Communications
ADVANCED MATERIALSsured reflections in the range 2 I 0 I 26'. 962 symmetry-independent reflections with I > 3 0 (I) used, without absorption correction ( p = 4.6 cm-I), in the structure solution (direct methods: SHELX-86) and least-squares refinement (SHELX-76) of 109 parameters. S and C atoms relined anisotropicdlly; H atoms, located in AFmaps, refined isotropically through some least squares cycles, and then held fixed. R = 0.029