Av400

All manipulations were performed under a nitrogen atmosphere using standard Schlenk techniques. All solvents used for catalysis were dried over and distilled from sodium (toluene) or CaH₂ (dichloromethane, hexane, ethyl acetate, methanol). All the cobalt-porphyrin catalysts [Co^II(P1)], [Co^II(P2)] [Co^II(P3)], and N tosylhydrazone sodium salts were synthesized according to published procedures.^{7a (link),8 (link),11 (link)} All the alkynes were used as purchased from Aldrich. All other chemicals were purchased from commercial suppliers and used without further purification. NMR spectra (¹H and ¹³C) were measured on a Varian INOVA 500 MHz (125 MHZ for ¹³C), a Bruker AV400 (100 MHZ for ¹³C) or a Varian MERCURY 300 MHz (75 MHZ for ¹³C) spectrometer. Mass spectra of the newly synthesised compounds were recorded in Agilent-5973 GC-MS spectrometer the corresponding HRMS data were recorded on JEOL AccuTOF 4G via direct injection probe. Elemental analysis of the newly synthesized complexes were performed by the Mikroanalytisches Laboratorium Kolbe, Germany. EPR spectra were recorded on a Bruker EMXplus spectrometer.