IR-SEC of 1 in MeCN. At less negative potentials than the first reduction potential observed (–1.65 V vs Fc/Fc+ in the CV) (black) bands consistent with a pseudo-C3v octahedral fac-rhenium tricarbonyl species are observed. Holding the potential at (–1.64 V), the first reduction (red) quickly passes the single reduced species and instead generates a species consistent with a Re0–Re0 dimer at (1985, 1948, 1896, 1885, and 1851 cm−1) (blue) within ~1 minute. Conditions: 0.1 M TBAPF6/MeCN; 1 mM catalyst. glassy carbon working electrode, Pt counter electrode, bare metal Ag+/Ag pseudoreference electrode.