Heterogeneity of propyl-ammonium nitrate solid phases obtained under high pressure

Capitani, Francesco; Fasolato, Claudia; Mangialardo, Sara; Signorelli, Sara; Gontrani, Lorenzo; Postorino, P.

doi:10.1016/j.jpcs.2014.12.006

Cited by 17 publications

(17 citation statements)

References 25 publications

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“…The ruby fluorescence technique has been exploited for in situ pressure measurement. Exploiting a camera mounted on the microscope, images of the sample under pressure have been collected to verify the occurrence of liquid–solid transitions also by a simple visual inspection . Further experimental details of the temperature and the pressure Raman setups can be found in refs and , respectively.…”

Section: Methodsmentioning

confidence: 99%

Phase Transitions of PYR₁₄-TFSI as a Function of Pressure and Temperature: the Competition between Smaller Volume and Lower Energy Conformer

Capitani

Trequattrini

Palumbo³

et al. 2016

J. Phys. Chem. B

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A detailed Raman study has been carried out on the ionic liquid 1-butyl-1-methylpyrrolidinium bis(trifluoromethanesulfonyl)imide (PYR14-TFSI) over a wide pressure (0-8 GPa) and temperature (100-300 K) range. The explored thermodynamic region allowed us to study the evolution of the system across different solid and liquid phases. Calculated Raman spectra remarkably helped in the spectral data analysis. In particular, the pressure behavior of the most intense Raman peak and the shape analysis of the ruby fluorescence (used as a local pressure gauge) allowed us to identify a liquid-solid transition around 2.2 GPa at T = 300 K. The low-frequency Raman signal as well as the absence of remarkable spectral shape modifications on crossing the above threshold and the comparison with the spectra of the crystalline phase suggest a glassy nature of the high-pressure phase. A detailed analysis of the pressure dependence of the relative concentration of two conformers of TFSI allowed us to obtain an estimate of the volume variation between trans-TFSI and the smaller cis-TFSI, which is the favored configuration on applying the pressure. Finally, the combined use of both visual inspection and Raman spectroscopy confirmed the peculiar sequence of phase transitions observed as a function of temperature at ambient pressure and the different spectral/morphological characteristics of the two crystalline phases.

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Section: Methodsmentioning

confidence: 99%

Phase Transitions of PYR₁₄-TFSI as a Function of Pressure and Temperature: the Competition between Smaller Volume and Lower Energy Conformer

Capitani

Trequattrini

Palumbo³

et al. 2016

J. Phys. Chem. B

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“…Currently, the elucidations of all types of interactions in ILs are carried out combining theoretical calculations with different spectroscopic techniques [9,12,14,15]. So far, various quaternary ammoniums ILs with different cations and anions have been reported for Aliquat 336, including a recent study on the synthesis and structural and thermal properties of [Aliquat + ][NTF 2 -] IL [15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30][31] but the structural, electronic, vibrational and topological properties of [Aliquat + ][Cl -] IL was no reported yet. Hence, the aims of this work are: (i) to optimize the structure of [Aliquat + ][Cl -] IL in order to predict structural, electronic, topological and vibrational properties, (ii) to find the coordination mode between cation and anion by using natural bond orbital (NBO) and atoms in molecules (AIM) calculations, (iii) to characterize experimentally [Aliquat + ][Cl -] IL by using the infrared, Raman, 1 H-and 13 C-NMR spectra and, (vi) to perform comparisons of this IL with the reported for [Aliquat + ][NTF 2 -] IL [15].…”

Section: Introductionmentioning

confidence: 99%

Experimental and DFT studies on structure, spectroscopic and thermal properties of N-Methyl-N,N,N-trioctylammonium chloride ionic liquid

