Octadecane-, sodium

By increasing the molar proportion of the monocarboxylic acid, the yield of (II) is improved. Thus electrolysis of a mixture of decanoic acid (n-decoic acid capric acid) (V) (2 mols) and methyl hydrogen adipate (VI) (1 mol) in anhydrous methanol in the presence of a little sodium methoxide gives, after hydrolysis of the esters formed, n-octadecane (VII), tetradecanoic or myristic acid (VIH) and sebacic acid (IX) ... 

The reactive species in this system are apparently the unionized CuHp and CuHp molecules. CuHp undergoes some dimerization, but the dimer is inactive. Addition of sodium heptanoate to the solution results in the formation of higher cupric and cuprous complexes, probably Naj(CuHp4) and Na2(CuHp3) these species are also inactive. Heptanoic acid appears to function as an inert solvent in this system, since essentially similar results, apart from minor quantitative differences, were obtained in octadecane and diphenyl. 

Myristic acid (from decanoic acid and methyl hydrogen adipate). Dissolve 55-2 g. of pure decanoic acid (capric acid decoic acid), m.p. 31-32°, and 25 -6 g. of methyl hydrogen adipate in 200 ml. of absolute methanol to which 0-25 g. of sodium has been added. Electrolyse at 2-0 amps, at 25-35° until the pH of the electrolyte is 8-2 (ca. 9 hours). Neutralise the contents of the electrolytic cell with acetic acid, distil off the methanol on a water bath, dissolve the residue in about 200 ml. of ether, wash with three 50 ml. portions of saturated sodium bicarbonate solution, and remove the ether on a water bath. Treat the residue with a solution of 8 0 g. of sodium hydroxide in 200 ml. of 80 per cent, methanol, reflux for 2 hours, and distil off the methanol on a water bath. Add about 600 ml. of water to the residue to dissolve the mixture of sodium salts extract the hydrocarbon with four 50 ml. portions of ether, and dry the combined ethereal extracts with anhydrous magnesium sulphate. After removal of the ether, 23-1 g. of almost pure n-octadecane, m.p. 23-24°, remains. Acidify the aqueous solution with concentrated hydrochloric acid (ca. 25 ml.), cool to 0°, filter off the mixture of acids, wash well with cold water and dry in a vacuum desiccator. The yield of the mixture of sebacic and myristic acids, m.p. 52-67°, is 26 g. Separate the mixture by extraction with six 50 ml. portions of almost boiling light petroleum, b.p. 40-60°. The residue (5 2 g.), m.p. 132°, is sebacic acid. Evaporation of the solvent gives 20 g. of myristic acid, m.p. 52-53° the m.p. is raised slightly upon recrystallisation from methanol. 

A potassium opto-sensor was recently described [75] for the continuous determination of electrolytes. Certain fluorescent dyes respond to an electric potential at the interface between the aqueous and lipid phases. This potential is created by the neutral ion carrier. The lipid layer is formed on a glass support by the Langmuir-Blodgett thin-fllm technique. This layer incorporates Rhodamine B as a dye and valinomycin as the carrier. The lipid membrane is made of arachidic acid. The fluorescence intensity decreases when this layer is exposed to potassium ions (linearity between 0.01 and 10 mM). This optode is also sensitive to sodium ions [76]. The selectivity factor of potassium in comparison with sodium ions varies from 10 - to 10 , and in relation to ammonium ions by 10. Interferences can be compensated for by a reference optode. However, better selectivity is obtained with new lipid membrane compositions (octadecan-l-ol-valinomycin) [77]. Tetralayers (Figure 17-9) give a maximum response for K". The K /Na selectivity is about 10 in a wide range (0.01-100 mM). 

Nonflex CBP Noclizer M-17 Octadecane ODO Oleamide Palmitic acid Palmitamide Permanax WSP Sanol LS744 Sanol LS770 Santonox Santowhite Seesorb 101 Seesorb 202 Seenox DM Sodium benzoate... 

Phase change material pellets consist of a tnixmre of paraffin (n-octadecane), a polymer, and a thermal conductivity improver (expandable graphite, graphite microfiber pieces, or graphite powder), a nucleating agent (sodium and calcium chloride and 1-octa-decanol). ... 

The formation of hexadecane-l 2-diol and octadecane-l 2-diol from 1-hexadecene and 1-octadecene, respectively, by Candida lipolytica ATCC 8661 involves the incorporation of oxygen derived from the atmosphere (Ishikura and Foster, 1961). The cells of a bacterium growing at the expense of ethylene in the presence of oxygen-18 contained 18 to 35 times more oxygen-18 than cells of the same organism growing at the expense of sodium acetate. It was concluded that molecular oxygen is involved in the attack of the olefinic double bond. 

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