Kinetics and mechanism of the substitution reactions of some monofunctional Pt(II) complexes with heterocyclic nitrogen donor molecules. Crystal structure of [Pt(bpma)(pzBr)]Cl<sub>2</sub>·2H<sub>2</sub>O

Author(s)
Milica Kosovic, Snežana Jovanović, Goran A. Bogdanović, Gerald Giester, Zeljko K. Jacimovic, Živadin D. Bugarčić, Biljana Petrović
Abstract

Substitution reactions of [Pt(terpy)Cl]

+ (terpy = 2,2′;6′,2′′-terpyridine), [Pt(bpma)Cl]

+ (bpma = bis(2-pyridylmethyl)amine), [Pt(dien)Cl]

+ (dien = diethylenetriamine or 1,5-diamino-3-azapentane) and [Pt(tpdm)Cl]

+ (tpdm = tripyridinedimethane) with nitrogen donor heterocyclic molecules, such as 3-amino-4-iodo-pyrazole (pzI), 5-amino-4-bromo-3-methyl-pyrazole (pzBr) and imidazole (Im), were studied in aqueous 0.10 M NaClO

4 in the presence of 10 mM NaCl using variable-temperature UV–vis spectrophotometry. The second-order rate constants k

2 indicate decrease in reactivity in the order [Pt(terpy)Cl]

+ > [Pt(bpma)Cl]

+ > [Pt(tpdm)Cl]

+ > [Pt(dien)Cl]

+. The most reactive nucleophile among the heterocyclic compounds is imidazole, while pzI shows slightly higher reactivity than pzBr. Activation parameters were also determined and the negative values for entropies of activation, ΔS

, support an associative mode of substitution for all substitution processes. Crystal structure of [Pt(bpma)(pzBr)]Cl

2·2H

2O was determined by single-crystal X-ray analysis. The coordination geometry of the complex is distorted square-planar while the bond distance Pt–N2(pzBr) is longer than the other three Pt–N distances.

Organisation(s)
Department of Mineralogy and Crystallography
External organisation(s)
University of Kragujevac, University of Montenegro, University of Belgrade
Journal
Journal of Coordination Chemistry
Volume
69
Pages
2819-2831
No. of pages
13
ISSN
0095-8972
DOI
https://doi.org/10.1080/00958972.2016.1224336
Publication date
08-2016
Peer reviewed
Yes
Austrian Fields of Science 2012
104015 Organic chemistry, 104011 Materials chemistry, 105113 Crystallography
Keywords
ASJC Scopus subject areas
Materials Chemistry, Physical and Theoretical Chemistry
Portal url
https://ucrisportal.univie.ac.at/en/publications/26aa2bd8-9c71-4bf6-ba9c-78d579f4d8da