Synthesis of oxygen bridged corona[n]arene[n]pyrazines and their fullerene binding property

Oxygen bridged corona[n]arene[n]pyrazines (n = 3, 4, 6) were synthesised conveniently by means of a fragment coupling strategy starting from 2,5-dimethyl-1,4-hydroquinone and 2,5-dibromopyrazine. The acquired novel macrocycles were able to form 1:1 complexes with fullerenes C₆₀ and C₇₀ in toluene at 25 °C with association constants in the range of (5.45 ± 0.02) × 10⁴ M⁻¹ to (2.21 ± 0.05) × 10⁵ M⁻¹.