CaltechAUTHORS
Published 1995 | Version public
Journal Article Metadata-only

Spectrophotometric Determination of the Stability Constants of Co(II) and DPKBH (Di-2-Pyridyl Ketone Benzoylhydrazone)

Creators

  • 1. ROR icon Universidade de São Paulo
  • 2. ROR icon California Institute of Technology

Abstract

In order to have more information about the thermodynamic properties of the complexes formed by Cobalt(II) and DPKBH (di-2-pyridyl ketone benzoylhydrazone) and for the development of speciation methods for cobalt, the respective stepwise formation constants were determined in ethanolic solution 50% (V/V), at pH 5.3 and 25.0°C. The spectrophotometric method of corresponding solutions was used and the following overall formation constants were obtained: β_1 = 5.305 × 10^6 M^(−1) and β_2 = 8.476 × 10^(10) M^(−2). The molar absorptivities of the 1:1 (ε_1) and 1:2 (ε_2) complexes (Co(II):DPKBH) were determined to be 4.475 × 10^3 and 2.994 × 10^4 (M^(−1)cm^(−1)), respectively. The calculated distribution diagram shows the percentage of the species at equilibrium as a function of the free DPKBH concentration.

Additional Information

© 1995 by Marcel Dekker, Inc. Date Received: May 25, 1995, Date Accepted : July 5, 1995. M. E. V. Suárez-Iha is grateful to the Fundação de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP) for the financial support. We are also grateful to the NSF (ATM 9Q15775) for providing the financial resources for this project.

Additional details

Identifiers

Eprint ID
59369
Resolver ID
CaltechAUTHORS:20150810-152946428

Funding

Fundação de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP)
NSF
ATM 9Q15775

Dates

Created
2015-08-11
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Updated
2023-10-23
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