Stability and flexibility of heterometallic formate perovskites with the dimethylammonium cation: Pressure-induced phase transitions

MacIej Ptak, Katrine Louise Svane, Aron Walsh, Waldeci Paraguassu

Research output: Contribution to journalArticle

4 Citations (Scopus)

Abstract

We report the high-pressure properties of two heterometallic perovskite-type metal-organic frameworks (MOFs) templated by dimethylammonium (NH 2 (CH 3 ) 2 , DMA + ) with the general formula [DMA]MI0.5CrIII0.5(HCOO) 3 , where M I = Na + (DMANaCr) and K + (DMAKCr). The high-pressure Raman scattering studies show crystal instabilities in the 4.0-4.4 GPa and 2.0-2.5 GPa ranges for DMANaCr and DMAKCr, respectively. The mechanism is similar in the two compounds and involves strong deformation of the metal-formate framework, especially pronounced for the subnetwork of CrO 6 octahedra, accompanied by substantial compressibility of the DMA + cations. Comparison with previous high-pressure Raman studies of sodium-chromium heterometallic MOFs show that the stability depends on the templated cation and increases as follows: Ammonium < imidazolium < DMA + . Density functional theory (DFT) calculations are performed to get a better understanding of the structural properties leading to the existence of phase transitions. We calculate the energy of the hydrogen bonds (HBs) between the DMA + cation and the metal formate cage, revealing a stronger interaction in the DMAKCr compound due to a HB arrangement that primarily involves the energetically preferred bonding to KO 6 octahedra. This material however also has a smaller structural tolerance factor (TF) and a higher vibrational entropy than DMANaCr. This indicates a more flexible crystal structure, explaining the lower phase transition pressure, as well as the previously observed phase transition at 190 K, which is absent in the DMANaCr compound. The DFT high-pressure simulations show the largest contraction to be along the trigonal axis, leading to a minimal distortion of the HBs formed between the DMA + cations and the metal-formate sublattice.

Original languageEnglish
Pages (from-to)4200-4208
Number of pages9
JournalPhysical Chemistry Chemical Physics
Volume21
Issue number8
DOIs
Publication statusPublished - 2019 Jan 1

Fingerprint

formic acid
formates
Dynamic mechanical analysis
perovskites
Cations
flexibility
Phase transitions
Metals
cations
Hydrogen bonds
metals
hydrogen bonds
Density functional theory
density functional theory
transition pressure
Chromium
Compressibility
Ammonium Compounds
sublattices
compressibility

All Science Journal Classification (ASJC) codes

  • Physics and Astronomy(all)
  • Physical and Theoretical Chemistry

Cite this

@article{9f422adcf935496cb5216a2c736da947,
title = "Stability and flexibility of heterometallic formate perovskites with the dimethylammonium cation: Pressure-induced phase transitions",
abstract = "We report the high-pressure properties of two heterometallic perovskite-type metal-organic frameworks (MOFs) templated by dimethylammonium (NH 2 (CH 3 ) 2 , DMA + ) with the general formula [DMA]MI0.5CrIII0.5(HCOO) 3 , where M I = Na + (DMANaCr) and K + (DMAKCr). The high-pressure Raman scattering studies show crystal instabilities in the 4.0-4.4 GPa and 2.0-2.5 GPa ranges for DMANaCr and DMAKCr, respectively. The mechanism is similar in the two compounds and involves strong deformation of the metal-formate framework, especially pronounced for the subnetwork of CrO 6 octahedra, accompanied by substantial compressibility of the DMA + cations. Comparison with previous high-pressure Raman studies of sodium-chromium heterometallic MOFs show that the stability depends on the templated cation and increases as follows: Ammonium < imidazolium < DMA + . Density functional theory (DFT) calculations are performed to get a better understanding of the structural properties leading to the existence of phase transitions. We calculate the energy of the hydrogen bonds (HBs) between the DMA + cation and the metal formate cage, revealing a stronger interaction in the DMAKCr compound due to a HB arrangement that primarily involves the energetically preferred bonding to KO 6 octahedra. This material however also has a smaller structural tolerance factor (TF) and a higher vibrational entropy than DMANaCr. This indicates a more flexible crystal structure, explaining the lower phase transition pressure, as well as the previously observed phase transition at 190 K, which is absent in the DMANaCr compound. The DFT high-pressure simulations show the largest contraction to be along the trigonal axis, leading to a minimal distortion of the HBs formed between the DMA + cations and the metal-formate sublattice.",
author = "MacIej Ptak and Svane, {Katrine Louise} and Aron Walsh and Waldeci Paraguassu",
year = "2019",
month = "1",
day = "1",
doi = "10.1039/c8cp07131d",
language = "English",
volume = "21",
pages = "4200--4208",
journal = "Physical Chemistry Chemical Physics",
issn = "1463-9076",
publisher = "Royal Society of Chemistry",
number = "8",

}

Stability and flexibility of heterometallic formate perovskites with the dimethylammonium cation : Pressure-induced phase transitions. / Ptak, MacIej; Svane, Katrine Louise; Walsh, Aron; Paraguassu, Waldeci.

