scholarly journals A Reversible Phase Transition of 2D Coordination Layers by B–H∙∙∙Cu(II) Interactions in a Coordination Polymer

Molecules ◽  
2019 ◽  
Vol 24 (17) ◽  
pp. 3204 ◽  
Author(s):  
Lei Gan ◽  
Pol G. Fonquernie ◽  
Mark E. Light ◽  
Gantulga Norjmaa ◽  
Gregori Ujaque ◽  
...  
Keyword(s):  
Phase Transition ◽  
Coordination Polymer ◽  
Thermal Activation ◽  
Bet Surface Area ◽  
Co2 Uptake ◽  
X Ray Diffraction ◽  
X Ray ◽  
Reversible Phase Transition ◽  
Open Metal Sites ◽  
Reversible Phase

Materials that combine flexibility and open metal sites are crucial for myriad applications. In this article, we report a 2D coordination polymer (CP) assembled from CuII ions and a flexible meta-carborane-based linker [Cu2(L1)2(Solv)2]•xSolv (1-DMA, 1-DMF, and 1-MeOH; L1: 1,7-di(4-carboxyphenyl)-1,7-dicarba-closo-dodecaborane). 1-DMF undergoes an unusual example of reversible phase transition on solvent treatment (i.e., MeOH and CH2Cl2). Solvent exchange, followed by thermal activation provided a new porous phase that exhibits an estimated Brunauer-Emmett-Teller (BET) surface area of 301 m2 g−1 and is capable of a CO2 uptake of 41 cm3 g−1. The transformation is reversible and 1-DMF is reformed on addition of DMF to the porous phase. We provide evidence for the reversible process being the result of the formation/cleavage of weak but attractive B–H∙∙∙Cu interactions by a combination of single-crystal (SCXRD), powder (PXRD) X-ray diffraction, Raman spectroscopy, and DFT calculations.

scholarly journals Reversible phase transition in laser-shocked 3Y-TZP ceramics observed via nanosecond time-resolved x-ray diffraction

2012 ◽  
Vol 111 (5) ◽  
pp. 053526 ◽  
Author(s):  
Jianbo Hu ◽  
Kouhei Ichiyanagi ◽  
Hiroshi Takahashi ◽  
Hiroaki Koguchi ◽  
Takeaki Akasaka ◽  
...  
Keyword(s):  
Phase Transition ◽  
X Ray Diffraction ◽  
Time Resolved ◽  
X Ray ◽  
Reversible Phase Transition ◽  
Reversible Phase

scholarly journals Tris(ethylenediamine) Cobalt(II) and Manganese(II) Nitrates

Crystals ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 472
Author(s):  
Miguel Cortijo ◽  
Ángela Valentín-Pérez ◽  
Mathieu Rouzières ◽  
Rodolphe Clérac ◽  
Patrick Rosa ◽  
...  
Keyword(s):  
Phase Transition ◽  
X Ray Diffraction ◽  
Temperature Dependent ◽  
Scanning Calorimetry ◽  
Orbital Contribution ◽  
X Ray ◽  
Reversible Phase Transition ◽  
Heat Capacity Measurements ◽  
Reversible Phase

Octahedral tris(ethylenediamine) coordination complexes demonstrate helicoidal chirality, due to the arrangement of the ligands around the metal core. The enantiomers of the nitrate salts [Ni(en)3](NO3)2 and [Zn(en)3](NO3)2 spontaneously resolve to form a mixture of conglomerate crystals, which present a reversible phase transition from space group P6322 to enantiomorphic P6522 or P6122, with the latter depending on the handedness of the enantiomer. We report here the synthesis and characterization of [Mn(en)3](NO3)2 and [Co(en)3](NO3)2, which are isostructural to the Zn(II) and Ni(II) derivatives. The Mn(II) analogue undergoes the same phase transition centered at 150(2) K, as determined by single-crystal X-ray diffraction, Raman spectroscopy, and differential scanning calorimetry. The Co(II) derivative does not demonstrate a phase transition down to 2 K, as evidenced by powder X-ray diffraction and heat capacity measurements. The phase transition does not impact the magnetic properties of the Ni(II) and Mn(II) analogues; these high spin compounds display Curie behavior that is consistent with S = 1 and 5/2, respectively, down to 20 K, while the temperature-dependent magnetic moment for the Co(II) compound reveals a significant orbital contribution.

