open access

https://hdl.handle.net/2115/84850

Molecular motion of halogenated ethylammonium/[18]crown-6 supramolecular ions in nickel dithiolate magnetic crystals

英語

2021-04-14

Royal Society of Chemistry

CrystEngComm

14

2756-2763

Supramolecular cations, consisting of ethylammonium derivatives (X-CH2CH2-NH3+) complexed with [18] crown-6, were incorporated into [Ni(dmit)(2)](-) crystals in order to promote molecular motion. Crystals of (X-CH2CH2-NH3+)([18]crown-6)[Ni(dmit)(2)](-) (1: X = H, 2: X = F, 3: X = Cl and 4: X = Br) were prepared for this purpose. Although large amplitude molecular motions do not occur in crystal 1, dynamic disorder of F-CH2 groups takes place between two sites in crystal 2. Similar disorder of Cl-CH2 groups along with rotation of [18]crown-6 molecules also exists in crystal 3. Crystal 4 exhibits dynamic disorder of Br-CH2-CH2 groups between four sites. This is especially the case for crystal 4 which undergoes a distinct dielectric response with relaxer-like behavior in the temperature dependence of the dielectric loss tangent. Interactions between [Ni(dmit)(2)](-) ions in all crystals are antiferromagnetic, and the magnitudes of the interactions are qualitatively consistent with the strength of intermolecular interactions estimated from transfer integrals, where interactions within [Ni(dmit)(2)](-) dimers are the larger than the others in all crystals.

学術雑誌論文

Accepted Manuscript

1466-8033