CRC Handbook of Organic Analytical Reagents, Second Edition

Download CRC Handbook of Organic Analytical Reagents, Second Edition PDF Online Free

Author :
Publisher : CRC Press
ISBN 13 : 9780849342875
Total Pages : 628 pages
Book Rating : 4.3/5 (428 download)

DOWNLOAD NOW!


Book Synopsis CRC Handbook of Organic Analytical Reagents, Second Edition by : Kuang Lu Cheng

Download or read book CRC Handbook of Organic Analytical Reagents, Second Edition written by Kuang Lu Cheng and published by CRC Press. This book was released on 1992-09-25 with total page 628 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Handbook of Organic Analytical Reagents, 2nd Edition, is an indispensable source book of physico-chemical properties, preparation, and analytical applications of the most commonly used organic reagents. Updated from the 1st Edition, this volume includes data on 40 new reagents (such as ultra-high sensitive azo dyes, fluorescent calcium indicators, and chromogenic crown ethers and porphyrin reagents), a new Reagent Index listing reagents according to the elements to be assayed, and completely updated references. Each entry contains information on synonyms, sources and methods of synthesis, analytical applications, complexation reactions and the properties of complexes, purification and purity of the reagent, and other regeants with a related structure. The Handbook of Organic Analytical Reagents, 2nd Edition, is an invaluable bench-side reference for professional analytical chemists and graduate students.

Organic Reagents Used in Gravimetric and Volumetric Analysis

Download Organic Reagents Used in Gravimetric and Volumetric Analysis PDF Online Free

Author :
Publisher :
ISBN 13 :
Total Pages : 330 pages
Book Rating : 4.:/5 (38 download)

DOWNLOAD NOW!


Book Synopsis Organic Reagents Used in Gravimetric and Volumetric Analysis by : John Ferard Flagg

Download or read book Organic Reagents Used in Gravimetric and Volumetric Analysis written by John Ferard Flagg and published by . This book was released on 1948 with total page 330 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Organic Reagents Used in Gravimetric and Volumetric Analysis

Download Organic Reagents Used in Gravimetric and Volumetric Analysis PDF Online Free

Author :
Publisher :
ISBN 13 :
Total Pages : 328 pages
Book Rating : 4.3/5 (91 download)

DOWNLOAD NOW!


Book Synopsis Organic Reagents Used in Gravimetric and Volumetric Analysis by : John Ferard Flagg

Download or read book Organic Reagents Used in Gravimetric and Volumetric Analysis written by John Ferard Flagg and published by . This book was released on 1948 with total page 328 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Basic Concepts Of Analytical Chemistry

Download Basic Concepts Of Analytical Chemistry PDF Online Free

Author :
Publisher : New Age International
ISBN 13 : 9788122411591
Total Pages : 506 pages
Book Rating : 4.4/5 (115 download)

DOWNLOAD NOW!


Book Synopsis Basic Concepts Of Analytical Chemistry by : S M Khopkar

Download or read book Basic Concepts Of Analytical Chemistry written by S M Khopkar and published by New Age International. This book was released on 1998 with total page 506 pages. Available in PDF, EPUB and Kindle. Book excerpt: Analytical Chemistry Has Made Significant Progress In The Last Two Decades. Several Methods Have Come To The Forefront While Some Classical Methods Have Been Relegated. An Attempt Has Been Made In This Edition To Strike A Balance Between These Two Extremes, By Retaining Most Significant Methods And Incorporating Some Novel Techniques. Thus An Endeavour Has Been Made To Make This Book Up To Date With Recent Methods.The First Part Of This Book Covers The Classical Volumetric As Well As Gravimetric Methods Of Analysis. The Separation Methods Are Prerequisite For Dependable Quantitative Methods Of Analysis. Therefore Not Only Solvent Extraction Separations But Also Chromatographic Methods Such As Adsorption, Partition, Ion- Exchange, Exclusion Andelectro Chromatography Have Been Included. To Keep Pace With Modern Developments The Newly Discovered Techniques Such As Ion Chromatography, Super-Critical Fluid Chromatography And Capillary Electrophoresis Have Been Included.The Next Part Of The Book Encompases The Well Known Spectroscopic Methods Such As Uv, Visible, Ir, Nmr, And Esr Techniques And Also Atomic Absorption And Plasma Spectroscopy And Molecular Luminescences Methods. Novel Analytical Techniques Such As Auger, Esca And Photo Accoustic Spectroscopy Of Surfaces Are Also Included.The Final Part Of This Book Covers Thermal And Radioanalytical Methods Of Analysis. The Concluding Chapters On Electroanalytical Techniques Include Potientometry, Conductometry. Coulometry And Voltametry Inclusive Of All Kinds Of A Polarography. The Theme Of On Line Analysis Is Covered In Automated Methods Of Analysis.To Sustain The Interest Of The Reader Each Chapter Is Provided With Latest References To The Monographs In The Field. Further, To Test The Comprehension Of The Subject Each Chapter Is Provided With Large Number Of Solved And Unsolved Problems.This Book Should Be Useful To Those Reads Who Have Requisite Knowledge In Chemistry And Are Majoring In Analytical Chemistry. It Is Also Useful To Practising Chemists Whose Sole Aim Is To Keep Abreast With Modern Developments In The Field.

