Mechanism of the fluxional behaviour in (1–5-η-cycloheptadienyl)-(1–5-η-cycloheptatrienyl)iron

Abstract

Evidence for a 1,2-shift mechanism of the 1–5-η-cycloheptatrienyl moiety with respect to the central iron atom of the title compound is presented together with absolute assignments of the ¹³C n.m.r. chemical shifts of the C₇H₇ ring. A low-temperature rocking motion of both rings can be frozen out at –70 °C.