The use of Raman and infrared spectroscopy in determining the space symmetry group among the groups with the same rules of systematic absence in the diffraction patterns: Some basic principles and applications

Author(s):  
Tatyana N. Moroz ◽  
Howell G. M. Edwards
Author(s):  
Polina Sechenykh

The paper presents the calculation of the metric parameters of crystalline compounds according to a given chemical formula and a space symmetry group. The structures of perovskite and double perovskite are considered.


Author(s):  
Vladimir V. Sharutin ◽  
Olga K. Sharutina ◽  
Natalya M. Tarasova ◽  
Evgeniya V. Lobanova ◽  
Pavel V. Andreev

Triphenylbut-2-enyl- (1a) and triphenylmetoxymethylphosphonium (1b) hexachlorozirconates have been synthesized by the reactions of zirconium tetrachloride with the triphenylalkylphosphonium chlorides in acetonitrile for the first time and characterized by the IR, NMR spectroscopy and X-ray analysis. The most intensive bands in IR spectra correspond to the valence vibrations of the CAr-H and the СAr-СAr bonds in the triphenylalkylphosphonium cations. The splitting of carbon atoms signals is observed due to the presence of  13C – 31P coupling. SSCC for carbon atoms directly connected with phosphorus are about 48–85 Hz. According to the X-Ray data, compound 1a crystallizes in the monoclinic crystal lattice (the P21/c space symmetry group). Hexachlorozirconate 1b forms the triclinic crystals belong to the P-1 space symmetry group. Crystals of compound 1a is characterized by the less dense molecular packing in the crystal lattice in comparison with compound 1b. Calculated densities for the structures 1a,b are 1.355 g/cm3 and 1.466 g/сm3, respectively. Structural organization of the complexes in crystals is caused by the formation of hydrogen bonds between chlorine atoms of the anion and hydrogens of phenyl and alkyl groups of the cations. The phosphorus atoms in the triphenylalkylphosphonium cations have distorted tetrahedral coordination (CPC 107.01(4)°-114.10(6)°  for 1а, 107.38(9)°-112.06(7)° for 1b, the P-С bonds are 1.790(14)-1.865(14) Å for 1а, 1.7838(12)-1.8293(18) Å for 1b). In centrosymmetric octahedral anions [ZrCl6]2− (trans-ClZrCl 180°) the Zr-Cl distances are 2.4654(15)-2.4952(17) Å for 1а and 2.4641(14)-2.4711(12) Å for 1b.


2022 ◽  
Vol 130 (1) ◽  
pp. 104
Author(s):  
Е.П. Чукалина ◽  
А. Яблуновский ◽  
И.А. Гудим

Iron borates NdFe3(BO3)4 and SmFe3(BO3)4 activated with 1% erbium, with a huntite structure (space symmetry group R32) were investigated by the method of erbium spectroscopic probe. From an analysis of the temperature dependence of the transmission spectra in the region of the 4I15/2→4I13/2 transition in the Er3+ ion, it was found that both studied compounds order antiferromagnetically at TN ≈ 33 K into an easy-plane magnetic structure. No other phase transitions were found.


2005 ◽  
Vol 10 (3) ◽  
pp. 031106 ◽  
Author(s):  
Judith R. Mourant ◽  
Kurt W. Short ◽  
Susan Carpenter ◽  
Nagapratima Kunapareddy ◽  
Leslie Coburn ◽  
...  

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