Solvent-Dependent Delamination, Restacking, and Ferroelectric Behavior in a New Charge-Separated Layered Compound: [NH4][Ag3(C9H5NO4S)2(C13H14N2)2]⋅8 H2O

Autor: Somnath Pal, Shivanna Mohana, Srinivasan Natarajan, Sringeri Ramesh Sushrutha
Rok vydání: 2016
Předmět:
Zdroj: Chemistry - An Asian Journal. 12:101-109
ISSN: 1861-4728
Popis: A new anionic coordination polymer, NH4] Ag-3( C9H5NO4S)(2)( C13H14N2)(2)]center dot 8H(2)O, with a two-dimensional structure, has been synthesized by a reaction between silver nitrate, 8-hydroxyquinoline-5-sulfonic acid (HQS), and 4,4'-tri-methylene dipyridine (TMDP). The compound stabilizes in a noncentrosymmetric space group, and the lattice water molecules and the charge-compensating NH4](+) group occupy the inter-lamellar spaces. The lattice water molecules can be fully removed and reinserted, which is accompanied by a crystalline-amorphous-crystalline transformation. This transformation resembles the collapse/delamination and restacking of the layers. To the best of our knowledge, this is the first observation of delamination and restacking in an inorganic coordination polymer that contains silver. The presence of a natural dipole (the anionic framework and cationic ammonium ions) along with the noncentrosymmetric space group gives rise to the room-temperature ferroelectric behavior of the compound. The ferroelectric behavior is also water-dependent and exhibits a ferroelectric-paraelectric transformation. The temperature-dependent dielectric measurements indicate that the ferroelectric/paraelectric transformation occurs at 320 K. This transformation has also been investigated by using in-situ IR spectroscopy and PXRD studies. The second-harmonic generation (SHG) study indicated values that are comparable to some of the known SHG solids, such as potassium dihydrogen phosphate (KDP) and urea.
Databáze: OpenAIRE