ISSN:
1434-1948
Keywords:
Metallomesogens
;
Liquid crystals
;
Silver
;
N ligands
;
Amines
;
Chemistry
;
General Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
The liquid crystalline properties of a series of ionic silver complexes [Ag(NH2n-CnH2n+1)2]X (X = NO3, n = 6, 8, 10, 12, 14; X = BF4, n = 8, 10, 12, 14), derived from silver nitrate or tetrafluoroborate and aliphatic amines, have been investigated by optical microscopy, DSC, and X-ray diffraction. The materials exhibit a birefringent fluid phase identified as a smectic A mesophase by optical microscopy and X-ray diffraction. Some of the complexes are liquid crystalline at temperatures close to room temperature. The X-ray results are consistent with the existence in the mesophase of a bilayer organization. The silver cations adopt a U-shape, which allows for the adoption of this bilayer arrangement, with alternating ionic and apolar regions and a short-range square-planar array inside the cationic sublayers. The thermodynamic parameters suggest that the melting transition clearly involves only disorder (melting) of the chains, whereas the clearing transition implies breaking the anion-cation arrangement.
Additional Material:
6 Ill.
Type of Medium:
Electronic Resource
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