  Molecular Nanomagnets have attracted the attention of the scientific
community since the rich physics behind their magnetic behaviour make them
ideal test-beds for fundamental concepts in quantum mechanics. Sophisticated
experiments and targeted research activities have also unveiled their potential
for several technological applications. Inelastic neutron scattering is a
powerful and widely used technique to investigate the properties of these
systems. The new generation of spectrometers, equipped with arrays of
position-sensitive detectors, enable to efficiently measure the neutron
cross-sections as a function of energy and of the three component of the
momentum transfer vector Q, in vast portions of the reciprocal space.
Exploiting these capabilities together with the availability of sufficiently
large single-crystal samples of MNMs, it is now possible to obtain an
unprecedented insight into the coherent spin dynamics of these molecular
clusters. This is witnessed by several recent results, that we present in this
review. By using the benchmark system Cr$_8$, it has been demonstrated that the
richness of the four-dimensional inelastic neutrons scattering technique
enables to extract dynamical correlation functions directly from the data. This
technique has been also applied to the archetypical single-molecule magnet
Mn$_{12}$ to unambiguously characterise its Spin Hamiltonian as well as to
portray the entanglement between molecular qubits in (Cr$_7$Ni)$_2$.
