Journal
DALTON TRANSACTIONS
Volume 42, Issue 23, Pages 8426-8436Publisher
ROYAL SOC CHEMISTRY
DOI: 10.1039/c3dt00022b
Keywords
-
Categories
Funding
- University of KwaZulu-Natal
Ask authors/readers for more resources
The kinetics of chloride substitution from a series of square-planar platinum(II) complexes, viz. [Pt(terpyridine)Cl](+), (Pt1), [Pt{2-(2'-pyridyl)-1,10-phenanthroline}Cl]Cl, (Pt2), [Pt{4'-(2'''-CH3-phenyl)-2,2': 6',2 ''-terpyridine}Cl]CF3SO3 (Pt3) and [Pt{4'-(2'''-CH3-phenyl)-6-(3 ''-isoquinoyl)-2,2'bipyridine} Cl]SbF6 (Pt4) were studied using a series of five-membered heterocyclic neutral nitrogen donor nucleophiles, viz. pyrazole (Pz), triazole (Tz), imidazole (Im), 1-methylimidazole (MIm) and 1,2-dimethylimidazole (DMIm) under pseudo-first-order conditions in methanol using UV/Visible spectrophotometry and conventional stopped-flow techniques. The observed second-order rate constants, k(2), followed a two term rate law k(obs) = k(2)[nucleophile] + k(s) except for DMIm with Pt1, Pt3, Pt4 and Pz, Tz with Pt1. Increasing the pi-conjugation in the cis position decreases the rate of chloride substitution by decreasing the pi-acceptor property of the terpy moiety. However, increasing the pi-conjugation in the cis/trans position increases the rate of substitution by enhancing the pi-acceptor property within the ligand framework whereby increasing the reactivity of the metal centre. The observed trend for the reactivity was Pt2 > Pt1 > Pt3 > Pt4. The substitution kinetics was influenced by the basicity of the incoming nucleophiles except for the sterically hindered nucleophile, DMIm. The general trend observed for the reactivity of the nucleophiles is MIm > Im > DMIm > Pz > Tz.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available