Table Of ContentCHIROPTICAL
SPECTROSCOPY
CHIROPTICAL
SPECTROSCOPY
Fundamentals and
Applications
Prasad L. Polavarapu
Vanderbuilt University, Nashville, Tennessee, USA
Boca Raton London New York
CRC Press is an imprint of the
Taylor & Francis Group, an informa business
CRC Press
Taylor & Francis Group
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Boca Raton, FL 33487-2742
© 2017 by Taylor & Francis Group, LLC
CRC Press is an imprint of Taylor & Francis Group, an Informa business
No claim to original U.S. Government works
Printed on acid-free paper
Version Date: 20160711
International Standard Book Number-13: 978-1-4200-9246-2 (Hardback)
This book contains information obtained from authentic and highly regarded sources. Reasonable efforts
have been made to publish reliable data and information, but the author and publisher cannot assume
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have attempted to trace the copyright holders of all material reproduced in this publication and apologize to
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Library of Congress Cataloging‑in‑Publication Data
Names: Polavarapu, Prasad L.
Title: Chiroptical spectroscopy : fundamentals and applications / Prasad L. Polavarapu.
Description: Boca Raton : Taylor & Francis, 2017. | “A CRC title.” | Includes
bibliographical references and index.
Identifiers: LCCN 2016009687 | ISBN 9781420092462 (alk. paper)
Subjects: LCSH: Optical spectroscopy. | Spectrum analysis. | Vibrational spectra.
Classification: LCC QC454.O66 P65 2017 | DDC 543/.5--dc23
LC record available at https://lccn.loc.gov/2016009687
Visit the Taylor & Francis Web site at
http://www.taylorandfrancis.com
and the CRC Press Web site at
http://www.crcpress.com
CRC Press
Taylor & Francis Group
6000 Broken Sound Parkway NW, Suite 300
Boca Raton, FL 33487-2742 To Bharathi, Sruthi, and Aaseesh
© 2017 by Taylor & Francis Group, LLC
CRC Press is an imprint of Taylor & Francis Group, an Informa business
No claim to original U.S. Government works
Printed on acid-free paper
Version Date: 20160711
International Standard Book Number-13: 978-1-4200-9246-2 (Hardback)
This book contains information obtained from authentic and highly regarded sources. Reasonable efforts
have been made to publish reliable data and information, but the author and publisher cannot assume
responsibility for the validity of all materials or the consequences of their use. The authors and publishers
have attempted to trace the copyright holders of all material reproduced in this publication and apologize to
copyright holders if permission to publish in this form has not been obtained. If any copyright material has
not been acknowledged please write and let us know so we may rectify in any future reprint.
Except as permitted under U.S. Copyright Law, no part of this book may be reprinted, reproduced, transmit-
ted, or utilized in any form by any electronic, mechanical, or other means, now known or hereafter invented,
including photocopying, microfilming, and recording, or in any information storage or retrieval system,
without written permission from the publishers.
For permission to photocopy or use material electronically from this work, please access www.copyright.
com (http://www.copyright.com/) or contact the Copyright Clearance Center, Inc. (CCC), 222 Rosewood
Drive, Danvers, MA 01923, 978-750-8400. CCC is a not-for-profit organization that provides licenses and
registration for a variety of users. For organizations that have been granted a photocopy license by the CCC,
a separate system of payment has been arranged.
Trademark Notice: Product or corporate names may be trademarks or registered trademarks, and are used
only for identification and explanation without intent to infringe.
Library of Congress Cataloging‑in‑Publication Data
Names: Polavarapu, Prasad L.
Title: Chiroptical spectroscopy : fundamentals and applications / Prasad L. Polavarapu.
Description: Boca Raton : Taylor & Francis, 2017. | “A CRC title.” | Includes
bibliographical references and index.
Identifiers: LCCN 2016009687 | ISBN 9781420092462 (alk. paper)
Subjects: LCSH: Optical spectroscopy. | Spectrum analysis. | Vibrational spectra.
