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Journal of the Brazilian Chemical Society

Print version ISSN 0103-5053

Abstract

BITZER, Rodrigo S.; SAN GIL, Rosane A. S.  and  FILGUEIRAS, Carlos A. L.. A novel oxidative addition product from [Pt2(dba)3]: synthesis and spectroscopic characterization of a bimetallic Pt-h2-tetracyanoethylene complex containing 2,3,5,6-tetrakis(a-pyridyl)pyrazine. J. Braz. Chem. Soc. [online]. 2006, vol.17, n.8, pp. 1600-1604. ISSN 0103-5053.  http://dx.doi.org/10.1590/S0103-50532006000800017.

{[Pt(h2-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(a-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 (d 128-155) and to the nitrile carbon atoms (d 115.1), the 13C-CP/MAS NMR spectrum of 1 exhibits a double doublet [d1 -2.6, 1J(195Pt-13 C) = 223 Hz and d2 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-h2-TCNE moieties is best described according to the metalacyclopropane model.

Keywords : organoplatinum chemistry; bimetallic complexes; nitrogen heterocyclic ligand; 13C-CP/MAS.

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