Oxidative Addition of Halogens to Homoleptic Perfluoromethyl or Perfluorophenyl Derivatives of Platinum(II): A Comparative Study

 
This item is provided by the institution :
University of Ioannina
Repository :
Repository of UOI Olympias
see the original item page
in the repository's web site and access all digital files if the item*
share



2009 (EN)
Oxidative Addition of Halogens to Homoleptic Perfluoromethyl or Perfluorophenyl Derivatives of Platinum(II): A Comparative Study (EN)

Menjon, B. (EN)

Πανεπιστήμιο Ιωαννίνων. Σχολή Θετικών Επιστημών. Τμήμα Χημείας (EL)
Menjon, B. (EN)

The equilibrium geometries of the homoleptic perfluorinated organoplatinate(II) anions [Pt(CF(3))(4)](2-) and [Pt(C(6)F(5))(4)](2-) have been computed at the B3P86/LANL2DZ level of theory. Remarkably good agreement with the experimentally determined structures has been obtained by X-ray diffraction methods. The reactivity of [NBu(4)](2)[Pt(CF(3))(4)] (1) towards halogens (Cl(2), Br(2), and I(2)) has been investigated by using a combined experimental and theoretical approach. The perfluoromethyl derivative 1. has been found to undergo clean oxidative addition of the three halogens under investigation, giving rise to [NBu(4)](2)[trans-Pt(CF(3))(4)X(2)] (X = Cl (7), Br (10), I (13)) in a quantitative and stereoselective way. In the low-temperature reaction of the perfluorophenyl derivative [NBu(4)](2)[Pt(C(6)F(5))(4)] (3) with Cl(2) or Br(2), the corresponding oxidative-addition products [NBu(4)](2)[trans-Pt (C(6)F(5))(4)X(2)] (X = Cl (14), Br (15)) can also be obtained. In the case in which X = Br and working in CHCl(3) at -55 degrees C. it has been possible to detect the formation of an intermediate species to which we assign the formula [trans-Pt(C(6)F(5))(4)Br(ClCHCl(2))](-) (16). The solvento complex 16 is thermally unstable and prone to undergo reductive elimination Of C(6)F(5)-C(6)F(5). In the presence of PhCN, complex [NBu(4)][trans-Pt(C(6)F(5))(4)Br(NCPh)] (17) was isolated and structurally characterized. The reaction of 3 with I(2) gave no organoplatinum(IV) compound. Our comparative study reveals that the CF(3) group is especially suited to stabilize organometallic compounds in high oxidation states. This ability can be attributed to a combination of factors: its hardness, its high group electronegativity, its small size, and its reluctance to undergo reductive elimination processes. (EN)

density functional calculations (EN)

Πανεπιστήμιο Ιωαννίνων (EL)
University of Ioannina (EN)

Chemistry-a European Journal (EN)

English

2009

<Go to ISI>://000267721500010



*Institutions are responsible for keeping their URLs functional (digital file, item page in repository site)