Ifs 66 s spectrometer

FTIR spectra in the area of carbonyl valence vibrations (between wave numbers ν = 1600 and 1760 cm⁻¹) of the investigated samples were recorded using a IFS-66/S spectrometer (Bruker, Germany) with spectral resolution of 1 cm⁻¹. The spectra were normalized with respect to the band at 2860 cm⁻¹, corresponding to symmetric vibrations of aliphatic –CH₂ groups [24 ].

Melting points were determined with a Reichert Thermovar apparatus and are uncorrected (Reichert Technologies, Buffalo, NY, USA). Optical rotations were determined at room temperature on a Perkin Elmer 343 polarimeter (Perkin Elmer, Waltham, MA, USA). IR spectra were taken in a Bruker IFS 66/S spectrometer. NMR spectra were run on a Bruker AMX-500 spectrometer with pulsed field gradient using the solvent (CDCl₃) as internal standard (Bruker Corporation, Billerica, MA, USA). EIMS and exact mass measurements were recorded on a Micromass Autospec instrument at 70 eV. Preparative and semipreparative HPLC was carried out with a Beckman Coulter 125P equipped with a diode-array detector Beckman Coulter 168 (Beckman Coulter Life Sciences, Brea, CA, USA) and preparative Interstil Prep-sil 20 mm × 250 mm, 10 µm particle size (Gasukuro Kogio, Shinjuku-ku, Tokyo, Japan) and semipreparative Ultrasphere silica 10 mm × 250 mm, 5 µm particle (Beckman Coulter Life Sciences, Brea, CA, USA) size columns. Silica gel 60 F₂₅₄ (Merck 105715, Darmstadt, Germany) and Sephadex LH-20 (Sigma-Aldrich, St. Louis, MO, USA) were used for column chromatography. Computational analysis was carried out with the Hyperchem 7.0 program applying the Polak-Ribiere minimization algorithm.

All spectroscopic measurements have been performed with an IFS 66/S spectrometer (Bruker) using the ATR-FTIR technique. For the spectroelectrochemical cell, shown schematically in Figure 1, we used ZnSe/Pt/studied material as a WE, Pt electrode as a CE and an Ag/AgCl electrode as a QRE. ZnSe was covered with a thin layer of Pt (≈7 nm) serving as IR-transparent electrode for contacting the WE. We used the same electrolyte solution as mentioned above, which flows through the cell during the measurement.
We changed the potential for P3HT between 0 mV and 600 mV in steps of 100 mV and for quinacridone from 0 mV to 1300 mV, also in steps of 100 mV. We plotted the spectra as −log(T_ox/T_ref), where T_ref is the spectrum obtained at 0 mV for quinacridone and P3HT, respectively, and all other related spectra during oxidation are denoted as T_ox.