Selective inclusion of p-xylene by bis-hydrazone compounds

Abstract

Separation of xylene isomers from its mixture is a challenging task. Present study describes highly selective inclusion of p-xylene (now onwards p-XY) from a mixture of xylene isomers by three...

Highly Selective p-Xylene Separation from Mixtures of C8 Aromatics by a Nonporous Molecular Apohost

“…However, despite combining low cost and comparative simplicity, this class of materials remains understudied in the context of C8 separations. It has been reported that nonporous molecular solids, e.g., bishydrazones, 56 can distinguish one isomer from a mixture of C8 aromatics, highlighting the significance of phase transformations and conformational flexibility in adapting host cavities to fit guest molecules. 57 We herein report the C8 aromatic inclusion properties of a hitherto unstudied molecular compound, 4-(1H-1,2,4-triazol-1-yl)-phenyl-1H-benzo[de]isoquinoline-1,3(2H)-dione, TPBD, which was prepared by cocrystal-controlled solid-state synthesis 58−60 (solvent-drop grinding, SDG, 61−63 followed by heating).…”

Versatile Solid-State Inclusion Property of a New Bis-hydrazone Compound

“…On the other hand, solid-state inclusion of molecules containing intrinsic cavities is widely known. – In addition, solid-state inclusion properties have been observed in several host molecules which contain neither a hydrogen bonding functional group nor an intrinsic cavity. – Recently, a new class of van der Waals compounds based on benzophenone bis-hydrazone were reported for solid-state inclusion property. , The conformational flexibility of the terminal aryl rings on both sides of the CN–NC–CN–NC spine and the awkward shape of the molecules might be the driving force for the inclusion property of the compounds. Dwivedi et al reported selective inclusion of para -xylene ( p XY) from a mixture of three isomers of xylene by ethanedial-1,2-bis­(4,4′-dichlorobenzophenone hydrazone), ethanedial-1,2-bis­(4,4′-dibromobenzophenone hydrazone), and ethanedial-1,2-bis­(4,4′- diiodobenzophenone hydrazone) . In addition, 100% selective inclusion of 1,4-dioxane by bis­[2-(diphenylmethylene)­hydrazone] and bis­[2-(ditolylmethylene)­hydrazone] was reported before .…”

“…45−47 Recently, a new class of van der Waals compounds based on benzophenone bis-hydrazone were reported for solid-state inclusion property. 48,49 The conformational flexibility of the terminal aryl rings on both sides of the C�N−N�C−C� N−N�C spine and the awkward shape of the molecules might be the driving force for the inclusion property of the compounds. bis-hydrazone compound butane-2,3-dione 2,3-bis({bis[4-(dimethylamino)phenyl]methylidene}hydrazone) (DMABH) (Scheme 1).…”