  We study theoretically the spin dynamics of the ferric wheel, an
antiferromagnetic molecular ring. For a single nuclear or impurity spin coupled
to one of the electron spins of the ring, we calculate nuclear and electronic
spin correlation functions and show that nuclear magnetic resonance (NMR) and
electron spin resonance (ESR) techniques can be used to detect coherent
tunneling of the Neel vector in these rings. The location of the NMR/ESR
resonances gives the tunnel splitting and its linewidth an upper bound on the
decoherence rate of the electron spin dynamics. We illustrate the experimental
feasibility of our proposal with estimates for Fe_10 molecules.