CRC Handbook of Organic Analytical Reagents

Download CRC Handbook of Organic Analytical Reagents PDF Online Free

Author :
Publisher : Routledge
ISBN 13 : 1351457225
Total Pages : 625 pages
Book Rating : 4.3/5 (514 download)

DOWNLOAD NOW!


Book Synopsis CRC Handbook of Organic Analytical Reagents by : Kuang Lu Cheng

Download or read book CRC Handbook of Organic Analytical Reagents written by Kuang Lu Cheng and published by Routledge. This book was released on 2017-09-29 with total page 625 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Handbook of Organic Analytical Reagents, 2nd Edition, is an indispensable source book of physico-chemical properties, preparation, and analytical applications of the most commonly used organic reagents. Updated from the 1st Edition, this volume includes data on 40 new reagents (such as ultra-high sensitive azo dyes, fluorescent calcium indicators, and chromogenic crown ethers and porphyrin reagents), a new Reagent Index listing reagents according to the elements to be assayed, and completely updated references. Each entry contains information on synonyms, sources and methods of synthesis, analytical applications, complexation reactions and the properties of complexes, purification and purity of the reagent, and other regeants with a related structure. The Handbook of Organic Analytical Reagents, 2nd Edition, is an invaluable bench-side reference for professional analytical chemists and graduate students.

Dictionary of Analytical Reagents

Download Dictionary of Analytical Reagents PDF Online Free

Author :
Publisher : CRC Press
ISBN 13 : 0412351501
Total Pages : 1422 pages
Book Rating : 4.4/5 (123 download)

DOWNLOAD NOW!


Book Synopsis Dictionary of Analytical Reagents by : A. Townshend

Download or read book Dictionary of Analytical Reagents written by A. Townshend and published by CRC Press. This book was released on 1993-06-17 with total page 1422 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume dictionary brings together accurate chemical, structural and bibliographic data on the most commonly used reagents in the various branches of analytical chemistry. Covering both organic and inorganic compounds, the "Dictionary of Analytical Reagents" contains over 5,000 reagents significant in analytical chemistry, grouped into 5,000 entries. All the reagents included in the dictionary have been synthesized, characterized by or are of proven use to analytical chemists. Compiled by a distinguished board of leading figures in the world of analytical chemistry, each an expert in their own specialist field, the "Dictionary of Analytical Reagents" is a companion volume to the renowned "Dictionary of Organic Compounds" and follows a similar format. The dictionary is arranged in such a way as to facilitate browsing, with entries ordered alphabetically by entry name (often its trivial name). Clearly laid out in an easy-to-follow manner, each entry contains a wealth of data invaluable to the analytical chemist including synonyms, analytical applications, extensive and up-to-date hazard/toxicity data, solubility, dissociation constant and selected references labelled to indicate their content (e.g. analytical application, spectral data, synthesis). High quality structure diagrams are included to assist the analytical chemist in identifying the reagent needed and are drawn to standard orientations. Coverage extends to metal extractants, spectrophotometric reagents, indicators, fluorescence labelling reagents, resolving agents, nmr shift reagents and reference standards, buffers, gc and ms derivatisation reagents, amperometric reagents, titrimetric and gravimetric reagents, biological stains and dyes. Compounds are comprehensively indexed by Name, Molecular Formula, CAS Registry Number and Type of Compound. The unique Type of Compound Index is particularly valuable as compounds are indexed by use (eg NMR shift reagent), by analyte (eg nickel) and by compound group (eg formazan, crown ether), making the data accessible by a variety of criteria. Thus, chemists can use the dictionary to find information on how to analyze for a particular substance, how a particular compound may be used as an analytical reagent or what other reagents are available for a specific analytical use. Having located all appropriate reagents via the index, the user can then browse through the entries to obtain specific data, all fully referenced in the selective bibliography. Analytical chemists - be they in the manufacturing or pharmaceutical industry, working in hospital laboratories as clinical chemists or pollution analysts monitoring heavy metal residues in waste water - constantly need to make decisions about which reagent to choose for a particular application. This dictionary fulfils that need by being the most comprehensive, reliable and up-to-date compilation of reagents available. This book should be of interest to analytical chemists in academic and industrial establishments, forensic scientists, chromatographers, biochemists, standards institutions, companies selling laboratory chemicals, and water authorities.

