Benzene d6

Unless otherwise noted, all reactions were carried out in a nitrogen filled glovebox. All materials were purchased from Sigma-Aldrich and used without purification. Benzene-d₆ and toluene-d₈ were purchased from Cambridge Isotope Labs and dried over NaK prior to being vacuum distilled. Dichloromethane-d₂ was also purchased from Cambridge Isotope Labs and dried over CaH₂ prior to being vacuum distilled.
Other solvents were purchased from Fischer and dried using a “Grubbs type” Seca Solvent System installed by Glass-Contour. Tp^tBuCu^II-OCH₂CF₃,^{5 (link)} [Tp^tBuCu^I]₂,¹⁴ Tp^tBuZn^II-OTf,^{23 (link)} Tp^tBuZn^II-Cl,^{24 t}Bu₂-NO₂-ArO–H,^{25 t}Bu₃ArO^•,^{15 t}Bu₂NPArO^•,^{16 (link)} and TEMPO–H^{26 (link)} were prepared following published synthetic protocols. All glassware was dried in an oven at 150 °C overnight and pumped into a nitrogen filled glovebox while still hot.

All manipulations except ligand synthesis were performed inside an N₂-filled Innovative Technologies glovebox. Tetrahydrofuran (THF), benzene, toluene, and n-hexane were purchased from Sigma-Aldrich, dried under Ar using a solvent purification system (Innovative Technologies), transferred to the glovebox, and stored over activated 3A molecular sieves. Benzene-d₆, toluene-d₈, and THF-d₈ (Cambridge Isotope Laboratories) were distilled over CaH₂ or with Na/benzophenone and then degassed and stored over 3 A molecular sieves. ¹H Nuclear Magnetic Resonance (¹H NMR) spectra were recorded on a 500 MHz Varian Inova spectrometer or a 300 MHz Mercury spectrometer equipped with a three-channel 5 mm indirect detection probe with z-axis gradients. Chemical shifts were reported in δ (ppm) and were referenced to solvent resonances: δH = 7.26 ppm (CDCl₃), 7.16 ppm (C₆D₆), 2.09 ppm (C₇D₈), and 3.58 ppm (C₄D₈O). Fourier Transform Infrared (FT-IR) spectra were recorded as solids on a Thermo Fisher iS5 instrument equipped with an ATR diamond crystal stage using OMNIC software package. 2,4,6-heptatrione was synthesized following the literature procedure.²⁹

All manipulations except ligand synthesis were performed inside an N₂-filled Innovative Technologies glovebox unless otherwise stated. Tetrahydrofuran (THF), benzene, toluene, and n-hexane were purchased from Sigma-Aldrich, then dried using an Innovative Technologies solvent purification system, transferred under an inert atmosphere to the anaerobic chamber, and stored over activated 3 Å molecular sieves for at least 24 h prior to use. Benzene-d₆, toluene-d₈, and THF-d₈ were purchased from Cambridge Isotope Laboratories, dried over CaH₂ or Na/benzophenone under reflux, then distilled, degassed and stored over 3 Å molecular sieves.
¹H Nuclear Magnetic Resonance (¹H NMR) spectra were recorded on a 500 MHz Varian Inova spectrometer or a 300 MHz Mercury spectrometer equipped with a three-channel 5 mm indirect detection probe with z-axis gradients. Chemical shifts were reported in δ (ppm) and were referenced to solvent resonances of δH = 7.16 ppm for benzene-d₆, 7.01 ppm for toluene-d₈, and 3.58 ppm for THF-d₈. Fourier Transform Infrared (FT-IR) spectra were recorded as solids on a Thermo Fisher iS5 instrument equipped with an ATR diamond iD7 stage and operated by the OMNIC software package. H₃L¹, Fe₃Br₃L¹ (1),^{38 (link)} Fe₃H₃L¹ (2),^{29 (link)} and 1,3,5-tri(bromomethyl)-2,4,6-trimethoxybenzene^{39 (link)} were prepared following the previous literatures.