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Intermolecular interactions in compressed crystals

Damian Paliwoda

Abstract

Pressure is an effective tool for tuning crystal structure by changing energetical hierarchy of non-bonding forces. Pressure can induce phase transitions and structural changes, leading to new molecular arrangements, of varied physical properties, such as crystal polarity and optical properties. Three examples of pressure-induced transformations of molecular crystals have been presented in my thesis. High-pressure recrystallization of imidazole has led to its new polymorph, where the infinite NH•••N bonded chains of molecules assume polar arrangement. The lengths of NH•••N bonds are shorter in the high pressure polymorph, which facilitates proton hopping in a double-well potential. The conformation of metallocene molecules has been intensively investigated due to the very low energy barrier between staggered and eclipsed forms. It was postulated previously that at ambient conditions cyclopentadienyl rings in ferrocene are dynamically disordered in two sites. These disorder is eliminated at high pressure leading to unexpected anomalous evolution of lattice parameters with pressure. Aurophilic interaction is a very unusual type of intermetallic bonds, in which relativistic effects play a substantial role. So far studies on the high-pressure evolution of Au•••Au distances are very limited and this work reports the first compressibility measurements of this effect. It was shown in this thesis that pressure can partly unwind helical Au•••Au bonded filaments.
Record ID
UAM1393aafede8b426dac9ccff99356e8b2
Diploma type
Doctor of Philosophy
Author
Damian Paliwoda Damian Paliwoda,, NanoBiomedical Centre (Cb/CN)Centra badawcze [nowa struktura organizacyjna] (Cb)
Title in Polish
Oddziaływania międzycząsteczkowe w kryształach pod wysokim ciśnieniem
Title in English
Intermolecular interactions in compressed crystals
Language
(en) English
Certifying Unit
Wydział Chemii [nowa struktura organizacyjna] (SNŚ/WC)
Scientific discipline (2.0)
6.5 chemical sciences
Status
Finished
Year of creation
2014
Defense Date
27-03-2014
Title date
27-03-2014
Supervisor
Kamil Filip Dziubek - helping supervisor Kamil Filip Dziubek,, Wydział Chemii [nowa struktura organizacyjna] (SNŚ/WC)Szkoła Nauk Ścisłych [nowa struktura organizacyjna] (SNŚ)
URL
https://hdl.handle.net/10593/10361 Opening in a new tab
Keywords in English
high pressure,compressibility,high-pressure Crystallography,intermolecular interactions
Abstract in English
Pressure is an effective tool for tuning crystal structure by changing energetical hierarchy of non-bonding forces. Pressure can induce phase transitions and structural changes, leading to new molecular arrangements, of varied physical properties, such as crystal polarity and optical properties. Three examples of pressure-induced transformations of molecular crystals have been presented in my thesis. High-pressure recrystallization of imidazole has led to its new polymorph, where the infinite NH•••N bonded chains of molecules assume polar arrangement. The lengths of NH•••N bonds are shorter in the high pressure polymorph, which facilitates proton hopping in a double-well potential. The conformation of metallocene molecules has been intensively investigated due to the very low energy barrier between staggered and eclipsed forms. It was postulated previously that at ambient conditions cyclopentadienyl rings in ferrocene are dynamically disordered in two sites. These disorder is eliminated at high pressure leading to unexpected anomalous evolution of lattice parameters with pressure. Aurophilic interaction is a very unusual type of intermetallic bonds, in which relativistic effects play a substantial role. So far studies on the high-pressure evolution of Au•••Au distances are very limited and this work reports the first compressibility measurements of this effect. It was shown in this thesis that pressure can partly unwind helical Au•••Au bonded filaments.
Thesis file
  • File: 1
    PhDthesis_DPaliwoda.pdf
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Uniform Resource Identifier
https://researchportal.amu.edu.pl/info/phd/UAM1393aafede8b426dac9ccff99356e8b2/
URN
urn:amu-prod:UAM1393aafede8b426dac9ccff99356e8b2

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