Analysis of Cu(I) in copper sulfate electroplating solution was conducted by absorption of a chelate of Cu(I) with bathocuproinedisulfonic acid, disodium salt (BCS). Although the absorption of new copper sulfate electroplating solutions was negligible, the absorption of operating solutions was clear. The difference of new solutions and operating solutions was also verified using an electrochemical method for detection of Cu(I). We concluded that the Cu(I) ions are measurable using this chelate reagent. The absorption increased quickly in a few minutes after mixing with the chelate reagent and subsequently continued to increase slowly. To clarify this phenomenon, the organic compounds in the plating solutions were analyzed and Cu(I)-PEG (polyethylene glycol) complexes with different chain lengths were detected using MALDI-MS. Results show that Cu(I) ions exist in the plating solutions not only as small complexes with small organic compounds but also as large complexes with PEG. Small complexes of Cu(I) can react quickly with BCS and cause the rapid increase of the absorption in a few minutes after mixing. Cu(I)-PEG complexes prevent the chelating reaction of Cu(I) with BCS by steric hindrance of PEG, which explains the subsequent slow increase of the absorption. Using this chelate method, we monitored quantities of Cu(I) in copper sulfate electroplating production lines, detected the variation of Cu(I) quantities, and found the increase during the resting state of the lines.

Analysis of Cu(I) in copper sulfate electroplating solutions was conducted by absorption of a chelate of Cu(I) with bathocuproinedisulfonic acid, disodium salt (BCS). The absorbance of the color reaction of Cu(I) increased quickly in a few minutes after mixing with the chelate reagent and subsequently continued to increase slowly. To analyze the reaction kinetics of the color reaction, we divided Cu(I) complexes into two groups, small complexes and large Cu(I)-PEG complexes, and assumed the reaction of each group of complexes and BCS is a first order reaction with a specific reaction rate constant. We simulated the absorption curve with a good correlation and obtained the concentrations and the time constants, inverse of rate constants, of small complexes and large Cu(I)-PEG complexes. These concentrations and time constants are important parameters to control plating solutions. The time constant of small complexes can be attributed to the variation of the proportions of these small complexes. The smaller time constant of Cu(I)-PEG complexes can be considered the larger size distribution of Cu(I)-PEG with different chain lengths. Using this analysis, we monitored the variation of Cu(I) concentration in production lines for one month and found the increase of small complexes during the resting state of the lines. This increase corresponded to the tendency of occurring of brightening troubles.

Lanthanide / TBP / Hydrate melt / Hydration / Solvent extraction / Calcium nitrate tetra-hydrate SummaryDistributions of lanthanides between tri-butyl phosphate solution and molten calcium nitrate tetrahydrate (Ca(NO,) 2 · 4 H 2 0) were radiochemical^ studied. The apparent equilibrium constants of the extraction reactions of lanthanides were determined and their characteristic systematics along the lanthanide series was studied. In comparison with the similar systematics reported for the extraction systems using nitric acid solutions, the characteristics of the hydration of lanthanides under water-deficient condition of calcium nitrate tetrahydrate was discussed.

The title material, where TM-TPDS is 2-[4,5-bis(methylthio)-1,3-diselenol-2-ylidene]-5-(thiopyran-4-ylidene)-1,3,4,6-tetrathiapentalene, has three-dimensional (3D) donor array, in which 1D donor columns are tetragonally arranged with each other. It shows metal-like conducting behavior down to TMI = 100 K.

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