Raman and infrared studies of structural phase transition in (CH3)2NH2NO3
TL;DR: In this article, a temperature dependent study of the frequencies and band widths showed the existence of a phase transition at 297 K. The spectral features indicate that the high temperature phase I is disordered in which both cations and anions exhibit reorientational motion and the transition to phase II is brought about by freezing out the disorder of both the cations.
About: This article is published in Journal of Physics and Chemistry of Solids.The article was published on 1988-01-01. It has received 12 citations till now. The article focuses on the topics: Phase transition & Raman spectroscopy.
Citations
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TL;DR: The symmetry changes and temperature for 3446 phase transitions and the references for each of 2242 registered crystalline materials with well defined stoichoimetry are the main data in this database table.
Abstract: The database on structural phase transitions is presented in the simple and easy accessible form of table. The symmetry changes and temperature for 3446 phase transitions and the references for each of 2242 registered crystalline materials with well defined stoichoimetry are the main data in this table. The rules for constructing and reading the database table are also presented.
178 citations
TL;DR: The structural features from the crystal structure, in concert with a Raman spectroscopic analysis of the ions, provide direct insight as to why EtNH( 3)NO(3) melts below ambient temperature, while other related salts do not.
Abstract: The crystal structure of the salt ethylammonium nitrate (EtNH3NO3) has been determined. EtNH3NO3 is one of the most widely studied protic ionic liquids (PILs)—ILs formed by proton transfer from a Bronsted acid to a Bronsted base. The structural features from the crystal structure, in concert with a Raman spectroscopic analysis of the ions, provide direct insight as to why EtNH3NO3 melts below ambient temperature, while other related salts (such as EtNH3Cl) do not.
37 citations
TL;DR: Semicarbazone of p-dimethylamino benzaldehyde (SCPDB) is a new organic material with interesting quadratic nonlinear optical properties, in particular second harmonic generation (SHG) as mentioned in this paper.
28 citations
TL;DR: The Pbca (no. 61) space group of orthorhombic system, Z=8, a=10.158(2), b=9.277(2), c=16.177(3) A. The crystals of anilinium nitrate were obtained by slow evaporation of an aqueous solution as mentioned in this paper.
23 citations
TL;DR: In this article, the synthesis and analysis of two novel luminescent MOFs, [(CH3)2NH2][Dy(HCOO)4] and [N2H5], were reported.
Abstract: We report the synthesis, crystal structures, Raman, infrared, electron absorption and emission spectra of two novel luminescent MOFs, [(CH3)2NH2][Dy(HCOO)4] and [N2H5][Dy(HCOO)4]. These data show that [(CH3)2NH2][Dy(HCOO)4] and [N2H5][Dy(HCOO)4] crystallize in polar space groups of Pna21 and Pca21 symmetry, respectively. The polar properties of [N2H5][Dy(HCOO)4] come from the arrangement of template cations that possess an internal dipole moment as well as from the symmetry of the framework. In [(CH3)2NH2][Dy(HCOO)4], the Dy(III)–formate framework is centrosymmetric and the polar properties of this compound arise from the arrangement of the DMA+ cations. Vibrational studies reveal that the position of the ν(NN) band, which is very sensitive to coordination changes, is characteristic for hydrazine molecules forming onium ions. Optical studies show that both compounds exhibit emission of Dy(III) ions, in spite of full concentration of dysprosium ions in the studied compounds. Our data also show that radiative decay times, 57 μs for [(CH3)2NH2][Dy(HCOO)4] and 96 μs for [N2H5][Dy(HCOO)4], are very long compared to lifetimes observed in inorganic compounds. We have also preformed Judd–Ofelt analysis of the optical absorption spectrum of the hydrazinium analogue that provides information on various optical parameters such as electric-dipole oscillator strengths, Judd–Ofelt parameters Ωλ, branching ratios and spontaneous emission probabilities.
16 citations
References
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TL;DR: In this article, the infrared spectra of a number of secondary bases and of their salts have been examined, and the spectrum of the salts differ from those of the corresponding bases in containing several absorption ban...
Abstract: The infrared spectra of a number of secondary bases and of their salts have been examined. The spectra of the salts differ from those of the corresponding bases in containing several absorption ban...
157 citations
TL;DR: In this article, the infra-red spectra of di-, tri-and tetramethylammonium iodides have been determined and interpreted in terms of the vibrations of the cations.
107 citations
TL;DR: In this paper, the infra-red spectra of solids can be studied by the pressed-disk technique, which involves pulverizing a little of the sample with a powdered alkali halide and pressing in vacuo under pressure to give a transparent disk.
80 citations
63 citations
TL;DR: In this paper, the Raman spectra of NH 4 NO 3, and ND 4 NO3, were studied from 250 to 420K and the results showed that there are four phases separated by first order transitions.
61 citations