Isoreticular Crystallization of Highly Porous Cubic Covalent Organic Cage Compounds**

Abstract

Modular frameworks featuring well-defined pore structures in microscale domains establish tailor-made porous materials. For open molecular solids however, maintaining long-range order after desolvation is inherently challenging, since packing is usually governed by only a few supramolecular interactions. Here we report on two series of nanocubes obtained by co-condensation of two different hexahydroxy tribenzotriquinacenes (TBTQs) and benzene-1,4-diboronic acids (BDBAs) with varying linear alkyl chains in 2,5-position.n Butyl groups at the apical position of the TBTQ vertices yielded soluble model compounds, which were analyzed by mass spectrometry and NMR spectroscopy. In contrast, methyl-substituted cages spontaneously crystallized as isostructural and highly porous solids with BET surface areas and pore volumes of up to 3426 m 2 g −1 and 1.82 cm 3 g −1 . Single crystal X-ray diffraction and sorption measurements revealed an intricate cubic arrangement of alternating micro-and mesopores in the range of 0.97-2.2 nm that are fine-tuned by the alkyl substituents at the BDBA linker. File list (8) download file view on ChemRxiv 2021_02_Ivanova_manuscript_ChemRxiv.pdf (3.17 MiB) download file view on ChemRxiv 2021_02_Ivanova_SI_ChemRxiv.pdf (9.00 MiB) download file view on ChemRxiv ek20_sq-finalcif.cif (3.79 MiB) download file view on ChemRxiv ek27_sq-finalcif.cif (2.93 MiB) download file view on ChemRxiv si30_sq-finalcif.cif (1.64 MiB) download file view on ChemRxiv 2Me_channel.mp4 (2.20 MiB) download file view on ChemRxiv 2Et_channel.mp4 (2.33 MiB) download file view on ChemRxiv 2nBu_channel.mp4 (2.64 MiB)

Isoretikuläre Kristallisation von hochporösen kubischen kovalentorganischen Käfigverbindungen**

“…Die daraus resultierende, extrem schwache Beugungskraft dieser Verbindungen erforderte Synchrotronstrahlung fürdie Strukturaufklärung. [41] An der makromolekularen Strahllinie P11 am DESY (Hamburg) [42] bei einer gewählten Wellenlänge zwischen 0.77 und 0.98 wurde eine experimentelle Auflçsung zwischen 1.3 und 1.4 erreicht, die gerade noch füre ine Ab-initio-Strukturlçsung mit SHELXT ausreichte. [43] Für 2-Me und 2-Et wurden die Käfigmoleküle in der nachfolgenden Verfeinerung vollständig modelliert.…”

Chiral proline-substituted porous organic cages in asymmetric organocatalysis

“…Porous organic cages (POC), [16][17][18][19][20][21][22][23][24][25] which are assembled by individual organic molecules with guest-accessible intrinsic cavities, have shown vigorous development trends in many elds, such as gas storage and separation, [26][27][28][29][30][31][32] sensing, [33][34][35][36] hostguest chemistry, [37][38][39][40][41] and catalyst supports. [42][43][44][45][46][47] Compared with extended porous frameworks, POCs have clear advantages in solution processing, regeneration and functionalization.…”

Enantioselective assembly and recognition of heterochiral porous organic cages deduced from binary chiral components

“… 3 Their advantages originate from the intrinsic and extrinsic voids together with the functional groups attached on POCs. Thus far, molecular POCs are mainly formed from the self-assembly of discrete reactive building blocks driven by dynamic covalent chemistry (DCC) including the reactions of boronic acid condensation, 4 imine condensation, 5 and alkyne/alkene metathesis. 6 In particular, various amine- and aldehyde-decorated building blocks are available to assemble POC molecules with different cavities, dimensions, and topologies.…”