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Mesomorphic properties of an homologous series of thioalkyl-terminated azomesogens.

Al-Hamdani UJ - Int J Mol Sci (2011)

Bottom Line: A new homologous series (ten compounds) of 2-hydroxy azo compounds SR(n) (where n:1-10) were synthesized.Their structures were elucidated using spectroscopic techniques such as IR (Infrared), (1)H-NMR as well as elemental analysis.It has been found that all compounds in the series are pure nematogens.

View Article: PubMed Central - PubMed

Affiliation: Department of Chemistry, College of Education, Basrah University, P.O. Box 716, Basrah, Iraq; E-Mail: Uhood1959@yahoo.com ; Tel.: +009647712616545;

ABSTRACT
A new homologous series (ten compounds) of 2-hydroxy azo compounds SR(n) (where n:1-10) were synthesized. Their structures were elucidated using spectroscopic techniques such as IR (Infrared), (1)H-NMR as well as elemental analysis. Mesomorphic properties and phase transitions were studied using polarized hot stage optical microscopy and differential scanning calorimetry (DSC), and are discussed as a function of the number of carbon atoms in the thioalkyl chain. It has been found that all compounds in the series are pure nematogens.

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Structures of the studied compounds SR1–SR10).
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f1-ijms-12-03182: Structures of the studied compounds SR1–SR10).

Mentions: Liquid crystalline materials are of great interest for materials science as well as for life science. Their properties can be tuned by appropriate molecular design. Thus, it is well known that the mesomorphic properties of calamitic liquid crystals can largely be influenced by the structural variation in terminal substituents, like alkyl, alkyloxy and thioalkyl groups [1–5]. This can influence the melting points and mesophase types, etc. [6–10]. Numerous studies have been carried out in recent years of the effects of changes in molecular framework on the incidence and stability of azo ester liquid crystal phase [11–14]. However, a literature survey indicates that liquid crystalline azo esters with thioalkyl chains comprising different kinds of terminal groups are very rare, so, in the present work, we have prepared ten members (Figure 1) of homologous series of (SRn) in order to establish the effect of introducing sulfur atom instead of oxygen atom with the increase in the terminal thioalkyl chain on liquid crystalline properties.


Mesomorphic properties of an homologous series of thioalkyl-terminated azomesogens.

Al-Hamdani UJ - Int J Mol Sci (2011)

Structures of the studied compounds SR1–SR10).
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC3116184&req=5

f1-ijms-12-03182: Structures of the studied compounds SR1–SR10).
Mentions: Liquid crystalline materials are of great interest for materials science as well as for life science. Their properties can be tuned by appropriate molecular design. Thus, it is well known that the mesomorphic properties of calamitic liquid crystals can largely be influenced by the structural variation in terminal substituents, like alkyl, alkyloxy and thioalkyl groups [1–5]. This can influence the melting points and mesophase types, etc. [6–10]. Numerous studies have been carried out in recent years of the effects of changes in molecular framework on the incidence and stability of azo ester liquid crystal phase [11–14]. However, a literature survey indicates that liquid crystalline azo esters with thioalkyl chains comprising different kinds of terminal groups are very rare, so, in the present work, we have prepared ten members (Figure 1) of homologous series of (SRn) in order to establish the effect of introducing sulfur atom instead of oxygen atom with the increase in the terminal thioalkyl chain on liquid crystalline properties.

Bottom Line: A new homologous series (ten compounds) of 2-hydroxy azo compounds SR(n) (where n:1-10) were synthesized.Their structures were elucidated using spectroscopic techniques such as IR (Infrared), (1)H-NMR as well as elemental analysis.It has been found that all compounds in the series are pure nematogens.

View Article: PubMed Central - PubMed

Affiliation: Department of Chemistry, College of Education, Basrah University, P.O. Box 716, Basrah, Iraq; E-Mail: Uhood1959@yahoo.com ; Tel.: +009647712616545;

ABSTRACT
A new homologous series (ten compounds) of 2-hydroxy azo compounds SR(n) (where n:1-10) were synthesized. Their structures were elucidated using spectroscopic techniques such as IR (Infrared), (1)H-NMR as well as elemental analysis. Mesomorphic properties and phase transitions were studied using polarized hot stage optical microscopy and differential scanning calorimetry (DSC), and are discussed as a function of the number of carbon atoms in the thioalkyl chain. It has been found that all compounds in the series are pure nematogens.

Show MeSH