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## Polymorphism and dielectric properties of crystals of dabco·HA(HA = HI, HBr, HClO4)

### Anna Olejniczak

#### Abstract

Materials with exceptional dielectric properties are coveted for electronic applications. It results from the miniaturization process of electronic devices, increasing their working speed and searching for effective ways of information and energy storage. The NH+···N hydrogen bonded ferroelectrics and relaxors are the materials with the desired properties. In this work I studied the polymorphism, NH+···N hydrogen bonds and other intermolecular interactions. As the objects of my research I chose the 1,4-diazabicyclo[2.2.2]octane complexes with HBr and HI (dabcoHI and dabcoHBr), because of their exceptional properties and potential applications, and the ferroelectric complex of 1,4-diazabicyclo[2.2.2]octane with HClO4. I obtained the crystals of new polymorphs at high pressure from the substance dissolved in water, methanol or ethanol, crystallized them and carried out the diffraction measurements. My studies revealed that dabcoHI forms at least ten polymorphs, dabcoHBr forms only two polymorphs and for dabcoHClO4 I obtained one new high-pressure form, different from those five obtained previously at atmospheric pressure.
Record ID
UAM67a8227e55ca4bcba7ac180446a74d7a
Diploma type
Doctor of Philosophy
Author
Title in Polish
Polimorfizm i właściwości dielektryczne kryształów dabco·HA(HA = HI, HBr, HClO4)
Title in English
Polymorphism and dielectric properties of crystals of dabco·HA(HA = HI, HBr, HClO4)
Language
pol (pl) Polish
Certifying Unit
Faculty of Chemistry (SNŚ/WC/FoC)
Discipline
chemistry / (chemical sciences domain) / (physical sciences)
Scientific discipline (2.0)
6.5 chemical sciences
Status
Finished
Defense Date
09-06-2010
Title date
09-06-2010
Supervisor
URL
http://hdl.handle.net/10593/441 Opening in a new tab
Keywords in English
high-pressure crystallization, polymorphism, dielectric properties, hydrogen bonds
Abstract in English
Materials with exceptional dielectric properties are coveted for electronic applications. It results from the miniaturization process of electronic devices, increasing their working speed and searching for effective ways of information and energy storage. The NH+···N hydrogen bonded ferroelectrics and relaxors are the materials with the desired properties. In this work I studied the polymorphism, NH+···N hydrogen bonds and other intermolecular interactions. As the objects of my research I chose the 1,4-diazabicyclo[2.2.2]octane complexes with HBr and HI (dabcoHI and dabcoHBr), because of their exceptional properties and potential applications, and the ferroelectric complex of 1,4-diazabicyclo[2.2.2]octane with HClO4. I obtained the crystals of new polymorphs at high pressure from the substance dissolved in water, methanol or ethanol, crystallized them and carried out the diffraction measurements. My studies revealed that dabcoHI forms at least ten polymorphs, dabcoHBr forms only two polymorphs and for dabcoHClO4 I obtained one new high-pressure form, different from those five obtained previously at atmospheric pressure.
Thesis file
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Uniform Resource Identifier
https://researchportal.amu.edu.pl/info/phd/UAM67a8227e55ca4bcba7ac180446a74d7a/
URN
urn:amu-prod:UAM67a8227e55ca4bcba7ac180446a74d7a

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