Synthesis of Cyclometalated Ruthenium Complexes

Benzo[h]quinoline and iodopentoxide, were purchased from Sigma-Aldrich. The formylthiophenes 2-thiophenecarboxaldehyde, 2,2′-bithiophene-5-carboxaldehyde, and 5-[5-(2-thienyl)-2-thienyl]thiophene-2-carbaldehyde were purchased from Maybridge. Ethylene diamine was purchased from Alfa Aesar, and benzaldehyde was purchased from ACP. All of these chemicals were used without further purification. [Ru(bpy)₂Cl₂]·2H₂O was prepared as previously described.¹⁷ The cyclometalating ligands IBQ-nT, where n=1–4, were synthesized from benzo[h]quinoline-5,6-dione¹⁸ and the corresponding formylthiophenes by a method previously reported by us.^{14 (link)} Formyltetrathiophene was synthesized following a published method,^{19 ,20} with full characterization details reported previously by us.^{14 (link)} We are not aware of any unexpected, new, and/or significant hazards or risks associated with the reported work. However, utmost precaution should be taken when working with novel compounds of unknown risk.