Modern Analytical Methodologies in Fat- and Water-Soluble Vitamins

Download Modern Analytical Methodologies in Fat- and Water-Soluble Vitamins PDF Online Free

Author :
Publisher : John Wiley & Sons
ISBN 13 : 0471179426
Total Pages : 500 pages
Book Rating : 4.4/5 (711 download)

DOWNLOAD NOW!


Book Synopsis Modern Analytical Methodologies in Fat- and Water-Soluble Vitamins by : Won O. Song

Download or read book Modern Analytical Methodologies in Fat- and Water-Soluble Vitamins written by Won O. Song and published by John Wiley & Sons. This book was released on 2000-03-27 with total page 500 pages. Available in PDF, EPUB and Kindle. Book excerpt: This self-contained book provides modern and practical analytical methodologies for the assays in foods, pharmaceuticals and clinical samples. It covers the fat-soluble Vitamins: A, beta-carotene, D, E and K as well as the water soluble vitamins, C, folate, thiamin, biotin, pyridoxin and cyancobalims.

Organic Reagents in Metal Analysis

Download Organic Reagents in Metal Analysis PDF Online Free

Author :
Publisher : Elsevier
ISBN 13 : 1483160262
Total Pages : 269 pages
Book Rating : 4.4/5 (831 download)

DOWNLOAD NOW!


Book Synopsis Organic Reagents in Metal Analysis by : K. Burger

Download or read book Organic Reagents in Metal Analysis written by K. Burger and published by Elsevier. This book was released on 2013-10-22 with total page 269 pages. Available in PDF, EPUB and Kindle. Book excerpt: International Series of Monographs in Analytical Chemistry, Volume 54: Organic Reagents in Metal Analysis focuses on the factors determining the analytical selectivity of complexation reactions. This book consists of three chapters. Chapter 1 deals with the effects of stability and electronic structure of complexes and formation of mixed ligand complexes on analytical selectivity. The analytical procedures for the accomplishment of many metal analytical tasks are reviewed in Chapter 2. The last chapter provides a tabulated data that facilitates experimental work in the field of metal analysis. This volume is useful to practical analysts and researchers engaged with developments in the field of analytical chemistry and routine metal analyses.

Large (C> = 24) Polycyclic Aromatic Hydrocarbons

Download Large (C> = 24) Polycyclic Aromatic Hydrocarbons PDF Online Free

Author :
Publisher : John Wiley & Sons
ISBN 13 : 9780471363545
Total Pages : 308 pages
Book Rating : 4.3/5 (635 download)

DOWNLOAD NOW!


