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Proton NMR Kinetic Study of Ligand Exchange on Bis(1,4-dithiane)platinum(II), Bis(1,4-dithiane)palladium(II) and Tetrakis(dimethylsulfide)platinum(II) : High Presssure NMR Kinetics 51

Frey, Urban ; Elmroth, Sofi K.C. LU ; Moullet, B. ; Elding, Lars Ivar LU and Merbach, Andre E. (1991) In Inorganic Chemistry 30(26). p.5033-5037
Abstract
Ligand exchange on square-planar Pt(1,4-dithiane)2(2+), Pd(1,4-dithiane)2(2+), and Pt(Me2S)4(2+) has been studied as a function of temperature and pressure by H-1 NMR line-broadening, isotopic labeling, and magnetization transfer experiments with deuteriated nitromethane as solvent. Second-order rate constants and activation parameters are as follows: for 1,4-dithiane exchange on Pt(1,4-dithiane)2(2+), k2(298) = 28.8 +/- 4.8 m-1 s-1, DELTA-H double-ended dagger = 32.9 +/- 3.6 kJ mol-1, DELTA-S double-ended dagger = -106 +/- 11 J K-1 mol-1, and DELTA-V double-ended dagger = -12.6 +/- 1.1 cm3 mol-1; for 1,4-dithiane exchange on Pd(1,4-dithiane)2(2+), k2(298) = 9780 +/- 300 m-1 s-1, DELTA-H double-ended dagger = 22.9 +/- 0.6 kJ mol-1, DELTA-S... (More)
Ligand exchange on square-planar Pt(1,4-dithiane)2(2+), Pd(1,4-dithiane)2(2+), and Pt(Me2S)4(2+) has been studied as a function of temperature and pressure by H-1 NMR line-broadening, isotopic labeling, and magnetization transfer experiments with deuteriated nitromethane as solvent. Second-order rate constants and activation parameters are as follows: for 1,4-dithiane exchange on Pt(1,4-dithiane)2(2+), k2(298) = 28.8 +/- 4.8 m-1 s-1, DELTA-H double-ended dagger = 32.9 +/- 3.6 kJ mol-1, DELTA-S double-ended dagger = -106 +/- 11 J K-1 mol-1, and DELTA-V double-ended dagger = -12.6 +/- 1.1 cm3 mol-1; for 1,4-dithiane exchange on Pd(1,4-dithiane)2(2+), k2(298) = 9780 +/- 300 m-1 s-1, DELTA-H double-ended dagger = 22.9 +/- 0.6 kJ mol-1, DELTA-S double-ended dagger = -91.6 +/- 2.1 J K-1 mol-1, and DELTA-V double-ended dagger = -9.8 +/- 0.4 cm3 mol-1; for Me2S exchange on Pt(Me2S)4(2+), k2(298) = 1.54 +/- 0.07 m-1 s-1, DELTA-H double-ended dagger = 42.1 +/- 0.7 kJ mol-1, DELTA-S double-ended dagger = -100.2 +/- 2.2 J K-1 mol-1, and DELTA-V double-ended dagger = -22.0 +/- 1.3 cm3 mol-1. Second-order kinetics and negative entropies and volumes of activation indicate associative, I(a) or A, exchange mechanisms. For both metal centers, exchange of the chelated and strongly bound 1,4-dithiane, corrected for statistics, is faster than that of Me2S, probably due to steric factors. The ratio in reactivity for Pd/Pt is only ca. 1300 for Me2S and 340 for 1,4-dithiane, indicating a more pronounced sensitivity of Pt(II) to the electronic properties of the coordinated and entering ligands. Accordingly, activation volumes are more negative in the case of platinum. DELTA-V double-ended dagger for the Me2S exchange on Pt(II) is the most negative one reported so far for a square-planar solvent exchange. (Less)
Abstract (Swedish)
Ligand exchange on square-planar Pt(1,4-dithiane)2(2+), Pd(1,4-dithiane)2(2+), and Pt(Me2S)4(2+) has been studied as a function of temperature and pressure by H-1 NMR line-broadening, isotopic labeling, and magnetization transfer experiments with deuteriated nitromethane as solvent. Second-order rate constants and activation parameters are as follows: for 1,4-dithiane exchange on Pt(1,4-dithiane)2(2+), k2(298) = 28.8 +/- 4.8 m-1 s-1, DELTA-H double-ended dagger = 32.9 +/- 3.6 kJ mol-1, DELTA-S double-ended dagger = -106 +/- 11 J K-1 mol-1, and DELTA-V double-ended dagger = -12.6 +/- 1.1 cm3 mol-1; for 1,4-dithiane exchange on Pd(1,4-dithiane)2(2+), k2(298) = 9780 +/- 300 m-1 s-1, DELTA-H double-ended dagger = 22.9 +/- 0.6 kJ mol-1, DELTA-S... (More)
Ligand exchange on square-planar Pt(1,4-dithiane)2(2+), Pd(1,4-dithiane)2(2+), and Pt(Me2S)4(2+) has been studied as a function of temperature and pressure by H-1 NMR line-broadening, isotopic labeling, and magnetization transfer experiments with deuteriated nitromethane as solvent. Second-order rate constants and activation parameters are as follows: for 1,4-dithiane exchange on Pt(1,4-dithiane)2(2+), k2(298) = 28.8 +/- 4.8 m-1 s-1, DELTA-H double-ended dagger = 32.9 +/- 3.6 kJ mol-1, DELTA-S double-ended dagger = -106 +/- 11 J K-1 mol-1, and DELTA-V double-ended dagger = -12.6 +/- 1.1 cm3 mol-1; for 1,4-dithiane exchange on Pd(1,4-dithiane)2(2+), k2(298) = 9780 +/- 300 m-1 s-1, DELTA-H