Raman Spectroscopy of Conformational Rearrangements at Low Temperatures

Folding and Stretching of Alkanes in Supersonic Jets

  • Nils Olaf Bernd Lüttschwager
Part of the Springer Theses book series (Springer Theses)

Table of contents

  1. Front Matter
    Pages i-xii
  2. Nils Olaf Bernd Lüttschwager
    Pages 1-6
  3. Nils Olaf Bernd Lüttschwager
    Pages 7-17
  4. Nils Olaf Bernd Lüttschwager
    Pages 19-36
  5. Nils Olaf Bernd Lüttschwager
    Pages 37-117
  6. Nils Olaf Bernd Lüttschwager
    Pages 119-126
  7. Nils Olaf Bernd Lüttschwager
    Pages 127-144
  8. Nils Olaf Bernd Lüttschwager
    Pages 145-148
  9. Back Matter
    Pages 149-183

About this book

Introduction

This thesis identifies the turning point in chain length, after which alkanes self-solvate into a folded structure instead of an extended stretched conformation. After this turning point, London dispersion forces rearrange isolated n-alkanes into a particular hairpin-structure, while for shorter chain lengths, a simple stretched conformation is energetically preferred. This thesis can locate the experimental turning point for the first time in an interaction-free manner from measurements of unbranched alkanes at low temperatures in supersonic jet expansions. It contains a detailed analysis of the vibrational Raman spectra of the chain molecules, which is supported by comprehensive quantum chemical simulations. In this way, the detailed balance between inter-chain attraction and conformational flexibility can be quantified.The investigations are complemented by measurements of perfluoroalkanes, and similarities and differences between the compounds are discussed. Furthermore, Nils Lüttschwager determines the stiffnesses (elastic moduli) of two of the most common industrial polymers: polyethylene and polytetrafluorethylene. He uses in this thesis a sophisticated extrapolation to calculate this value from quantities of their building blocks, showing that the single polymer molecules can be as stiff as a rod of steel.

Keywords

Alkane Conformations Elastic Modulus of Polyethylene Gas Phase Spectroscopy of Low Volatile Compounds Longitudinal acoustic modes (LAM) Molecular Folding Raman Spectroscopy of Alkanes Self-solvation of Alkanes Spontaneous Raman Scattering in Supersonic Jets Stiffness of Polytetrafluorethylene Supersonic Jet Spectroscopy

Authors and affiliations

  • Nils Olaf Bernd Lüttschwager
    • 1
  1. 1.Institute for Physical ChemistryGeorg August UniversityGöttingenGermany

Bibliographic information

  • DOI https://doi.org/10.1007/978-3-319-08566-1
  • Copyright Information Springer International Publishing Switzerland 2014
  • Publisher Name Springer, Cham
  • eBook Packages Chemistry and Materials Science
  • Print ISBN 978-3-319-08565-4
  • Online ISBN 978-3-319-08566-1
  • Series Print ISSN 2190-5053
  • Series Online ISSN 2190-5061
  • About this book