Silicon-29 and oxygen-17 relaxation in H8Si8O12 in solution

Abstract

Silicon-29 and oxygen-17 NMR relaxation data have been obtained for the spherosiloxane H₈Si₈O₁₂ in perdeuteriocyclohexane solution at 303 and 323 K. The spin–lattice relaxation rates and the nuclear Overhauser enhancement factors for silicon were used to determine the dipole–dipole contributions to the relaxation rates which, together with the known silicon–proton distance, yield the rotational correlation times for the silicon–proton axis. The oxygen linewidths provide the quadrupolar spin–spin relaxation rates, which were used to estimate a quadrupole coupling constant for oxygen-17 of 4.9 ± 0.5 MHz.