摘要:
X-ray diffraction analyses of dimethyl ansa-metallocenes (CH3)(2)C(C5H4)(C29H36)M(CH3)(2) (M = Zr or Hf) have revealed diffuse diffraction bands in the 0kl and h0l single-crystal reciprocal lattice images, but not in the hk0 plane. This is consistent with metallic disorder in two dimensions and constitutes a rare example of diffuse diffraction for an organometallic compound. The metal is apparently partitioned between two sites with a 60:40 occupancy ratio. Structural interpretation of the X-ray data is consistent with a 60:40 ratio of parallel/antiparallel (+z, -z) metallocene pillars dispersed in the x-y directions. Diffuse diffractionalbeit weakeris also observed for the half-metallocene (C29H37)Mn(CO)(3), which occupies parallel/antiparallel pillars in an 80:20 ratio.