1 H NMR spectra were acquired using Varian VNMR-S 400 MHz spectrometer (Palo Alto, USA) with TMS as the internal standard, using deuterated dimethylsulfoxide (DMSO-d6) as a solvent. Samples of 0.1 ±0.001 g were dissolved in 0.6 cm 3 of DMSO-d6 to obtain comparable spectra. 13 C NMR spectra were obtained with the same instrument at 100 MHz. The FT-IR spectra were recorded on IFS 66v/S spectrometer (Bruker Optics, Ettlinger, Germany). The data were sampled from 4000 to 400 cm -1 and visualized using Spectragryph 1.2.13 software.