scholarly journals Luminescence Properties of Tetrahedral Coordinated Mn2+; Genthelvite and Willemite Examples

Minerals ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1215
Author(s):  
Maria Czaja ◽  
Radosław Lisiecki ◽  
Rafał Juroszek ◽  
Tomasz Krzykawski
Keyword(s):  
Crystal Structure ◽  
Crystal Field ◽  
Raman Spectra ◽  
Energy Levels ◽  
Excited Level ◽  
Covalent Bond ◽  
Spectroscopic Parameter ◽  
X Ray ◽  
Geometric Deformation ◽  
Bond Theory

The cause of the split of 4A4E(4G) Mn2+ excited level measured on minerals spectra is discussed. It is our view that ∆E = |4E(4G) − 4A(4G)| should be considered an important spectroscopic parameter. Among the possible reasons for the energy levels splitting taken under consideration, such as the covalent bond theory, the geometric deformation of the coordination polyhedron and the lattice site’s symmetry, the first one was found to be inappropriate. Two studied willemite samples showed that the impurities occur in one of the two available lattice sites differently in both crystals. Moreover, it was revealed that the calculated crystal field Dq parameter can indicate which of the two non-equivalent lattice sites positions in the willemite crystal structure was occupied by Mn2+. The above conclusions were confirmed by X-ray structure measurements. Significant differences were also noted in the Raman spectra of these willemites.

scholarly journals Darstellung, Kristallstruktur und Schwingungsspektren von cyclo-Undekaschwefel (S11) und von cyclo-Tridekaschwefel (S13) / Preparation, Crystal Structure, and Vibrational Spectra of cyclo-Undecasulfur (S11) and of cyclo-Tridecasulfur (S13)

1986 ◽  
Vol 41 (8) ◽  
pp. 958-970 ◽  
Author(s):  
Ralf Steudel ◽  
Jürgen Steidel ◽  
Torsten Sandow
Keyword(s):  
Crystal Structure ◽  
Single Crystals ◽  
Raman Spectra ◽  
Vibrational Spectra ◽  
Infrared And Raman Spectra ◽  
X Ray ◽  
Bond Angles ◽  
Torsional Angles

AbstractThe homocyclic S11 and S13 molecules have been synthesized from titanocenepentasulfide and S6Cl2 or S8Cl2, respectively, and obtained as yellow crystals which are metastable for several days at 20 °C. X-Ray structural analyses of single crystals at -105± 5 °C exhibited molecules of approximately C2 symmetry with bond distances (d), bond angles (a) and torsional angles (r) in the following ranges: S11 : d = 203.2 -211.0 pm, α = 103.3-108.6°, τ = 69.3 - 140.5°; S13: d = 197.8 - 211.3 pm, α = 102.8-111.1°, τ = 29.5 - 116.3°. Infrared and Raman spectra of S11 and S13 are reported. In addition, the synthesis of S6Cl2 and S8Cl2 from S6 or S8, respectively, and chlorine is described.

The Vibrational Spectra and Crystal Structure of Acenaphthylene

1973 ◽  
Vol 51 (3) ◽  
pp. 402-404 ◽  
Author(s):  
A. Bree ◽  
R. A. Kydd ◽  
V. V. B. Vilkos ◽  
R. S. Williams
Keyword(s):  
Crystal Structure ◽  
Single Crystals ◽  
Raman Spectra ◽  
Vibrational Spectra ◽  
Room Temperature ◽  
Infrared And Raman Spectra ◽  
Depolarization Ratio ◽  
X Ray

A study of the polarized infrared and Raman spectra of acenaphthylene single crystals has been made. These results, together with Gordon and Yang's preliminary X-ray work, suggest that the molecules pack in some disordered arrangement in the solid at room temperature. Most of the A1 fundamentals were identified in the Raman solution spectrum from their low depolarization ratio, and a few tentative assignments of nontotally symmetric fundamentals were made.

