Donglin Jiang

National University of Singapore | NUS · Department of Chemistry

Covalent organic frameworks with unique π architectures and pores could be developed as photocatalysts for transformations. However, they usually form π‐stacking layers, so that only surface layers function in photocatalysis. Here we report a strategy for developing vertically expanded frameworks to expose originally inaccessible active sites hidde...

Covalent organic frameworks with unique π architectures and pores could be developed as photocatalysts for transformations. However, they usually form π‐stacking layers, so that only surface layers function in photocatalysis. Here we report a strategy for developing vertically expanded frameworks to expose originally inaccessible active sites hidde...

Covalent organic frameworks are a class of crystalline porous polymers formed by linking organic units into periodically aligned skeletons and pores. Here we report a strategy for wiring these frameworks with conducting polymers via wall engineering and polymerization. We anchored each edge site with one pyrrole unit, which is densely packed along...

Covalent organic frameworks are a class of crystalline porous polymers formed by linking organic units into periodically aligned skeletons and pores. Here we report a strategy for wiring these frameworks with conducting polymers via wall engineering and polymerization. We anchored each edge site with one pyrrole unit, which is densely packed along...

Helicenes represent a class of fascinating π compounds with fused yet folded backbones. Despite their broad structural diversity, harnessing helicenes to develop well‐defined materials is still a formidable challenge. Here we report the synthesis of crystalline porous helicene materials by exploring helicenes to synthesize covalent 2D lattices and...

Helicenes represent a class of fascinating π compounds with fused yet folded backbones. Despite their broad structural diversity, harnessing helicenes to develop well‐defined materials is still a formidable challenge. Here we report the synthesis of crystalline porous helicene materials by exploring helicenes to synthesize covalent 2D lattices and...

Proton conduction is important in both fundamental research and technological development. Here we report designed synthesis of crystalline porous covalent organic frameworks as a new platform for high‐rate anhydrous proton conduction. By developing nanochannels with different topologies as proton pathways and loading neat phosphoric acid to constr...

Proton conduction is important in both fundamental research and technological development. Here we report designed synthesis of crystalline porous covalent organic frameworks as a new platform for high‐rate anhydrous proton conduction. By developing nanochannels with different topologies as proton pathways and loading neat phosphoric acid to constr...

Covalent organic frameworks (COFs) provide a molecular platform for designing a novel class of functional materials with well‐defined structures. A crucial structural parameter is the linkage, which dictates how knot and linker units are connected to form two‐dimensional polymers and layer frameworks, shaping ordered π‐array and porous architecture...

Covalent organic frameworks (COFs) provide a molecular platform for designing a novel class of functional materials with well‐defined structures. A crucial structural parameter is the linkage, which dictates how knot and linker units are connected to form two‐dimensional polymers and layer frameworks, shaping ordered π‐array and porous architecture...

Covalent organic frameworks are a novel class of crystalline porous polymers that enable molecular design of extended polygonal skeletons to attain well‐defined porous structures. However, construction of a framework that allows remote control of pores remains a challenge. Here we report a strategy that merges covalent, noncovalent, and photo chemi...

Covalent organic frameworks are a novel class of crystalline porous polymers that enable molecular design of extended polygonal skeletons to attain well‐defined porous structures. However, construction of a framework that allows remote control of pores remains a challenge. Here we report a strategy that merges covalent, noncovalent, and photo chemi...

Charge transfer and mass transport to catalytic sites are critical factors in photocatalysis. However, achieving both simultaneously is challenging due to inherent trade-offs and interdependencies. Here we develop a microporous covalent organic framework featuring dense donor–acceptor lattices with engineered linkages. The donor–acceptor columnar π...

Helicenes are a class of fascinating chiral helical molecules with rich chemistry developed continuously over the past 100 years. Their helical, conjugated, and twisted structures make them attractive for constructing molecular systems. However, studies over the past century are mainly focused on synthesizing helicenes with increased numbers of aro...

Helicenes are a class of fascinating chiral helical molecules with rich chemistry developed continuously over the past 100 years. Their helical, conjugated, and twisted structures make them attractive for constructing molecular systems. However, studies over the past century are mainly focused on synthesizing helicenes with increased numbers of aro...

Attempts to develop photocatalysts for hydrogen production from water usually result in low efficiency. Here we report the finding of photocatalysts by integrated interfacial design of stable covalent organic frameworks. We predesigned and constructed different molecular interfaces by fabricating ordered or amorphous π skeletons, installing ligatin...

