Two Dimensional Infrared (2D IR) Spectroscopy of Molecular Vibrational Polaritons (MVPs)

Two Dimensional Infrared (2D IR) Spectroscopy of Molecular Vibrational Polaritons (MVPs) PDF Author: Bo Xiang
Publisher:
ISBN:
Category :
Languages : en
Pages : 129

Get Book Here

Book Description
In this dissertation, the application of advanced spectroscopy, such as two-dimensional infrared (2D IR) spectroscopy to vibrational-polaritons challenges and advances our understanding in both fields, as mentioned detailly in the introduction. In the fourth chapter, 2D IR uniquely resolves excitation of hybrid light-matter polaritons and unexpected dark states in a state-selective manner, revealing otherwise hidden interactions between them. Moreover, 2D IR signals highlight the impact of molecular anharmonicities which are applicable to virtually all molecular systems. Besides revealing the polariton-dark modes interactions, the spectroscopy tools has also been employed to study the optical nonlinearities of the molecular vibrational polaritons. In the fifth chapter, the control of vibrational polariton coherent nonlinearities has been fulfilled by manipulation of macroscopic parameters such as cavity longitudinal length or molecular concentration. In chapter six, we studied the long-lived dynamics of vibrational polaritons in various solvent environments. While the relaxation from upper polariton (UP) to dark modes is always fast (

Two Dimensional Infrared (2D IR) Spectroscopy of Molecular Vibrational Polaritons (MVPs)

Two Dimensional Infrared (2D IR) Spectroscopy of Molecular Vibrational Polaritons (MVPs) PDF Author: Bo Xiang
Publisher:
ISBN:
Category :
Languages : en
Pages : 129

Get Book Here

Book Description
In this dissertation, the application of advanced spectroscopy, such as two-dimensional infrared (2D IR) spectroscopy to vibrational-polaritons challenges and advances our understanding in both fields, as mentioned detailly in the introduction. In the fourth chapter, 2D IR uniquely resolves excitation of hybrid light-matter polaritons and unexpected dark states in a state-selective manner, revealing otherwise hidden interactions between them. Moreover, 2D IR signals highlight the impact of molecular anharmonicities which are applicable to virtually all molecular systems. Besides revealing the polariton-dark modes interactions, the spectroscopy tools has also been employed to study the optical nonlinearities of the molecular vibrational polaritons. In the fifth chapter, the control of vibrational polariton coherent nonlinearities has been fulfilled by manipulation of macroscopic parameters such as cavity longitudinal length or molecular concentration. In chapter six, we studied the long-lived dynamics of vibrational polaritons in various solvent environments. While the relaxation from upper polariton (UP) to dark modes is always fast (

Ultrafast Infrared Vibrational Spectroscopy

Ultrafast Infrared Vibrational Spectroscopy PDF Author: Michael D. Fayer
Publisher: CRC Press
ISBN: 1466510145
Category : Science
Languages : en
Pages : 475

Get Book Here

Book Description
The advent of laser-based sources of ultrafast infrared pulses has extended the study of very fast molecular dynamics to the observation of processes manifested through their effects on the vibrations of molecules. In addition, non-linear infrared spectroscopic techniques make it possible to examine intra- and intermolecular interactions and how su

Watching Ultrafast Molecular Motions with 2D IR Chemical Exchange Spectroscopy

Watching Ultrafast Molecular Motions with 2D IR Chemical Exchange Spectroscopy PDF Author: Michael D. Fayer
Publisher: World Scientific
ISBN: 9814355623
Category : Science
Languages : en
Pages : 383

Get Book Here

Book Description
This unique volume presents a comprehensive but accessible introduction to the field of ultrafast two-dimension infrared (2D IR) vibrational echo spectroscopy based on the pioneering work of Professor Michael D Fayer, Department of Chemistry, Stanford University, USA. It contains in one place a qualitative introduction to the field of 2D IR spectroscopy and a comprehensive set of scientific papers that underlie the qualitative discussion. The introductory material contains several detailed illustrations, and is based on the Centenary Lecture at the Indian Institute of Science given by Professor Fayer July 16, 2008 as part of the celebration of the 100th anniversary of the founding of IIS in Bangalore, India. The second part of the volume contains reprints of Fayer's relevant papers. The compilation will be very useful because it presents the historical background, motivation, methodology, and experimental results at a level that is accessible to the non-expert. The reprints of the scientific papers, from review articles to detailed theoretical papers, provide rigorous supporting material so that the reader can delve as deeply as desired into the subject.

