Kinetics and mechanism of substitution reactions of the new bimetallic [{PdCl(bipy)}{mu-(NH2(CH2)(6)H2N)}{PtCl(biPY)}]Cl(ClO4) complex with important bio-molecules
Само за регистроване кориснике
2015
Чланак у часопису (Објављена верзија)
Метаподаци
Приказ свих података о документуАпстракт
The new dinuclear bimetallic complex, [{PdCl(bipy)}{mu-(NH2(CH2)(6)H2N)}{PtCl(biPY)}]Cl(ClO4) (bipy is 2,2-bipyridine), has been prepared and characterized by elemental microanalysis, IR, H-1 NMR spectroscopy and MALDI-TOF mass spectrometry. Substitution reactions of the studied complex with selected biologically important ligands such as: thiourea (Tu), L-methionine (L-Met), L-cysteine (L-Cys), L-histidine (L-His) and guanosine-5-monophosphate (5-GMP), were studied under the pseudo-first order conditions as a function of concentration and temperature using stopped-flow and UV-Vis spectrophotometry. The reactions were monitored in 0.1 M NaClO4 at pH 5.0, in the presence of 40 mM NaCI. All fast reactions were monitored by stopped-flow at three temperatures (288 K, 298 K, 308 K) to determine the activation parameters, while the reactions studied by UV-Vis spectrophotometry were tested only at 298 K. Observed order of reactivity of the used ligands is: Tu GT L-Met GT L-Cys GT L-His GT 5-G...MP. Substitution reactions of the investigated bimetallic complex with Tu, L-Cys and L-His were followed by degradation to the corresponding substituted mononuclear complexes of palladium (II) and platinum (II), [Pd(bipy)(Nu)(2)] and [Pt(bipy)(Nu)(2)] (where Nu = Tu, L-Cys, L-His), by releasing of the bridge ligand,1,6-diaminohexane. In contrast, during the substitution reactions with L-Met and 5-GMP, the structure of starting bimetallic complex was preserved and the process of degradation can be halted. The proposed pathways of the substitution reactions of [{PdCl(bipy)}{mu-(NH2(CH2)(6)H2N)}{PtCl(biPY)}]Cl(ClO4) complex with all selected ligands were confirmed by H-1 NMR spectroscopy at 295 K. Additionally, the two pK(a) values of studied diaqua complex, [(Pd(H2O)(bipy)}(mu-(NH2(CH2)(6)H2N)}(Pt(H2O)(biPY)}](4+), were determined by spectrophotometric pH titration. The large negative values for the entropy of activation, Delta S-not equal, support an associative substitution mechanism. (C) 2015 Elsevier Ltd. All rights reserved.
Кључне речи:
Platinum / Palladium / Kinetic / Mechanism / Bimetallic complexИзвор:
Polyhedron, 2015, 101, 206-214Издавач:
- Elsevier
Финансирање / пројекти:
- Испитивање механизма реакција комплекса јона прелазних метала са биолошки значајним молекулима (RS-MESTD-Basic Research (BR or ON)-172011)
DOI: 10.1016/j.poly.2015.09.021
ISSN: 0277-5387
WoS: 000366077600028
Scopus: 2-s2.0-84942517617
Колекције
Институција/група
VinčaTY - JOUR AU - Jovanović, Snežana AU - Petrović, Biljana AU - Petković, Marijana AU - Bugarčić, Živadin D. PY - 2015 UR - https://vinar.vin.bg.ac.rs/handle/123456789/841 AB - The new dinuclear bimetallic complex, [{PdCl(bipy)}{mu-(NH2(CH2)(6)H2N)}{PtCl(biPY)}]Cl(ClO4) (bipy is 2,2-bipyridine), has been prepared and characterized by elemental microanalysis, IR, H-1 NMR spectroscopy and MALDI-TOF mass spectrometry. Substitution reactions of the studied complex with selected biologically important ligands such as: thiourea (Tu), L-methionine (L-Met), L-cysteine (L-Cys), L-histidine (L-His) and guanosine-5-monophosphate (5-GMP), were studied under the pseudo-first order conditions as a function of concentration and temperature using stopped-flow and UV-Vis spectrophotometry. The reactions were monitored in 0.1 M NaClO4 at pH 5.0, in the presence of 40 mM NaCI. All fast reactions were monitored by stopped-flow at three temperatures (288 K, 298 K, 308 K) to determine the activation parameters, while the reactions studied by UV-Vis spectrophotometry were tested only at 298 K. Observed order of reactivity of the used ligands is: Tu GT L-Met GT L-Cys GT L-His GT 5-GMP. Substitution reactions of the investigated bimetallic complex with Tu, L-Cys and L-His were followed by degradation to the corresponding substituted mononuclear complexes of palladium (II) and platinum (II), [Pd(bipy)(Nu)(2)] and [Pt(bipy)(Nu)(2)] (where Nu = Tu, L-Cys, L-His), by releasing of the bridge ligand,1,6-diaminohexane. In contrast, during the substitution reactions with