Synthesis, Characterization, and Structural Studies of In(C5H4Me) by X-ray Diffraction and Electron Diffraction Techniques and a Reinvestigation of the Crystalline State of In(C5H5) by X-ray Diffraction Studies
Beachley, OT, Jr; Pazik, JC; Glassman, TE; Churchill, MR; Fettinger, JC; Blom, R
The compound In(C5H4Me) has been prepared from InCl and Li(C5H4Me) in diethyl ether and fully characterized according to its physical and solubility properties, reaction with dilute HCl, a cryoscopic molecular weight study in cyclohexane, infrared and 1H NMR spectroscopic properties, an X-ray structural study, and a gas-phase electron diffraction study. In addition, a quantitative X-ray structural study has been used to reinvestigate the nature of the solid state of In(C5H5). The compound In(C5H4Me) crystallizes in the centrosymmetric space group P21/n (No. i4, variation) with a = 6.1636 (14) Å, b = 11.5684 (17) Å, c = 9.1723 (15) Å, β = 103.561 (15)°, V = 635.78 (19) Å3, and Z = 4. Diffractometer data (Mo Ka, 2θ = 4.0-50.0°) were collected, and the structure was refined to RF = 4.0% and RwF = 3.9% for all 1115 independent reflections. The parent compound In(C5H5) crystallizes in the acentric monoclinic space group Cc (No. 9) with a = 9.1480 (2) Å, b = 10.0875 (19) Å, c = 5.9116 (25) Å, β = 102.795 (26)°, V = 531.98 (27) Å3, and Z = 4. Diffractometer data (Mo Kα, 2θ = 5.0-55.0°) were collected, and the structure was refined to RF = 4.4% and RwF = 5.3% for all 1226 independent reflections. Each structure consists of zigzag chains of InCp units (Cp = C5H5 or C5H4Me) in which indium atoms interact with each side of the Cp ring and two Cp rings interact with each indium atom. For In(C5H5), the centroid-In-centroid' angle is 128.02°, the In-centroid-In' angle is 176.99° (centroid = centroid of carbocyclic C5 system), and In-C distances are 2.853 (22)-3.091 (21) Å; for In(C5H4Me), the centroid-In-centroid' angle is 130.66°, the In-centroid-In' angle is 179.74°, and In-C distances are 2.800 (5)-2.924 (5) Å. Weak interchain In-In interactions at 3.986 (1) Å are observed for both In(C5H5) and In(C5H4Me), although they crystallize in different space groups. The molecular structure of In(C5H4Me) in the gas-phase consists of discrete monomeric units with the indium(I) atom being situated above the ring centroid. The available data permit comparisons of the properties and structural parameters of In(C5H5), In(C5H4Me), and In(C5Me5). 1988, American Chemical Society. All rights reserved.