Ag ₂ CO ₃ ‐Mediated Oxidative Access to Calix[4]Diphenoquinones: Synthesis, Conformational Features, and Cavity Encapsulation

Calix[4]diphenoquinones represent a promising class of redox-active macrocycles with potential applications in supramolecular chemistry and functional organic materials, yet their systematic synthesis and structural characterization have remained limited. Here, we report a mild and efficient Ag₂CO₃-mediated oxidation strategy that enables the near-quantitative synthesis of DPQ1∼4. Electrochemical measurements reveal well-defined quinone redox behavior and LUMO levels around -4.0 eV, indicative of air-stable electron-transporting characteristics. NMR analyses demonstrate tunable conformations, with most intermediates adopting cone arrangements, whereas DPQ3 and DPQ4 preferentially form 1,3-alternate structures due to intramolecular hydrogen bonding or steric effects. Single-crystal analysis further shows that DPQ2 assembles into a chair-like 1,3-alternate macrocycle capable of encapsulating an ethanol molecule.