Electric deflection studies of rhodium clusters

The static electric dipole polarizabilities of rhodium clusters Rh n , n = 5 - 28 , have been measured via a molecular beam deflection method. Uniform high-field beam deflections, indicative of induced polarization, were observed for all Rh n except Rh 7 and Rh 10 which by contrast exhibited beam broadening and anomalously high effective polarizabilities. Analysis of the beam deflection profile of Rh 7 indicates that it possesses a permanent dipole moment of 0.24 ± 0.02 D . Unlike the other clusters in the n = 5 - 28 size range, the polarizability of Rh 10 is observed to decrease with increasing source temperature. We attribute this temperature dependence to paraelectric behavior, suggesting that Rh 10 is a fluxional molecule possessing a dipole moment that spatially fluctuates, uncorrelated with overall rotation.