A novel oxidative addition product from [Pt2(dba)3]: synthesis and spectroscopic characterization of a bimetallic Pt-eta2-tetracyanoethylene complex containing 2,3,5,6-tetrakis(alpha-pyridyl)pyrazine

• Published in: Journal of the Brazilian Chemical Society 2006-12, Vol.17 (8), p.1600-1604
• Main Authors: Bitzer, Rodrigo S., San Gil, Rosane A. S., Filgueiras, Carlos A. L.
• Format: Article
• Language: English
• Subjects: CHEMISTRY, MULTIDISCIPLINARY
• ISSN: 0103-5053; 1678-4790
• DOI: 10.1590/S0103-50532006000800017

{[Pt(eta2-TCNE)]2(µ-TPP)} (1) has been prepared from the Pt(0) compound [Pt2(dba)3] (dba = dibenzylideneacetone), tetracyanoethylene (TCNE), and 2,3,5,6-tetrakis(alpha-pyridyl)pyrazine (TPP) in the 1:2:1 stoichiometric ratio, respectively. 1 has been characterized by elemental analysis, infrared spectroscopy, solution ¹H NMR and solid-state 13C (CP/MAS) NMR spectroscopy. According to the NMR spectra of 1, TPP binds to each metal through two pyridine nitrogen atoms. In addition to the signals assigned to the TPP carbon atoms (delta 128-155) and to the nitrile carbon atoms (delta 115.1), the 13C-CP/MAS NMR spectrum of 1 exhibits a double doublet [delta1 -2.6, ¹J(195Pt-13 C) = 223 Hz and delta2 1.6, ¹J(195Pt-13 C) = 188 Hz] in the low frequency region. These signals are assigned to the ethylenic TCNE carbon atoms attached to platinum and confirm that the bonding at the Pt-eta2-TCNE moieties is best described according to the metalacyclopropane model.