Ft ir 6100 spectrophotometer

The starting materials and solvents
were obtained commercially
and used as supplied. The acetonitrile complexes [ReX(CH₃CN)₂(CO)₃] (X = Cl, Br) were synthesized^{32 (link)} from the corresponding [ReX(CO)₅]
(X = Cl and Br)^{33 (link)} obtained from commercial
[Re₂(CO)₁₀]. Elemental analyses (carbon, hydrogen,
nitrogen, and sulfur) were carried out on a FlashEA 1112 Series microanalyzer.
IR spectra were recorded in the solid phase by attenuated total reflectance
(ATR; 4000–400 cm^–1) on a Jasco FT/IR-6100
spectrophotometer. ¹H NMR spectra were obtained on a Bruker
AMX 400 spectrometer. Mass spectrometry (MS) (positive-ion ESI) was
carried out on a microTOF-Focus (Bruker Daltonics) mass spectrometer.

Reagents and solvents used in this study were of analytical grade purity and purchased from Sigma-Aldrich Chemicals (Buchs, Switzerland) and Alfa Aesar (Karlsruhe, Germany). The progress of all reactions was checked by thin layer chromatography (TLC) using precoated Silica Gel 60F₂₅₄ sheets (Merck, Darmstadt, Germany). The spots on plates were visualized under UV light (254 nm). Melting points (m.p.) were determined using an MPM-H1 melting point apparatus (Schorpp Gerätetechnik, Überlingen, Germany) and are uncorrected. Elemental analyses for C, H, N and S were carried out on a Vario El CHNS instrument (Hanau, Germany). FT-IR spectra were recorded on a JASCO FT-IR-6100 spectrophotometer (Cremella, Italy). ¹H-NMR and ¹³C-NMR analyses were performed on an Avance NMR spectrometer (Bruker, Karlsruhe, Germany), operating at 500 MHz and 125 MHz respectively, in DMSO-d₆, using tetramethylsilane (TMS) as internal standard. Chemical shifts (δ values) are expressed in parts per million (ppm). M + 1 peaks were determined on an Agilent 1100 series and an Agilent Ion Trap SL mass spectrometer (Santa Clara, CA, USA), operating at 70 eV.