| Raman Spectroscopy of Conformational Rearrangements at Low Temperatures: Folding and Stretching of Alkanes in Supersonic Jets Softcover Repri Edition Contributor(s): Lüttschwager, Nils Olaf Bernd (Author) |
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ISBN: 3319359762 ISBN-13: 9783319359762 Publisher: Springer OUR PRICE: $104.49 Product Type: Paperback - Other Formats Published: September 2016 |
| Additional Information |
| BISAC Categories: - Science | Chemistry - Physical & Theoretical - Science | Physics - Atomic & Molecular - Science | Spectroscopy & Spectrum Analysis |
| Dewey: 539 |
| Series: Springer Theses |
| Physical Information: 0.42" H x 6.14" W x 9.21" (0.62 lbs) 183 pages |
| Descriptions, Reviews, Etc. |
| Publisher Description: 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 L ttschwager 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. |
