Reversible Accommodation and Desorption of Aromatics on a Charge Transfer Cocrystal Involving an Anthracene Derivative and TCNQ
作者：Wu, Xiaojuan; Wang, Mingliang; Du, Man; 等.
關鍵字：Charge Transfer Cocrystal
論文來源：期刊
發表時間：2015年
A charge transfer organic cocrystal 1 was constructed from an anthracene derivative, 1-(5-(anthracen-9-yl)-3-(4-methoxyphen-yl)-4,5-dihydropyrazol-1-yl)ethanone (AMPE) and TCNQ. Eight cocrystal solvates which can be placed into types I and II were obtained from solution. Type I solvates include 1·toluene, 1·chlorobenzene, 1·o-chlorotoluene, 1·p-chlorotoluene, 1·o-xylene, 1·m-xylene, and 1·p-xylene-1, while 1·p-xylene-2 belongs to type II solvate. Crystal structure analysis revealed that cocrystal 1 was an isomorphic desolvate of type I solvates. Slitlike channels were created in 1 through charge transfer, hydrogen bond, and π–π interactions, which are expanded in corresponding type I solvates, while the type II solvate shows a different structure from that of type I solvates. The neighboring racemic chains were connected by one kind of p-xylene molecules through C–H···π interactions and formed square-grid channels. Cocrystal 1 selectively accommodates aromatic solvents over other polar and nonpolar nonaromatic solvents such as acetone, CH2Cl2, and cyclohexane to form type I solvates. These solvates converted to 1 again upon desolvation, and the transformation occurs in a crystal-to-crystal manner. Type II solvate (1·p-xylene-2) can also be converted to 1 upon desolvation, but 1 cannot accommodate p-xylene to form the type II solvate again. This result can be used to certify the conversion from 1 to type I solvates by the absorption mechanism.