5d and 4f electron configuration of CeB6 at 340 and 535 K

2008 ◽  
Vol 64 (5) ◽  
pp. 534-549 ◽  
Author(s):  
Ryoko Makita ◽  
Kiyoaki Tanaka ◽  
Yoshichika Ōnuki
Keyword(s):  
Electron Transfer ◽  
Crystal Field ◽  
Ground State ◽  
Room Temperature ◽  
Atomic Orbital ◽  
Energy Levels ◽  
Electron Configuration ◽  
Acta Cryst ◽  
X Ray ◽  
The Difference

X-ray atomic orbital (XAO) analysis revealed that at both temperatures the electrons are transferred from B 2px (= py ) to Ce 5d and 4f orbitals. At 340 K 5d(j = 5/2)Γ8 orbitals are occupied partially, but 4f(j = 5/2)Γ8 orbitals are more populated than 4f(j = 5/2)Γ7 orbitals, in contrast to our observation at 430 K [Makita et al. (2007). Acta Cryst. B63, 683–692]. At 535 K the XAO analysis revealed clearly that the order of the energy levels of 4f(j = 5/2)Γ8 and Γ7 states reversed again and is the same as that at room temperature. It also limited the possible 5d configurations to three models among the nine possible ones. However, the XAO analysis could not decide which of the three models was the best with the present accuracy of the measurement. Two of them have partially and fully occupied 5d(j = 5/2)Γ7 orbitals and the remaining one has a fully occupied 5d(j = 3/2)Γ8 orbital. Since the lobes of 5d(j = 3/2)Γ8 or 5d(j = 5/2)Γ7 orbitals do not overlap with the 4f(j = 5/2)Γ8 orbitals as well as the 5d(j = 5/2)Γ8 orbitals, the order of the energy levels of the 4f(j = 5/2) orbitals became the same as that at room temperature. These results indicate that the crystal field varies with temperature due to the electron transfer from B 2p to Ce 5d orbitals. The difference densities after the spherical-atom refinement at the three temperatures clearly revealed the different combinations of 4f and 5d orbitals which are occupied. In the present study positive peaks due to the 4f electrons appear near the Ce nucleus and those due to 5d orbitals are found in the area outside the 4f peaks. Between the two areas there is a negative area distributed spherically at 340 K. The negative area produced by the contraction of 4f(j = 5/2)Γ8 orbitals seems to reduce the electron repulsion of the 5d(j = 5/2)Γ8 orbitals and helps the 4f(j = 5/2)Γ8 orbitals to remain as the ground state.

The crystal and molecular structure of copper(II) bis-(ethylenediamine)nitrate selenocyanate

1982 ◽  
Vol 47 (2) ◽  
pp. 409-420 ◽  
Author(s):  
Viktor Vrábel ◽  
Ján Garaj
Keyword(s):  
Crystal Structure ◽  
Least Squares Method ◽  
Crystal And Molecular Structure ◽  
Central Atom ◽  
Covalent Bond ◽  
Axial Direction ◽  
Analysis Method ◽  
Monoclinic System ◽  
X Ray ◽  
Intermolecular Contacts

The crystal structure of [Cuen2(NO3)]SeCN was solved by the single-crystal X-ray structural analysis method. The compound crystallizes in the monoclinic system with space group Pc. The unit cell has dimensions: a = 0.9254(3), b = 1.4018(3), c = 0.9722(5) nm, β = 99.20(3)°. The structure was refined by the least squares method to a final value of R = 6.8% for 1965 observed reflections. The crystal structure consits of polymeric cation chain [Cuen2(NO3)]+ and of free uncoordinated SeCN- anions. The nitrate ion NO-3 forms a bridging unit between two [Cuen3]2+ cations. The coordination polyhedron around the Cu(II) atom is a deformed octahedron, formed of two ethylendiamine molecules and two oxygen atoms of the NO-3 ions, bonded to divalent copper in the axial direction along the long coordinates. The crystal structure contains selenocyanate which is not bonded through a covalent bond to the central atom, but there are intermolecular contacts with its immediate surroundings.

