Comparison of Magnetic Deflection among Neutral Sodium-Doped Clusters: Na(H₂O)_n , Na(NH₃)_n , Na(MeOH)_n , and Na(DME)_n

Using a pulsed Stern-Gerlach deflection experiment, we present the results of a comparative study on the magnetic properties of neutral sodium-doped solvent clusters Na(Sol)(n) with n = 1-4 (Sol: H2O, NH3, CH3OH, CH3OCH3). Experimental deflection ratios are compared with values calculated from molecular dynamics simulations. NaNH3 and NaH2O are deflected as a spin 1/2 system, consistent with spin transitions occurring on a time scale significantly longer than 100 mu s. For all other clusters, reduced deflection is observed. The observed magnetic deflection behavior is correlated to the number of thermally populated rotational states in the clusters. We discuss that spin-rotational couplings allow for avoided crossings and a reduction in the effective magnetic moment of the cluster. This work attempts to understand the evolution of magnetic properties in isolated weakly bound clusters and is relevant to diamagnetic and paramagnetic species expected to exist in solvated electron systems.