Die quaternären Systeme ZnAl2S4-ZnGa2S4, ZnAl2S4-CdAl2S4 und ZnAl2S4-ZnAl2Se4. Röntgenographische und schwingungsspektroskopisehe Untersuchungen / Investigation of the Quaternary Systems ZnAl2S4-ZnGa2S4, ZnAl2S4-CdAl2S4 and ZnAl2S4-ZnAl2Se4 by X-Ray Diffraction and Vibrational Spectroscopy

1983 ◽  
Vol 38 (3) ◽  
pp. 311-316 ◽  
Author(s):  
H. Haeuseler ◽  
A. Cansiz
Keyword(s):  
Phase Transition ◽  
Vibrational Spectroscopy ◽  
Solid Solutions ◽  
Homogeneity Range ◽  
Binary Systems ◽  
X Ray Diffraction ◽  
X Ray ◽  
Reversible Phase Transition ◽  
Reversible Phase ◽  
Fir Spectra

The quasi-binary systems Zn1-xCdxAl2S4, ZnAl2(1-x)Ga2xS4 and ZnAl2S4(1-x)Se4x have been investigated by X-ray diffraction and vibrational spectroscopy. In the spinel ZnAI2S4 up to 20% of Zn can be replaced by Cd. In the two other systems, ZnAl2S4 has no detectable homogeneity range. The thiogallate phases have much broader ranges of homogeneity. The compositions of the compounds at the phase boundary of the thiogallate phase are Zn0.4Cd0.6Al2S4, ZnGa0.4Al1.6S4, and ZnAl2S2.8Se1.2. At approximately 950 °C ZnAl2Se4 undergoes a reversible phase transition to a wurtzite-type structure. This phase transition is also observed for the solid solutions ZnAl2S4(1-x)Se4x; with 1.0 > x > 0.3. The FIR spectra are discussed.

Erratum: “Reversible phase transition in laser-shocked 3Y-TZP ceramics observed via nanosecond time-resolved x-ray diffraction” [J. Appl. Phys. 111, 053526 (2012)]

2013 ◽  
Vol 113 (3) ◽  
pp. 039901 ◽  
Author(s):  
Jianbo Hu ◽  
Kouhei Ichiyanagi ◽  
Hiroshi Takahashi ◽  
Hiroaki Koguchi ◽  
Takeaki Akasaka ◽  
...  
Keyword(s):  
Phase Transition ◽  
X Ray Diffraction ◽  
Time Resolved ◽  
X Ray ◽  
Reversible Phase Transition ◽  
Reversible Phase

Phase Transition of Na3As under Pressure

1990 ◽  
Vol 45 (10) ◽  
pp. 1388-1392 ◽  
Author(s):  
Heinz Jürgen Beister ◽  
Karl Syassen ◽  
Jürgen Klein
Keyword(s):  
Phase Transition ◽  
High Pressure ◽  
Structural Properties ◽  
Pressure Range ◽  
Structure Type ◽  
X Ray Diffraction ◽  
X Ray ◽  
Equation Of States ◽  
Reversible Phase Transition ◽  
Reversible Phase

We have investigated the high pressure behaviour of Na3As by powder X-ray diffraction. At 3.6 GPa the material undergoes a reversible phase transition from the Na3As structure (P 63/mmc, a = 487.4(8) pm, c = 851.5(20) pm, Z = 2, at 3.6 GPa) to the Li3Bi structure type (Fm 3̅ m, a = 683.5(15) pm, Z = 4, at 3.6 GaP). The equation of states is given for the pressure range up to 26 GPa. Results are discussed with respect to structural properties of related A3IBV-compounds

scholarly journals Pressure-induced Jahn-Teller Switch in the Homoleptic Hybrid Perovskite [(CH3)2NH2]Cu(HCOO)3: Orbital Reordering by Unconventional Degrees of Freedom

2021 ◽  
Author(s):  
Rebecca Scatena ◽  
Michał Andrzejewski ◽  
Roger D Johnson ◽  
Piero Macchi
Keyword(s):  
Phase Transition ◽  
High Pressure ◽  
Coordination Polymer ◽  
Degrees Of Freedom ◽  
X Ray Diffraction ◽  
X Ray ◽  
Hybrid Perovskite ◽  
Jahn Teller

Through in-situ, high-pressure x-ray diffraction experiments we have shown that the homoleptic perovskite-like coordination polymer [(CH3)2NH2]Cu(HCOO)3 undergoes a pressure-induced orbital reordering phase transition above 5.20 GPa. This transition is distinct...

