Synthesis, structure, and reactivity of arylfluoro platinum(II) complexes.
(2003) In Organometallics 22(25). p.5235-5242- Abstract
- Complexes of the type trans-[PtPhFL2], where L = PPh3 (4), PMe2Ph (5), were synthesized. Complex 4 was characterized by X-ray crystallography. The equilibrium constant for the substitution of the fluoride trans to phenyl in 4 by Cl- and I- was determined, and the stability sequence follows the normal trend seen in "soft" metal centers: i.e., the Pt has a preference for the halide in the order I > Cl > F; the difference is, however, fairly small. The substitution kinetics follow the usual two-term rate law, and the rate constants for the solvolytic (k1) and the direct (k2) reaction pathways were determined to be k1 = (9.7 ± 2.4) × 10-5 s-1, k2 = (11.7 ± 0.3) × 10-2 M-1 s-1 and k1 = (7.1 ± 4.9) × 10-5 s-1, k2 = (23.0 ± 1.3) × 10-2 M-1... (More)
- Complexes of the type trans-[PtPhFL2], where L = PPh3 (4), PMe2Ph (5), were synthesized. Complex 4 was characterized by X-ray crystallography. The equilibrium constant for the substitution of the fluoride trans to phenyl in 4 by Cl- and I- was determined, and the stability sequence follows the normal trend seen in "soft" metal centers: i.e., the Pt has a preference for the halide in the order I > Cl > F; the difference is, however, fairly small. The substitution kinetics follow the usual two-term rate law, and the rate constants for the solvolytic (k1) and the direct (k2) reaction pathways were determined to be k1 = (9.7 ± 2.4) × 10-5 s-1, k2 = (11.7 ± 0.3) × 10-2 M-1 s-1 and k1 = (7.1 ± 4.9) × 10-5 s-1, k2 = (23.0 ± 1.3) × 10-2 M-1 s-1 for Cl- and I-, respectively. Activation parameters for the solvolytic and direct pathways with Cl- as incoming ligand are typical for associative processes and were determined to be H = 77.8 ± 5.5 kJ mol-1, S = -56 ± 18 J K-1mol-1 and H = 67.6 ± 1.8 kJ mol-1, S = -37 ± 6 J K-1mol-1, respectively. Complexes 4 and 5 react with Me3SnPh, and within 2-15 min there is a complete conversion to products. 4 gives a single product, trans-[PtPhMe(PPh3)2], which was characterized by X-ray crystallography. 5 gives two products: trans-[PtPhMe(PMe2Ph)2] and trans-[PtPh2(PMe2Ph)2]. Steric effects on the reactivity speak in favor of an associative mechanism. The surprisingly high reactivity for the transmetalations, compared to the substitution reactions, can be explained in terms of an associative mechanism, where a strong, bridging Sn-F interaction stabilizes the transition state. Furthermore, only trans products are formed; i.e., we have an exclusive F-for-R (R = Me, Ph) substitution at these platinum fluoro complexes. Treatment of 4 with phenylacetylene in benzene at room temperature gives the alkynyl complex trans-[PtPh(CCPh)(PPh3)2] (8). (Less)
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https://lup.lub.lu.se/record/128370
- author
- Nilsson, Patrik LU ; Plamper, Felix and Wendt, Ola LU
- organization
- publishing date
- 2003
- type
- Contribution to journal
- publication status
- published
- subject
- in
- Organometallics
- volume
- 22
- issue
- 25
- pages
- 5235 - 5242
- publisher
- The American Chemical Society (ACS)
- external identifiers
-
- wos:000186977200011
- scopus:0346148368
- ISSN
- 1520-6041
- DOI
- 10.1021/om030524i
- language
- English
- LU publication?
- yes
- id
- 035aad2c-e10e-4713-ae50-71647fefecb2 (old id 128370)
- date added to LUP
- 2016-04-01 11:40:48
- date last changed
- 2022-01-26 08:39:17
@article{035aad2c-e10e-4713-ae50-71647fefecb2,
abstract = {{Complexes of the type trans-[PtPhFL2], where L = PPh3 (4), PMe2Ph (5), were synthesized. Complex 4 was characterized by X-ray crystallography. The equilibrium constant for the substitution of the fluoride trans to phenyl in 4 by Cl- and I- was determined, and the stability sequence follows the normal trend seen in "soft" metal centers: i.e., the Pt has a preference for the halide in the order I > Cl > F; the difference is, however, fairly small. The substitution kinetics follow the usual two-term rate law, and the rate constants for the solvolytic (k1) and the direct (k2) reaction pathways were determined to be k1 = (9.7 ± 2.4) × 10-5 s-1, k2 = (11.7 ± 0.3) × 10-2 M-1 s-1 and k1 = (7.1 ± 4.9) × 10-5 s-1, k2 = (23.0 ± 1.3) × 10-2 M-1 s-1 for Cl- and I-, respectively. Activation parameters for the solvolytic and direct pathways with Cl- as incoming ligand are typical for associative processes and were determined to be H = 77.8 ± 5.5 kJ mol-1, S = -56 ± 18 J K-1mol-1 and H = 67.6 ± 1.8 kJ mol-1, S = -37 ± 6 J K-1mol-1, respectively. Complexes 4 and 5 react with Me3SnPh, and within 2-15 min there is a complete conversion to products. 4 gives a single product, trans-[PtPhMe(PPh3)2], which was characterized by X-ray crystallography. 5 gives two products: trans-[PtPhMe(PMe2Ph)2] and trans-[PtPh2(PMe2Ph)2]. Steric effects on the reactivity speak in favor of an associative mechanism. The surprisingly high reactivity for the transmetalations, compared to the substitution reactions, can be explained in terms of an associative mechanism, where a strong, bridging Sn-F interaction stabilizes the transition state. Furthermore, only trans products are formed; i.e., we have an exclusive F-for-R (R = Me, Ph) substitution at these platinum fluoro complexes. Treatment of 4 with phenylacetylene in benzene at room temperature gives the alkynyl complex trans-[PtPh(CCPh)(PPh3)2] (8).}},
author = {{Nilsson, Patrik and Plamper, Felix and Wendt, Ola}},
issn = {{1520-6041}},
language = {{eng}},
number = {{25}},
pages = {{5235--5242}},
publisher = {{The American Chemical Society (ACS)}},
series = {{Organometallics}},
title = {{Synthesis, structure, and reactivity of arylfluoro platinum(II) complexes.}},
url = {{http://dx.doi.org/10.1021/om030524i}},
doi = {{10.1021/om030524i}},
volume = {{22}},
year = {{2003}},
}