Reversible Phase Transition with Ultralarge Dielectric Relaxation Behaviors in Succinimide Lithium(I) Hybrids

Abstract

Dielectric relaxations have widely applied on high permittivity capacitors, dielectric switches, ferroelectrics, pyroelectrics, and electrical insulating materials. However, few investigations of large dielectric relaxation behaviors on organic−inorganic hybrid materials have been documented before. Here we present a novel two-dimensional succinimide lithium(I) hybrid compound, [Li(PDD) 2 ClO 4 ] n , 1, (PDD = 2,5-pyrrolidinedione = succinimide) which shows reversible phase transition behavior in the vicinity of 228 K accompanied by an unusual symmetry breaking from I4 1 /amd to C2/c. X-ray single crystal diffractions analysis indicates the twist motion of pyrrolidine heterocycles, and order−disorder motion of ClO 4 − anions triggered the reversible phase transition. By means of an intuitive crystallographic model (rattling ion model), we further illustrated the mechanism of the interesting reversible phase transition. Particularly, 1 shows ultralarge dielectric relaxation behavior in the vicinity of the phase transition by its dielectric constant dependence on temperatures and frequencies as well as its Cole−Cole relation.

High‐Temperature Reversible Phase Transition and Switchable Dielectric and Semiconductor Properties in a 2D Hybrid [(C3H12N2O)CdCl4]n

“…), following a slowly increasing slope, while a reverse process appears around 393 K for the cooling run, where the dielectric constant falls from 9.5 to 8.4 (a.u.). Relative to heat response for phase transition, dielectric constant changes is slightly lagged; this dielectric constant switched mode was also reported in other early work , , , , . Besides, similar dielectric variation law also applies to other frequencies, such as 100 kHz (Figure S4).…”

“…On the one hand, all the atoms except of the hydroxyl from propanol group in 1‐LTP are completely ordered (Figure a), while the whole 1,3‐diamino‐2‐propanol guest molecules in 1‐HTP are highly disordered (C1, C1a split into four part and O1 splits into eight part ), which can be regarded as four‐fold disorder, suggesting an apparent order‐disorder type phase transition, On the other hand, the framework grid, which linked by bridging chloride and cadmium atoms, have been turned from an irregular quadrilateral in 1‐LTP (Figure c) to a regular square grid in 1‐HTP (Figure d), meanwhile, the Cd–Cl bond length has lessened from 2.671 and 2.762 Å to 2.650 Å during this phase transition process, which is unusual abnormal shrinkage with increasing temperature. However, Cd–Cd bond lengths increase from 5.264 to 5.300 Å due to the more space needed for highly disordered 1,3‐diamino‐2‐propanol molecules, which these interesting grids changes also afford an important contribution to the phase transition and have been reported detailly in our previous work …”

“…Inspired by these remarkable works, we have always devoted to construct some new organic‐inorganic hybrids with multifunction. For example, we have reported an interesting succinimide lithium(I) hybrid compound [Li(PDD) 2 ClO 4 ] n , which exhibits an ultra large dielectric relaxation behaviour, however, it has a low phase transition temperature of 228 K, far below the room temperature and limits its application. As our ongoing work, it is very significant that utilizing different molecular to assembly new organic‐inorganic hybrids with high phase transition temperature.…”

Designing and Constructing a High‐Temperature Molecular Ferroelectric by Anion and Cation Replacement in a Simple Crown Ether Clathrate

“…Most reversible phase transition will accompany by the thermal anomaly behaviors . For a first order phase transition, there exists latent heat during the phase transition process, whereas for a second phase transition, specific heat capacity ( C p ) is apparently different around the phase transition.…”

“…Most reversible phase transition will accompany by the thermal anomaly behaviors. [40][41][42][43][44][45] For af irst order phase transition, there exists latent heat during the phase transition process, whereas forasecond phaset ransition, specific heat capacity (C p )i sa pparently different aroundt he phase transition. Therefore, we carried out the differential scanning calorimetry( DSC) measurement by TA-Instruments DSC TA2000 instrumen.…”