Synthesis, x-ray crystal structure, and chemical and physical properties of the new linear-chain mixed-valence complex (.mu.-iodo)tetrakis(dithioacetato)dinickel, Ni2(CH3CS2)4I, and x-ray crystal structure of the precursor tetrakis(dithioacetato)dinickel(II), Ni2(CH3CS2)4

1985 ◽  
Vol 24 (18) ◽  
pp. 2815-2820 ◽  
Author(s):  
Carlo Bellitto ◽  
Giulia Dessy ◽  
Vincenzo Fares
Keyword(s):  
Crystal Structure ◽  
Physical Properties ◽  
Linear Chain ◽  
Mixed Valence ◽  
X Ray ◽  
Mixed Valence Complex

Effects of Electron Beam on Structure and Physical Properties of Natural Colorless Topaz

2015 ◽  
Vol 1125 ◽  
pp. 60-63
Author(s):  
Chutharat Paikaew ◽  
Juthamas Inthanont ◽  
Adisak Punyanut ◽  
Ekachai Hoonnivathana ◽  
Pichet Limsuwan ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Electron Beam ◽  
Physical Properties ◽  
Orthorhombic Structure ◽  
X Ray Diffraction ◽  
X Ray ◽  
Spin Resonance ◽  
Function Group ◽  
And Function ◽  
Beam Dose

The purpose of this research was to investigate physical properties, configuration and color of topaz. Topazes were irradiated with electron beam linear accelerator at different dose from 40 to 180 MGy. The color of topaz was analyzed by UV-vis and it was shown that the color of topaz was becoming strong color with increased electron beam dose. Crystal structure and function group of topaz were characterized by X- ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy. The results showed that the topaz has orthorhombic structure and no other crystalline. After irradiated, topaz released OH indicating higher crystallinity of topaz and this was confirmed with the results of electron spin resonance (ESR). Electron beam dose response of topaz was investigated. ESR results showed that the Al3+ ion was substituted in Si4+ site and Ti3+ impurity in Al4+ site and this result corresponds to the results of FTIR. The experiment result indicated that electron beam could be making defect on crystal structure and color enhancement of topaz.

Gemischtvalente Oxovanadate, I Ein neuer Strukturtyp für die Verbindung BaV10O15/Oxovanadates with Mixed Valence, I A New Crystal Structure of BaV10O15

1980 ◽  
Vol 35 (6) ◽  
pp. 669-671 ◽  
Author(s):  
D. Chales de Beaulieu ◽  
Hk. Müller-Buschbaum
Keyword(s):  
Crystal Structure ◽  
Mixed Valence ◽  
Structure Type ◽  
Orthorhombic Symmetry ◽  
Temperature Reaction ◽  
X Ray ◽  
High Temperature Reaction ◽  
Group D ◽  
Symmetry Space ◽  
Symmetry Space Group

Abstract BaV10O15 was prepared by high temperature reaction of BaO and V2O3 in H2-atmosphere (T > 1800°). X-ray investigations of single crystals show a new structure type with octa-hedral coordination of V3+/V2+ (statistical distribution) and cuboctahedral surrounding of Ba2+ . Orthorhombic symmetry, space group D182h-Ccmb, a = 995,8; b = 1161,8; c = 941,0; Z = 4.

The crystal structures of the mixed-valence tellurium oxysalts tlapallite, (Ca,Pb)3CaCu6[Te4+3Te6+O12]2(Te4+O3)2(SO4)2·3H2O, and carlfriesite, CaTe4+2Te6+O8

2019 ◽  
Vol 83 (4) ◽  
pp. 539-549 ◽  
Author(s):  
Owen P. Missen ◽  
Anthony R. Kampf ◽  
Stuart J. Mills ◽  
Robert M. Housley ◽  
John Spratt ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Mixed Valence ◽  
Oxidation States ◽  
Structural Refinement ◽  
X Ray Diffraction ◽  
X Ray ◽  
Naturally Occurring ◽  
The One ◽  
Micro Analysis ◽  
Secondary Bonding

ABSTRACTThe crystal structure of tlapallite has been determined using single-crystal X-ray diffraction and supported by electron probe micro-analysis, powder diffraction and Raman spectroscopy. Tlapallite is trigonal, space groupP321, witha= 9.1219(17) Å,c= 11.9320(9) Å andV= 859.8(3) Å3, and was refined toR1= 0.0296 for 786 reflections withI> 2σ(I). This study resulted from the discovery of well-crystallised tlapallite at the Wildcat prospect, Utah, USA. The chemical formula of tlapallite has been revised to (Ca,Pb)3CaCu6[Te4+3Te6+O12]2(Te4+O3)2(SO4)2·3H2O, or more simply (Ca,Pb)3CaCu6Te4+8Te6+2O30(SO4)2·3H2O, from H6(Ca,Pb)2(Cu,Zn)3(TeO3)4(TeO6)(SO4). The tlapallite structure consists of layers containing distorted Cu2+O6octahedra, Te6+O6octahedra and Te4+O4disphenoids (which together form the new mixed-valence phyllotellurate anion [Te4+3Te6+O12]12−), Te4+O3trigonal pyramids and CaO8polyhedra. SO4tetrahedra, Ca(H2O)3O6polyhedra and H2O groups fill the space between the layers. Tlapallite is only the second naturally occurring compound containing tellurium in both the 4+and 6+oxidation states with a known crystal structure, the other being carlfriesite, CaTe4+2Te6+O8. Carlfriesite is the predominant secondary tellurium mineral at the Wildcat prospect. We also present an updated structure for carlfriesite, which has been refined toR1= 0.0230 for 874 reflections withI> 2σ(I). This updated structural refinement improves upon the one reported previously by refining all atoms anisotropically and presenting models of bond valence and Te4+secondary bonding.

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