American Chemical Society
ic034448n_si_001.cif (14.77 kB)

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

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posted on 2003-07-29, 00:00 authored by Berthold 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.