Characterization of Organometallic Compounds

NMR spectra were measured on a Bruker Avance 500 DMX spectrometer. ¹H
NMR spectra are reported in ppm relative to SiMe₄ (δ = 0) and were
referenced internally with respect to the protio solvent impurity (δ 7.26 for
CDCl₃ and 2.50 for
Me₂SO-d₅).^{32 (link)13}C NMR spectra are reported in ppm relative to SiMe₄ (δ =
0) and were referenced internally with respect to the solvent (δ 77.16 for
CDCl₃).^{32 (link)} Coupling
constants are given in hertz. IR spectra were recorded in diffuse reflectance (DR) mode on
a Thermo Nicolet 6700 spectrometer (ThermoScientific) equipped with a smart collector
accessory, and the data are reported in reciprocal centimeters. Samples were finely ground
with KBr and a similarly prepared sample of KBr was used to obtain a background spectrum.
All chemicals were purchased from Sigma-Aldrich. [Tm^MeBenz]K was prepared by
the literature method.^{19b (link)}