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Solid‐State Hosts by the Template Polymerization of Columnar Liquid Crystals: Locked Supramolecular Architectures around Chiral 2‐Amino Alcohols
Author(s) -
Amano Sayaka,
Ishida Yasuhiro,
Saigo Kazuhiko
Publication year - 2007
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.200601656
Subject(s) - polymerization , chemistry , enantiopure drug , liquid crystal , polymer , supramolecular chemistry , substituent , amine gas treating , polymer chemistry , chirality (physics) , organic chemistry , chemical engineering , materials science , enantioselective synthesis , crystal structure , catalysis , nambu–jona lasinio model , optoelectronics , chiral symmetry breaking , engineering , physics , quantum mechanics , quark
The cross‐linking of multicomponent liquid crystals could be applied to the synthesis of nanometer‐sized porous materials with a well‐defined structure. In this work we demonstrate the template polymerization of columnar liquid crystals composed of the salts of a carboxylic acid and enantiopure 2‐amino alcohols, and the application of one of them as a solid‐state host. The salts of 3,4,5‐tris(11‐acryloyloxyundecyloxy)benzoic acid with ( S )‐2‐amino‐1‐propanol and with (1 R ,2 S )‐norephedrine showed hexagonal and rectangular columnar liquid‐crystalline structures, respectively. The successful application of γ‐ray‐induced polymerization to the cross‐linking of the liquid‐crystalline salts, which was more advantageous than photoinduced polymerization from the standpoint of the retention of the original structural order in the gram‐scale preparation of the polymers with a homogeneous columnar structure. The cross‐linked polymer thus obtained from the gallic acid derivative and (1 R ,2 S )‐norephedrine was applicable as a heterogeneous host to capture amines from a guest solution through acid–amine interactions. When (1 R ,2 S )‐norephedrine was replaced with other amines through the guest‐exchange reaction, a “template effect” was observed; the size and shape of the guests were determining factors for the efficiency of the guest exchange. The guest adsorption was found to proceed in an enantioselective manner when racemic 2‐amino alcohols were used as guests, especially in the cases of substrates possessing a bulky substituent at the C1‐position. The guest preference was again elucidated by the template effect, although the enantioselection mode was switched depending on the presence of a C2 substituent.