Book Synopsis Large (C> = 24) Polycyclic Aromatic Hydrocarbons by : John C. Fetzer

Download or read book Large (C> = 24) Polycyclic Aromatic Hydrocarbons written by John C. Fetzer and published by John Wiley & Sons. This book was released on 2000-08-28 with total page 308 pages. Available in PDF, EPUB and Kindle. Book excerpt: Polycyclische aromatische Kohlenwasserstoffe (PAHs) gehören zu den ersten Chemikalien, die als krebserregend für den Menschen erkannt wurden. Erstmals werden in diesem Buch PAHs mit mehr als sieben Ringen auf modernem Stand systematisch abgehandelt. Spezielle Kapitel beschäftigen sich mit Probenvorbereitung und -handling; auch ein Vergleich verschiedener Analyseverfahren ist enthalten. Besonders nützlich für den Laboralltag ist ein ausführlicher Anhang mit Strukturformeln sowie UV-Absorptions- und Fluoreszenz-Emissionsspektren von fast 50 Verbindungen.

Electroanalytical Chemistry

Download Electroanalytical Chemistry PDF Online Free

Author :
Publisher : John Wiley & Sons
ISBN 13 : 1119538580
Total Pages : 466 pages
Book Rating : 4.1/5 (195 download)

DOWNLOAD NOW!


Book Synopsis Electroanalytical Chemistry by : Gary A. Mabbott

Download or read book Electroanalytical Chemistry written by Gary A. Mabbott and published by John Wiley & Sons. This book was released on 2020-01-31 with total page 466 pages. Available in PDF, EPUB and Kindle. Book excerpt: Provides a strong foundation in electrochemical principles and best practices Written for undergraduate majors in chemistry and chemical engineering, this book teaches the basic principles of electroanalytical chemistry and illustrates best practices through the use of case studies of organic reactions and catalysis using voltammetric methods and of the measurement of clinical and environmental analytes by potentiometric techniques. It provides insight beyond the field of analysis as students address problems arising in many areas of science and technology. The book also emphasizes electrochemical phenomena and conceptual models to help readers understand the influence of experimental conditions and the interpretation of results for common potentiometric and voltammetric methods. Electroanalytical Chemistry: Principles, Best Practices, and Case Studies begins by introducing some basic concepts in electrical phenomena. It then moves on to a chapter that examines the potentiometry of oxidation-reduction processes, followed by another on the potentiometry of ion selective electrodes. Other sections look at: applications of ion selective electrodes; controlled potential methods; case studies in controlled potential methods; and instrumentation. The book also features several appendixes covering: Ionic Strength, Activity and Activity Coefficients; The Nicolsky-Eisenman Equation; The Henderson Equation for Liquid Junction Potentials; Selected Standard Electrode Potentials; and The Nernst Equation Derivation. Introduces the principles of modern electrochemical sensors and instrumental chemical analysis using potentiometric and voltammetric methods Develops conceptual models underlying electrochemical phenomena and useful equations Illustrates best practice with short case studies of organic reaction mechanisms using voltammetry and quantitative analysis with ion selective electrodes Offers instructors the opportunity to select focus areas and tailor the book to their course by providing a collection of shorter texts, each dedicated to a single field Intended as one of a series of modules for teaching undergraduate courses in instrumental chemical analysis Electroanalytical Chemistry: Principles, Best Practices, and Case Studies is an ideal textbook for undergraduate majors in chemistry and chemical engineering taking instrumental analysis courses. It would also benefit professional chemists who need an introduction to potentiometry or voltammetry.

Modern Supercritical Fluid Chromatography

Download Modern Supercritical Fluid Chromatography PDF Online Free

Author :
Publisher : John Wiley & Sons
ISBN 13 : 1119626005
Total Pages : 458 pages
Book Rating : 4.1/5 (196 download)

DOWNLOAD NOW!


