REAGENTS BASED ON CYCLOPENTADIENYL DERIVATIVES OF THE GROUP-14 ELEMENTS FOR THE SYNTHESIS OF INDIUM(I) DERIVATIVES - CRYSTAL AND MOLECULAR-STRUCTURE OF IN(C5H4SIME3)

Cyclopentadienyl trimethyl derivatives of the group 14 elements (C5H4MMe3, M = Si, Ge, Sn) have been investigated for their effects on indium 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 XH 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 (C52h; No. 14) with a= 9.171 Å, b = 9.910 Å, c = 11.677 Å,?- 97.30 (5)°, V = 1052.6 Å3, and Z = 4. Diffraction data (Mo K α radiation, 2θ = 4.5-50.0°) were collected on a Syntex P21 automated four-circle diffractometer, and the structure was solved and refined to RF- 5.0% and RWF = 4.0% for all 1851 independent reflections (RF = 3.1% and RwF = 3.5% for those 1336 data with |F0| > 6a|.F0|)). 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 Å. Thus, In(C5H4SiMe3) is the first cyclopentadienylindium derivative with no apparent indium-indium interactions. © 1990, American Chemical Society. All rights reserved.