double-ended dagger = 22.9 +/- 0.6 kJ mol-1, DELTA-S double-ended dagger = -91.6 +/- 2.1 J K-1 mol-1, and DELTA-V double-ended dagger = -9.8 +/- 0.4 cm3 mol-1; for Me2S exchange on Pt(Me2S)4(2+), k2(298) = 1.54 +/- 0.07 m-1 s-1, DELTA-H double-ended dagger = 42.1 +/- 0.7 kJ mol-1, DELTA-S double-ended dagger = -100.2 +/- 2.2 J K-1 mol-1, and DELTA-V double-ended dagger = -22.0 +/- 1.3 cm3 mol-1. Second-order kinetics and negative entropies and volumes of activation indicate associative, I(a) or A, exchange mechanisms. For both metal centers, exchange of the chelated and strongly bound 1,4-dithiane, corrected for statistics, is faster than that of Me2S, probably due to steric factors. The ratio in reactivity for Pd/Pt is only ca. 1300 for Me2S and 340 for 1,4-dithiane, indicating a more pronounced sensitivity of Pt(II) to the electronic properties of the coordinated and entering ligands. Accordingly, activation volumes are more negative in the case of platinum. DELTA-V double-ended dagger for the Me2S exchange on Pt(II) is the most negative one reported so far for a square-planar solvent exchange. (Less)
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organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Platinum(II), Palladium(II), 1,4-dithiane, Tetrakis(dimethylsulfide, Ligand exchange, Proton NMR, Kinetics, Reaction mechanism
in
Inorganic Chemistry
volume
30
issue
26
pages
5033 - 5037
publisher
The American Chemical Society (ACS)
external identifiers
  • scopus:0001169247
ISSN
1520-510X
DOI
10.1021/ic00026a034
language
English
LU publication?
yes
id
64ccc866-abd3-433b-b3f4-fdaa04cdc63a
date added to LUP
2017-01-08 19:15:50
date last changed
2021-01-03 04:36:55
@article{64ccc866-abd3-433b-b3f4-fdaa04cdc63a,
  abstract     = {{Ligand exchange on square-planar Pt(1,4-dithiane)2(2+), Pd(1,4-dithiane)2(2+), and Pt(Me2S)4(2+) has been studied as a function of temperature and pressure by H-1 NMR line-broadening, isotopic labeling, and magnetization transfer experiments with deuteriated nitromethane as solvent. Second-order rate constants and activation parameters are as follows: for 1,4-dithiane exchange on Pt(1,4-dithiane)2(2+), k2(298) = 28.8 +/- 4.8 m-1 s-1, DELTA-H double-ended dagger = 32.9 +/- 3.6 kJ mol-1, DELTA-S double-ended dagger = -106 +/- 11 J K-1 mol-1, and DELTA-V double-ended dagger = -12.6 +/- 1.1 cm3 mol-1; for 1,4-dithiane exchange on Pd(1,4-dithiane)2(2+), k2(298) = 9780 +/- 300 m-1 s-1, DELTA-H double-ended dagger = 22.9 +/- 0.6 kJ mol-1, DELTA-S double-ended dagger = -91.6 +/- 2.1 J K-1 mol-1, and DELTA-V double-ended dagger = -9.8 +/- 0.4 cm3 mol-1; for Me2S exchange on Pt(Me2S)4(2+), k2(298) = 1.54 +/- 0.07 m-1 s-1, DELTA-H double-ended dagger = 42.1 +/- 0.7 kJ mol-1, DELTA-S double-ended dagger = -100.2 +/- 2.2 J K-1 mol-1, and DELTA-V double-ended dagger = -22.0 +/- 1.3 cm3 mol-1. Second-order kinetics and negative entropies and volumes of activation indicate associative, I(a) or A, exchange mechanisms. For both metal centers, exchange of the chelated and strongly bound 1,4-dithiane, corrected for statistics, is faster than that of Me2S, probably due to steric factors. The ratio in reactivity for Pd/Pt is only ca. 1300 for Me2S and 340 for 1,4-dithiane, indicating a more pronounced sensitivity of Pt(II) to the electronic properties of the coordinated and entering ligands. Accordingly, activation volumes are more negative in the case of platinum. DELTA-V double-ended dagger for the Me2S exchange on Pt(II) is the most negative one reported so far for a square-planar solvent exchange.}},
  author       = {{Frey, Urban and Elmroth, Sofi K.C. and Moullet, B. and Elding, Lars Ivar and Merbach, Andre E.}},
  issn         = {{1520-510X}},
  keywords     = {{Platinum(II); Palladium(II); 1,4-dithiane; Tetrakis(dimethylsulfide; Ligand exchange; Proton NMR; Kinetics; Reaction mechanism}},
  language     = {{eng}},
  month        = {{12}},
  number       = {{26}},
  pages        = {{5033--5037}},
  publisher    = {{The American Chemical Society (ACS)}},
  series       = {{Inorganic Chemistry}},
  title        = {{Proton NMR Kinetic Study of Ligand Exchange on Bis(1,4-dithiane)platinum(II), Bis(1,4-dithiane)palladium(II) and Tetrakis(dimethylsulfide)platinum(II) : High Presssure NMR Kinetics 51}},
  url          = {{http://dx.doi.org/10.1021/ic00026a034}},
  doi          = {{10.1021/ic00026a034}},
  volume       = {{30}},
  year         = {{1991}},
}