In: Physical Chemistry Chemical Physics, Vol. 21, No. 8, 01.01.2019, p. 4200-4208.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Stability and flexibility of heterometallic formate perovskites with the dimethylammonium cation

T2 - Pressure-induced phase transitions

AU - Ptak, MacIej

AU - Svane, Katrine Louise

AU - Walsh, Aron

AU - Paraguassu, Waldeci

PY - 2019/1/1

Y1 - 2019/1/1

N2 - We report the high-pressure properties of two heterometallic perovskite-type metal-organic frameworks (MOFs) templated by dimethylammonium (NH 2 (CH 3 ) 2 , DMA + ) with the general formula [DMA]MI0.5CrIII0.5(HCOO) 3 , where M I = Na + (DMANaCr) and K + (DMAKCr). The high-pressure Raman scattering studies show crystal instabilities in the 4.0-4.4 GPa and 2.0-2.5 GPa ranges for DMANaCr and DMAKCr, respectively. The mechanism is similar in the two compounds and involves strong deformation of the metal-formate framework, especially pronounced for the subnetwork of CrO 6 octahedra, accompanied by substantial compressibility of the DMA + cations. Comparison with previous high-pressure Raman studies of sodium-chromium heterometallic MOFs show that the stability depends on the templated cation and increases as follows: Ammonium < imidazolium < DMA + . Density functional theory (DFT) calculations are performed to get a better understanding of the structural properties leading to the existence of phase transitions. We calculate the energy of the hydrogen bonds (HBs) between the DMA + cation and the metal formate cage, revealing a stronger interaction in the DMAKCr compound due to a HB arrangement that primarily involves the energetically preferred bonding to KO 6 octahedra. This material however also has a smaller structural tolerance factor (TF) and a higher vibrational entropy than DMANaCr. This indicates a more flexible crystal structure, explaining the lower phase transition pressure, as well as the previously observed phase transition at 190 K, which is absent in the DMANaCr compound. The DFT high-pressure simulations show the largest contraction to be along the trigonal axis, leading to a minimal distortion of the HBs formed between the DMA + cations and the metal-formate sublattice.

AB - We report the high-pressure properties of two heterometallic perovskite-type metal-organic frameworks (MOFs) templated by dimethylammonium (NH 2 (CH 3 ) 2 , DMA + ) with the general formula [DMA]MI0.5CrIII0.5(HCOO) 3 , where M I = Na + (DMANaCr) and K + (DMAKCr). The high-pressure Raman scattering studies show crystal instabilities in the 4.0-4.4 GPa and 2.0-2.5 GPa ranges for DMANaCr and DMAKCr, respectively. The mechanism is similar in the two compounds and involves strong deformation of the metal-formate framework, especially pronounced for the subnetwork of CrO 6 octahedra, accompanied by substantial compressibility of the DMA + cations. Comparison with previous high-pressure Raman studies of sodium-chromium heterometallic MOFs show that the stability depends on the templated cation and increases as follows: Ammonium < imidazolium < DMA + . Density functional theory (DFT) calculations are performed to get a better understanding of the structural properties leading to the existence of phase transitions. We calculate the energy of the hydrogen bonds (HBs) between the DMA + cation and the metal formate cage, revealing a stronger interaction in the DMAKCr compound due to a HB arrangement that primarily involves the energetically preferred bonding to KO 6 octahedra. This material however also has a smaller structural tolerance factor (TF) and a higher vibrational entropy than DMANaCr. This indicates a more flexible crystal structure, explaining the lower phase transition pressure, as well as the previously observed phase transition at 190 K, which is absent in the DMANaCr compound. The DFT high-pressure simulations show the largest contraction to be along the trigonal axis, leading to a minimal distortion of the HBs formed between the DMA + cations and the metal-formate sublattice.

UR - http://www.scopus.com/inward/record.url?scp=85061845955&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85061845955&partnerID=8YFLogxK

U2 - 10.1039/c8cp07131d

DO - 10.1039/c8cp07131d

M3 - Article

C2 - 30741281

AN - SCOPUS:85061845955

VL - 21

SP - 4200

EP - 4208

JO - Physical Chemistry Chemical Physics

JF - Physical Chemistry Chemical Physics

SN - 1463-9076

IS - 8

ER -