Regiospecific C(naphthyl)-H bond activation by platinum(II)-isolation, characterization, reactivity and TD-DFT study of the cycloplatinate complexes
- Citation data:
European Journal of Inorganic Chemistry, ISSN: 1434-1948, Vol: 2011, Issue: 25, Page: 3739-3748
- Publication Year:
- Chemistry; C-H activation; Cyclometallation; Density functional calculations; Oxidation; Platinum; C-H activation; Cyclometallation; Density functional calculations; Oxidation; Platinum
The regiospecific activation of C(naphthyl)-H bonds in a group of naphthylazo-2′-hydroxyarene ligands (HL) has been achieved by platinum(II) compounds under different reaction conditions, and stable cycloplatinates [PtL(D)] have been isolated in presence of neutral Lewis bases (D). Structures of the cycloplatinate complexes of platinum(II) have been established by single-crystal X-ray crystallography. The platinum(II) centres are surrounded by a C,N,O-terdentate ligand frame (L) and Lewis base (D) in a distorted square planar fashion. These cycloplatinate species have been found to react with halogens and methyl iodide undergoing metal-centered two electron oxidation affording platinum(IV) cycloplatinates with distorted octahedral geometry. In the reactions with halogens and methyl iodide, trans oxidative addition has been found for [Pt(L)D] (D = 4-picoline), whereas cis addition has been observed for [Pt(L)D] where D is a more sterically demanding triphenylphosphane. Structures of two representative platinum(IV) cycloplatinate species have been determined by single-crystal X-ray crystallography. A time dependent (TD)-DFT study of representative cycloplatinate compounds has been performed. Optical absorption spectra of the cycloplatinate compounds in dichloromethane have been simulated using the TD-DFT method, and the experimental spectra are in very good agreement. © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.