Low‐temperature structural phase transitions in crystalline bromo and iodo 9‐hydroxyphenalenone derivatives: Quantum chemistry employment

Abstract

ABSTRACT:The model approaches and quantum chemical calculations are employed to explain the peculiarities of the ferroelectric behavior of new "zerodimensional" H-bonded materials, i.e., 5-bromo and 5-iodo derivatives of 9-hydroxyphenalenone (9HPO) and its deuteroxy analogue (9DPO). The tunneling parameters ⍀ (H/D) and the Ising model coupling parameters J ij are evaluated and discussed. Analysis of these parameters for the hydroxy and deuteroxy species demonstrates the quantum paraelectric behavior of both Br and I 9HPO derivatives due to the large values of the ⍀(H)/J 0 relation, where J 0 is the molecular field parameter describing the coupling of any given H-bond proton with all rest ones. In contrast, small values ⍀(D)/J 0 for their 9DPO analogues favor the low-temperature structural phase transition into an ordered phase, which has a rather antiferroelectric than ferroelectric character. The estimates obtained and the resulting conclusions are in line with the overall observed trends in behavior of the substances under examination that emerge from the available experimental data.

Three‐dimensional H‐bonding and ferroelectric transition in KDP. Quantum‐chemical study

“…4 where with the same lengths and geometries of H bonds the second cluster doesn't contain the P atom [13]. The results show that really for the first case the Ising parameters values U ϭ Ϫ320 K, V ϭ 350 K are close to those from Table II, whereas for the second case, they fall down to U ϭ Ϫ30 K, V ϭ 40 K becoming comparable with the J ij values [3,12] for 0d materials.…”

“…For these "zero-dimensional" (0d) materials with isolated H/D bonds, the orderdisorder transition appears only upon deuteration. The reason is in the transition suppression by protons quantum motion [3,12]. Apparently such suppression doesn't occur for KDP family because of the growth of the Ising parameters values and accompanying growth of J 0 due to the association of H-bonds into three-dimensional network by P or As atoms.…”

The role of intermolecular hydrogen bond on dielectric properties in hydrogen-bonded material 5-bromo-9-hydroxyphenalenone: theoretical investigation

“…30,31 More recently, quantum chemical calculations were performed for several neighboring dimers of BrHPLN and 5-iodo-9-hydroxyphenalenone (IHPLN). 32,33 The tunneling parameter and the interaction parameter of the transverse Ising model 10,34 were calculated and the ordered phase at the low temperature limit was discussed on the basis of the mean field approximation. Although these works have provided intriguing clues under their approximations, in our view, more extensive analysis will be needed for elucidation of the dielectric properties arising from the intricate intermolecular interactions in the crystal.…”

Path integral Monte Carlo study of hydrogen tunneling effect on dielectric properties of molecular crystal 5-Bromo-9-hydroxyphenalenone

“…A three-site model has been proposed to describe the isotope effect in zero-dimensional hydrogen-bonded (anti) ferroelectric materials [24]. More realistic quantum chemical calculations have been performed for several neighboring dimers of BHP and 5-iodo-9-hydroxyphenalenone [25,26], in which the tunneling and interaction parameters were calculated to determine the ordered phase in the low-temperature limit using the mean field approximation. To complement these studies with the bulk properties of crystals, density functional theory calculations with plane-wave basis sets can be useful (e.g., see Fig.…”