Organolanthanoids. XI. The Crystal and Molecular Structures of Two Tris(η⁵-cyclopentadienyl)(pyridine) lanthanoid(III) Compounds

Abstract

The crystal structures of tris (η⁵-cyclopentadienyl) (pyridine) samarium(III), monoclinic, space group P2₁/c, a 10.906(4), b 8.636(2), c 17.825(3) Å, β 96.44(2)º, Z 4, R 0.027 and R_w 0.032 for 3619 'observed' reflections, and tris (η⁵-cyclopentadienyl)(pyridine)neodymium(III), monoclinic, space group P2₁ / c, a 14-206(4), b 8.619(2), c 15.190(7) Å, β 107.38(2)º, Z 4, R 0.035 and R, 0.039 for 2677 'observed' reflections have been determined. Both compounds have pseudotetrahedral geometry with a coordination number of 10 for the lanthanoid metal but there is a difference in the coordination of pyridine and in unit cell packing between the two structures.