Book Synopsis Modern Supercritical Fluid Chromatography by : Larry M. Miller

Download or read book Modern Supercritical Fluid Chromatography written by Larry M. Miller and published by John Wiley & Sons. This book was released on 2019-11-06 with total page 458 pages. Available in PDF, EPUB and Kindle. Book excerpt: Explains why modern supercritical fluid chromatography (SFC) is the leading "green" analytical and purification separations technology. Modern supercritical fluid chromatography (SFC) is the leading method used to analyze and purify chiral and achiral chemical compounds, many of which are pharmaceuticals, pharmaceutical candidates, and natural products including cannabis-related compounds. This book covers current SFC instrumentation as it relates to greater robustness, better reproducibility, and increased analytical sensitivity. Modern Supercritical Fluid Chromatography: Carbon Dioxide Containing Mobile Phases covers the history, instrumentation, method development and applications of SFC. The authors provided readers with an overview of analytical and preparative SFC equipment, stationary phases, and mobile phase choices. Topics covered include: Milestones of Supercritical Fluid Chromatography; Physical Properties of Supercritical Fluids; Instrumentation for SFC; Detection in SFC; Achiral SFC Method Development; Chiral SFC Method Development; and Preparative Scale SFC. The book also includes highlights of modern applications of SFC in the final chapters—namely pharmaceuticals, consumer products, foods, polymers, petroleum-related mixtures, and cannabis—and discusses the future of SFC. Provides a clear explanation of the physical and chemical properties of supercritical fluids, which gives the reader a better understanding of the basis for improved performance in SFC compared to HPLC and GC Describes the advantages of SFC as a green alternative to HPLC and GC for the analysis of both polar, water-soluble, and non-polar analytes Details both achiral and chiral SFC method development, including modifiers, additives, the impact of temperature and pressure, and stationary phase choices Details why SFC is the premier modern preparative chromatographic technique used to purify components of mixtures for subsequent uses, both from performance and economic perspectives Covers numerous detectors, with an emphasis on SFC-MS, SFC-UV, and SFC-ELSD (evaporative light scattering detection) Describes the application of SFC to numerous high-value application areas Modern Supercritical Fluid Chromatography: Carbon Dioxide Containing Mobile Phases will be of great interest to professionals, students, and professors involved in analytical, bioanalytical, separations science, medicinal, petroleum, and environmental chemistries. It will also appeal to pharmaceutical scientists, natural-product scientists, food and consumer-products scientists, chemical engineers, and managers in these areas.

Chemometrics

Download Chemometrics PDF Online Free

Author :
Publisher : John Wiley & Sons
ISBN 13 : 0471202428
Total Pages : 342 pages
Book Rating : 4.4/5 (712 download)

DOWNLOAD NOW!


Book Synopsis Chemometrics by : Foo-Tim Chau

Download or read book Chemometrics written by Foo-Tim Chau and published by John Wiley & Sons. This book was released on 2004-03-25 with total page 342 pages. Available in PDF, EPUB and Kindle. Book excerpt: Wavelet Transformations and Their Applications in Chemistry pioneers a new approach to classifying existing chemometric techniques for data analysis in one and two dimensions, using a practical applications approach to illustrating chemical examples and problems. Written in a simple, balanced, applications-based style, the book is geared to both theorists and non-mathematicians. This text emphasizes practical applications in chemistry. It employs straightforward language and examples to show the power of wavelet transforms without overwhelming mathematics, reviews other methods, and compares wavelets with other techniques that provide similar capabilities. It uses examples illustrated in MATLAB codes to assist chemists in developing applications, and includes access to a supplementary Web site providing code and data sets for work examples. Wavelet Transformations and Their Applications in Chemistry will prove essential to professionals and students working in analytical chemistry and process chemistry, as well as physical chemistry, spectroscopy, and statistics.

Photothermal Spectroscopy Methods

Download Photothermal Spectroscopy Methods PDF Online Free

Author :
Publisher : John Wiley & Sons
ISBN 13 : 1119279097
Total Pages : 726 pages
Book Rating : 4.1/5 (192 download)

DOWNLOAD NOW!


