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A comparative kinetic study of modified Pt(dppf)Cl-2 complexes and their interactions with L-cys and L-met

Puxty, Graeme LU ; Bjelosevic, Haris LU ; Persson, Tina LU and Elmroth, Sofi LU (2005) In Dalton Transactions 2005(18). p.3032-3038
Abstract
With the success of cisplatin (cis-diamminedichloroplatinum(II)), strong interest has developed in the application of inorganic metal complexes to the treatment of cancer. Research has focused on platinum( II) complexes with a variety of spectator ligands that provide novel physicochemical properties. In this paper we report a kinetic study of 1', 1'-bis(diphenylphosphino) ferrocenedichloroplatinum( II) and two related compounds with either an acetate or amide ester substituent attached to the cyclopentadienyl ring. For all compounds the reactivity towards L-cysteine and L-methionine in aqueous solution has been investigated (25 degrees C, I = 0.010 M and pseudo-first-order conditions). For the reactions with L-cysteine and L-methionine... (More)
With the success of cisplatin (cis-diamminedichloroplatinum(II)), strong interest has developed in the application of inorganic metal complexes to the treatment of cancer. Research has focused on platinum( II) complexes with a variety of spectator ligands that provide novel physicochemical properties. In this paper we report a kinetic study of 1', 1'-bis(diphenylphosphino) ferrocenedichloroplatinum( II) and two related compounds with either an acetate or amide ester substituent attached to the cyclopentadienyl ring. For all compounds the reactivity towards L-cysteine and L-methionine in aqueous solution has been investigated (25 degrees C, I = 0.010 M and pseudo-first-order conditions). For the reactions with L-cysteine and L-methionine the reactions proceeded via a steady-state aquated intermediate to form mono (0.92(2) - 3.25( 4)) x 10(-3) s(-1)) and bis adducts (0.97( 2) - 3.67(4)) x 10(-4) s(-1)). For reactions with L- cysteine, direct reactions with the starting complex also contributed ( mono adduct: 0.36( 2) - 1.41(4) M-1 s(-1), bis adduct: 0.080(1) - 0.96(1) M-1 s(-1)). The attached substituents were found to have a significant effect upon the reaction kinetics, with the substituted complexes found to have increased reactivity. It is proposed that the increased reactivity stems from hydrogen bonding between the substituent and the entering ligand and subsequent outer-sphere complex stabilisation. Evidence in support of this theory was obtained form measurements in dichloromethane with 1-propanethiol as the entering ligand. The reactivity of the dppf containing complexes was also compared to that of cisplatin ( mono adduct: (0.170( 1) - 0.175(1)) x 10(-3) s(-1), bis adduct: (0.183( 1) - 0.397( 1)) x 10(-4) s(-1)) and found to be significantly enhanced. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Dalton Transactions
volume
2005
issue
18
pages
3032 - 3038
publisher
Royal Society of Chemistry
external identifiers
  • wos:000231524000011
  • scopus:25144465637
ISSN
1477-9234
DOI
10.1039/b504129e
language
English
LU publication?
yes
id
aa778a7b-774c-4d40-97fe-41dbc3eb2c65 (old id 152357)
alternative location
http://www.rsc.org/Publishing/Journals/DT/article.asp?doi=b504129e
http://www.rsc.org/ej/DT/2005/b504129e.pdf
date added to LUP
2007-07-10 13:40:08
date last changed
2017-08-20 03:46:09
@article{aa778a7b-774c-4d40-97fe-41dbc3eb2c65,
  abstract     = {With the success of cisplatin (cis-diamminedichloroplatinum(II)), strong interest has developed in the application of inorganic metal complexes to the treatment of cancer. Research has focused on platinum( II) complexes with a variety of spectator ligands that provide novel physicochemical properties. In this paper we report a kinetic study of 1', 1'-bis(diphenylphosphino) ferrocenedichloroplatinum( II) and two related compounds with either an acetate or amide ester substituent attached to the cyclopentadienyl ring. For all compounds the reactivity towards L-cysteine and L-methionine in aqueous solution has been investigated (25 degrees C, I = 0.010 M and pseudo-first-order conditions). For the reactions with L-cysteine and L-methionine the reactions proceeded via a steady-state aquated intermediate to form mono (0.92(2) - 3.25( 4)) x 10(-3) s(-1)) and bis adducts (0.97( 2) - 3.67(4)) x 10(-4) s(-1)). For reactions with L- cysteine, direct reactions with the starting complex also contributed ( mono adduct: 0.36( 2) - 1.41(4) M-1 s(-1), bis adduct: 0.080(1) - 0.96(1) M-1 s(-1)). The attached substituents were found to have a significant effect upon the reaction kinetics, with the substituted complexes found to have increased reactivity. It is proposed that the increased reactivity stems from hydrogen bonding between the substituent and the entering ligand and subsequent outer-sphere complex stabilisation. Evidence in support of this theory was obtained form measurements in dichloromethane with 1-propanethiol as the entering ligand. The reactivity of the dppf containing complexes was also compared to that of cisplatin ( mono adduct: (0.170( 1) - 0.175(1)) x 10(-3) s(-1), bis adduct: (0.183( 1) - 0.397( 1)) x 10(-4) s(-1)) and found to be significantly enhanced.},
  author       = {Puxty, Graeme and Bjelosevic, Haris and Persson, Tina and Elmroth, Sofi},
  issn         = {1477-9234},
  language     = {eng},
  number       = {18},
  pages        = {3032--3038},
  publisher    = {Royal Society of Chemistry},
  series       = {Dalton Transactions},
  title        = {A comparative kinetic study of modified Pt(dppf)Cl-2 complexes and their interactions with L-cys and L-met},
  url          = {http://dx.doi.org/10.1039/b504129e},
  volume       = {2005},
  year         = {2005},
}