Gray electronic properties

Fig. 3.1 The optimized ground-state structures of SiQDs. The silicon, carbon, hydrogen, and oxygen atoms are cyan, gray, white, and red, respectively. The three different adsorption positions are labeled by number 1, 2, or 3 in (a) and (b) [22]. Reprinted with permission from (Li QS, Zhang RQ, Niehaus TA, Frauenheim T, Lee ST (2007) Theoretical studies on optical and electronic properties of propionic-acid-terminated sdicon quantum dots, J Chem Theory Comput 3 1518-1526). Copyright (2007), American Chemical Society...

Figure 7. One hundred common organic substituents represented in the space of principal properties. PP, is mainly related with the size of the substituents, while PP2 expresses their electronic properties. The four substituents highlighted with the dark gray circles are possible representatives of the four quadrants of this space. The n-Bu, highlighted in light gray is a possible alternative to OBu when these derivatives are not easily accessible.

Grinstaff, M.W., M.G. Hill, E.R. Bimbaum, W.P. Schaefer, J.A. Labinger, and H.B. Gray (1995). Structures, electronic properties, and oxidation-reduction reactivity of halogenated iron porphyrins. Inorg. Chem. 34, 4896-4902. 

Gray DG (1994) Chiral nematic ordering of polysaccharides. Carbohydr Pol5fm 25(4) 277-284 Greiner A, Hou H, Reuning A, Thomas A, Wendorff JH, Zinunermami S (2003) Synthesis and opto electronic properties of cholesteric cellulose esters. Cellulose 10(l) 37-52 Habibi Y, Lucia LA, Rojas OJ (2010) Cellulose nanocrystals chemistry, self-assembly, and applications. Chem Rev 110(6) 3479-3500... 

Hafnium [7440-58-6] Hf, is in Group 4 (IVB) of the Periodic Table as are the lighter elements zirconium and titanium. Hafnium is a heavy gray-white metallic element never found free in nature. It is always found associated with the more plentiful zirconium. The two elements are almost identical in chemical behavior. This close similarity in chemical properties is related to the configuration of the valence electrons, and for zirconium and... 

The liquid crystalline state may be identified as a distinct and unique state of matter which is characterised by properties which resemble those of both solids and liquids. It was first recognised in the middle of the last century through the study of nerve myelin and derivatives of cholesterol. The research in the area really gathered momentum, however, when as a result of the pioneering work of Gray in the early 1970 s organic compounds exhibiting liquid crystalline properties were shown to be suitable to form the basis of display devices in the electronic products. 

Trigonal selenium is variously called metallic gray or black selenium and occurs in lustrous hexagonal crystals, which melt at 220.5 °C. Its structure, which has no sulfur analogue, consists of infinite, unbranched helical chains. Its density, 4.82 g cm , is the highest of any form of the element. Trigonal selenium is a semiconductor (intrinsic p-type with a rather indirect transition at about 1.85 eV [5]), and its electronic and photoelectric properties are the basis for many industrial uses of this element. 

We may illustrate this approach to the determination of the nuclear factor by the elegant studies performed by Gray and co-workers, who have determined the thermodynamic properties and the rate temperature dependence for the electron transfer between Ru(NH3) covalently bound to the histidine residues of some proteins, and the redox eenter of these proteins [110, 111, 112, 113]. The experimental results obtained for cytochrome c [110] and azurin [111, 112] are very similar. Using the thermodynamic data and the value or the upper limit of Ea reported in these studies, we deduce from Eq. (23) ... 

Chromium is a silvery white/gray, hard, brittle noncorrosive metal that has chemical and physical properties similar to the two preceding elements in period 4 (V andTi). As one of the transition elements, its uses its M shell rather than its outer N shell for valence electrons when combining with other elements. Its melting point is 1,857°C, its boiling point is 2,672°C, and its density is 7.19 g/cm. ... 

Gray and Waddington [57,120] examined the physico-chemical properties of silver azide and state that its melting point is 300°C. On the basis of the latest opinion that the explosive decomposition of azides results from processes involving ions and electrons caused by imperfection and deficiencies in the crystal lattice (Jacobs and Tompkins [22]), the authors incorporated silver cyanide, Ag2(CN)2,... 

Samples of HY zeolite were exhaustively treated with successive doses of tetramethylsilane in a static reactor at different temperatures in the range 250°-650°C. Rate data for methane evolution were obtained, and the kinetics were discussed. Silicon and some carbon were incorporated, giving gray materials parts of which were calcined in oxygen. Samples of the original H Y, the treated zeolite, and calcined materials were tested for their abilities to accept electrons from perylene and to isomerize cyclopropane and protoadamantane. The treated zeolite had good electron transfer properties but low and high activities for the isomerizations, respectively. However, the opposite was true for the calcined materials. These results are discussed in terms of the acidic properties of the modified zeolites. 

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