Lithium germanate

The introduction of vacancies into lithium germanate or silicate can be illustrated by two substitutions. The replacements ... 

In order to overcome these stability problems a wide-range of alternative dopants have been studied in an effort to reproduce the transport properties of LISICON whilst eliminating the problems of aging. The introduction of trivalent cations into the basic lithium germanate structure can cause an adjustment in the lithium concentration, but in this case it is possible to introduce additional, interstitial, lithium cations or vacancies on the lithium position. Which of these types of doping occurs depends on the nature of the substitution that occurs. This can be most clearly illustrated by looking at the introduction of aluminium cations. These can enter the structure in place of and so introduce an interstitial lithium cation ... 

It is an unexpected observation that similar conductivity can result for systems that show different dopant mechanisms and this can be illustrated by looking at the effect of doping on the properties of lithium germanate. 

Studies of the effect of Ga " " doping of lithium germanate have identified a solid solution that exists across the composition range Li4 3 jGaxGe04 0.08 x 0. 35 although the upper limit for Ga doping can be extended considerably above 1100 The dependence of con-... 

The behaviour of these compounds seems to be largely independent of the trivalent cation used to dope the lithium germanate Fe " and AP" " reach similar conductivities to the Li4 3xGa,cGe04 system and an activation energy of ca 0.5 eV is consistently observed for all compositions across the solid solution ranges, albeit with a small dependence on the thermal history of the sample. 

Sodium—lead alloys that contain other metals, eg, the alkaline-earth metals, are hard even at high temperatures, and are thus suitable as beating metals. Tempered lead, for example, is a beating alloy that contains 1.3 wt % sodium, 0.12 wt % antimony, 0.08 wt % tin, and the remainder lead. The German BahnmetaH, which was used ia axle beatings on railroad engines and cars, contains 0.6 wt % sodium, 0.04 wt % lithium, 0.6 wt % calcium, and the remainder lead, and has a Brinell hardness of 34 (see Bearing MATERIALS). 

The correct explanation of the peculiar behaviour of the butadiene-styrene system was provided by O Driscoll and Kuntz 144). As stated previously, under conditions of these experiments butadiene is indeed more reactive than styrene, whether towards lithium polystyrene or polybutadiene, contrary to a naive expectation. This was verified by Ells and Morton 1451 and by Worsfold 146,147) who determined the respective cross-propagation rate constants. It is germane to stress here that the coordination of the monomers with Li4, assumed to be the cause for this gradation of reactivities, takes place in the transition state of the addition and should be distinguished from the formation of an intermediate complex. The formation of a complex ... 

Germenes and germaphosphenes can be reduced with lithium aluminum hydride to give the corresponding germanes. This reaction apparently has not been examined for other unsaturated germanium derivatives. 

The THF-containing complexes formed between trinitrobenzene and the lithium or potassium salts of trimethyl-, triethyl- or triphenyl-germanate, -silanate or -stannate decompose explosively on heating, though trinitrobenzene-potassium trimethyl-stannate decomposes explosively at ambient temperature. 

Two derivatives of a cyclosilyl ether 148 have been synthesized by a German team <1994TL4335>. The enolizable cyclic hydroxamic acid 147 when treated with 2equiv of lithium diisopropylamide followed by reaction with di-fert-butyldichlorosilane in toluene yielded the stable [l,3,4,2]dioxazasilolo[5,4-c][l,4]oxazine derivative 148. 

Metal hydrides Germane, lithium aluminum hydride, potassium hydride, sodium hydride... 

Lithium - the atomic number is 3 and the chemical symbol is Li. The name derives from the Latin lithos for stone because lithium was thought to exist only in minerals at that time. It was discovered by the Swedish mineralogist Johan August Arfwedson in 1818 in the mineral petalite LiAl(Si205)2. It was isolated in 1855 by the German chemist Robert Wilhelm Bunsen and Augustus Matthiessen. 

Thus the lithium compcxinds and groupings put together in Scheme 11 are very unstable and can be used, if at all, only at very low temperature as nucleophilic reagents. The german chemist Kobrich did a very fine work when he nevertheless aicceeded in finding out some preparative applications of aich compounds. 

Umpolung The reversal of polarity of the carbonyl carbon atom is termed umpolung (German for polarity reversal). Normally the carbonyl carbon atom of an aldehyde (or a ketone) is partially positive i.e., electrophilic and therefore it reacts with nucleophiles. When the aldehyde is converted to a dithiane by reaction with 1,3-propanedithiol and reacted with butyl lithium the same carbon now becomes negatively charged to react with electrophiles. This reversed polarity of the carbonyl carbon is termed umpolung which increases the versatility of the carbonyl group in synthesis. The sulphur atoms stabilize... 

When it reaches its full capability, TASCC will accelerate all ions between lithium and uranium to energies up to 50 MeV/u and 10 MeV/u, respectively, It will feed some major pieces of apparatus the Q3D magnetic spectrometer, the isotope separator, a growing array of gas and solid-state detectors housed in a 1.5 m diameter scattering chamber, and the 8ir" Y-ray spectrometer [AND 84], All are currently operational except the 8ir spectrometer, which is being built by a consortium of Canadian universities and AECL Chalk River, with completion scheduled for late 1986. It will comprise two subsystems i) a spin spectrometer of 72 bismuth germanate (BGO) detectors, and ii) an array of 20 Compton-suppressed hyperpure (HP) Ge detectors. 

Metal Azides. Vapor with silver or sodium azide forms explosive bromine azide.10 Metals. Impact-sensitive mixtures are formed from lithium or sodium in dry bromine.11 Potassium, germanium, antimony, and rubidium ignite in bromine vapor.12 Violent reaction occurs with aluminum, mercury, or titanium.13 Methanol. Vigorously exothermic reaction on mixing the liquids.14 Nonmetal Hydrides. At room temperature, violent explosion and ignition occur with silane and its homologs15,16 and with germane.17... 

---