Role of intermolecular interactions and conformational changes in the polymorphism and vitrification process of 2,2 ''-bis-substituted para-terphenyls
The result's identifiers
Result code in IS VaVaI
<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F62690094%3A18470%2F20%3A50017092" target="_blank" >RIV/62690094:18470/20:50017092 - isvavai.cz</a>
Result on the web
<a href="https://pubs.rsc.org/en/content/articlelanding/2020/CE/D0CE00351D#!divAbstract" target="_blank" >https://pubs.rsc.org/en/content/articlelanding/2020/CE/D0CE00351D#!divAbstract</a>
DOI - Digital Object Identifier
<a href="http://dx.doi.org/10.1039/d0ce00351d" target="_blank" >10.1039/d0ce00351d</a>
Alternative languages
Result language
angličtina
Original language name
Role of intermolecular interactions and conformational changes in the polymorphism and vitrification process of 2,2 ''-bis-substituted para-terphenyls
Original language description
In the past decades, para-terphenyls have been attracting tremendous attention due to their polymorphism and conformational diversity. In this work we report the synthesis, crystal structure, polymorphism and dielectric properties of two 2,2 ''-bis-substituted para-terphenyls: 2,2 ''-bis(hydroxymethyl)-para-terphenyl and 2,2 ''-bis(acetyloxymethyl)-para-terphenyl. On the basis of calorimetric and X-ray studies, we showed that the latter compound occurs in at least four polymorphic forms with melting points equal to 364, 345, 341 and 326 K, differentiated also in terms of thermodynamic stability and crystal symmetry. The most stable polymorph I is characterized by the P2(1)/n space group. 2,2 ''-Bis(hydroxymethyl)-para-terphenyl crystallizes in the monoclinic P2(1)/c space group. Both 2,2 ''-bis-substituted para-terphenyls can undergo vitrification, which is a highly exceptional feature for this class of chemical compounds and has not been reported before. Consequently, the molecular dynamics and conformational changes in the glassy and supercooled liquid states were analyzed by means of IR and broadband dielectric spectroscopy. Two relaxation processes were observed for both compounds: structural alpha-relaxation, connected with reorientational motions of molecules in supercooled liquid, and intermolecular.-relaxation, ascribed to rotational motions of substituents of the para-terphenyl skeleton. Taking into account the ongoing discussion about the conformational diversity of the para-terphenyl skeleton, we showed that although free rotation of benzene rings is suppressed, the molecules in the glassy and liquid states can adopt both twisted and helical conformations, which results in diversity of the polymorphic forms.
Czech name
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Czech description
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Classification
Type
J<sub>imp</sub> - Article in a specialist periodical, which is included in the Web of Science database
CEP classification
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OECD FORD branch
10403 - Physical chemistry
Result continuities
Project
—
Continuities
I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace
Others
Publication year
2020
Confidentiality
S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů
Data specific for result type
Name of the periodical
CRYSTENGCOMM
ISSN
1466-8033
e-ISSN
—
Volume of the periodical
22
Issue of the periodical within the volume
18
Country of publishing house
GB - UNITED KINGDOM
Number of pages
15
Pages from-to
3164-3178
UT code for WoS article
000536772800011
EID of the result in the Scopus database
2-s2.0-85084950940