The high-resolution Fourier transform spectrum of the m8 CO-stretching band of CH318OH between 900and 1100 cm1 has been recorded at the Canadian Light Source (CLS) synchrotron facility in Saskatoon,and the majority of the torsion–rotation structure has been analyzed. For the mt = 0 torsional ground state,subbands have been identified for K values from 0 to 11 for A and E torsional symmetries up to J valuestypically well over 30. For mt =1, A and E subbands have been assigned up to K = 7, and several mt = 2 sub-bands have also been identified. Upper-state term values determined from the assigned transitions usingthe Ritz program have been fitted to J(J + 1) power-series expansions to obtain substate origins and sets ofstate-specific parameters giving a compact representation of the substate J-dependence. The mt = 0 sub-band origins have been fitted to effective molecular constants for the excited CO-stretching state and atorsional barrier of 377.49(32) cm1 is found, representing a 0.89% increase over the ground-state value.The vibrational energy for the CO-stretch state was found to be 1007.49(7) cm1. A number of subband-wide and J-localized perturbations have been seen in the spectrum, arising both from anharmonic andCoriolis interactions, and several of the interacting states have been identified. 2009 Elsevier Inc. All rights reserved.