The FTIR absorption spectrum of the solid state compound was
recorded from KBr pellets in the 4000–400 cm
1
frequency range
with a Perkin–Elmer GX1 Fourier Transform infrared instrument.
The corresponding Raman dispersive spectrum was measured in
the 3500–50 cm
1
interval with a Thermoscientific DXR Raman
microscope. The Raman data were collected (at 5 cm1
spectral
resolution) using a diode-pump solid state laser of 532 nm wavelength, a con-focal aperture of 25lm pinhole and 10x objective.
The sample was placed on gold-coated sample slides. To achieve
a sufficient signal to noise ratio, 30 spectral scans of 2 s each were
accumulated during the measurements with the laser power maintained at 10 mW. UV–Vis measurements were recorded using
quartz cells (10 mm optical path length) on a Beckman/DU 7500
spectrophotometer. For this purpose, a solution of 10
4
mol/L of
the complex in DMSO was prepared. The spectrum was recorded
between 800 and 200 nm. Calorimetric measurements were performed using a differential scanning calorimeter Perkin Elmer
Pyris DSC 6. The experiments were carried out using 3.980 mg of
powdered sample sealed in aluminum pans with a mechanical
crimp. Temperature and heat flow calibrations were made with
standard samples of indium by using its melting transition.
Enthalpy changes associated with the dehydration of the sampl