Nitrates alcohol inversion

Uniformly, within this group of cations, perchlorate ion accompanying the transition-element cation is replaced by nitrate (7,31), thiocyanate (7,52), or halide (7,6). Nitrate is probably replaced by thiocyanate, but a secondary change takes place in many systems, which makes direct comparison difficult (see below). If one then makes the further reasonable assumption that solvent interference can be used as an inverse measure of tendency to bind to the central metal cations, thiocyanate, whose competition with alcohol is less efficient (52) than that of chloride (6), should be somewhat replaceable with chloride. Comparisons between chloride and thiocyanate in acetonitrile show also that the formation of a complex with a given anion/cation ratio takes place much more readily with chloride than with thiocyanate (55, 34). By the same criterion, from experiments in alcoholic solution (55), bromide should replace chloride, and an extrapolation of the behavior to iodide seems reasonable. 

INVERSION, ALCOHOLS Potassium nitrite. Silver nitrate. 

By esterifying (+)2-octanol using a mixture of nitric and sulphuric acid, it was established that the nitrate produced did not undergo inversion. The (+)2-octyl nitrate obtained was heated during a period of 50 hr in a 10% alcoholic solution of sodium hydroxide. The optical rotation of all the reaction products was nil. Analysis by means of Grignard s reagent indicated 45.6% of 2-octanol, 39.8% of ketone and 14.6% of ether (by difference). A sample of the alcohol contained 76% of (+)2-octanol and 24% of racemate, i.e. 88% of (+)2-octanol and 12% of (—)2-octa-nol. 

Inversion of mesylates or tosylates.2 Mesylates or tosylates undergo displacement with inversion by Bu4N+N03 or Amberlyst A-26 N03 form. Milder conditions and shorter reaction times are possible using pyridylsulfonates. The nitrate esters are readily converted into alcohols by Zn-HOAc or by catalytic hydrogenation. 

Nitrate ion can be another effective nucleophile for inversion. It has been demonstrated that, due to the low basicity of the nucleophile, the competing elimination reaction is almost completely suppressed and the resulting nitro esters can be readily converted into alcohols by reductive processes. One serious... 

Hydrophilic materials can be encapsulated with the inverse minianulsions by using interfacial polymerization such as polyaddition and polycondensation, radical, or anionic polymerization. Crespy et al. reported that silver nitrate was encapsulated and subsequently reduced to give silver nanoparticles inside the nanocapsules. The miniemulsions were prepared by anulsilying a solution of amines or alcohols in a polar solvent with cyclohexane as the nonpolar continuous phase. The addition of suitable hydrophobic diisocyanate or diisothiocyanate monomers to the continuous phase allows the polycondensation or the cross-linking reactions to occur at the interface of the droplets. By using different monomers, polyurea, polythiourea, or polyurethane nanocapsules can be formed. The waU thickness of the capsules can be directly tuned by the quantity of the reactants. The nature of the monomers and the continuous phase are the critical factors for the formation of the hollow capsules, which is explained by the interfacial properties of the systan. The resulting polymer nanocapsules could be subsequently dispersed in water. 

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