文摘
Two flexible porous coordination materials, [Mn(pybimc)2]路2H2O路G (G = toluene, 1tol; THF, 1thf), where pybimc = 2-(2鈥?pyridyl)-benzimidazole-5-carboxylate, featuring identical one-dimensional chain structure have been characterized. Guest exchange studies have exhibited that 1tol cannot be converted to 1thf through direct replacement of guest toluene molecules by THF molecules, but, of particular interest, 1thf is actually converted to 1tol and 1aromatic (where aromatic = o-, m-, p-xylene) upon the exchange of THF to toluene and other aromatic molecules, respectively. This signifies a single-crystal to single-crystal transformation accompanied irreversible crystal expansion. In-depth analyses reveal that the nature of the weak yet sufficiently strong framework鈥揼uest C鈥揌路路路蟺 interactions, rather than the guest size, observed in this system plays a key role in guiding the adsorption of liquid-phase aromatics in the soft crystalline materials.