Halides nitrogen family

The first family of the so-called anion receptors was aza-ethers that were based on cyclic or linear amides, where the nitrogen core was made electron-deficient by the perfluoroalkylsulfonyl substituents so that these amides would preferentially interact with the electron-rich anions through Coulombic attraction, contrary to how their unsubstituted counterparts would act. Two selected representatives from the aza-ether family are shown in Table 8. When used as additives in solutions of various lithium halides LiX in THF, these novel compounds were found to increase both the solubility and the ion conductivity of these solutions. For example, the ion conductivity of the LiCl/THF solution was 0.0016 mS cm while the LiCl/THF solution with one of the linear aza-ethers containing eight perfluoroalkylsulfonyl substituents n = 5 for the linear aza-ether shown in... 

The family of reactions, one of which is the Curtins reaction (the others being Ho nann, Lossen, and Sdimidt reactions), serve to transform such acyl derivatives (acid halides, acids, amides) into compounds in which the group originally attached to the carbon of the carbonyl is subsequently attached to nitrogen. These rearrangements will be considered again later in this chapter. 

Fj with appropriate delocalization on the central atom and the ligands. Since would be a antibonding to ammonia and water, this may also explain the chemical fact that the s -family forms very strong complexes with halides, while amine (and cyanide) complexes are not known. OrgeF discusses the rather peculiar stereochemistry of the s -family and concludes that similar effects occur as in the hemiedric lone-pairs of nitrogen(III) in NO and sulfur(IV) in SO and SO2 (cf. also Gillespie and Nyholm ). 

Nitride halides and nitride sulfides constitute another family of rare-earth-containing compounds. The variety concerns the richness of the different formulations as well as the nature itself of the compounds. Except in the case of nitride fluorides which have a clear salt behavior, nitrogen atoms generally do not play the same role as Cl" or S anions in some cases it is even difficult to know whether the borderline between a valence compound and a cluster compound has not been crossed. 

---