Thermodynamics for complex formation between palladium(II) and oxalate
(2014) In Dalton Transactions 43(32). p.12243-12250- Abstract
- Complex formation between [Pd(H2O)(4)](2+) and oxalate (ox = C2O42-) has been studied spectrophotometrically in aqueous solution at variable temperature, ionic strength and pH. Thermodynamic parameters at 298.2 K and 1.00 mol dm(-3) HCIO4 ionic medium for the complex formation [Pd(H2O)(4)](2+) + H(2)ox (sic) Pd(H2O)(2)(ox)] + 2H(3)O(+) with equilibrium constant K-1H (in mol dm(-3)) are logio K-1,K-H = 3.38 +/- 0.08, Delta H-1(0) = -33 +/- 3 kJ mol(-1), and Delta S-1(0) = 48 +/- 11 J K-1 morl, as determined from spectrophotometric equilibrium titrations at 15.0, 20.0, 25.0 and 31.0 degrees C. Thermodynamic overall stability constants beta(0)(n) (in (mol dm-(3))(-n), n = 1,2) for [pd(H2O)(2)(ox)] and [Pd(ox)(2])(2) at zero ionic strength and... (More)
- Complex formation between [Pd(H2O)(4)](2+) and oxalate (ox = C2O42-) has been studied spectrophotometrically in aqueous solution at variable temperature, ionic strength and pH. Thermodynamic parameters at 298.2 K and 1.00 mol dm(-3) HCIO4 ionic medium for the complex formation [Pd(H2O)(4)](2+) + H(2)ox (sic) Pd(H2O)(2)(ox)] + 2H(3)O(+) with equilibrium constant K-1H (in mol dm(-3)) are logio K-1,K-H = 3.38 +/- 0.08, Delta H-1(0) = -33 +/- 3 kJ mol(-1), and Delta S-1(0) = 48 +/- 11 J K-1 morl, as determined from spectrophotometric equilibrium titrations at 15.0, 20.0, 25.0 and 31.0 degrees C. Thermodynamic overall stability constants beta(0)(n) (in (mol dm-(3))(-n), n = 1,2) for [pd(H2O)(2)(ox)] and [Pd(ox)(2])(2) at zero ionic strength and 298.2 K, defined as the equilibrium constants for the reaction Pd2+ nox(2) (sic) Pd(ox)](2-2n) (water molecules omitted) are logio beta(0)(1) = 9.04 +/- 0.06 and logio beta(0)(1) = 13.1 +/- 0.3, respectively, calculated by use of Specific Ion Interaction Theory from spectrophotometric titrations with initial hydrogen ion concentrations of 1.00, 0.100 and 0.0100 mol dm-3 and ionic strengths of 1.00, 2.00 or 3.00 mol dm-3. The values derived together with literature data give estimated overall stability constants for Pd(o) compounds such as Pd(en)(ox)1 and cis-IPd(NH3)2021, some of them analogs to Pt(s) complexes used in cancer treatment. The palladium oxatato complexes are significantly more stable than palladium(v) complexes with monodentate 0-bonding ligands. A comparison between several different palladium complexes shows that different parameters contribute to the stability variations observed. These are discussed together with the so-called chelate effect. (Less)
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https://lup.lub.lu.se/record/4665691
- author
- Pilny, Radomir ; Lubal, Premysl and Elding, Lars Ivar LU
- organization
- publishing date
- 2014
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- Complex formation, Palladium, Oxalate
- in
- Dalton Transactions
- volume
- 43
- issue
- 32
- pages
- 12243 - 12250
- publisher
- Royal Society of Chemistry
- external identifiers
-
- wos:000339862000016
- scopus:84904665681
- pmid:24912768
- ISSN
- 1477-9234
- DOI
- 10.1039/c4dt01062k
- language
- English
- LU publication?
- yes
- id
- 62e2616e-7fed-43b5-9c17-eb183463668f (old id 4665691)
- date added to LUP
- 2016-04-01 09:54:32
- date last changed
- 2022-03-19 07:30:47
@article{62e2616e-7fed-43b5-9c17-eb183463668f,
abstract = {{Complex formation between [Pd(H2O)(4)](2+) and oxalate (ox = C2O42-) has been studied spectrophotometrically in aqueous solution at variable temperature, ionic strength and pH. Thermodynamic parameters at 298.2 K and 1.00 mol dm(-3) HCIO4 ionic medium for the complex formation [Pd(H2O)(4)](2+) + H(2)ox (sic) Pd(H2O)(2)(ox)] + 2H(3)O(+) with equilibrium constant K-1H (in mol dm(-3)) are logio K-1,K-H = 3.38 +/- 0.08, Delta H-1(0) = -33 +/- 3 kJ mol(-1), and Delta S-1(0) = 48 +/- 11 J K-1 morl, as determined from spectrophotometric equilibrium titrations at 15.0, 20.0, 25.0 and 31.0 degrees C. Thermodynamic overall stability constants beta(0)(n) (in (mol dm-(3))(-n), n = 1,2) for [pd(H2O)(2)(ox)] and [Pd(ox)(2])(2) at zero ionic strength and 298.2 K, defined as the equilibrium constants for the reaction Pd2+ nox(2) (sic) Pd(ox)](2-2n) (water molecules omitted) are logio beta(0)(1) = 9.04 +/- 0.06 and logio beta(0)(1) = 13.1 +/- 0.3, respectively, calculated by use of Specific Ion Interaction Theory from spectrophotometric titrations with initial hydrogen ion concentrations of 1.00, 0.100 and 0.0100 mol dm-3 and ionic strengths of 1.00, 2.00 or 3.00 mol dm-3. The values derived together with literature data give estimated overall stability constants for Pd(o) compounds such as Pd(en)(ox)1 and cis-IPd(NH3)2021, some of them analogs to Pt(s) complexes used in cancer treatment. The palladium oxatato complexes are significantly more stable than palladium(v) complexes with monodentate 0-bonding ligands. A comparison between several different palladium complexes shows that different parameters contribute to the stability variations observed. These are discussed together with the so-called chelate effect.}},
author = {{Pilny, Radomir and Lubal, Premysl and Elding, Lars Ivar}},
issn = {{1477-9234}},
keywords = {{Complex formation; Palladium; Oxalate}},
language = {{eng}},
number = {{32}},
pages = {{12243--12250}},
publisher = {{Royal Society of Chemistry}},
series = {{Dalton Transactions}},
title = {{Thermodynamics for complex formation between palladium(II) and oxalate}},
url = {{http://dx.doi.org/10.1039/c4dt01062k}},
doi = {{10.1039/c4dt01062k}},
volume = {{43}},
year = {{2014}},
}