The Gluconate Complexes. I. Copper Gluconate Complexes in Strongly Basic Media¹

Abstract

Vol. 77 1,5-(bistrimethylammonium) -pen tame thylene dibromide °2 = 77.3 while for compound IV °2 = 79.4. Higher mobility for the substituted ethers presumably means a more compact structure. This readily can be obtained if we assume that the ether oxygen is pulled toward one of the cationic nitrogens; molecular models show that there is ample space between methyl groups for near N+0~c ontact. The presence of the negative oxygen near the nitrogen weakens the attraction of the latter for an approaching anion, i.e., acts in the direction of increasing ki. Increase of R also increases k¡. Hence we conclude that the NC2OC2N chain is shorter than the NC6N chain and that the near equality of the k¡s is the result of compensating effects.

Codeposition of copper and tin from acid sulphate solutions containing gluconic acid

“…We have found that the limiting step Cu 2+ + e ? Cu + is characterized by relatively low (1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20) processes occurring simultaneously and resulting in the deposition of bronze coatings are discussed in the present paper.…”

“…Gluconic acid HO-CH 2 -(CH-OH) 4 -COOH fall into this category. Much information concerning this ecological substance may be obtained from Sawyer's review [1].…”

“…Particularly stable Cu(II)-gluconate complexes are formed in strongly alkaline solutions due to the dissociation of OH À groups in the ligand [1,4]. However, the latter process is very weak in acidic solutions and in consequence a complexation degree of Cu(II) becomes considerably lower in this case.…”

“…[9] that deals with the deposition of tin from neutral gluconate baths containing PEG and formaldehyde. According to [4], reversible polarograms were recorded in Cu(II) gluconate solutions. In contrast, the cathodic process on the solid copper electrode proceeds irreversibly via a consecutive transfer of two electrons [18].…”

Complexes of Cu(II) with D-aldonic and D-alduronic acids in aqueous solution

“…The Cu(I1) -D-gluconic acid system was studied in strongly basic medium by Pecsok and Juvet, and two different species Cu2H-,L2-and CU,H-,L;-in less basic solution were proposed by these authors (14). Other D-aldonic acids have not been previously investigated with Cu(I1).…”