Zur Darstellung phosphido-chalkogenido-verbrückter Dirheniumkomplexe vom Typ Re2(μ-PCy2)(μ-ER)(CO)8 (E = S, Se, Te; R = org. Rest)
摘要:
The reaction of Re-2(mu -Br)(mu -PCy2)(CO)(8) with nucleophiles MER (M = Na, Li; E = S, Se, Te; R = org. residue) gives via substitution of the bromide bridge phosphido chalcogenido bridged dirhenium complexes of the general for mula Re-2(mu -PCy2)(mu -ER)(CO)(8). The new compounds were characterized by IR, H-1 and C-13 NMR spectroscopic data and by elemental analyses. In addition the molecular structures for E = S, Se, Te and R = Ph as well as for E = S and R = H, n-Bu, 2-pyridyl have been established by single crystal X-ray analysis. C-13 NMR spectra of Re-2(mu -PCy2)(mu -EPh)(CO)(8) (E = S, Se, Te) prove that the sulfur and selenium compounds are at room temperature dynamic molecules due to inversion of the pyramidal. chalcogenido bridge. The tellurium compound, however, is rigid on the time scale of C-13 NMR spectroscopy eventually the reactivity of the SH function of the novel complex Re-2(mu -PCy2)(mu -SH)(CO)(8) was investigated by reaction with Re-2(CO)(8)(MeCN)(2). In toluene at 90 degreesC the novel spirocyclic complex Re-2(mu -PCy2)(CO)(8)(mu (4)-S)Re-2(mu -H)(CO)(8) was formed by SH oxidative addition.