The dream to prepare well-defined materials drives the methodological evolution for molecular synthesis, structural control and materials manufacturing. Among various methods, chemical approaches to design, synthesize, control and engineer small molecules, polymers and networks offer the fundamental strategies. Merging covalent bonds and non-covale...

Assembling molecular catalytic centers into crosslinked networks is widely used to fabricate heterogeneous catalysts but they often suffer loss in activity and selectivity accompanied by unclear causes. Here we report a strategy for the construction of heterogeneous catalysts to induce activity and selectivity by bottom‐up introduction of segregate...

To optimize the optical and optoelectronic functionalities of two-dimensional (2D) covalent organic frameworks (COFs), detailed properties of emissive and nonradiative pathways after photoexcitation need to be elucidated and linked to particular structural designs. Here, we use transient absorption (TA) spectroscopy to study the colloidal suspensio...

Despite rapid progress over the past decade, most polycondensation systems even upon a small structural variation of the building units eventually result in amorphous polymers other than the desired crystalline covalent organic frameworks. This synthetic dilemma is a central and challenging issue of the field. Here we report a novel approach based...

Despite a rapid progress over the past decade, most polycondensation systems even upon a small structural variation of building units eventually result in amorphous polymers other than desired crystalline covalent organic frameworks. This synthetic dilemma is a central and challenging issue of the field. Here we report a novel approach based on mod...

Progress over the past decades in water confinement has generated a variety of polymers and porous materials. However, most studies are based on a preconception that small hydrophobic pores eventually repulse water molecules, which precludes the exploration of hydrophobic microporous materials for water confinement. Here, we demonstrate water confi...

Most organic/polymeric semiconductors are p-type semiconductors, whereas their n-type versions are limited in both availability and carrier mobility. How to develop high-rate n-type organic/polymeric semiconductors remains challenging. Here, we report an approach to high-rate n-type semiconductors via topology-directed polycondensation of conventio...

The ordered π skeletons of covalent organic frameworks make them viable light‐emitting materials but their limited tunability has precluded further implementation. Here we report the synthesis of hydrazone‐linked frameworks which are stable in water, acid, and base, and demonstrate their utility as a platform for light emission. The polygonal backb...

Hydroxide anion transport is essential for alkaline fuel cells, but hydroxide anion has an inherently low conductivity owing to its small diffusion coefficient and high mass. Ordered open channels found in covalent organic frameworks are promising as pathways to enable hydroxide anion transport, but this remains to be explored. Here we report desig...

The ordered π skeletons of covalent organic frameworks make them viable light‐emitting materials but their limited tunability has precluded further implementation. Here we report the synthesis of hydrazone‐linked frameworks which are stable in water, acid, and base, and demonstrate their utility as a platform for light emission. The polygonal backb...

Polybenzimidazoles are engineering plastics with superb thermal stability and this specificity has sparked a wide‐ranging research to explore proton‐conducting materials. Nevertheless, such materials encounter challenging issues owing to phosphoric acid proton carrier leakage and slow proton transport. We report a strategy for designing porous poly...

Covalent organic frameworks (COFs) are a class of crystalline polymers that integrate organic units into 2D and 3D skeletons to achieve ordered yet extended structures via topology-directed polymerization. Recent progress in chemistry over the past 4 years has greatly raised the ability to design the frameworks to attain fully π-conjugated all sp²...

Condensing benzimidazole units via topology-directed polymerization allows the construction of stable covalent organic frameworks with ordered one-dimensional channels. The walls trigger multiple hierarchical interactions so that the proton networks are locked in the pores via spatial confinement and activated via deprotonation. Ultrafast and stabl...

We designed and synthesized A2B2 type tetraphenyl benzene monomers (p‐, m‐, and o‐TetPB) which have the para‐, meta, and ortho‐substituted isomeric structures, for the direct construction of isomeric frameworks. Interestingly, both kagome (kgm) and monoclinic square (sql) framework isomers are produced from either p‐TetPB (C2h symmetry) or m‐TetPB...

Covalent organic frameworks offer a molecular platform for integrating organic units into periodically ordered yet extended 2D and 3D polymers to create topologically well-defined polygonal lattices and built-in discrete micropores and/or mesopores.

A strategy was developed for selective growth of isomeric covalent organic frameworks by designing monomer isomers and tuning reaction conditions. Three A2B2 type tetraphenyl benzene monomers (p‐, m‐, and o‐TetPB) afford five different 2D TetPB‐COF isomers that exhibit selective adsorption of vitamin B12 owing to a great difference in their pore sh...

Covalent organic frameworks (COF) are a class of crystalline porous polymer that enables the covalent integration of organic units into periodically ordered skeletons and aligned polygonal pores. This structural feature sets a new polymer platform that enables the design of not only structures but also functions. Especially, primary- and high-order...