Classification: LCC QC454.O66 P65 2017 | DDC 543/.5--dc23
LC record available at https://lccn.loc.gov/2016009687
Visit the Taylor & Francis Web site at
http://www.taylorandfrancis.com
and the CRC Press Web site at
http://www.crcpress.com
Contents
Preface .....................................................................................................................xv
Author ..................................................................................................................xvii
1. Polarized Light ................................................................................................1
1.1 Introduction to Light ............................................................................1
1.2 Polarization States .................................................................................4
1.2.1 Dependence on Phase Difference ..........................................5
1.2.2 Dependence on Amplitude Difference ...............................11
1.2.3 Dependence on Both Phase and Amplitude Differences ....12
1.2.4 Generalization ........................................................................14
1.2.5 Advanced Representations ...................................................14
1.3 Energies ................................................................................................14
References .......................................................................................................15
2. Chiral Molecules ...........................................................................................17
2.1 Classification of Molecules ................................................................17
2.2 Configurations of Chiral Molecules .................................................21
2.2.1 Central Chirality ....................................................................22
2.2.2 Axial Chirality ........................................................................27
2.2.3 Helical Chirality .....................................................................29
2.2.4 Planar Chirality ......................................................................30
2.2.5 Propeller Chirality .................................................................31
2.2.6 Other Sources of Chirality ....................................................31
2.3 Conformations .....................................................................................32
2.4 Biomolecular Structures .....................................................................35
References .......................................................................................................35
3. Interaction of Circularly Polarized Light with Chiral Molecules ......37
3.1 Introduction .........................................................................................37
3.2 Optical Rotation ..................................................................................37
3.3 Circular Dichroism .............................................................................42
3.4 Vibrational Raman Optical Activity (VROA) .................................46
3.5 Summary ..............................................................................................54
References .......................................................................................................55
4. Quantum Chemical Formulation of Chiroptical Spectroscopy ..........57
4.1 Interaction of Molecules with Electric Field ....................................58
4.2 Time-Independent Perturbation Theory .........................................60
4.2.1 First-Order Corrections .........................................................61
4.2.2 Molecules in Static Electric Field .........................................62
4.2.3 Second-Order Corrections ....................................................64
vii
viii Contents
4.3 Time-Dependent Perturbation Theory ............................................66
4.4 Molecules in Dynamic Fields ............................................................67
4.4.1 Electric Field Perturbation ....................................................68
4.4.1.1 Dynamic Electric Dipole–Electric Dipole
Polarizability ...........................................................68
4.4.2 Magnetic Field Perturbation .................................................71
4.4.2.1 Dynamic Electric Dipole–Magnetic Dipole
Polarizability ...........................................................71
4.5 Interaction of Molecules with CPL ...................................................72
4.5.1 Electric and Magnetic Fields of CPL ...................................73
4.5.1.1 Electric Field ............................................................73
4.5.1.2 Magnetic Field ........................................................73
4.5.2 Electric Dipole Moment Induced by Electric and
Magnetic Fields of CPL .........................................................74
4.5.3 Specific Optical Rotation .......................................................78
4.5.4 Transition Rates for Molecules Interacting with CPL ......79
4.5.5 Relation to Experimental Absorption and Circular
Dichroism ................................................................................84
4.6 Transition Polarizabilities ..................................................................87
4.7 Summary ..............................................................................................87
References .......................................................................................................88
5. Prediction of Chiroptical Spectra..............................................................89
5.1 Introduction .........................................................................................89
5.2 Spectral Predictions Using Quantum Chemical Methods ...........89
5.2.1 Optical Rotatory Dispersion .................................................90
5.2.1.1 Practical Considerations ........................................93
5.2.2 Electronic Absorption and Circular Dichroism Spectra ....94
5.2.2.1 Practical Considerations ........................................95
5.2.3 Vibrational Absorption and Circular Dichroism Spectra ...95
5.2.3.1 Practical Considerations ......................................101
5.2.4 Vibrational Raman and Raman Optical Activity
spectra....................................................................................102
5.2.4.1 Practical Considerations ......................................104
5.2.4.2 Resonance ROA Spectra ......................................105
5.2.4.3 Surface-Enhanced VROA Spectra ......................105
5.2.5 Role of Solvation on Chiroptical Spectra ..........................105
5.2.6 Approximate Methods for Large Molecules:
Cartesian Tensor Transfer and Fragmentation ................108
5.2.7 Accurate Calculations on Large Molecules:
Molecules-in-Molecules Fragmentation Method ............109
5.3 Spectral Predictions Using Approximate Models ........................110
5.3.1 Optical Rotatory Dispersion ...............................................110
5.3.2 Electronic Circular Dichroism ...........................................110
Contents ix
5.3.3 Vibrational Circular Dichroism .........................................111
5.3.4 Vibrational Raman Optical Activity .................................112
5.4 Summary ............................................................................................112
References .....................................................................................................113
6. Conformational Analysis ..........................................................................123
6.1 Conformational Analysis of Solute Molecule ...................................123
6.1.1 Designation of Bonds..............................................................124
6.1.2 Ring-Puckering Angles ..........................................................124
6.1.3 Symmetries of Generated Conformations ...........................126
6.1.4 Structures with Equivalent Energies ....................................126
6.1.5 Atropisomers ...........................................................................127
6.1.6 Molecular Ions and Radicals .................................................128
6.1.7 Dimeric Structures ..................................................................128
6.1.8 Enantiomer Structures ............................................................129
6.1.9 Boltzmann Populations ..........................................................129
6.2 Conformational Analysis of Solute–Solvent Clusters......................130
6.3 Summary ................................................................................................130
References .....................................................................................................130
7. Experimental Methods for Measuring Chiroptical Spectra ..............133
7.1 Introduction .......................................................................................133
7.2 Optical Rotatory Dispersion ............................................................133
7.2.1 Optical Rotation of Liquid Solutions ................................133
7.2.2 OR of Gas-Phase Samples ...................................................140
7.2.3 Time-Resolved ORD Measurements .................................141
7.2.4 Evanescent Wave OR Measurements ................................141
7.3 Circular Dichroism Measurements ................................................141
7.3.1 Dispersive Spectrometers ...................................................144
7.3.2 FT Spectrometers .................................................................145
7.3.3 Potential Artifacts ................................................................147
7.3.4 Practical Considerations .....................................................150
7.3.5 Tunable Laser-Based Spectrometers .................................157
7.3.6 Time-Resolved Circular Dichroism ..................................157
7.3.7 Nonlinear Spectroscopic Methods ....................................158
7.4 Interconversion of CD and ORD .....................................................158
7.5 VROA Measurements .......................................................................159
7.5.1 Normal VROA Measurements ...........................................159
7.5.2 FT-VROA Measurements ....................................................163
7.5.3 Resonance VROA Measurements ......................................163
7.5.4 Induced Resonance ROA Measurements .........................164
7.5.5 Surface-Enhanced VROA Measurements ........................164
7.5.6 Coherent Anti-Stokes VROA Measurements ...................164
7.5.7 Magnetic VROA Measurements ........................................164
7.6 Related Methods ...............................................................................165
