2.2. Instrumental techniques
Different techniques were employed in the characterization of the ligand, coordination compounds and tricyclic derivative synthesized. Elemental analyses were performed with a Perkin Elmer series II CHNS/O 2400 analyzer. Gold concentration was determined with a VISTA-MPX charged-coupled simultaneous ICP-OES spectrometer (inductively coupled plasma optical emission spectrometer), which was measured in mg/L at 242.794 and 267.594 nm. The experiments were carried out in duplicate. Electrospray mass spectra were recorded on a Finnigan TSQ-quantum instrument using an electrospray ionization technique (ESI-MS). The eluent used was the mixture acetonitrile:water 80:20. The UV–visible (UV–vis) spectra were recorded using a Varian CARY 50 UV/vis spectrophotometer. NMR experiments were carried out with a Bruker 300 DPX spectrometer. All spectra were recorded at 21 C, unless otherwise indicated. Temperature was kept constant using a variable temperature unit. The software XWIN-NMR and XWIN–PLOT were used for edition of the NMR spectra. Tetramethylsilane (TMS) or the deuterated solvent residual peaks were used for calibration. In addition 2D 1 H COSY spectra were recorded to confirm the proton assignments. The IR spectra obtained for the products mentioned in this work in the 4000–300 cm1 range were recorded as solid with a Perkin Elmer FT-IR Paragon 1000 spectrophotometer with a single-reflection diamond ATR P/N 10500. Conductivity measurements were carried out with a Philips PW9526 digital conductivity meter for freshly prepared 1 mM solutions in nitromethane (AR grade) at 25 C. The measuring cell consists of two parallel platinum electrodes at a distance of 1 cm.