EXPERIMENTAL AND THEORETICAL-STUDY OF THE DIPOLE POLARIZABILITY OF FERROCENE FE(C5H5)(2)

The mean dipole-polarizability alpha(omega) of ferrocene at 440 K is o btained from measurements of the gas-phase refractivity [n(rho, omega) - 1] in the frequency range between omega = 0.05 au and 0.14 au. alph a(omega) obtained via quasi-continuous white-light interferometry and from additional absolute measurements at three discrete frequencies (a lpha(0.07198 au) = 131.51(32) au, alpha(0.08383 au) = 133.74(34) au an d alpha(0.14014 au) = 150.7(1.1) au) has been extrapolated to zero fre quency, yielding alpha(0) = 126.2(1.0) au. The experimental results ar e compared to those of time-dependent density functional calculations for the staggered and eclipsed conformers. Good agreement between theo retical and experimental results is found (errors are 1% for the stati c value and 2-4% for alpha(omega)). A large increase in the polarizabi lity anisotropy of 50% in the measured omega range is found Hartree-Fo ck theory fails to predict the correct alpha(0) value. (C) 1997 Publis hed by Elsevier Science B.V.