Supporting Information

Assembly of Cyclometalated Platinum(II) Complexes via 1,1′-Bis(diphenylphosphino)ferrocene Ligand: Kinetics and Mechanisms

Terms & Conditions

- Hide

Electronic Supporting Information files are available without a subscription to ACS Web Editions. The American Chemical Society holds a copyright ownership interest in any copyrightable Supporting Information. Files available from the ACS website may be downloaded for personal use only. Users are not otherwise permitted to reproduce, republish, redistribute, or sell any Supporting Information from the ACS website, either in whole or in part, in either machine-readable form or any other form without permission from the American Chemical Society. For permission to reproduce, republish and redistribute this material, requesters must process their own requests via the RightsLink permission system. Information about how to use the RightsLink permission system can be found at

Assembly of Cyclometalated Platinum(II) Complexes via 1,1′-Bis(diphenylphosphino)ferrocene Ligand: Kinetics and Mechanisms

Department of Chemistry, College of Sciences, Shiraz University, Shiraz 71454, Iran
Department of Chemistry, Science and Research Branch, Islamic Azad University, Tehran, Iran
§ Department of Chemistry, Faculty of Sciences, Central Tehran Branch, Islamic Azad University, Shahrak Gharb, Tehran, Iran
Department of Chemistry, Islamic Azad University, Shiraz Branch, Shiraz 71993-37635, Iran
Department of Electrical and Computer Engineering, Photonics Lab, Shiraz University, Shiraz, Iran
Organometallics, 2011, 30 (6), pp 1466–1477
DOI: 10.1021/om101055n
Publication Date (Web): February 16, 2011
Copyright © 2011 American Chemical Society


Abstract Image

The kinetics and mechanism of the reaction of the cyclometalated complexes [PtAr(C−N)(SMe2)], 1, in which Ar is Ph, p-MeC6H4, or p-MeOC6H4, and C−N is either ppy (deprotonated 2-phenylpyridine) or bhq (deprotonated benzo[h]quinoline), with 1,1′-bis(diphenylphosphino)ferrocene, dppf, were studied using UV−visible and 31P NMR spectroscopies. When 0.5 equiv of dppf was added, the binuclear Pt(II) complex [Pt2Ar2(C−N)2(μ-dppf)], 2, was formed in a good yield. The complexes were fully characterized using multinuclear (1H, 31P, and 195Pt) NMR spectroscopy, and the structure of complex [Pt2(p-MeOC6H4)2(bhq)2(μ-dppf)], 2c′·CH2Cl2, was further identified by X-ray crystallography. On the basis of low-temperature 31P NMR studies involving the starting complex [Pt(p-MeC6H4)(ppy)(SMe2)], 1b, we suggest that dppf displaces the labile ligand SMe2 to give an uncommon complex, [Pt(p-MeC6H4)(ppy)(dppf-κ1P)], A, in which dppf-κ1P is a monodentate dppf ligand, which rapidly forms an equilibrium with the chelating dppf isomer complex [Pt(p-MeC6H4)(dppf)(ppy-κ1C)], B, in which ppy-κ1C is the deprotonated ppy ligand that is C-ligated with the dangling N atom. In the second step, A is reacted with the remaining second half of starting complex 1b to give the final Pt(II)−Pt(II) binuclear complex [Pt2(p-MeC6H4)2(ppy)2(μ-dppf)], 2b. A competitive-consecutive second-order reaction mechanism was suggested for the reaction using chemometric studies, and the rate constants at 5 °C for first and second steps were estimated as k2 = 10.7 ± 0.2 L mol−1 s−1 and k2′ = 0.68 ± 0.05 L mol−1 s−1, respectively. When the starting complex [Pt(p-MeC6H4)(ppy)(SMe2)], 1b, was reacted with 1 equiv of dppf, similarly the complex A, in equilibrium with B, was formed first, with the rate constant at 5 °C being k2 = 10.5 ± 0.5 L mol−1 s−1, estimated using UV−visible spectroscopy. Subsequently, however, A and B would slowly and reversibly react with each other to form a new species, C, the structure of which, on the basis of 31P and 195Pt NMR spectra, was proposed to be [(p-MeC6H4)(ppy)Pt(μ-dppf)Pt(p-MeC6H4)(ppy-κ1C)(dppf-κ1P)]; the same results were obtained when more than 1, e.g., 2, equiv of dppf was used, with a similar rate constant of k2 = 10.6 ± 0.6 L mol−1 s−1. The complexes 1b and 2b were shown to have some interesting photophysical properties as investigated by absorption and electroluminescence spectroscopies.

Supporting Information

Crystallographic data in CIF format and details of the chemometric method used for the kinetic study. These materials are available free of charge via the Internet at


Received 10 November 2010
Published online 16 February 2011
Published in print 28 March 2011
Explore by: