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Title: Pressure-Induced Conductivity and Yellow-to-Black Piezochromism in a Layered Cu¿Cl Hybrid Perovskite

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Publication Date:
Research Org.:
Brookhaven National Laboratory (BNL), Upton, NY (United States)
Sponsoring Org.:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
OSTI Identifier:
Report Number(s):
Journal ID: ISSN 0002-7863
DOE Contract Number:
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of the American Chemical Society; Journal Volume: 137; Journal Issue: 4
Country of Publication:
United States

Citation Formats

Jaffe, A, Lin, Y, Mao, W, and Karunadasa, H. Pressure-Induced Conductivity and Yellow-to-Black Piezochromism in a Layered Cu¿Cl Hybrid Perovskite. United States: N. p., 2015. Web. doi:10.1021/ja512396m.
Jaffe, A, Lin, Y, Mao, W, & Karunadasa, H. Pressure-Induced Conductivity and Yellow-to-Black Piezochromism in a Layered Cu¿Cl Hybrid Perovskite. United States. doi:10.1021/ja512396m.
Jaffe, A, Lin, Y, Mao, W, and Karunadasa, H. 2015. "Pressure-Induced Conductivity and Yellow-to-Black Piezochromism in a Layered Cu¿Cl Hybrid Perovskite". United States. doi:10.1021/ja512396m.
title = {Pressure-Induced Conductivity and Yellow-to-Black Piezochromism in a Layered Cu¿Cl Hybrid Perovskite},
author = {Jaffe, A and Lin, Y and Mao, W and Karunadasa, H},
abstractNote = {},
doi = {10.1021/ja512396m},
journal = {Journal of the American Chemical Society},
number = 4,
volume = 137,
place = {United States},
year = 2015,
month = 1
  • The effects of high pressure on (Cu(dien)(bipyam))X{sub 2}{center dot}nH{sub 2}O (dien = diethylenetriamine, bipyam = 2,2{prime}-dipyridylamine; X = Cl{sup {minus}}, n = 2(1); X = ClO{sub 4}{sup {minus}}, n = 1 (2); and X = NO{sub 3}{sup {minus}}, n = 0 (3)) are described. Pressure-dependent electronic spectroscopy indicates a continuous transformation of 1 and 2 from distorted to more regular square pyramidal configurations with increasing pressure. A rearrangement in 3 from a distorted trigonal bipyramidal to a distorted square pyramidal configuration is observed over a pressure range of 30 kbar beginning at 45 kbar. Supporting infrared data are presented, andmore » a discussion of the rearrangement based on cation-anion interactions is given. As dopants in a poly(4-vinylpyridine) environment all three complexes possess distorted square pyramidal configurations that become more regular at high pressure.« less
  • The effects of high pressure on the thermochromic and related complexes (CuL{sub 2})X{sub 2} (L = N,N-diethylethylenediamine (dieten), X = BF{sub 4}{sup {minus}}, ClO{sub 4}{sup {minus}}, Cl{sup {minus}}; L = N,N-dimethylenediamine (dimeen), X = BF{sub 4}{sup {minus}}; L = ethylenediamine (en), X = BF{sub 4}{sup {minus}}) are described. Electronic and infrared spectroscopies indicate an increase in the interaction between anion and molecular CuN{sub 4} plane of all complexes with increasing pressure. For both the electronic and infrared spectra, the similarity between the high-pressure spectra of the dieten complexes and the low-pressure spectra of the en and dimeen complexes indicates thatmore » the former transform to a geometry similar to that of the latter with pressure. A color change is associated with the transformation. The short pressure range over which the rearrangement occurs in the crystal indicates that it is a highly cooperative process. Studies of some of the complexes in polymeric environments (sodium polystyrenesulfonate and/or poly(2-vinylpyridine)) show that the rearrangement occurs at lower pressure and is much less cooperative in the polymers.« less
  • The effects of high pressure on Cs{sub 2}CuCl{sub 4}, bis(trimethylbenzylammonium) tetrachlorocuprate, (N-phenylpiperazinium) tetrachlorocuprate, bis(N-benzylpiperazinium) tetrachlorocuprate bis(hydrochloride), and bis(N-methylphenethylammonium) tetrachlorocuprate are reported. Electronic spectroscopy indicates molecular rearrangements in the tetrachlorocuprate ions with increasing pressure. The changes in geometry and nature of the rearrangements are discussed.
  • We report a combined experimental and theoretical study of the high pressure behavior of a herringbone-type hydrocarbon benz[a]anthracene (BaA) using fluorescence spectroscopy, X-ray diffraction, optical absorption, photoconductivity measurements, and first-principles density functional theory (DFT) calculations. The ambient-pressure molecular solid phase of BaA was found to be stable up to ~15.0 GPa. Increasing the external pressure within this region would induce a reversible piezochromic colour change in the sample, from yellow-green to light brown. The reversibility of the colour change was confirmed by both optical observations and fluorescence measurements. Further compression beyond 15 GPa leads to polymerization of the sample andmore » formation of an amorphous hydrogenated carbon. The low pressure crystalline phase is not recoverable when the sample is decompressed from pressure above 15 GPa. DFT investigation of the structures at zero temperature suggests that the formation of a crystalline polymeric phase can take place between 30 and 117 GPa, however the kinetic barriers hinder the process at low pressure regions. The phase transition is therefore suggested to proceed along a gradual transition path to an amorphous phase at a lower reaction threshold, activated by finite temperature effects. Optical absorption measurements reveal that the band gap of BaA decreases at high pressure, from 2.4 eV at 0.5 GPa to 1.0 eV at 50.6 GPa. The DFT calculations further suggest that the band gap of BaA in the molecular phase could reduce to ~0.1 eV at 117 GPa. Photoconductivity measurements show a continuous increase of photocurrent in the molecular phase region, which most likely originated from the increase of carrier mobility under pressure.« less
  • A layered perovskite compound, AgLaNb[sub 2]O[sub 7], was newly prepared by an ion-exchange reaction. The compound showed an irreversible phase transition at 330[degrees]C. The crystal structures of low-temperature and high-temperature phases were determined by the Rietveld analysis for the X-ray powder diffraction patterns. The unit cell is tetragonal with a = 7.7757(4) [angstrom], c = 42.587(2) [angstrom], and Z = 16 with I4[sub 1]/acd space group for the [beta]-phase (low-temperature phase), and tetragonal with a = 3.8996(9) [angstrom], c = 21.688(5) [angstrom], and Z = 2 with I4/mmm space group for the [alpha]-phase (high-temperature phase). The main structural difference betweenmore » the two phases is due to the arrangement of silver ions located in the interlayer of the perovskite layers. The ionic conductivity attributed to the interlayer silver ions was observed, but its magnitude was rather small, [approximately]10[sup [minus]5] S cm[sup [minus]1] at 25[degrees]C. An abrupt decrease in the ionic conductivity was observed at the phase transition temperature. This behavior is discussed on the basis of the crystal structures of the two phases.« less