System 2000

The presence of the Cp^*Ru⁺ fragment was characterized via Fourier transform infrared spectroscopy (FT-IR, Perkin Elmer System 2000) and X-ray photoelectron spectroscopy (XPS). The XPS spectra were recorded on a VG ESCALAB 220i spectrometer using Mg Kα radiation (1253.6 eV), which was operated at 15 kV and 20 mA. To exclude the effect of [Cp^*Ru(CH₃CN)₃]⁺ residue on the substrate, the substrate was washed with copious amounts of ethanol prior to the measurements. To visualize the Cp^*Ru⁺ fragments on the HOPG surface, we used an atomic force microscope (Digital Instruments NanoScope III) and a scanning tunneling microscope (Digital Instruments NanoScope III). PtIr tips were used in the STM measurements. During the STM measurement, an insulating liquid, 1-phenyloctane (Aldrich Chem.) was used between the tip and the surface to allow high-quality atomic-scale imaging. During operation, the bias voltages and tunneling currents were varied from -10 to -500 mV and from 50 pA to 1 nA, respectively, to obtain high-quality images. A confocal backscattering Raman spectrum with a spot size of approximately 4 μm² was measured using a 40X objective focused through the cell window. Furthermore, 3.2 mW of 633 nm He–Ne laser was used as the excitation source.

The IR spectrum of 3,4,5-tHCA was recorded with the Cary 630 FTIR Agilent Technologies spectrometer (Santa Clara, CA, USA) within the range of 400–4000 cm⁻¹. Spectral resolution was 1 cm⁻¹. Solid sample was measured in the KBr matrix. Raman spectrum was recorded in the range of 4000–100 cm⁻¹ with an FT Raman instrument of the Perkin–Elmer System 2000 (Billerica, MA, USA). Spectral parametersof three other derivatives were compiled on the basis of literature data [24 (link),25 (link),26 (link)]. The UV spectra of derivatives dissolved in methanol were scanned on a DR 5000 HACH UV-Vis spectrophotometer (Loveland, CO, USA) in the wavelength range of 200–400 nm. The concentration of the derivatives was 0.01 mM. The NMR spectrum of the DMSO 3,4,5-tHCA solution was recorded with a Bruker Avance II 400 MHz unit at room temperature. Tetramethylsilane was used as an internal reference. The chemical shift values in the ¹H and ¹³C NMR spectra of the three other derivatives were summarized based on the literature data [24 (link),25 (link),26 (link),27 (link)].

For the purpose of the effect of the plasma on the treatment bags, two different analysis level have been carried out. First, Fourier Transform Infrared (FTIR) measurements were collected to determine if a chemical reaction of the plasma exposed bags had taken place. Chemical changes produced at the surface after plasma treatment were studied using FTIR with Attenuated Total Reflectance (ATR) accessory. FTIR spectra were recorded with Perkin–Elmer System 2000, in the 4000–500 cm^-1 wave-number range with 10 scans at a resolution of 2 cm^-1. Second, X-ray Photoelectron Spectrometry (XPS) analysis was utilized to determine the changes of the chemical composition at the internal surfaces of the sealed bag using the ESCALAB 250 system (Thermo-VG Scientific Co., Ltd., England). The X-ray source was Al Kα (15 kV) at an operating power of 150 W and a 500 μm in spot size.

Infrared spectra were recorded with use of Perkin Elmer System 2000 spectrometer in middle range, i.e., 4000–400 cm^–1. The resolution was set at 2 cm^–1. Drop of fat of 0.05 cm³ volume was placed between ZnSe plates to form film. Instrument was operated by Pegrams software running on Windows 95.