Syntheses, Structures, and Mössbauer Effect Spectroscopy of Triple-Decker Complexes Incorporating Nonamethylferrocene
作者:Andrew J. Schwartz、Robert D. Pike、Rolfe H. Herber、Eric J. Watson
DOI:10.1021/acs.organomet.5b00913
日期:2016.1.11
Three new triple-decker complexes were Cp'FeCp* (Cp' = C5Me4H, Cp* = C5Me5), with synthesized by the reaction of nonamethylferrocene, coordinatively unsaturated transition-metal complexes. The reaction of ruthenium cations [(C5R5)Ru](+) (R = H, Me) with Cp'FeCp* afforded the purple heterometallic triple-decker complexes [(C5R5)Ru(mu-Cp')FeCp*](+) by electrophilic addilion of ruthenium to the Cp' ring of nonamethylferrocene. The analogous reaction with the manganese cation [Mn(CO)(3)](+) produced the blue homometallic triple-decker complex [Cp*Fe(mu-Cp')FeCp*](+) by abstraction of the Cp' ring from Cp'FeCp* and subsequent addition of the newly generated cation [Cp*Fe](+) to 1 equiv of Cp'FeCp*. These experiments demonstrate that the asymmetry of Cp/FeCp* gives rise to a remarkable degree of regioselectivity such that ruthenium electrophiles add only to the Cp' ring and never to the Cp* ring. In a similar way, [Mn(CO)(3)](+) abstracts only the Cp' ring from Cp'FeCp* to produce [Cp*Fe](+), which in turn adds only to the Cp' ring of Cp'FeCp* to produce [Cp*Fe(mu-Cp')FeCp*]. Three air-stable triple-decker complexes incorporating nonamethylferrocene, [Cp*Fe(mu-Cp')FeCp*](+) (1), [CpRu(mu-Cp')FeCp*](+) (2), and [Cp*Ru(mu-Cp')FeCp*](+) (3), have been characterized by NMR spectroscopy, elemental analysis, single-crystal X-ray diffraction analysis, and temperature-dependent Fe-57 Mossbauer spectroscopy.