Preparation and Characterization of [Hg{P(C6F5)2}2],
[Hg{(μ-P(C6F5)2)W(CO)5}2], and [Hg{(μ-P(CF3)2)W(CO)5}2] and the X-ray
Crystal Structure of [Hg{(μ-P(C6F5)2)W(CO)5}2]·2DMF
posted on 2003-07-29, 00:00authored byBerthold Hoge, Tobias Herrmann, Christoph Thösen, Ingo Pantenburg
The thermally unstable compound [Hg{P(C6F5)2}2] was obtained from the reaction of mercury cyanide and bis(pentafluorophenyl)phosphane in DMF solution and characterized by multinuclear NMR spectroscopy. The thermally
stable trinuclear compounds [Hg{(μ-P(CF3)2)W(CO)5}2] and [Hg{(μ-P(C6F5)2)W(CO)5}2] are isolated and completely
characterized. The higher order NMR spectra exhibiting multinuclear satellite systems have been sufficiently analyzed.
[Hg{(μ-P(CF3)2)W(CO)5}2]·2DMF crystallizes in the monoclinic space group C2/c with a = 2366.2(3) pm, b =
1046.9(1) pm, c = 104.0(1) pm, and β = 104.01(1)°. Structural, NMR spectroscopic, and vibrational data prove
a weak coordination of the two DMF molecules. Structural, vibrational, and NMR spectroscopic evidence is given
for a successive weakening of the π back-bonding effect of the W−P bond in the order [W(CO)5PH(Rf)2], [Hg{(μ-P(Rf)2)W(CO)5}2], and [W{P(Rf)2}(CO)5]- with Rf = C6F5 and CF3. The π back-bonding effect of the W−C
bonds increases vice versa.