The title compound, [ZrCl 3 (C 19 H 25 N 2 Si)(C 4 H 8 O)], was prepared from bis(N,N-dimethylamido-N)(2-{2-[(1,2,3,3a,-7a-)-indenyl]-2-methylpropyl}-1H-imidazolido-N 1)zirconium(IV) [(C 16 H 16 N 2)Zr(NMe 2)] by reaction with excess Me 3 SiCl in tetrahydrofuran (THF) at elevated temperature. The crystal studied contained a minor non-merohedral twin contaminant [6.3 (4)%] which was taken into account during the refinement. The coordination polyhedron of the Zr IV atom is a distorted octahedron [assuming that the five-membered ring of the indenyl group (Cp) occupies one coordination site], with the Cp group and a THF O atom at the apical positions and the three Cl and ligating N atoms at the equatorial positions. The Zr, Si and the methylene C atoms deviate noticeably from the imidazole ring plane [by À0.197 (5), À0.207 (5) and 0.119 (6) Å , respectively]. The THF ligand adopts an envelope conformation. Related literature For general practical utility of geometry-constrained complexes, including those derived from group 4 transition metals, see: Erker (2006); Braunschweig & Breitling (2006).