Reticular Synthesis of Covalent Organic Borosilicate Frameworks

Abstract

This paper reports the synthesis and characterization of a new crystalline 3D covalent organic framework, COF-202: [C(C6H4)4]3[B3O6 (tBuSi)2]4, formed from condensation of a divergent boronic acid, tetra(4-dihydroxyborylphenyl)methane, and tert-butylsilane triol, tBuSi(OH)3. This framework is constructed through strong covalent bonds (Si-O, B-O) that link triangular and tetrahedral building units to form a structure based on the carbon nitride topology. COF-202 demonstrates high thermal stability, low density, and high porosity with a surface area of 2690 m2 g-1. The design and synthesis of COF-202 expand the type of linkage that could be used to crystallize new materials with extended covalent organic frameworks.

An assessment of strategies for the development of solid-state adsorbents for vehicular hydrogen storage

“…217 This class of crystalline materials, known as covalent organic frameworks (COFs), now encompasses two-dimensional layered structures and three-dimensional frameworks with various linkages such as B-O, C-N, B-N, and B-O-Si. [217][218][219][220][221] Two-dimensional layered…”

Recent advances on simulation and theory of hydrogen storage in metal–organic frameworks and covalent organic frameworks

“…Although the H 2 uptake amount for MOF-5 at 77 K was reported again later as 1.30 14 wt% at 1.01 bar (1 atm) and 1.51 15 wt% at 1.13 bar, the result was still exciting enough to activate many researchers to study this topic. Representatively, Wong-Foy et al 16 Recently, the Yaghi group also synthesized twodimensional 18,19 and three-dimensional 20,21 covalent organic frameworks (COFs) where the organic building units are held together by strong covalent bonds, such as C-C, C-O, B-O, and Si-C, rather than metal ions to produce the materials. COF-108).…”

Self-templated chemically stable hollow spherical covalent organic framework

“…The hollow spherical COF (DhaTab), reported in this paper, consists of a macroporous inner cavity (pore width 0.5-2 mm) wrapped up by the mesoporous COF shell (width 20-40 nm). It is noteworthy that the application of COFs is still mostly limited to the storage of gas molecules, since most of the COFs synthesized are microporous in nature and their pores are not sizable enough to hold larger guests, such as enzymes [38][39][40] . While examples of mesoporous boronic acid-based COFs have been reported in the literature 41,42 their chemical instability prevents the usage of these materials for the storage of drugs and enzymes 43,44 .…”