Spectrophotometric and potentiometric investigations of copper (II)-ethanolamine complexes
- Cite this article as:
- Mahapatra, S. & Subrahmanya, R.S. Proc. Indian Acad. Sci. (1963) 58: 161. doi:10.1007/BF03049426
Spectrophotometric and potentiometric investigations have been carried out on copper-monoethanolamine complexes. Job plots at 920, 760 and 620 mµ have indicated the formation of CuA++, CuA2/++ and CuA3 ++. The\(\bar n - pA\) curves have been obtained by a slight modification of the method of corresponding solutions and by pH measurements. The\(\bar n\) vs. pA curves obtained at different metal concentrations coincide indicating the formation of mononuclear complexes. Experiments conducted with 0·1. 0·2, 0·5 and 1·0 M monoethanolammonium ion indicate the formation of mononuclear hydroxy complexes above pH 6. The nature of E m vs pA curves is closely analogous to that of\(\bar n\) vs. pA curves. Absorption spectra taken at pH 9·8 with different amounts of monoethanolamine has given evidence for the formation of (CuA3OH·A)+.\(\bar n - pA\) curves have been analyzed and the values ofβ 1, 1,β 1, 2 andβ 1, 3 have been obtained. Curves showing the distribution of complexes and the absorption curves of the individual complexes (CuA++, CuA2/++, and CuA3/++) have been calculated.