Assenine

Haddad

Paolone³

et al. 2021

Journal of Molecular Structure

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The [Aliquat + ][Cl -] ionic liquid (IL) has been structural and vibrationally characterized combining experimental FT-IR, FT-Raman and 1 H-and 13 C-NMR spectroscopies with theoretical studies based on the hybrid B3LYP/6-31G* method. The theoretical determination of structure of IL in gas phase and aqueous solution by using that level of theory shows three ionic C-H•••Cl bonds, as supported by atomic Merz-Kollman (MK) charges, bond orders, natural bond orbital (NBO) and atoms in molecules (AIM) calculations. Hence, a monodentate coordination between the [Aliquat + ] cation and Cl anion has been proposed for IL because only one of three ionic C-H•••Cl bonds presents higher energy and lower distance. The optimized structure confirmed by NMR measurements has allowed the assignments of 237 normal vibration modes to the bands observed in the infrared and Raman spectra with the aid of scaled quantum mechanical force field (SQMFF) methodology and the normal internal coordinates. The effect of Cl in the IL is the shifting of vibration modes corresponding to the CH 2 and CH 3 groups, as compared with the cation. The mapped MEP surface evidence a strong concentration of charges around the chloride anion compatible with nucleophilic sites the [Aliquat + ][Cl -] IL are also calculated and compared with the reported for the cation. The Cl anion modifies in notable form the properties of cation.

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“…Moreover, by probing the C−H and N−H vibrations of the MA cation, vibrational spectroscopy is also an effective tool to investigate the effect of pressure on the H-bonding network. 34 Finally, external pressure can also be used to simulate and understand the effects of chemical pressure and strain 35,36 which have been exploited to tune the optical properties of a hybrid perovskite film. 37−39 Here, we report on high-pressure (HP) spectroscopy study of the hybrid perovskite MAPbBr 3 .…”

Section: ■ Introductionmentioning

confidence: 99%

Locking of Methylammonium by Pressure-Enhanced H-Bonding in (CH₃NH₃)PbBr₃ Hybrid Perovskite

et al. 2017

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Organo-lead halide perovskites are nowadays considered to be an emerging photovoltaic material. It is clear that the peculiar hybrid nature of this class of materials is central for their outstanding optical and transport properties. However, the role of the organic cation and its interplay with the inorganic framework remains elusive. To get insight into the interactions at play, high-pressure Raman, infrared, and X-ray absorption spectroscopy measurements were performed on MAPbBr3 (MA = CH3NH3 +). Since lattice compression allows for a fine-tuning of the organic/inorganic interaction, we were able to follow the pressure evolution of the MA dynamics within the PbBr6 cage and identify different phases. From a MA dynamical disordered configuration, the system enters at first a cation ordered phase and, at higher pressure, a static disordered MA phase. Data analysis points at H-bonding as the driving force for molecular reorientation. Since the MA dynamics directly influence the formation of polarons in hybrid perovskites and their ferroelectric properties, the present results provide the basis for the understanding of the transport mechanisms at the core of the outstanding properties of this class of materials.

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Heterogeneity of propyl-ammonium nitrate solid phases obtained under high pressure

Cited by 17 publications

References 25 publications

Phase Transitions of PYR₁₄-TFSI as a Function of Pressure and Temperature: the Competition between Smaller Volume and Lower Energy Conformer

Phase Transitions of PYR₁₄-TFSI as a Function of Pressure and Temperature: the Competition between Smaller Volume and Lower Energy Conformer

Experimental and DFT studies on structure, spectroscopic and thermal properties of N-Methyl-N,N,N-trioctylammonium chloride ionic liquid

Locking of Methylammonium by Pressure-Enhanced H-Bonding in (CH₃NH₃)PbBr₃ Hybrid Perovskite

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Heterogeneity of propyl-ammonium nitrate solid phases obtained under high pressure

Cited by 17 publications

References 25 publications

Phase Transitions of PYR14-TFSI as a Function of Pressure and Temperature: the Competition between Smaller Volume and Lower Energy Conformer

Phase Transitions of PYR14-TFSI as a Function of Pressure and Temperature: the Competition between Smaller Volume and Lower Energy Conformer

Experimental and DFT studies on structure, spectroscopic and thermal properties of N-Methyl-N,N,N-trioctylammonium chloride ionic liquid

Locking of Methylammonium by Pressure-Enhanced H-Bonding in (CH3NH3)PbBr3 Hybrid Perovskite

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Phase Transitions of PYR₁₄-TFSI as a Function of Pressure and Temperature: the Competition between Smaller Volume and Lower Energy Conformer

Phase Transitions of PYR₁₄-TFSI as a Function of Pressure and Temperature: the Competition between Smaller Volume and Lower Energy Conformer

Locking of Methylammonium by Pressure-Enhanced H-Bonding in (CH₃NH₃)PbBr₃ Hybrid Perovskite