ConspectusNature evolves fascinating molecular pores to achieve unique biological functions based on a single pore or channel as observed for aquaporins and ion channels. An artificial system, on the other hand, explores porous structures to construct dense pores in materials. Progress in chemistry over the past century has greatly improved our cap...

Transformation of carbon dioxide to high value‐added chemicals becomes a significant challenge for clean energy studies. Here a stable and conductive covalent organic framework was developed for electrocatalytic carbon dioxide reduction to carbon monoxide in aqueous solution. The cobalt(II) phthalocyanine catalysts are topologically connected via r...

Heterogeneous catalysts offer a cyclable platform for exploring efficient transformation systems, and their promising applications underpin a broad research interest. Covalent organic frameworks (COFs) are a class of crystalline porous networks that can integrate organic units into ordered skeletons and pores, offering an insoluble and robust platf...

A strategy is presented for the synthesis of crystalline porous covalent organic frameworks via topology‐templated polymerization. The template is based on imine‐linked frameworks and their (001) facets seed the C=C bond formation reaction to constitute 2D sp² carbon‐conjugated frameworks. This strategy is applicable to templates with different top...

Covalent organic frameworks (COFs) enable precise reticulation of organic building units into extended 2D and 3D open networks using strong covalent bonds to constitute predesignable topologies and tunable pore structures, presenting an emerging class of crystalline porous polymers. Although rapid progress and substantial achievements in COF chemis...

Transformation of carbon dioxide to high value‐added chemicals becomes a significant challenge for clean energy study. Here we developed a stable and conductive covalent organic framework for electrocatalytic carbon dioxide reduction to carbon monoxide in aqueous solution. The cobalt(II) phthalocyanine catalysts are topologically connected via robu...

Development of porous materials combining stability and high performance has remained a challenge. This is particularly true for proton-transporting materials essential for applications in sensing, catalysis and energy conversion and storage. Here we report the topology guided synthesis of an imine-bonded (C=N) dually stable covalent organic framew...

Covalent organic frameworks (COFs) enable precise integration of various organic building blocks into porous skeletons through topology predesign. Here, we report the first example of COFs by integrating electron withdrawing bromine group onto the skeletons for triboelectric nanogenerators (TENG). The resulting framework exhibits high surface area...

Attract to plant lattice growth: Imine‐linked covalent organic frameworks (blue) attract organic building blocks on a 2D x−y surface and model C=C bond formation to create 2D sp² carbon lattices with different topologies (yellow). Frameworks are thus formed that cannot be produced by direct polymerization. The synthesis of such lattices leads to kn...

A strategy based on covalent organic frameworks for ultrafast ion transport involves designing an ionic interface to mediate ion motion. Electrolyte chains were integrated onto the walls of one‐dimensional channels to construct ionic frameworks via pore surface engineering, so that the ionic interface can be systematically tuned at the desired comp...

Covalent organic frameworks (COFs) are a class of crystalline porous organic polymers with permanent porosity and highly ordered structures. Unlike other polymers, a significant feature of COFs is that they are structurally predesignable, synthetically controllable, and functionally manageable. In principle, the topological design diagram offers ge...

Durch den Kanal: 1D-Nanokanäle ermöglichen Ionenleitung, wenn die Kanalwände mit einer ionischen Grenzfläche manipuliert werden. Kovalente organische Gerüste können solche 1D-Kanäle mit gewünschten Ionenketten-Zusammensetzungen und -dichten für ultraschnellen Ionentransport erschaffen. Dies führt zu einer exponentiellen Korrelation zwischen Grenzfl...

A new approach has been developed to design organic polymers using topology diagrams. This strategy enables covalent integration of organic units into ordered topologies and creates a new polymer form, that is, covalent organic frameworks. This is a breakthrough in chemistry because it sets a molecular platform for synthesizing polymers with predes...

Two‐dimensional covalent organic frameworks were synthesized in high yields by polycondensation in nonvolatile ionic liquids. The resulting crystallites are highly porous and exhibit exceptional capability of removing bisphenol A from water. The one reported is a general method to synthesize microporous and mesoporous frameworks, it allows to achie...

Covalent organic frameworks (COFs) allow elaborate manufacture of ordered one‐dimensional channels in the crystal. We defined a superlattice of COFs by engineering channels with a persistent triangular shape and discrete pore size. We observed a size‐recognition regime that is different from the characteristic adsorption of COFs, whereby pore windo...

