We began our study by interrogating the photophysical behavior of 1a via steady-state absorption and emission spectroscopies. 1a showcases four absorption bands at 314, 405, 476, and 631 nm, which explains the intense dark green color observed in MeCN solutions. These are assigned to Bi(I)→(N,C,N) MLCT transitions. 1a is weakly emissive in MeCN at 25 °C, with a maximum at 815 nm (12270 cm -1 , 1.5 eV) and a shift of only ~ 3600 cm -1 or 0.45 eV from the lowest absorption maximum at 630 nm (15830 cm -1 , 1.95 eV) (Figure ). The λmax and emission bandshapes were independent of the excitation wavelength (see Figure in the Supporting Information), and the excitation spectrum tracks well with the absorption spectrum. This suggests that, irrespective of the excitation wavelength, the most important deactivation channels of high-energy excited states funnel to the same emissive excited state, in accordance with Kasha's rule. This helps rationalize previous observations that 1a displays the same reactivity with wavelengths ranging from 450 to 660 nm. Broadness of the emission bandshape suggests a {Bi II (NCN •-)} MLCT origin for this excited state. An emission quantum yield of 3 × 10 -5 was determined via comparative actinometry with [Ru(bpy)3] 2+ using 475 nm excitation. This indicated that non-radiative deactivation to the ground state outcompeted emission, in line with the energy-gap law for low-energy MLCT excited states. The charge-transfer nature of the emissive excited state was examined using spectroelectrochemistry and femtosecond transient-absorption spectroscopy (fsTAS). This conceptually rests on interpreting the transient absorption spectrum of the {Bi II (NCN •-)} MLCT excited state (discussed next) as a linear combination of the oxidized and reduced forms of the ground state. In order to interrogate the potential Bi(II) character of the excited state, the spectroscopic fingerprints of Bi(I) upon oxidation were investigated. The cyclic voltammogram (CV) of 1a in MeCN, recorded under anaerobic conditions reveals a quasi-reversible redox couple centered at E1/2 = -0.85 V vs. Fc +/0 , attributed to the Bi(I)/Bi(II) redox process (see Figures and in the Supporting Information). Subsequently, spectroelectrochemical experiments were performed via controlled potential electrolysis (CPE) until a stable spectrum for Bi(II) was obtained. Figure illustrates the in-situ evolution of the UV-Vis spectrum during an anodic applied potential, with the spectral progression monitored simultaneously. During oxidation to Bi(II), a clear increase in absorbance at 410 nm is observed, accompanied by a significant decrease in the feature at 314 nm and the disappearance of bands at 476 and 631 nm. Additionally, isosbestic points are noted at 335 and 450 nm, indicating a clean Bi(I)to-Bi(II) transformation. The application of a reductive potential cleanly restores the original Bi(I) spectrum, confirming the chemical reversibility of the redox process and the stability of both species. Next, fsTAS in MeCN at 25 °C was utilized to study the excited-state dynamics (Figure ). Excitation of 1a at 600 nm afforded differential spectra with minima at 405, 475 and 635 nm corresponding to ground-state bleaching (see also Figure in the Supporting Information). Additionally, maxima at 360, 430 and 530 nm were observed. During the observation time window, differential spectra evolved slightly, with a minor hypsochromic shift of the λmax at 360 nm to 350 nm. This indicated that no major changes in the electronic configuration take place during excitedstate decay. We posit that the spectral feature at 430 nm observed using fsTAS corresponds to the feature at 410 nm observed during anodic spectroelectrochemistry experiments. Therefore it is diagnostic of the formation of a species with Bi(II) character in the excited state, confirming its {Bi II (NCN •-)} MLCT nature. Global fitting of the data afforded three exponential decays, with lifetimes of 2.2 ps, 58 ps and 9.1 ns. An all-sequential target model was considered to fit the data, and the corresponding species-associated differential spectra are shown in Figure . Upon excitation, a vibrationally hot MLCT is populated (Figure , blue line), which undergoes intersystem crossing to a vibrationally hot 3 MLCT with τ = 2.2 ps (Figure orange line). This state cools down in 58 ps populating the emissive MLCT, which showed a lifetime of 9.1 ns (Figure , black line). The lifetime of the key emissive excited state is consistent with the ability of 1a to engage in bimolecular reactivity. In line with steady-state spectroscopy measurements, excitation at 400, 475 or 660 nm afforded very similar results (Figures S31-S34 in the Supporting Information). This revealed that all the processes originating from Franck-Condon excited states to hot 1 MLCT are faster than our time resolution (ca. 150 fs). Furthermore, the concentration of 1a played no role in the range of 0.1-0.4 mM, indicating the absence of self-quenching processes in this concentration range.