects of preparative chemistry, it seems worthwhile to summarize historic and more recent achievements in the rapidly progressing knowledge of silicon-containing molecules, and their molecular state properties, which are via Koopmans theorem intimately connected to quantum chemical calculations. Above all, some selected cases are well-suited to illustrate... 

This contribution deals with the use of ultraviolet photoelectron spectroscopy (UPS) for the study of the surface and bulk electronic structure of organic molecular and polymeric solids. In so far as is necessary, some features of the UPS of isolated model monomer molecules in the gas phase are described in order to provide a basis for an understanding of certain phenomena that occur in the corresponding condensed molecular and polymeric solids. Some features of photoelectron spectroscopy in general are outlined with an emphasis on the phenomenological interpretation of spectra for the several case studies to be reviewed. The complimentary nature of X-ray photoelectron spectroscopy (XPS or sometimes ESCA) and UPS is pointed out. The discussions presented are focused upon the experimental aspects of the UPS of insulating organic molecular and polymeric solids, but specific hardware considerations are not included. A variety of references, some of a review nature, are included, but the content is not intended to be historically complete. Examples for examination are drawn primarily from the author s own experience. 

All these theories are now only of historical interest because developments in spectroscopic techniques and the application of the quantum theory and wave mechanics are throwing an entirely new light upon our understanding of the causes of colour. In the first place, spectroscopy has shown that all organic compounds, whether they contain chromophores or not, absorb radiation. The fact that some are coloured is purely fortuitous because it so happens that their strong absorption bands lie within the narrow range of radiation to which the human eye is sensitive. Colour, therefore, is only a special aspect of a general phenomenon. 

The thirty three papers in the proceedings of QSCP-Xni are divided between the present two volumes in the following manner. The first volume, with the subtitle Conceptual and Computational Advances in Quantum Chemistry, contains twenty papers and is divided into six parts. The first part focuses on historical overviews of significance to the QSCP workshop series and quantum chemistry. The remaining five parts, entitled High-Precision Quantum Chemistry, Beyond Nonrelativistic Theory Relativity and QED, Advances in Wave Function Methods, Advances in Density Functional Theory, and Advances in Concepts and Models, address different aspects of quantum mechanics as applied to electronic structure theory and its foundations. The second volume, with the subtitle Dynamics, Spectroscopy, Clusters, and Nanostructures, contains the remaining thirteen papers and is divided into three parts Quantum Dynamics and Spectroscopy, Complexes and Clusters, and Nanostructures and Complex Systems. ... 

There have been a number of recent review articles on the application of EXAFS spectroscopy to the study of metalloproteins [1-8]. The theory of EXAFS spectroscopy and the historical development of the field have also been extensively discussed [1-5,7-19]. Here we will briefly cover the practical aspects of data analysis for biological heme (iron porphyrin) systems eind the appropriate model complexes. We will then focus on the EXAFS of two types of biological heme system (a) thiolate-ligated heme enzymes and (b) oxo-ferryl [oxo-iron (IV), Fe =0] states of heme enzymes. All of the enzymes discussed herein have in common the iron protoporphyrin IX ( heme ) as the prosthetic group, Fig. 1. 

Since scientific achievements in laser physics have been pushed forward by a few pioneers, it is interesting to look back to the historical development and to the people who influenced it. Such a personal view can be found in [1.32,1.33]. The reference list at the end of the book might be helpful in finding more details of a special experiment or to dig deeper into theoretical and experimental aspects of each chapter. A useful Encyclopedia of spectroscopy [1.34] gives a good survey on different aspects of laser spectroscopy. 

This book is intended as an introduction to the basic methods and instrumentation of spectroscopy, with special emphasis placed on laser spectroscopy. The examples in each chapter illustrate the text and may suggest other possible applications. They are mainly concerned with the spectroscopy of free atoms and molecules and are, of course, not complete, but have been selected from the literature or from our own laboratory work for didactic purposes and may not represent the priorities of publication dates. For a far more extensive survey of the latest publications in the broad field of laser spectroscopy, the reader is referred to the proceedings of various conferences on laser spectroscopy [1-11] and to textbooks or collections of articles on modem aspects of laser spectroscopy [12-32]. Since scientific achievements in laser physics have been pushed forward by a few pioneers, it is interesting to look back to the historical development and to the people who influenced it. Snch a personal view can be found in [33, 34]. The reference list at the end of the book might be helpful in finding more details of a special experiment or to dig deeper into theoretical and experimental aspects of each chapter. A useful Encyclopedia of spectroscopy [35, 36] gives a good survey on different aspects of laser speclroscopy. 

Abstract The chapter describes the most important fluorescence studies of polymer systems. It maps the progress in the study of polymer conformations, dynamics, self-assembly, and other properties of polymer systems by different fluorescence methods from the historical perspective. It offers the selection of seminal studies by pioneers of polymer fluorescence (as representative as possible), papers that significantly contributed to the solution of important problems, and also the up-to-date studies that follow the world trends of polymer research. Great attention is given to studies of dynamic processes. The end of the chapter addresses the opto-electroactive jt-conjugated polymers. This topic exceeds the scope of the chapter and only some aspects of the fluorescence of it-conjugated polymers are reviewed. Special attention is devoted to the application of single-molecule fluorescence spectroscopy in the research of opto-electroactive polymers. 

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