Differential scanning calorimetry was performed between 110 K and the isotropic melt region on potassium «.alka noates from octanoate to dodecanoate. Clearing, melting and (crystalline) solid state transition temperatures and heat effects were measured. In the higher homologues the occur rence of phases (likely "waxy") intermediate between crys talline solid and mesomorphic liquid could also be argued. The phase relationships are discussed in comparison with some roentgenographic and microscopic results of previous authors.

Di-(2-hydroxy-l-phenazinyl)methane, Phenazines, Bacterial Constituents, Pseudomonas aureofaciensThe structure elucidation of di-(2-hydroxy-l-phenazinyl)methane from Pseudomonas aureofaciens is described. In addition to the phenazine derivatives isolated earlier from this bacterium 2,3,4-trihydroxyphenazine-l-carboxylic acid and phenazine-1,6-dicarboxylic acid could be identified.

A bifunctional extractant (H L) carrying phosphine oxide and phosphoric acid complexing centres has been synthesized by the cyclic enediol phosphate method, using a two-step reaction with dihexyl (hydroxymethy1)phosphine oxide and 2-ethylhexanol. The bifunctional complexant complexes both UIv and Uv'. The complexation process, as shown by 31P n.m.r. spectroscopy, involves both the R3P=0 and (R'O),PO,H centres ( R=C6H,3, R' =C,H,,).The compound H L exists as hydrogen-bonded associates in the organic (hexane) phase. Involvement of anions in the complex structures is evident for Uv' ( NO3-), UIv( CI-, N O ; , or H PO,,-), and Fe( CIor SCN-).Complexing ligands of high affinity for metal ions can be either solvating or chelating donors.' Both classes are subject to strong competition from inorganic ligands. As a consequence of this competition, only chelating ligands that form stable ring systems are generally strong complexing ligands.The admixture of high concentrations of complexing agents in the appropriate solvents and in the right ratios provides, in some cases, an alternative to the careful design of bifunctional ligands. So-called 'synergistic' extractants show enhanced extraction power when mixed together, in comparison to the individual extractants in separate solutions.2aSynergistic extraction is a well known phenomenon in the extraction of uranium ions from phosphoric acid solution^.^-^The pair of extractants is composed of phosphoric acid esters, i.e. di(2-ethylhexy1)phosphate and trioctylphosphine oxide. This system has its limitations, under the following conditions:(1) either the extractant or metal-ion concentration is low;(2) extractants are diluted in a solid matrix, such as a polymeric carrier or membrane; and (3) in the presence of strong competing ions, such as a high concentration of phosphate ions.A bifunctional extractant composed of a molecule with two centres, a phosphine oxide and alkyl ester of phosphoric acid, linked through a spacer group, is proposed as a single molecular entity combining the overall properties of the synergistic single components. The synthesis of such bifunctional complexing

The various compounds obtained by the reaction P 4 0 10 + 4ROH (where R represents hydrocarbon radicals of various length and structure) were identified by infrared spectrophotometry of the fractions separated by column chromatography. The identification was made possible by a comparison between the relative values of the integrated absorption for the P = 0, p-o-P, P-O-C and O-H bands with those of known standards. For the reaction of phosphorus pentoxide with ethanol, the compounds formed were found to be; mono-, di-and triethyl phosphate, mono-, (1,2) di-and triethylpyrophosphate; (1,3) di-and (1,2,3) triethyl triphosphate; mono-and diethyl trimetaphosphate, With other alcohols, only homologs of these compounds were found, but always fewer compounds. Uncertainty between possible isomers was resolved by identification of their acid hydrolysis products.In the preceding parts [1,2] of this series, it has been shown that the reaction P 4 0 10 + 4ROH yields a mixture of phosphorus compounds. While theoretically this mixture could contain up to 34 different compounds [l], chromatographic separation methods showed that the number ranged from a maximum of 10, obtained with ethanol, down to 3 when heptadecanol was used [2]. The identity of these compounds, however, had to be determined, and infrared spectrophotometry appeared as the only promising method.The investigated compounds could be expected to show absorption in the following ranges of the infrared spectrum.