The rotational dynamics of P4O6S and P4O7 in the solid state were studied b
y means of P-31 NMR spectra of spinning and static powder samples in the te
mperature range of 153-295 K and 295-388 K, respectively. All spectra were
simulated to confirm the type of the motion and to extract the time scales
as a function of the temperature. Good agreement between experimental and t
heoretical data was obtained on the basis of a three-site jump model. For P
4O6S, the activation energy and the pre-exponential factor derived from the
lineshape simulations amount to 51(2) kJ/mol and 6(3).10(15) s(-1). For P4
O7, the spectral analysis yields an activation energy of 67(1) kJ/mol and a
pre-exponential factor of 6(2).10(14) s(-1). The dynamic behavior was chec
ked independently by lineshape analyses under both MAS and static condition
s. Activation energies are consistent within the errors for the lineshape a
nalyses. Additionally, we have analyzed spin-lattice relaxation measurement
s, which show the correct trends for the activation energies. (C) 1999 Else
vier Science B,V. All rights reserved.