Synthesis of –CN– linked covalent organic frameworks via the direct condensation of acetals and amines

Li, Zhi Jun; Ding, San‐Yuan; Xue, H. Q.; Cao, Wu; Wang, Wei

doi:10.1039/c6cc00947f

Cited by 55 publications

(61 citation statements)

References 41 publications

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“…In line with the strategy, a one-pot reaction by combining selfassembly and imine condensation was conducted under solvothermal conditions. In 2,9-bis(4-(dimethoxymethyl)phenyl)-1,10-phenanthroline (II), an acetal group 38 is preferred for its good solubility which is beneficial for the self-assembly process; besides, the relatively low reactivity of acetal with amine groups can reduce the crystal nucleation rate to enable good crystals. Once AgBF 4 was added into the suspension of I and II, an immediate colour change was observed indicating the occurrence of self-assembly via coordination.…”

Section: Resultsmentioning

confidence: 99%

Single crystal of a one-dimensional metallo-covalent organic framework

Luo

et al. 2020

Nat Commun

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Although polymers have been studied for well over a century, there are few examples of covalently linked polymer crystals synthesised directly from solution. One-dimensional (1D) covalent polymers that are packed into a framework structure can be viewed as a 1D covalent organic framework (COF), but making a single crystal of this has been elusive. Herein, by combining labile metal coordination and dynamic covalent chemistry, we discover a strategy to synthesise single-crystal metallo-COFs under solvothermal conditions. The single-crystal structure is rigorously solved using single-crystal electron diffraction technique. The noncentrosymmetric metallo-COF allows second harmonic generation. Due to the presence of syntactic pendant amine groups along the polymer chains, the metallopolymer crystal can be further cross-linked into a crystalline woven network.

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Section: Resultsmentioning

confidence: 99%

Single crystal of a one-dimensional metallo-covalent organic framework

Luo

et al. 2020

Nat Commun

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“…Besides changing reaction conditions, yield and crystallinity also can be improved by changing precursors [ 199 , 200 , 201 , 202 , 203 ]. Usually, the building blocks of imine-based and boronate based COFs, cannot be completely dissolved in organic solvents.…”

Section: Developments Of Cofsmentioning

confidence: 99%

“…For the same reason, Yaghi and co-workers used tert -butyloxycarbonyl (Boc) groups to protect amine building blocks to improve the crystallinity of COFs [ 202 ]. Wang and co-workers applied dimethyl acetals and amines prepared imine-linked LZU-20, hydrazone-linked LZU-21 and azine-linked LZU-22 with highly crystalline and good thermal stability [ 203 ].…”

Section: Developments Of Cofsmentioning

confidence: 99%

Covalent Organic Frameworks: From Materials Design to Biomedical Application

et al. 2017

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Covalent organic frameworks (COFs) are newly emerged crystalline porous polymers with well-defined skeletons and nanopores mainly consisted of light-weight elements (H, B, C, N and O) linked by dynamic covalent bonds. Compared with conventional materials, COFs possess some unique and attractive features, such as large surface area, pre-designable pore geometry, excellent crystallinity, inherent adaptability and high flexibility in structural and functional design, thus exhibiting great potential for various applications. Especially, their large surface area and tunable porosity and π conjugation with unique photoelectric properties will enable COFs to serve as a promising platform for drug delivery, bioimaging, biosensing and theranostic applications. In this review, we trace the evolution of COFs in terms of linkages and highlight the important issues on synthetic method, structural design, morphological control and functionalization. And then we summarize the recent advances of COFs in the biomedical and pharmaceutical sectors and conclude with a discussion of the challenges and opportunities of COFs for biomedical purposes. Although currently still at its infancy stage, COFs as an innovative source have paved a new way to meet future challenges in human healthcare and disease theranostic.

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“…While high porosity and sharp PXRD reflections were observed using this method, one-pot deprotection turned out to be challenging. Aldehydes used for COF formation have been protected as acetals 163 and in situ generated by the oxidation of alcohols. 164 The former has been proven to work for imine, azine and hydrazone COFs, while the latter was used in the synthesis of Crystalline Triazine Frameworks (CTFs).…”

Section: Materials Advances Reviewmentioning

confidence: 99%

“…Also, Electrospray Ionization Mass Spectrometry (ESI-MS) measurements did not find aldehyde in the reaction mixture, indicating direct condensation of amine and acetal. 163 Highly crystalline and porous LZU-20, LZU-21 and LZU-22 were synthesized using this method. Alcohols could be used for synthesis of CTF-HUST-C1, CTF-HUST-C5, CTF-HUST-C6 via slow oxidation in DMSO.…”

Section: Materials Advances Reviewmentioning

confidence: 99%