Reagents based on cyclopentadienyl derivatives of the group 14 elements for the synthesis of indium(I) derivatives. Crystal and molecular structure of in(C5H4SiMe3)

Article abstract of DOI:10.1021/om00159a017

Cyclopentadienyl trimethyl derivatives of the group 14 elements (C₅H₄MMe₃, M = Si, Ge, Sn) have been investigated for their effects on indium(I) chemistry. The compounds In(C₅H₄SiMe₃) and In(C₅H₄GeMe₃) have been prepared from the corresponding lithium cyclopentadienyl reagent LiC₅H₄MMe₃ and InCl. Characterization data have included partial elemental analyses (C, H), physical properties, IR and ¹H NMR spectroscopic data, oxidation reactions with dilute aqueous HCl, and a single-crystal X-ray structural study in the case of In(C₅H₄SiMe₃). When cyclopentadienyltrimethyltin, C₅H₅SnMe₃, was combined with InCl in diethyl ether, In(C₅H₅) and Me₃SnCl were formed in good yields. In(C₅H₄SiMe₃) crystallizes in the centrosymmetric monoclinic space group P2₁/c (C_2h⁵; No. 14) with a = 9.171 (5) ?, b = 9.910 (6) ?, c = 11.677 (7) ?, β = 97.30 (5)°, V = 1052.6 (11) ?³, and Z = 4. Diffraction data (Mo Kα radiation, 2θ = 4.5-50.0°) were collected on a Syntex P2₁ automated four-circle diffractometer, and the structure was solved and refined to R_F = 5.0% and R_wF = 4.0% for all 1851 independent reflections (R_F = 3.1% and R_wF = 3.5% for those 1336 data with |F_o| > 6σ|F_o|)). The solid-state structure consists of infinite zigzag chains of [In(C₅H₄SiMe₃)]_∞. Each indium atom interacts with two η⁵-C₅H₄SiMe₃ ligands with a centroid?In?centroid angle of 131.78°, and each η⁵-C₅H₄SiMe₃ ligand is linked to two indium atoms with In?centroid?In angles of 175.94°. There are no short interstrand In?In interactions, the shortest such distance being 5.428 ?. Thus, In(C₅H₄SiMe₃) is the first cyclopentadienylindium(I) derivative with no apparent indium-indium interactions.