Book Synopsis Photothermal Spectroscopy Methods by : Stephen E. Bialkowski

Download or read book Photothermal Spectroscopy Methods written by Stephen E. Bialkowski and published by John Wiley & Sons. This book was released on 2019-03-21 with total page 726 pages. Available in PDF, EPUB and Kindle. Book excerpt: Covers the advantages of using photothermal spectroscopy over conventional absorption spectroscopy, including facilitating extremely sensitive measurements and non-destructive analysis This unique guide to the application and theory of photothermal spectroscopy has been newly revised and updated to include new methods and applications and expands on applications to chemical analysis and material science. The book covers the subject from the ground up, lists all practical considerations needed to obtain accurate results, and provides a working knowledge of the various methods in use. Photothermal Spectroscopy Methods, Second Edition includes the latest methods of solid state and materials analysis, and describes new chemical analysis procedures and apparatuses in the analytical chemistry sections. It offers a detailed look at the optics, physical principles of heat transfer, and signal analysis. Information in the temperature change and optical elements in homogeneous samples and photothermal spectroscopy in homogeneous samples has been updated with a better description of diffraction effects and calculations. Chapters on analytical measurement and data processing and analytical applications are also updated and include new information on modern applications and photothermal microscopy. Finally, the Photothermal Spectroscopy of Heterogeneous Sample chapter has been expanded to incorporate new methods for materials analysis. New edition updates and expands on applications to chemical analysis and materials science, including new methods of solid state and materials analysis Includes new chemical analysis procedures and apparatuses Provides an unmatched resource that develops a consistent mathematical basis for signal description, consolidates previous theories, and provides invaluable insight into laser technology Photothermal Spectroscopy Methods, Second Edition will appeal to researchers from both academia and industry (graduate students, postdocs, research scientists, and professors) in the general field of analytical chemistry, optics, and materials science, and researchers and engineers at scientific instrument developers in fields related to photonics and spectroscopy.

Acetylacetone as an Analytical Extraction Agent (thesis)

Download Acetylacetone as an Analytical Extraction Agent (thesis) PDF Online Free

Author :
Publisher :
ISBN 13 :
Total Pages : 130 pages
Book Rating : 4.3/5 (91 download)

DOWNLOAD NOW!


Book Synopsis Acetylacetone as an Analytical Extraction Agent (thesis) by : John Franklin Steinbach

Download or read book Acetylacetone as an Analytical Extraction Agent (thesis) written by John Franklin Steinbach and published by . This book was released on 1953 with total page 130 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Research and Development Progress Report

Download Research and Development Progress Report PDF Online Free

Author :
Publisher :
ISBN 13 :
Total Pages : 540 pages
Book Rating : 4.3/5 (91 download)

DOWNLOAD NOW!


Book Synopsis Research and Development Progress Report by : United States. Office of Saline Water

Download or read book Research and Development Progress Report written by United States. Office of Saline Water and published by . This book was released on 1971 with total page 540 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Raman Spectroscopy for Chemical Analysis

Download Raman Spectroscopy for Chemical Analysis PDF Online Free

Author :
Publisher : John Wiley & Sons
ISBN 13 : 0471231878
Total Pages : 451 pages
Book Rating : 4.4/5 (712 download)

DOWNLOAD NOW!


Book Synopsis Raman Spectroscopy for Chemical Analysis by : Richard L. McCreery

Download or read book Raman Spectroscopy for Chemical Analysis written by Richard L. McCreery and published by John Wiley & Sons. This book was released on 2005-02-25 with total page 451 pages. Available in PDF, EPUB and Kindle. Book excerpt: Minimaler Aufwand bei der Probenvorbereitung, hoher Informationsgehalt des Spektrums und die Möglichkeit, mit festen Proben zu arbeiten, machen die Raman-Spektroskopie zunehmend attraktiv. Wie man diese Methode mit modernster Ausrüstung effizient anwendet, zeigt Ihnen das vorliegende Buch. Im Mittelpunkt stehen neue Entwicklungen wie CCDs, Diodenlaser und Fourier-Transform-Techniken. Behandelt werden auch quantitative Analysen, die in der bisher vorhandenen Literatur häufig zu kurz kamen. (08/00)

Shpol'skii Spectroscopy and Other Site-Selection Methods

Download Shpol'skii Spectroscopy and Other Site-Selection Methods PDF Online Free

Author :
Publisher : John Wiley & Sons
ISBN 13 : 9780471245087
Total Pages : 580 pages
Book Rating : 4.2/5 (45 download)

DOWNLOAD NOW!


Book Synopsis Shpol'skii Spectroscopy and Other Site-Selection Methods by : Johannes W. Hofstraat

Download or read book Shpol'skii Spectroscopy and Other Site-Selection Methods written by Johannes W. Hofstraat and published by John Wiley & Sons. This book was released on 2000-08-07 with total page 580 pages. Available in PDF, EPUB and Kindle. Book excerpt: Recent technological breakthroughs, most notably in the field of lasers as well as detection and data processing, have made it possible to apply high-resolution molecular spectroscopy to such areas as environmental science, bioanalysis, and chemical physics. This book describes recent advances and applications of high-resolution molecular spectroscopy in low temperature solid matrices.