L-Met and 5-GMP, the structure of starting bimetallic complex was preserved and the process of degradation can be halted. The proposed pathways of the substitution reactions of [{PdCl(bipy)}{mu-(NH2(CH2)(6)H2N)}{PtCl(biPY)}]Cl(ClO4) complex with all selected ligands were confirmed by H-1 NMR spectroscopy at 295 K. Additionally, the two pK(a) values of studied diaqua complex, [(Pd(H2O)(bipy)}(mu-(NH2(CH2)(6)H2N)}(Pt(H2O)(biPY)}](4+), were determined by spectrophotometric pH titration. The large negative values for the entropy of activation, Delta S-not equal, support an associative substitution mechanism. (C) 2015 Elsevier Ltd. All rights reserved. PB - Elsevier T2 - Polyhedron T1 - Kinetics and mechanism of substitution reactions of the new bimetallic [{PdCl(bipy)}{mu-(NH2(CH2)(6)H2N)}{PtCl(biPY)}]Cl(ClO4) complex with important bio-molecules VL - 101 SP - 206 EP - 214 DO - 10.1016/j.poly.2015.09.021 ER -
@article{ author = "Jovanović, Snežana and Petrović, Biljana and Petković, Marijana and Bugarčić, Živadin D.", year = "2015", abstract = "The new dinuclear bimetallic complex, [{PdCl(bipy)}{mu-(NH2(CH2)(6)H2N)}{PtCl(biPY)}]Cl(ClO4) (bipy is 2,2-bipyridine), has been prepared and characterized by elemental microanalysis, IR, H-1 NMR spectroscopy and MALDI-TOF mass spectrometry. Substitution reactions of the studied complex with selected biologically important ligands such as: thiourea (Tu), L-methionine (L-Met), L-cysteine (L-Cys), L-histidine (L-His) and guanosine-5-monophosphate (5-GMP), were studied under the pseudo-first order conditions as a function of concentration and temperature using stopped-flow and UV-Vis spectrophotometry. The reactions were monitored in 0.1 M NaClO4 at pH 5.0, in the presence of 40 mM NaCI. All fast reactions were monitored by stopped-flow at three temperatures (288 K, 298 K, 308 K) to determine the activation parameters, while the reactions studied by UV-Vis spectrophotometry were tested only at 298 K. Observed order of reactivity of the used ligands is: Tu GT L-Met GT L-Cys GT L-His GT 5-GMP. Substitution reactions of the investigated bimetallic complex with Tu, L-Cys and L-His were followed by degradation to the corresponding substituted mononuclear complexes of palladium (II) and platinum (II), [Pd(bipy)(Nu)(2)] and [Pt(bipy)(Nu)(2)] (where Nu = Tu, L-Cys, L-His), by releasing of the bridge ligand,1,6-diaminohexane. In contrast, during the substitution reactions with L-Met and 5-GMP, the structure of starting bimetallic complex was preserved and the process of degradation can be halted. The proposed pathways of the substitution reactions of [{PdCl(bipy)}{mu-(NH2(CH2)(6)H2N)}{PtCl(biPY)}]Cl(ClO4) complex with all selected ligands were confirmed by H-1 NMR spectroscopy at 295 K. Additionally, the two pK(a) values of studied diaqua complex, [(Pd(H2O)(bipy)}(mu-(NH2(CH2)(6)H2N)}(Pt(H2O)(biPY)}](4+), were determined by spectrophotometric pH titration. The large negative values for the entropy of activation, Delta S-not equal, support an associative substitution mechanism. (C) 2015 Elsevier Ltd. All rights reserved.", publisher = "Elsevier", journal = "Polyhedron", title = "Kinetics and mechanism of substitution reactions of the new bimetallic [{PdCl(bipy)}{mu-(NH2(CH2)(6)H2N)}{PtCl(biPY)}]Cl(ClO4) complex with important bio-molecules", volume = "101", pages = "206-214", doi = "10.1016/j.poly.2015.09.021" }
Jovanović, S., Petrović, B., Petković, M.,& Bugarčić, Ž. D.. (2015). Kinetics and mechanism of substitution reactions of the new bimetallic [{PdCl(bipy)}{mu-(NH2(CH2)(6)H2N)}{PtCl(biPY)}]Cl(ClO4) complex with important bio-molecules. in Polyhedron Elsevier., 101, 206-214. https://doi.org/10.1016/j.poly.2015.09.021
Jovanović S, Petrović B, Petković M, Bugarčić ŽD. Kinetics and mechanism of substitution reactions of the new bimetallic [{PdCl(bipy)}{mu-(NH2(CH2)(6)H2N)}{PtCl(biPY)}]Cl(ClO4) complex with important bio-molecules. in Polyhedron. 2015;101:206-214. doi:10.1016/j.poly.2015.09.021 .
Jovanović, Snežana, Petrović, Biljana, Petković, Marijana, Bugarčić, Živadin D., "Kinetics and mechanism of substitution reactions of the new bimetallic [{PdCl(bipy)}{mu-(NH2(CH2)(6)H2N)}{PtCl(biPY)}]Cl(ClO4) complex with important bio-molecules" in Polyhedron, 101 (2015):206-214, https://doi.org/10.1016/j.poly.2015.09.021 . .