Dioxide single crystals

Titanium Dioxide Single-Crystal and Powder Surfaces in the Presence and Absence of Platinum... 

Kimizuk N., Ishii M., Kawada I., Saeki M. and Nakahira M., Behavior of vanadium dioxide single crystals synthesized under the various oxygen partial pressures at 1500 K. J. Solid State Chem. 9 (1974) pp. 69 - 77. 

Decomposition of Higher Alcohols on Titanium Dioxide Single Crystal Surfaces... 

Decomposition of higher alcohols on titanium dioxide single crystal 432... 

Neirinckx, R., Adams, F., Hoste, J. Determination of impurities in titanium and titanium dioxide by neutron activation analysis. Part IV Determination of trace impurities in titanium dioxide single crystals. Anal. C3iim. Acta 48, 1 (1969)... 

Results with oxides tested are compatible with results of Liao et al. for titanium dioxide single crystals (16). It is postulated that the enhancement depertds on the physical form of the oxide type of polymorph present bulk. 

Anatase and mtile are produced commercially, whereas brookite has been produced by heating amorphous titanium dioxide, which is prepared from an alkyl titanate or sodium titanate [12034-34-3] with sodium or potassium hydroxide in. an autoclave at 200—600°C for several days. Only mtile has been synthesized from melts in the form of large single crystals. More recentiy (57), a new polymorph of titanium dioxide, Ti02(B), has been demonstrated, which is formed by hydrolysis of K Ti O to form 20, followed by subsequent calcination/dehydration at 500°C. The relatively open stmcture... 

All of the observed reflections could be indexed on the basis of a cubic unit cell with Oo = 11.82 A the estimated probable error is 0.01 A. The only systematic absences were hhl with l odd this is characteristic of the space group 0 -PmP>n, which also was reported by von Stackelberg from his single-crystal work on sulfur dioxide hydrate. For 46 H20 and 6 Cl2 in the unit cell the calculated density is 1.26 densities reported by various observers range from 1.23 to 1.29. 

Furthermore, a series of single crystal X-ray diffraction studies were reported for several thiadiazole 1-monoxides and 1,1-dioxides, allowing a direct comparison in bond lengths and angles for an identical 3,4-substitution pattern (Table 4). The related fused phenanthro[9,10-r-]-l,2,5-thiadiazole 1,1-dioxide 51 and acenaphtho[l,2-f]-l,2,5-thiadiazole 1,1-dioxide 53 have similar bond lengths to 3,4-diphenyl-1,2,5-thiadiazole 1,1-dioxide 10 <2001JST157>. 

A formally antiaromatic 1,4-dihydropyrazinothiadiazole has been prepared and characterized by single crystal X-ray spectroscopy. The antiaromatic character of which has been supported computationally using NICS measurements <20070L1073>. CHIH-DFT computational studies on acenaphtho[l,2-f]-l,2,5-thiadiazole 1,1-dioxide led to simulations of its infrared (IR) and ultraviolate (LJV) spectra, the dipole moment and polarizability <2007JMT373>. 4,6-Dinitrobenzothiadiazole was determined to have an electrophilic reactivity of —8.40 which corresponds to a pK z° of 7.86 for Meisenheimer complexation with water and is close to the demarcation boundary (E = —8.5) between super-and normal-electrophiles and between reactive dienophiles and inert partners in Diels-Alder adduct formation <20070BC1744>. 

Figure 1.10 Variation of the length of a single crystal of oxygen-rich uranium dioxide, UO2+X, with oxygen partial pressure at 1200°C. [Data redrawn from L. Desgranges, M. Gramond, C. Petot, G. Petot-Ervas, P. Ruello, and B. Saadi, J. Eur. Ceram. Soc., 25, 2683-2686 (2005).]...

Rg. 11.2 Single crystals of morphologically enantiomeric quartz. Note the mirror symmetry of the facets on the respective crystals. Unlike amino acids, the component silicon dioxide molecules have no chirality. The spontaneous resolution of quartz into crystals of opposite morphological handedness is an example of local symmetry breaking in the environment. 

The nature of the anomeric effect in the bicyclic /ra r-fused octahydro-l-methyl-l//-2,l-benzothiazine 2,2-dioxide 37 has been examined by single crystal X-ray structure analysis (Figure 5) <1998CJC164>. The crystal structure of 37 shows that the A -Me group assumes an axial position in the solid state. The authors suggest that this conformation is also the most stable in solution and propose that this hyperconjugation effect is >2.0 kcal mol . ... 

The single crystal X-ray structure of 3-methyl-4//-pyrido[2,3- ] l>2,4-thiadiazine 1,1,-dioxide 13 was compared to that of diazoxide 14 in order to determine the predominant tautomeric form and it was found that both these thiadiazine-dioxides exist in the AH tautomeric form in the solid state <1995AXG2064>. 

Single-crystal precession data indicate orthorhombic symmetry with the crystallographic space group Fddd. This system is not isostructural with any other known metal oxyfluoride or metal dioxide. The cell dimensions, determined from Guinier data, are a = 8.370 1 A. b = 10.182 1 A. and c = 7.030 1 A. The indexed powder data are given in reference 6. 

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