Mesophase behavior of new linear supramolecular hydrogen-bonding complexes

H A Ahmed; M Hagar; A Aljuhani

doi:10.1039/c8ra07692h

Mesophase behavior of new linear supramolecular hydrogen-bonding complexes

RSC Adv. 2018 Oct 11;8(61):34937-34946. doi: 10.1039/c8ra07692h. eCollection 2018 Oct 10.

Authors

H A Ahmed^{1

2}, M Hagar^{1

3}, A Aljuhani⁴

Affiliations

¹ College of Sciences, Chemistry Department, Taibah University Yanbu Saudi Arabia hmahmoud@taibahu.edu.sa ahoda@sci.cu.edu.eg mohamedhaggar@gmail.com.
² Faculty of Science, Department of Chemistry, Cairo University Cairo Egypt.
³ Faculty of Science, Chemistry Department, Alexandria University Alexandria Egypt.
⁴ Faculty of Sciences, Chemistry Department, Taibah University Al-Madinah al-Munawwarah Saudi Arabia ateyatallah@hotmail.com.

Abstract

Thermal and mesophase behavior of four new series of hydrogen-bonded supramolecular complexes (In/IIm) were investigated by differential scanning calorimetry and phases identified by polarized light microscopy. All hydrogen-bonded complexes formed from 4-alkoxyphenylazobenzoic acid (In) and 4-(4'-pyridylazophenyl)-4''-alkoxybenzoates (IIm). The results revealed that the prepared complexes are dimorphic, possessing smectic C and nematic phases. The comparison, made between the present series and previously investigated simpler, In/IIIm and angular, In/IVm analogues, revealed that increasing the length of the mesogenic core and/or linearity of complex increase the stabilities of both the smectic C and nematic phases.