Browse by author
Lookup NU author(s): Ahmed Alwaaly, Professor William Clegg, Dr Ross Harrington, Professor Athinoula Petrou, Professor Richard Henderson
Full text for this publication is not currently held within this repository. Alternative links are provided below where available.
Earlier kinetic studies on the protonation of the coordinated thiolate in the square-planar [Ni(SC6H4R'-4)(triphos)](+) (R' = NO2, Cl, H, Me or MeO) by lutH(+) (lut = 2,6-dimethylpyridine) indicate a two-step mechanism involving initial formation of a (kinetically detectable) precursor intermediate, {[Ni(SC6H4R'-4)(triphos)]center dot center dot center dot Hlut}(2+) (K-1(R)), followed by an intramolecular proton transfer step (k(2)(R)). The analogous [Ni(SR)(triphos)]BPh4 {R = Et, Bu-t or Cy; triphos = PhP(CH2CH2PPh2)(2)} have been prepared and characterized by spectroscopy and X-ray crystallography. Similar to the aryl thiolate complexes, [Ni(SR)(triphos)](+) are protonated by lutH(+) in an equilibrium reaction but the observed rate law is simpler. Analysis of the kinetic data for both [Ni(SR)(triphos)](+) and [Ni(SC6H4R'-4)(triphos)](+) shows that both react by the same mechanism, but that K-1(R) is largest when the thiolate is poorly basic, or the 4-R' substituent in the aryl thiolates is electron-withdrawing. These results indicate that it is both NH center dot center dot center dot S hydrogen bonding and encapsulation of the bound lutH(+) (by the phenyl groups on triphos) which stabilize the precursor intermediate.
Author(s): Alwaaly A, Clegg W, Harrington RW, Petrou AL, Henderson RA
Publication type: Article
Publication status: Published
Journal: Dalton Transactions
Year: 2015
Volume: 44
Issue: 26
Pages: 11977-11983
Print publication date: 14/07/2015
Online publication date: 08/06/2015
Acceptance date: 08/06/2015
ISSN (print): 1477-9226
ISSN (electronic): 1477-9234
Publisher: Royal Society of Chemistry
URL: http://dx.doi.org/10.1039/c5dt01716e
DOI: 10.1039/c5dt01716e
Altmetrics provided by Altmetric
