giving a brown solution. The residue could be digested with
acetone to extract more material (about 30%). Both the fractions
were essentially the same.
UV/Vis spectra were recorded with a Perkin–Elmer
Lambda 25 spectrometer and FT-IR spectra were recorded
with a Perkin–Elmer Spectrum One instrument using 5%(by
weight) KBr pellets. Drop-cast films on carbon-coated grids
were imaged by transmission electron microscopy (Philips
CM12, 120 keV as well as JEOL 300 keV). Powder X-ray
diffraction data were collected with a Shimadzu XD-D1 diffractometer
with Cu Kα radiation (30 kV, 20 mA).