# Covalent organic frameworks: templates > COFs built atom by atom at real dimensions: the first boronate COFs, linkage chemistry, β-ketoenamine stability, 3D and triazine frameworks, characterization, catalysis, photocatalytic hydrogen and membranes. URL: https://www.labcanvas.com/templates/covalent-organic-frameworks 10 templates. All templates: https://www.labcanvas.com/templates - [COF-1 and COF-5: the first COFs](https://www.labcanvas.com/templates/covalent-organic-frameworks/cof-1-cof-5-boroxine-boronate-ester) ([Markdown](https://www.labcanvas.com/templates/covalent-organic-frameworks/cof-1-cof-5-boroxine-boronate-ester.md)): The first covalent organic frameworks were made in 2005 by condensing boronic acids. Benzene-1,4-diboronic acid alone loses water to form flat six-membered boroxine rings (COF-1); together with hexahydroxytriphenylene it forms five-membered boronate esters (COF-5). Both crystallize as porous layers built only from light elements: COF-1 stacks staggered, COF-5 eclipsed, leaving open channels 27 Å across. - [COF linkages: from reversible to robust](https://www.labcanvas.com/templates/covalent-organic-frameworks/cof-linkages-boroxine-imine-ketoenamine-triazine) ([Markdown](https://www.labcanvas.com/templates/covalent-organic-frameworks/cof-linkages-boroxine-imine-ketoenamine-triazine.md)): A COF crystallizes only if its bonds can break and re-form while it grows, so that mistakes heal. Boron–oxygen rings (boroxines, boronate esters) do this easily but fall apart in water; imines are sturdier; hydrazones and azines add hydrogen bonds; Tp-based imines turn irreversibly into β-ketoenamines that survive acid and base; and triazine rings made from nitriles in molten salt are tougher still. - [TpPa COFs: β-ketoenamine links that survive acid and base](https://www.labcanvas.com/templates/covalent-organic-frameworks/tppa-1-ketoenamine-cof-acid-base-stability) ([Markdown](https://www.labcanvas.com/templates/covalent-organic-frameworks/tppa-1-ketoenamine-cof-acid-base-stability.md)): TpPa-1 and TpPa-2 are made from 1,3,5-triformylphloroglucinol (Tp) and p-phenylenediamine or its 2,5-dimethyl analogue. The Schiff base forms first, as the enol-imine, but the proton moves irreversibly from oxygen to nitrogen and only the keto-enamine remains. With no imine bond left to hydrolyse, both COFs survive 9 N hydrochloric acid and boiling water; TpPa-2 also survives 9 N sodium hydroxide. - [COF-LZU1: an imine COF that holds palladium](https://www.labcanvas.com/templates/covalent-organic-frameworks/cof-lzu1-pd-suzuki-coupling-catalysis) ([Markdown](https://www.labcanvas.com/templates/covalent-organic-frameworks/cof-lzu1-pd-suzuki-coupling-catalysis.md)): COF-LZU1 condenses 1,3,5-triformylbenzene with p-phenylenediamine into imine-linked layers that stack eclipsed, so the imine nitrogens of neighbouring layers line up. A simple post-treatment loads Pd(II) into the framework. The resulting Pd/COF-LZU1 catalyses Suzuki–Miyaura cross-coupling across a broad range of aryl halides and boronic acids in 96–98% yield, and stays stable and easy to recycle. - [3D COFs: COF-102 and COF-300](https://www.labcanvas.com/templates/covalent-organic-frameworks/3d-cof-102-cof-300-diamond-net) ([Markdown](https://www.labcanvas.com/templates/covalent-organic-frameworks/3d-cof-102-cof-300-diamond-net.md)): Tetrahedral building blocks take covalent organic frameworks into three dimensions. Boronic acids on a tetraphenylmethane or -silane core condense into boroxine rings, each joining three tetrahedra (COF-102 and COF-103): crystals of very low density with surface areas of 3472 and 4210 m² g⁻¹. Tetra(4-anilyl)methane and terephthaldehyde give imine-linked COF-300 on a diamond net; five such nets grow through one another, yet 7.2 Å pores remain. - [CTF-1: triazine frameworks from molten salt](https://www.labcanvas.com/templates/covalent-organic-frameworks/ctf-1-ionothermal-covalent-triazine-framework) ([Markdown](https://www.labcanvas.com/templates/covalent-organic-frameworks/ctf-1-ionothermal-covalent-triazine-framework.md)): Covalent triazine frameworks are made without any condensation water: aromatic nitriles trimerize into triazine rings in molten zinc chloride at 400 °C, the salt serving as solvent and catalyst. 1,4-Dicyanobenzene gives CTF-1, layers of triazine rings joined by phenylene that can come out ordered or amorphous. The products are microporous, high-performance polymers with very large surface areas, suited to gas storage, sensing and catalyst supports. - [Characterizing a 2D COF](https://www.labcanvas.com/templates/covalent-organic-frameworks/cof-characterization-pxrd-ftir-nmr) ([Markdown](https://www.labcanvas.com/templates/covalent-organic-frameworks/cof-characterization-pxrd-ftir-nmr.md)): Four questions decide whether a new 2D COF is the framework that was designed. Does the powder pattern match the one computed for the layers, and for which stacking? Are the pores open, and how wide? Did the linkage form, with the starting groups used up? And how much heat does it take? Drawn with COF-5 for structure and porosity, and an imine COF for the bonds. - [COF-366-Co: cobalt porphyrin COF for CO₂ reduction](https://www.labcanvas.com/templates/covalent-organic-frameworks/cof-366-co-porphyrin-co2-reduction) ([Markdown](https://www.labcanvas.com/templates/covalent-organic-frameworks/cof-366-co-porphyrin-co2-reduction.md)): Cobalt porphyrins joined by imine struts form square-grid layers that stack into a porous solid with a catalytic cobalt site at every corner. On an electrode in water at pH 7, the framework reduces CO₂ to CO with 90% Faradaic efficiency and up to 290,000 turnovers per cobalt, at an overpotential of −0.55 V: a 26-fold gain in activity over the molecular cobalt complex, with no degradation over 24 hours. - [COF photocatalysts for hydrogen from water](https://www.labcanvas.com/templates/covalent-organic-frameworks/cof-photocatalytic-hydrogen-evolution) ([Markdown](https://www.labcanvas.com/templates/covalent-organic-frameworks/cof-photocatalytic-hydrogen-evolution.md)): Some COFs are semiconductors that absorb visible light. TFPT-COF, hydrazone-linked triazine and phenyl units in honeycomb layers with 3.8 nm pores, produces hydrogen from water under visible light once platinum is added as the proton reduction catalyst, and keeps doing so without degrading. In a series of azine-linked COFs made from hydrazine, swapping C–H for N in the central ring of the aldehyde (N₀ to N₃) raises the rate of hydrogen evolution step by step. - [COF thin films for molecular separation](https://www.labcanvas.com/templates/covalent-organic-frameworks/cof-thin-film-membranes-interfacial-crystallization) ([Markdown](https://www.labcanvas.com/templates/covalent-organic-frameworks/cof-thin-film-membranes-interfacial-crystallization.md)): COFs usually come out as insoluble powders. Grown instead where two liquids that do not mix meet, β-ketoenamine COFs form continuous, free-standing films under ambient conditions; they can be lifted onto any support and made thinner than 100 nm. Tp-Bpy, from Tp and a bipyridine diamine, has a surface area of 1151 m² g⁻¹ and lets acetonitrile through at 339 L m⁻² h⁻¹ bar⁻¹ while holding dissolved molecules back.