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Counterion Effects on the Mesomorphic Properties of Chiral Imidazolium and Pyridinium Ionic Liquids
Author(s) -
Kohnen Gilles,
Tosoni Martin,
Tussetschläger Stefan,
Baro Angelika,
Laschat Sabine
Publication year - 2009
Publication title -
european journal of organic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.825
H-Index - 155
eISSN - 1099-0690
pISSN - 1434-193X
DOI - 10.1002/ejoc.200900730
Subject(s) - counterion , chemistry , differential scanning calorimetry , ionic liquid , mesophase , pyridinium , crystallography , ionic bonding , organic chemistry , ion , phase (matter) , thermodynamics , catalysis , physics
Novel calamitic N ‐methylimidazolium and pyridinium salts with modified citronellyl side‐chains and various counterions 3 – 14 have been synthesised by utilising the commercially available ( R )‐citronellol ( 15 ) as the starting material. Differential scanning calorimetry (DSC), polarising optical microscopy (POM) and temperature‐dependent X‐ray diffraction studies revealed smectic A (SmA) mesophases for all the series. 1 H NMR studies of the N ‐methylimidazolium salts have shown that there is a correlation between the mesophase dependence on the counterion and the counterion‐dependent chemical shifts of the acidic 2‐H proton.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)