Extending Two-dimensional Infrared Spectroscopy to Study DNA Structure with Native and Non-native Infrared Probes

Extending Two-dimensional Infrared Spectroscopy to Study DNA Structure with Native and Non-native Infrared Probes PDF Author: Amber T. Krummel
Publisher:
ISBN:
Category :
Languages : en
Pages : 286

Get Book Here

Book Description


Coherent Two-dimensional Infrared Spectroscopy

Coherent Two-dimensional Infrared Spectroscopy PDF Author: Nurettin Demirdöven
Publisher:
ISBN:
Category :
Languages : en
Pages : 257

Get Book Here

Book Description
This thesis provides an introduction to experimental techniques used in two-dimensional (2D) infrared (IR) spectroscopy, outlines how third-order nonlinear response of a multi-level vibrational system is calculated, and provides a detailed methodology of line shape analysis in 2D spectroscopy. Specific emphasis is given to inherent sensitivity of 2D spectroscopy to correlated spectral broadening. The signatures of highly correlated transition energy fluctuations in a model system of two strongly coupled carbonyl stretching vibrations are reflected by the elongation of the cross peaks along the diagonal of the 2D spectrum. The dynamics of this correlation is monitored by the changes in the 2D line shapes and successfully modeled using a correlated spectral diffusion model. The sensitivity of 2D IR spectroscopy to interactions between multiple vibrational coordinates is also explored in conformationally complex polypeptides and proteins with well-defined secondary structures. 2D IR spectroscopy of [beta]-hairpins and globular proteins with antiparallel (AP) [beta]-sheet domains is studied to identify 2D markers of AP [beta]-sheet conformation. The experiments on [beta]-hairpins and proteins with varying percentage of [beta]-sheet character showed that the formation of cross peaks between the two characteristic vibrational modes of AP [beta]-sheets is a marker of AP [beta]-sheet secondary structure. The intensity, location and line shapes of the cross peaks are qualitatively related to the size, geometry and the conformational variations in the AP [beta]-sheet structure.

Concepts and Methods of 2D Infrared Spectroscopy

Concepts and Methods of 2D Infrared Spectroscopy PDF Author: Peter Hamm
Publisher: Cambridge University Press
ISBN: 1139497073
Category : Science
Languages : en
Pages : 297

Get Book Here

Book Description
2D infrared (IR) spectroscopy is a cutting-edge technique, with applications in subjects as diverse as the energy sciences, biophysics and physical chemistry. This book introduces the essential concepts of 2D IR spectroscopy step-by-step to build an intuitive and in-depth understanding of the method. This unique book introduces the mathematical formalism in a simple manner, examines the design considerations for implementing the methods in the laboratory, and contains working computer code to simulate 2D IR spectra and exercises to illustrate involved concepts. Readers will learn how to accurately interpret 2D IR spectra, design their own spectrometer and invent their own pulse sequences. It is an excellent starting point for graduate students and researchers new to this exciting field. Computer codes and answers to the exercises can be downloaded from the authors' website, available at www.cambridge.org/9781107000056.

Temperature-jump 2D IR Spectroscopy to Study Protein Conformational Dynamics

Temperature-jump 2D IR Spectroscopy to Study Protein Conformational Dynamics PDF Author: Kevin Chapman Jones
Publisher:
ISBN:
Category :
Languages : en
Pages : 324

Get Book Here

Book Description
Temperature-jump (T-jump) two-dimensional infrared spectroscopy (2D IR) is developed, characterized, and applied to the study of protein folding and association. In solution, protein conformational changes span a wide range of timescale from nanoseconds to minutes. Ultrafast 2D IR spectroscopy measures time-dependent structural changes within the protein ensemble by probing the frequency changes associated with amide I backbone vibrations. Combining 2D IR with a perturbing laser-induced T-jump enables the study of conformational dynamics from 5 ns to 50 ms. To access a finer time-sampling of the conformational evolution, a one-dimensional variant of 2D IR, heterodyne-detected dispersed vibrational echo spectroscopy (HDVE), is implemented. The framework for interpreting transient HDVE and 2D IR spectra is developed, and we propose a method to remove the linear absorption distortions along both frequency axes. We first present the T-jump 2D IR spectra of a dipeptide to reveal the general amide I baseline response expected in the absence of conformational change. To facilitate the analysis of T-jump data, singular value decomposition (SVD) is employed for reducing noise, identifying the number of distinguishable states, and separating spectral changes based on shared timescales. Finally, T-jump 2D IR spectroscopy is applied to study the unfolding of ubiquitin, disordering of the 12-residue p-hairpin peptide trpzip2 (TZ2), and the dissociation of insulin dimers to monomers. Experimental results for ubiquitin highlight the importance of linear absorption corrections for interpretation of the data. In response to the T-jump, 2D IR results indicate p-sheet structure melts in ubiquitin with a small amplitude (~10 gs) and large amplitude (17 ms) response. Isotope-labeling T-jump experiments on TZ2 allow for the proposal of a free energy surface in which transitions from a native and misfolded state proceed through a disordered hub-like state with a 1-2 gs timescale. Multiple timescales are observed in the T-jump induced dissociation of insulin. Based on their spectral features and concentration dependence, the insulin timescales can be assigned to dissociation, disordering, and oligomerization processes. With these applications, we demonstrate the capability of T-jump 2D IR spectroscopy to reveal detailed molecular dynamics.

