Friday, April 06, 2012

Platinum(II) Diimine Complexes with Halide/Pseudohalide Ligands and Dangling Trialkylamine or Ammonium Groups

Abstract Image
7/abril/2012
Paulina Levario Sánchez
A series of platinum(II) complexes with the formulas Pt(diimine)(pip2NCNH2)(L)2+[pip2NCNH2+ = 2,6-bis(piperidiniummethyl)phenyl cation; L = Cl, Br, I, NCS, OCN, and NO2; diimine = 1,10-phenanthroline (phen), 5-nitro-1,10-phenanthroline (NO2phen), and 5,5′-ditrifluoromethyl-2,2′-bipyridine (dtfmbpy)] were prepared by the treatment of Pt(pip2NCN)Cl with a silver(I) salt followed by the addition of the diimine and halide/pseudohalide under acidic conditions. Crystallographic data as well as 1H NMR spectra establish that the metal center is bonded to a bidentate phenanthroline and a monodentate halide/pseudohalide. The pip2NCNH2+ ligand with protonated piperidyl groups is monodentate and bonded to the platinum through the phenyl ring. Structural and spectroscopic data indicate that the halide/pseudohalide group (L) and the metal center in Pt(phen)(pip2NCNH2)(L)2+ behave as Brønsted bases, forming intramolecular NH···L/NH···Pt interactions involving the piperidinium groups. A close examination of the 10 structures reported here reveals linear correlations between N–H···Pt/L angles and H···Pt/L distances. In most cases, the N–H bond is directed toward the Pt–L bond, thereby giving the appearance that the proton bridges the Pt and L groups. In contrast to observations for Pt(tpy)(pip2NCN)+ (tpy = 2,2′;6′,2″-terpyridine), the electrochemical oxidation of deprotonated adducts, Pt(diimine)(L)(pip2NCN), is chemically and electrochemically irreversible.

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Platinum(II) Diimine Complexes with Halide/Pseudohalide Ligands and Dangling Trialkylamine or Ammonium Groups

Sayandev Chatterjee, Jeanette A. Krause, Kumudu Madduma-Liyanage, and William B. Connick
Inorganic Chemistry Article ASAP
Department of Chemistry, University of Cincinnati, P.O. Box 210172, Cincinnati, Ohio 45221-0172, United States
DOI: 10.1021/ic202462a
Publication Date (Web): April 2, 2012
Copyright © 2012 American Chemical Society

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