Phase Transition and Thermochromism of the Hybrid (C12H25NH3)2FeCl4

2006 ◽  
Vol 111 ◽  
pp. 55-58
Author(s):  
L.L. Guo ◽  
Y.D. Dai ◽  
H.X. Liu ◽  
Shi Xi Ouyang
Keyword(s):  
Phase Transition ◽  
Structural Changes ◽  
Energy Transition ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Thermal Gravimetry ◽  
Reversible Phase Transition ◽  
Rotational Motions ◽  
Xrd Patterns ◽  
Reversible Phase

This paper focuses on the structural change and the thermochromism of the phase transition of the hybrid (C12H25NH3)2FeCl4. The temperature and the structures of the phase transition is investigated by a thermal gravimetry (TG) and differential scanning calorimetry (DSC), an infrared spectra (IR) and X-ray diffraction (XRD) patterns. The UV adsorption spectra account for the thermochromism. The results suggest that the reversible phase transition arises from the structural changes of the organic chains. The thermochromism is presumably due to the electrons redistribution on the levels and to the energy transition to translational and rotational motions of the organic chains.

scholarly journals High-pressure reversibility in a plastically flexible coordination polymer crystal

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Xiaojiao Liu ◽  
Adam A. L. Michalchuk ◽  
Biswajit Bhattacharya ◽  
Nobuhiro Yasuda ◽  
Franziska Emmerling ◽  
...  
Keyword(s):  
Phase Transition ◽  
High Pressure ◽  
Coordination Polymer ◽  
Structural Phase ◽  
Low Frequency ◽  
Hydrostatic Compression ◽  
X Ray Diffraction ◽  
X Ray ◽  
Three Point Bending ◽  
Mechanical Responses

AbstractSingle crystals which exhibit mechanical flexibility are promising materials for advanced technological applications. Before such materials can be used, a detailed understanding of the mechanisms of bending is needed. Using single crystal X-ray diffraction and microfocus Raman spectroscopy, we study in atomic detail the high-pressure response of the plastically flexible coordination polymer [Zn(μ-Cl)2(3,5-dichloropyridine)2]n (1). Contradictory to three-point bending, quasi-hydrostatic compression of (1) is completely reversible, even following compression to over 9 GPa. A structural phase transition is observed at ca. 5 GPa. DFT calculations show this transition to result from the pressure-induced softening of low-frequency vibrations. This phase transition is not observed during three-point-bending. Microfocus synchrotron X-ray diffraction revealed that bending yields significant mosaicity, as opposed to compression. Hence, our studies indicate of overall disparate mechanical responses of bulk flexibility and quasi-hydrostatic compression within the same crystal lattice. We suspect this to be a general feature of plastically bendable materials.

A low temperature reversible phase transition for 1,1'-bis-(ferrocenyldimethylsilyl)ferrocenylene, (η5-FcSiMe2C5H4)2Fe, an oligomeric model for silyleneferrocenylene polymers

2000 ◽  
Vol 78 (11) ◽  
pp. 1511-1518 ◽  
Author(s):  
Mikhail Yu Antipin ◽  
Ivan I Vorontsov ◽  
Irene I Dubovik ◽  
Vladimir Papkov ◽  
Francisco Cervantes-Lee ◽  
...  
Keyword(s):  
Phase Transition ◽  
Solid State ◽  
Phase Space ◽  
Low Temperature ◽  
High Temperature Phase ◽  
Temperature Phase ◽  
X Ray Diffraction ◽  
Space Group ◽  
Reversible Phase Transition ◽  
Reversible Phase

We have reinvestigated the solid state structure of 1,1'-bis-(ferrocenyldimethylsilyl)ferrocenylene, (η5-FcSiMe2C5H4)2Fe, Fc = (η5-C5H5)Fe(η5-C5H4). Using a DSC technique we observed a reversible phase transition for this compound at 169(3)K with ΔH = 1.1 kJ/mol, and ΔS = 6.54 J/mol K. A single crystal X-ray diffraction study has demonstrated that this phase change involves a transformation from a high temperature phase, space group P21/c, Z = 2, to a triclinic low temperature phase, space group P[Formula: see text], Z = 4. The phase transition involves the loss of the molecular crystallographic center of symmetry and rotations about the terminal and central cyclopentadienyl ring pairs. The results are compared to those reported for ferrocene.Key words: solid state, phase transition, silyleneferrocenylene.

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