ChemInform Abstract: Synthesis, 77Se and 119Sn NMR Study, and X-Ray Crystal Structure of the Sn4Se4- 10 Anion and Raman Spectra of SnSe4- 4 and Sn4 Se4- 10.

ChemInform ◽  
2010 ◽  
Vol 27 (11) ◽  
pp. no-no
Author(s):  
J. CAMPBELL ◽  
D. P. DICIOMMO ◽  
H. P. A. MERCIER ◽  
A. M. PIRANI ◽  
G. J. SCHROBILGEN ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Raman Spectra ◽  
X Ray ◽  
Nmr Study ◽  
119Sn Nmr

Structural characterization of TiO2 ultrafine particles

1999 ◽  
Vol 14 (2) ◽  
pp. 442-446 ◽  
Author(s):  
Yingchun Zhu ◽  
Tiao Liu ◽  
Chuanxian Ding
Keyword(s):  
Crystal Structure ◽  
Raman Spectroscopy ◽  
Phase Transformation ◽  
Fourier Transform ◽  
Raman Spectra ◽  
Ultrafine Particles ◽  
X Ray Diffraction ◽  
X Ray ◽  
Factors Influencing

Four samples of TiO2 ultrafine particles (UFP) were obtained through different processes. The structure of TiO2 ultrafine particles and the factors influencing the structure were investigated with Raman spectroscopy, Fourier transform infrared (FTIR) spectroscopy, and x-ray diffraction (XRD). Both Raman spectra and x-ray diffractograms show the similar regularity of the phase transformation among the four samples. The observed bimodal lineshape-structure in the Raman spectra is attributed to the intragrain and grain-boundary components of TiO2 UFP. The crystal structure of TiO2 UFP is found to be distorted by the surface structure such as OH and OCH2CH3 groups coordinated on the surface of TiO2 UFP.

The crystal structure of RbCdCl3 and the polarized Raman spectra of RbCdX3 (X = Cl, Br)

1978 ◽  
Vol 56 (9) ◽  
pp. 1192-1195 ◽  
Author(s):  
Mahadevan Natarajan ◽  
Helen Elaine Howard-Lock ◽  
Ian David Brown
Keyword(s):  
Crystal Structure ◽  
Single Crystals ◽  
Raman Spectra ◽  
X Ray Diffraction ◽  
Frequency Shifts ◽  
X Ray ◽  
Polarized Raman

The polarized Raman spectra of single crystals of RbCdCI3 and RbCdBr3 (isostructural with NH4CdCl3) have been measured and analysed by comparison of the frequency shifts. The crystal structure of RbCdCl3 refined by X-ray diffraction is also reported.

Synthesis, Vibrational Spectra, Mass Spectrum and Crystal Structure of Tri-n-butyltin Diphenylphosphinate (n-Bu)3SnO2PPh2

1995 ◽  
Vol 50 (9) ◽  
pp. 1343-1347 ◽  
Author(s):  
Abdel-Fattah Shihada ◽  
Frank Weller
Keyword(s):  
Crystal Structure ◽  
Mass Spectrum ◽  
Diffraction Study ◽  
Raman Spectra ◽  
Vibrational Spectra ◽  
Ir And Raman Spectra ◽  
X Ray Diffraction ◽  
X Ray ◽  
Trigonal Bipyramidal ◽  
Ir And Raman

AbstractTri-n-butyltin diphenylphosphinate (n-Bu)3SnO2PPh2 has been synthesized by the reaction of (n-Bu3Sn)2O with Ph2POCl in toluene. An X-ray diffraction study of (n-Bu3)SnO2PPh2 shows that the structure is polymeric and consists of helical chains in which (n-Bu)3Sn groups are linked by O-P-O bridges. The geometry about tin is trigonal bipyramidal, with n-butyl groups in equatorial positions and an axial O-Sn-O angle of 176.2 (2)°. IR and Raman spectra of (n-Bu)3SnO2PPh2 are given and assigned. The mass spectrum is reported and discussed.

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