5 mmbb 1h

UV–vis
spectra were recorded
on a Cary 8454 spectrophotometer. ¹H NMR spectra were recorded
on a 400 MHz Bruker Avance III HD spectrometer (equipped with a 5-mm
BB/¹H SmartProbe) at a temperature of 298 K in tetrahydrofuran
(THF)-d₈ and referenced to residual THF
protons at 3.48 and 2.37 ppm. High-resolution (HR) mass spectra were
recorded (typically in the positive-ion mode) on a Thermo LTQ Orbitrap
XL spectrometer equipped with an electrospray ION MAX source. Elemental
analyses were performed by Atlantic Microlab, Inc.
Cyclic voltammetry
was carried out at 298 K with an EG&G model 263A potentiostat
having a three-electrode system: a glassy carbon working electrode,
a platinum wire counterelectrode, and a standard calomel reference
electrode (SCE). Tetra-n-butylammonium perchlorate,
recrystallized twice from absolute ethanol and dried in a desiccator
for at least two weeks, was used as the supporting electrolyte. Anhydrous
CH₂Cl₂ (Sigma-Aldrich) was used as a solvent.
The reference electrode was separated from the bulk solution by a
fritted-glass bridge filled with a saturated AgCl/KCl mixture. The
electrolyte solution was purged with argon for at least 2 min, and
all measurements were carried out under an argon blanket. All potentials
were referenced to the SCE.

UV–visible spectra were recorded on an HP 8453 spectrophotometer. ¹H NMR spectra (298 K, CDCl₃) were recorded on a 400 MHz Bruker Avance III HD spectrometer equipped with a 5-mm BB/1H SmartProbe and referenced to residual CHCl₃ at 7.26 ppm. High-resolution electrospray-ionization (HR-ESI) mass spectra were recorded from methanolic solution on an LTQ Orbitrap XL spectrometer.

UV–visible
spectra
were recorded on an HP 8454 spectrophotometer. ¹H NMR spectra
were recorded on a 400 MHz Bruker AVANCE III HD spectrometer equipped
with a 5 mm BB/1H SmartProbe and referenced to either residual CH₂Cl₂ at 5.32 ppm or residual CHCl₃ at
7.26 ppm. High-resolution electrospray-ionization mass spectra were
recorded on an Orbitrap Exploris 120 spectrometer using methanolic
solutions.
Cyclic voltammetry was carried out at ambient temperature
with a Gamry Reference 620 potentiostat equipped with a three-electrode
system: a glassy carbon working electrode, a platinum wire counter
electrode, and a saturated calomel reference electrode (SCE). Tetra(n-butyl)ammonium perchlorate (CAUTION!)
was used as the supporting electrolyte. Anhydrous CH₂Cl₂ (Aldrich) was used as the solvent. The electrolyte solution
was purged with argon for at least 2 min prior to all measurements,
which was carried out under an argon blanket. All potentials were
referenced to the SCE.