Daltonics ultraflex spectrometer

All chemicals were purchased from commercial suppliers, unless otherwise stated. The solvents were purified according to conventional methods [26 ]. Chromatographic purifications were performed with Macherey-Nagel, Silica 60, 0.063–0.2 mm. Merck aluminum plates (TLC Silica 60 F254, Darmstadt, Germany) were used for the TLC analysis, which was performed with dichloromethane/hexane mixtures as eluents.
¹H-NMR spectra of 10^–4 M solutions in CDCl₃ were recorded on a Bruker Avance III spectrometer (Billerica, MA, USA) at a frequency of 600 MHz at 303 K, using the resonance of the residual CHCl₃ as an internal reference (δ = 7.26 ppm). MALDI-TOF mass spectra were recorded on a Bruker Daltonics Ultraflex spectrometer (Billerica, MA, USA) in the positive ion mode without a matrix. UV–vis spectra were recorded on a Thermo Scientific Helios Alpha spectrophotometer (Waltham, MA, USA) in the 250 to 900 nm range using rectangular quartz cells with an optical path length of 0.0882–10 mm.
The free-base 5,10,15,20-tetraphenyl-2-(benzimidazol-2-yl)-porphyrin and 5,10,15,20-tetraphenyl-2-(N,N-dimethylbenzimidazol-2-yl)-porphyrin were prepared following the published procedure [27 (link)].

All solvents were distilled over appropriate drying agents prior to use. All starting reagents were applied from commercial suppliers. Phthalocyanines H₂[(BuO)₈Pc] and H₂[(15C5)₄Pc] [62 (link)] and the oxidizing agent phenoxathiinylium hexachloroantimonate, OxSbCl₆ [38 (link)], were synthesized according to the previously reported procedures.
UV–vis–NIR spectra in the range of 250–3000 nm were measured using a spectrophotometer V-770 (JASCO) in quartz cells with 1 cm optical path. Matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) mass spectra were measured on a Bruker Daltonics Ultraflex spectrometer. Mass spectra were registered in positive ion mode using 2,5- dihydroxybenzoic acid as a matrix. MALDI-TOF mass spectra of synthesized complexes are provided in Supplementary Information (Figures S1, S3, S5 and S7). NMR spectra were recorded using a Bruker Avance III spectrometer with 600 MHz proton frequency in CDCl3 at ambient temperature with the use of the residual solvent resonance as internal reference. NMR spectra of synthesized complexes are provided in Supplementary Information (Figures S2, S4, S6 and S8). Analytical characteristics of the synthesized complexes were in agreement with the previously reported data [63 (link),64 (link)].