![Challenges in modelling and optimisation of stability constants in the study of metal complexes with monoprotonated ligands Cu-DIPSO-OH system [An article from: Analytica Chimica Acta]](https://www.ebooknetworking.net/books/B00/0RR/bigB000RR034Y.jpg)
Challenges in modelling and optimisation of stability constants in the study of metal complexes with monoprotonated ligands Cu-DIPSO-OH system [An article from: Analytica Chimica Acta]
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This digital document is a journal article from Analytica Chimica Acta, published by Elsevier in 2004. The article is delivered in HTML format and is available in your Amazon.com Media Library immediately after purchase. You can view it with any web browser.
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The influence of 3-[N,N-bis(2-hydroxyethyl)amino]-2-hydroxypropanesulfonic acid (DIPSO) on solutions containing copper(II) was studied by two analytical techniques, glass electrode potentiometry (GEP) and direct current polarography (DCP). The readings were taken at fixed total DIPSO to total copper(II) concentration ratios and various pH values, at 25.0+/-0.1^oC and ionic strength 0.1M KNO"3. Combined interpretation of data from DCP and GEP indicated the formation of six main species, CuL^+, CuL(OH), CuL(OH)"2^-, CuL"2, CuL"2(OH)^- and CuL"2(OH)"2^2^- for which stability constants (as log@b) were found to be 4.2+/-0.2, 11.8+/-0.2, 17.6+/-0.1, 8.1+/-0.1, 14.5+/-0.2 and 20.6+/-0.2, respectively. These results warn users of DIPSO that this buffer should not be used for studies involving this metal ion, unless the extent of complexation is accounted for. In addition, the magnitude of stability constants of the species present in the buffer pH range suggests that DIPSO can be used simultaneously as pH and metal ion buffer.
Description:
The influence of 3-[N,N-bis(2-hydroxyethyl)amino]-2-hydroxypropanesulfonic acid (DIPSO) on solutions containing copper(II) was studied by two analytical techniques, glass electrode potentiometry (GEP) and direct current polarography (DCP). The readings were taken at fixed total DIPSO to total copper(II) concentration ratios and various pH values, at 25.0+/-0.1^oC and ionic strength 0.1M KNO"3. Combined interpretation of data from DCP and GEP indicated the formation of six main species, CuL^+, CuL(OH), CuL(OH)"2^-, CuL"2, CuL"2(OH)^- and CuL"2(OH)"2^2^- for which stability constants (as log@b) were found to be 4.2+/-0.2, 11.8+/-0.2, 17.6+/-0.1, 8.1+/-0.1, 14.5+/-0.2 and 20.6+/-0.2, respectively. These results warn users of DIPSO that this buffer should not be used for studies involving this metal ion, unless the extent of complexation is accounted for. In addition, the magnitude of stability constants of the species present in the buffer pH range suggests that DIPSO can be used simultaneously as pH and metal ion buffer.
