Triple-meso helices as alcohol reservoirs and discriminators: structural properties and thermal behaviors of silver(i) coordination molecular braids containing diethylbis(4-pyridyl)silanes

Abstract

Self-assembly of silver triflate with L in alcohol solvent produces characteristic triple-meso helices [Ag₃(L)₃(ROH)](CF₃SO₃)₃ (L = diethylbis(4-pyridyl)silane; R = Me, Et, n-Pr, and n-Bu) with six units in each turn. Their unit cell volumes are sensitive to the size of the coordinated alcohol molecules. An unusual “alcohol molecules at triple-meso helices” system is a characteristic reversible alcohol container and discriminator via appropriate association/dissociation. The meso helical solids are favored in the order MeOH > EtOH > n-PrOH > n-BuOH via an interaction between the silver(I) ion and the alcohol molecule. The crystals evaporate the coordinated alcohol molecules at low temperatures, and finally calcination at 600 °C produces micro-sized chaotic surface materials consisting of silver(0) without silicon(IV) oxide.