Alkali metals imides, amides

Thus amides are found to be only very weakly basic in water [pKa for ethanamide(acetamide) is =0-5], and if two C=0 groups are present the resultant imides, far from being basic, are often sufficiently acidic to form alkali metal salts, e.g. benzene-1,2-dicarboximide (phthalimide, 8) ... 

We will also include the recently determined structures of imides and amides of other alkali metals (viz. Na, K, Rb, and Cs). Only a few structures of derivatives of the heavier alkali metals are known (3), but this area can be expected to develop rapidly. 

The rate is slower in basic aprotic amide solvents, and faster in acidic solvents such as / -cresol. In general, the imidization reaction has been shown to be catalyzed by acid (14,32,33). Thermal imidization of poly(amic acid)s is catalyzed by tertiary amines (34). High temperature solution polymerization in -cresol is often performed in the presence of high boiling tertiary amines such as quinoline as catalyst. Dialkylaminopyridines and other tertiary amines are effective catalysts in neutral solvents such as dichlorobenzene (35). Alkali metal and zinc salts of carboxylic acids (36) and salts of certain organophosphorus compounds (37) are also very efficient catalysts in one-step polycondensation of polyimides. 

The lattice energies of the alkali metal hydroxides, the alkali metal amides, the alkaline earth chacogenides and the alkaline earth imides, give values for A/7/ OH (g) etc. and so enable the proton affinities of these groups to be calculated. The values obtained are given in Table XXIX. 

Lattice energies, alkali metal salt values, amides and, 196 azides and, 198-199 bifluorides and, 199 borofluorides and, 203 borohydrides and, 197 chalcogenides and, 192,193 cyanates and, 199-200 cyanides and, 196-197 halides and, 189, 190 hydrides and, 189, 191, 192 hydrosulfides and, 195-196 hydroxides and, 192,194, 195 nitrates and, 201 superoxides and, 197-198 thiocyanates and, 200 alkaline earth salt values, acetylides and, 198 carbonates and, 202-203 chalcogenides and, 192, 193 imides and, 196 peroxides and, 198 calculation uses, absolute enthalpies and, 206 electron affinity determination and, 203-204... 

Alkali metal nitride chemistry is effectively confined to that of lithium and sodium [2], and dominated by lithium nitride, Li3N, a compound that has long fascinated solid-state chemists since early reports of its synthesis and characterisation [3-5]. In the ternary phase system, Li-N-H, lithium also forms three stoichiometric ternary hydrogen-containing compounds, the imide, Li2NH, the amide, LiNH2, and the nitride hydride, Li4NH. The first... 

According to Mellor (Ref 1, p 255),KNHa reacts vigorously with w and the reaction iuay be accompanied by inflammation Potassamide can serve for the prepn of other metallic amides and imides, some of them expl, eg AgNH, or PbNH (See also Ref under Alkali Amides)... 

Step-by-step replacement of the hydrogen atoms in ammonia with metal atoms according to (34) or (35) leads to the amides MNH2, the imides M2NH, and the nitrides M3N. The alkali and alkaline-earth amides can be obtained from the reaction of the hot metals with ammonia. 

Amides and imides. These salts, formed only by the more electropositive metals, contain respectively the NHJ and NH " ions. The alkali, alkaline-earth, and zinc amides are colourless crystalline compounds formed directly by the action of ammonia on the molten metal or in solution in liquid ammonia. A solution of NaNH2 in liquid ammonia is a good conductor of electricity, indicating that the salt is ionized in this solvent. 

The alkali and alkaline-earth amides, imides, and nitrides are immediately decomposed by water to ammonia and the metal hydroxides. 

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