Advances in 2D IR Spectroscopy and Applications to Sensitized Thin Films

Advances in 2D IR Spectroscopy and Applications to Sensitized Thin Films PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 350

Get Book Here

Book Description
Two-dimensional infrared (2D IR) spectroscopy has been used to study molecular interactions and dynamics within complex systems for years. However, limitations in experimental design and sample concentration have limited its scientific breadth. In this thesis work, new technical advancements have been added to a 2D IR optical table to both increase the throughput of mid-IR to the sample cell as well as simplify the alignment when changing laser pulse wavelengths. By incorporating more reflective optics into a standard 2D IR pulse shaper, initial alignment and realignment due to a change in wavelengths are greatly simplified. Additionally, studies on dye-sensitized thin films have revealed the presence of dye aggregate domains at the interface. Vibrational coupling and energy transfer between aggregate domains could influence both the electron transfer mechanism and kinetics between the dye and semiconductor interface. With these new technological advances and thin film characterizations, preliminary work studying a monolayer of dyes on a glass window are presented. Using 2D IR to study monolayers gives interface specificity without the need of more complicated experimental designs like 2D sum frequency generation (SFG) spectroscopy. These technological advances will surely prove to expand the range of systems and problems that 2D IR spectroscopy can characterize and solve.

Coherent Two-dimensional Infrared Spectroscopy of Vibrational Excitons in Hydrogen-bonded Liquids

Coherent Two-dimensional Infrared Spectroscopy of Vibrational Excitons in Hydrogen-bonded Liquids PDF Author: Alexander Paarmann
Publisher:
ISBN: 9780494676752
Category :
Languages : en
Pages : 0

Get Book Here

Book Description
The structure and structural dynamics of hydrogen bonded liquids were studied experimentally and theoretically with coherent two-dimensional infrared (2DIR) spectroscopy. The resonant intermolecular interactions within the fully resonant hydrogen bond networks give access to spatial correlations in the dynamics of the liquid structures. New experimental and theoretical tools were developed that significantly reduced the technical challenges of these studies. A nanofluidic flow device was designed and manufactured providing sub-micron thin, actively stabilized liquid sample layers between similarly thin windows. A simulation protocol for nonlinear vibrational response calculations of disordered fluctuating vibrational excitons was developed that allowed for the first treatment of resonant intermolecular interactions in the 2DIR response of liquid water. The 2DIR spectrum of the O-H stretching vibration of pure liquid water was studied experimentally at different temperatures. At ambient conditions the loss of frequency correlations is extremely fast, and is attributed to very efficient modulations of the two-dimensional O-H stretching vibrational potential through librational motions in the hydrogen bond network. At temperatures near freezing, the librational motions are significantly reduced leading to a pronounced slowing down of spectral diffusion dynamics. Comparison with energy transfer time scales revealed the first direct proof of delocalization of the vibrational excitations. This work establishes a fundamentally new view of vibrations in liquid water by providing a spatial length scale of correlated hydrogen-bond motions. The linear and 2DIR response of the amide I mode in neat liquid formamide was found to be dominated by excitonic effects due to largely delocalized vibrational excitations. The spectral response and dynamics are very sensitive to the excitonic mode structure and infrared activity distributions, leading to a pronounced asymmetry of linear and 2DIR line shapes. This was attributed to structurally different species in the liquid characterized by their degree of medium range structural order. The response is dominated by energy transfer effects, sensitive to time-averaged medium range structural order, while being essentially insensitive to structural dynamics. This work is the first to recognize the importance of energy transfer contributions to the 2DIR response in a liquid, and provides additional proof of the well-structured character of liquid formamide.

Vibrational Dynamics in Peptides and Proteins Using Two Dimensional Infrared Spectroscopy

Vibrational Dynamics in Peptides and Proteins Using Two Dimensional Infrared Spectroscopy PDF Author: Ayanjeet Ghosh
Publisher:
ISBN:
Category :
Languages : en
Pages : 285

Get Book Here

Book Description