Salicylaldehyde alkali metal complexes

Salicylaldehyde alkali metal complexes, 30 Salvosan, 255 Samarium complexes dipositive oxidation state hydrated ions, 1109 Sampsonite, 265... 

The Fe(III) complexes of the dianion of pyruvic acid thiosemicarbazone (thpu2- Fig. 7), (cation+)[Fe(thpu)2]-nH20, are very similar to those of the salicylaldehyde derivatives (Fig. 6) discussed above. The spin state properties are quite sensitive to changes in the counter-cation (typically an alkali-metal cation or a protonated nitrogenous base) and the lattice water content of the material. The parent compound, NH4[Fe(thpu)2], is low spin at room temperature [113]. Li[Fe(thpu)2]-3H20 is also low spin but K[Fe(thpu)2] 2-H20 shows almost complete spin crossover between 80 and 300 K [108]. 

The general structure of alkali metal alcoholates of polyhydroxy compounds is probably very similar to those proposed by Martell and Calvin1 for the alkali metal chelates of o-salicylaldehyde (see Figs. 9 and 10). 148 1M>IM Unfortunately, because of the highly amorphous nature of nearly all pf the alcoholates and adducts formed by the interaction of metal hydroxides with carbohydrates, x-ray diffraction studies have failed to furnish information regarding the precise location of the metal in these complexes. 

Few stable complexes of alkali metals have been reported. Complexes of the alkali metals with j -diketone derivaties, o-nitrophenol, and sali-cylaldehyde have been described in the literature.The sodium compounds ranged from hydrated ionic salts such as Na (acac)-2 H2O to adducts like Na(Sal) HSal (HSal = Salicylaldehyde). PfeiflFer and others have reported the isolation of a complex of sodium perchlorate with 1,10-phenan-throline. Brady and Badger have presented evidence for chelation in sodium salts of o-hydroxybenzaldehydes. More recently, Popp and Joesten have isolated and characterized a number of alkali metal and alkaline earth metal salts with the ligand octamethylpyrophosphoramide (OMPA). Gentile and co-workers have also reported complexes of diacetamide with alkali and alkaline earth metal salts. 

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