RESUMO
Finding new ways to construct crystalline multiple-component covalent organic frameworks (COFs) has become an important focus. Herein we report the synthesis of three novel COFs containing a homogeneous and heterogeneous distribution of π-conjugated dehydrobenzoannulene (DBA) vertex units. The COFs were synthesized by reacting different ratios of C3-symmetric DBA catechol monomers with C2-symmetric pyrene-2,7-diboronic acid (PDBA) to yield three COFs, Py-DBA-COF 1, Py-DBA-COF 2, and Py-MV-DBA-COF. All three materials are highly crystalline and display unique luminescent properties in the solid state.
RESUMO
Constructing metalated three-dimensional (3D) covalent organic frameworks is a challenging synthetic task. Herein, we report the synthesis and characterization of a highly porous (SABET = 5083 m2 g-1) 3D COF with a record low density (0.13 g cm-3) containing π-electron conjugated dehydrobenzoannulene (DBA) units. Metalation of DBA-3D-COF 1 with Ni to produce Ni-DBA-3D-COF results in a minimal reduction in the surface area (SABET = 4763 m2 g-1) of the material due to the incorporation of the metal within the cavity of the DBA units, and retention of crystallinity. Both 3D DBA-COFs also display great uptake capacities for ethane and ethylene gas.
RESUMO
Developing novel synthetic strategies to construct crystalline polymeric materials with excellent chemical stability and high carbon capture capacity has become a challenging process. Herein, we report the synthesis of two novel 2D benzobisoxazole-linked covalent organic frameworks (BBO-COFs) utilizing C3-symmetric formyl- and C2-symmetric o-aminophenol-substituted molecular building blocks. The BBO-COFs exhibit excellent water stability, high surface areas, and great CO2 uptake capacities. This general synthetic method affords the opportunity to prepare ordered BBO-based polymeric materials for carbon capture, chemical sensing, and organic electronic applications.