Use of Intermolecular Hydrogen Bonding between Imidazolyl Moieties and Carboxylic Acids for the Supramolecular Self-Association of Liquid-Crystalline Side-Chain Polymers and Networks

1998 ◽  
Vol 31 (14) ◽  
pp. 4475-4479 ◽  
Author(s):  
Taihei Kawakami ◽  
Takashi Kato
1981 ◽  
Vol 34 (9) ◽  
pp. 1869 ◽  
Author(s):  
CW Fong ◽  
HG Grant

The interaction of dimethyl sulfoxide with N-benzoyl amino acids in deuterochloroform has been investigated by 13C n.m.r. spectroscopy. Examination of the chemical shifts of the benzene ring reveals that intermolecular hydrogen bonding between dimethyl sulfoxide and the amido-hydrogen atom increase the effective steric size of the amino hydrogen, resulting in an increase in the torsional angle between the benzene ring and the C(O)NHCH(R)COOH side chain. Self-association of N- benzoyl amino acids in deuterochloroform occurs largely through two COOH...O=C hydrogen bonds and does not involve intermolecular hydrogen bonding to the N-H proton.


1974 ◽  
Vol 52 (4) ◽  
pp. 653-660 ◽  
Author(s):  
Earl M. Woolley ◽  
Dennis S. Rushforth

The intermolecular hydrogen-bonding self-association of the three cresols in CCl4 solutions at 25 °C has been investigated by calorimetric means. Calorimetrically determined heats of dilution of each of the cresols in anhydrous CCl4 are interpreted in terms of two different models: (i) dimerization and trimerization self-association reactions, and (ii) dimerization followed by stepwise polymerization self-association reactions. Values of K, ΔH0, and ΔS0 for these reactions are calculated using least-squares and other methods. Results show that o-cresol is clearly less associated in anhydrous CCl4 solution at 25 °C than either m- or p-cresol. Values of K2 and K3 (both based on molar concentrations of solutes) and ΔH20and ΔH30 (kcal) for the reactions [Formula: see text] respectively, are o-cresol: 0.7, 1.3,−3.4,−12.5; m-cresol: 0.8, 5.0,−5.0,−13.6; p-cresol: 0.35, 6.5,−5.5,−13.4. Values of K2 and Ks (both based on molar concentrations of solutes) and ΔH20 and ΔHs0 (kcal) for the reactions [Formula: see text] (all n > 2 with same Ks and ΔHS0), respectively, are o-cresol: 0.7, 1.6, −4.2, −4.5; m-cresol: 1.2, 4.0, −5.0, −4.3; p-cresol: 1.0, 7.0, −3.3, −3.5.


1983 ◽  
Vol 36 (12) ◽  
pp. 2455 ◽  
Author(s):  
G Smith ◽  
CHL Kennard ◽  
GF Katekar

The crystal structures of three geotropically active phthalamic acid derivatives have been determined by means of X-ray diffraction and the structural systematics for the series compared. The three acids are conformationally similar and, in contrast to the tendency among carboxylic acids to form hydrogen-bonded dimers, they exist as monomers with intermolecular hydrogen bonding between the carboxylic acid groups and the nitrogen or oxygen of the amide side chains.


2008 ◽  
Vol 891 (1-3) ◽  
pp. 312-316 ◽  
Author(s):  
Dan Sui ◽  
Qiufei Hou ◽  
Jia Chai ◽  
Ling Ye ◽  
Liyan Zhao ◽  
...  

1996 ◽  
Vol 425 ◽  
Author(s):  
T. Mihara ◽  
N. Koide

AbstractMesomorphic properties and temperature dependence of the hydrogen bonding between urethane bonds (H-bonding) for side chain type liquid crystalline polyurethane(SLCPU)s were studied by thermally controlled FT-IR spectroscopy. A remarkable change in the strength of H-bonding for SLCPUs with a flexible chain in the polymer backbone(flexible SLCPUs) was displayed near the phase transition temperatures, while small changes in the strength of H-bonding for SLCPUs with a rigid moiety in the polymer backbone(rigid SLCPUs) was influenced by a mesogenic group in the side chain and the flexible chain length in the polymer backbone. Furthermore, in order to study the influence of H-bonding in rigid SLCPUs, polyurethane derivatives with methyl group were synthesized replacing hydrogen in urethane bonds. No mesomorphic properties for polyurethane derivatives obtained were exhibited. It was concluded that H-bonding played an important role to exhibit mesomorphic properties of rigid SLCPUs.


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