Lithium oxide, susceptibility

Lithium oxides of Pu, magnetic measurements and reciprocal molar susceptibility vs. 

Finally, Al (/= 5/2) and Co NMR spectroscopy have been used to probe AP+ in Al-doped lithium cobalt oxides and lithium nickel oxides. A Al chemical shift of 62.5 ppm was observed for the environment Al(OCo)e for an AP+ ion in the transition-metal layers, surrounded by six Co + ions. Somewhat surprisingly, this is in the typical chemical shift range expected for tetrahedral environments (ca. 60—80 ppm), but no evidence for occupancy of the tetrahedral site was obtained from X-ray diffraction and IR studies on the same materials. Substitution of the Co + by AF+ in the first cation coordination shell leads to an additive chemical shift decrease of ca. 7 ppm, and the shift of the environment A1(0A1)6 (20 ppm) seen in spectra of materials with higher A1 content is closer to that expected for octahedral Al. The spectra are consistent with a continuous solid solution involving octahedral sites randomly occupied by Al and Co. It is possible that the unusual Al shifts seen for this compound are related to the Van-Vleck susceptibility of this compound. 

Thus, permethylated aldehydo sugars (6) have been found very susceptible to alkaline conditions, and suffer rapid /8-elimination, because of the acidity of the a-proton, with the formation of the enolic derivative (8) through a possible intermediate anion (7), as shown in equation 2. This phenomenon may explain the absence of interaction17 between the protected dialdose 9 and phenylenedimethylene-bis(triphenylphosphonium) chloride in the presence of lithium eth-oxide. Dialdose 9, indeed, is rapidly transformed18 in an alkaline medium into the unsaturated aldehyde 10 (see also, Ref. 19). Un-... 

Lithium sulphite, Li2S03.- Evaporation of the solution obtained by the action of sulphur dioxide on lithium carbonate suspended in water yields the monohydrate, Li2S03,H20 addition of alcohol or ether precipitates the dihydrate, Li2S03,2H20. The sulphite is readily soluble in water, and is susceptible to atmospheric oxidation. Heat expels the water of crystallization, and causes partial decomposition into sulphate and sulphide. Double sulphites of lithium with potassium and sodium have been prepared.1... 

Removal of lattice oxygen from the surface of nickel oxide in vcumo at 250° or incorporation of gallium ions at the same temperature [Eq. (14)] causes the reduction of surface nickel ions into metal atoms. Nucleation of nickel crystallites leaves cationic vacancies in the surface layer of the oxide lattice. The existence of these metal crystallites was demonstrated by magnetic susceptibility measurements (33). Cationic vacancies should thus exist on the surface of all samples prepared in vacuo at 250°. However, since incorporation of lithium ions at 250° creates anionic vacancies, the probability of formation of vacancy pairs (anion and cation) increases and consequently, the number of free cationic vacancies should be low on the surface of lithiated nickel oxides. Carbon monoxide is liable to be adsorbed at room temperature on cationic vacancies and the differences in the chemisorption of this gas are related to the different number of isolated cationic vacancies on the surface of the different samples. 

Thus, the aldol shown, which is susceptible to Sharpless-type epoxidation, has been obtained from phytal and the protected hydroquinone (ref. 120). Formation of the epoxide presumably with a chiral peracid (or perhaps with a conventional peracid relying on the asymmetry of the substrate) and then cleavage reductively in t-butyl methyl ketone containing lithium aluminium hydride led to a diol. The benzylic hydroxyl group of this was hydrogenolysed to afford the hydroquinone dimethyl ether in 85% yield. Ceric ammonium nitrate (CAN) oxidation afforded the intermediate benzoquinone hydrogenation of which was reported to result in 2R,4 R,8 R-a-tocopherol by, presumably, avoidance of a racemisation step. 

The reduction of 569e with lithium aluminum hydride followed by monoprotection with er -butyldimethylsilyl chloride and Dess-Martin oxidation of the free hydroxyl group to an aldehyde affords 610. An aldol reaction of 610 with ( S)-(y-alkoxyallyl)stannane (611) in the presence of boron trifluoride etherate provides exculsively, in 80% yield, the alcohol 612. Ozonolysis of the olefin followed by sodium borohydride reduction affords diol 613, which is converted to acetonide 614 (Scheme 135). Interestingly, alcohol 612, the double bond of which is susceptible to stereocontrolled introduction of hydroxyl groups, could lead to o)-deoxy sugars [197]. 

Tetrahydrofuran forms explosive mixtnres with air within the range 2.0-11.8% by volume in air. It is susceptible to form organic peroxides when exposed to air or light. Severe explosion can occur during distillation, purification, or use of impure tetrahydrofuran. Solvent containing peroxide can explode when dried with caustic soda or caustic potash, or when evaporated and may catch Are in contact with lithium aluminum hydride or other metal hydrides. Violent reactions can occur when combined with strong oxidizers. 

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