Der richtige Kanal: Offene 1D‐Kanäle, deren Poren in dreieckiger Form und einer diskreten Größe in kovalenten organischen Gerüsten gestaltet wurden, konnten molekulare Größenunterschiede erkennen. Dieser Befund eröffnet die Möglichkeit, 1D‐Kanäle für den selektiven Transport und die sofortige molekulare Trennung mit unendlicher Selektivität zu nutz...

Production of sustainable and renewable energy is a subject of global importance and is a challenging goal in the fields of chemistry and materials science. This perspective focuses on the use of two sustainable resources on this planet, i.e. water and sunlight, for the produc-tion of green chemical energy — hydrogen. Special interests are directed...

Progress over the past decade in chemistry has showcased a new way to design organic polymers using topology diagram. This strategy enables the covalent integration of organic units into ordered topologies and creates a new polymer form, i.e. covalent organic framework. This is a breakthrough in chemistry because it sets a molecular platform for sy...

The aligned one-dimensional channels found in covalent organic frameworks offer a unique space for energy storage. However, physical isolation of sulfur in the channels is not sufficient to prevent the shuttle of lithium-sulfide intermediates that eventually results in a poor performance of lithium-sulfur energy storage. Herein, we report a strateg...

Photo-to-chemical energy conversion requires a systematic and complex molecular design to manage consecutive photochemical processes, including energy harvesting, exciton migration, electron transfer, charge separation, and charge transport. However, such an integrated design remains a substantial challenge. Here, we report a seamless system in man...

Enrichment of radioactive iodine in the waste of nuclear industries threatens the health of humans, and efficient capture of iodine has attracted a great deal of attention in recent years. Porous organic polymers (POPs) and metal-organic frameworks (MOFs), new classes of porous materials, act as outstanding candidate adsorbent materials in this fie...

Covalent organic frameworks enable the topological connection of organic chromophores into π lattices, making them attractive for creating light-emitting polymers that are predesignable for both the primary- and high-order structures. However, owing to linkages, covalent organic frameworks are either unstable or poor luminescent, leaving the practi...

Covalent organic frameworks (COFs) offer ordered π structures that are useful for developing light-emitting materials. However, most COFs are weak in lumines-cence. Here we report the conversion of less emissive COFs into light-emitting materials via a pinpoint surgery on the pore walls. Deprotonation of the N–H bond to form an anionic nitrogen spe...

This chapter focuses on reviewing the design, synthesis, and functions of porous carbons based on the porous organic polymers, by elucidating structural effects of porous organic polymers on resulting porous carbons. Conjugated microporous polymers (CMPs) are a unique class of porous amorphous polymers in which organic units are covalently linked i...

Covalent organic frameworks (COFs) with ordered one-dimensional channels could offer a predesigned pathway for ion motion. However, implanting salts into bare channels of COFs gives rise to a limited ion conductivity. Here, we report the first example of polyelectrolyte COFs by integrating flexible oligo(ethylene oxide) chains onto the pore walls....

Rational design and synthesis of 2D organic–inorganic hybrid materials is important for transformative technological advances for energy storage. Here, a 2D conductive hybrid lamella and its intercalation properties for thin‐film supercapacitors are reported. The 2D organic–inorganic hybrid lamella comprises periodically stacked 2D nanosheets with...

Progress over the past decades in porous materials has exerted great effect on the design of metal-free carbon electrochemical catalysts in fuel cells. The carbon material must combine three functions, i.e., electrical conductivity for electron transport, optimal pores for ion motion, and abundant heteroatom sites for catalysis. Here, an ideal carb...

Conducting layered capacitive materials that utilize interlayer space to store charges usually exhibit higher areal and volumetric capacitive performance than porous carbons as a result of the bulk storage mechanism. Here, an organic-inorganic hybrid conducting layered material is designed through a ‘bottom-up’ strategy, and is synthesized facilely...

Progress in chemistry over the past four decades has generated a variety of porous materials for removing iodine—a radioactive emission accompanying nuclear fission. However, most studies are still based on the notion that entangled pores together with specific binding sites are essential for iodine capture. Here, an unraveled physical picture of i...

Covalent organic frameworks (COFs) are a class of crystalline porous polymer that is structurally predesignable and synthetically controllable at both levels of primary and high-order structures. Topological design diagram in conjunction with geometry matching of monomers enables the atomically precise integration of organic units into periodically...

Zirconium-based metal−organic frameworks (Zr-MOFs) exhibit great structural tunability and outstanding chemical sta-bility, rendering them promising candidates for a wide range of practical applications. In this work, we synthesized a series of isostructural PCN-224 analogues functionalized by ethyl, bromo, chloro, and fluoro groups on the porphyri...