Chromoselective photocatalysis offers an intriguing opportunity to enable a specific reaction pathway out of a potentially possible multiplicity for a given substrate by using a sensitizer that converts the energy of incident photon into the redox potential of the corresponding magnitude. Several sensitizers possessing different discrete redox potentials (high/low) upon excitation with photons of specific wavelength (short/long) have been reported. Herein, we report design of molecular structures of two-dimensional amorphous covalent triazine-based frameworks (CTFs) possessing intraband states close to the valence band with strong red edge effect (REE). REE enables generation of a continuum of excited sites characterized by their own redox potentials, with the magnitude proportional to the wavelength of incident photons. Separation of charge carriers in such materials depends strongly on the wavelength of incident light and is the primary parameter that defines efficacy of the materials in photocatalytic bromination of electron rich aromatic compounds. In dual Ni-photocatalysis, excitation of electrons from the intraband states to the conduction band of the CTF with 625 nm photons enables selective formation of C‒N cross-coupling products from arylhalides and pyrrolidine, while an undesirable dehalogenation process is completely suppressed.

We report on the convenient synthesis of a CNC pincer ligand com¬po-sed of car¬ba¬zole and two mesoionic carbenes, as well as the corresponding lithium- and magnesium complexes. Mono-deprotonation affords a...

Among external stimuli used to promote a chemical reaction, photocatalysis possesses a unique one—light. Photons are traceless reagents that provide an exclusive opportunity to alter chemoselectivity of the photocatalytic reaction varying the color of incident light. This strategy may be implemented by using a sensitizer capable to activate a specific reaction pathway depending on the excitation light. Herein, we use potassium poly(heptazine imide) (K‐PHI), a type of carbon nitride, to generate selectively three different products from S‐arylthioacetates simply varying the excitation light and otherwise identical conditions. Namely, arylchlorides are produced under UV/purple, sulfonyl chlorides with blue/white, and diaryldisulfides at green to red light. A combination of the negatively charged polyanion, highly positive potential of the valence band, presence of intraband states, ability to sensitize singlet oxygen, and multi‐electron transfer is shown to enable this chromoselective conversion of thioacetates.

In photocatalysis,s mall organic molecules are converted into desired products using light responsive materials,e lectromagnetic radiation, and electron mediators.S ubstitution of low molecular weight reagents with redox active functional materials mayi ncrease the utility of photocatalysis beyond organic synthesis and environmental applications. Guided by the general principles of photocatalysis,w ed esign hybrid nanocomposites composed of n-type semiconducting potassium poly(heptazine imide) (K-PHI), and p-type conducting poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) as the redoxa ctive substrate.E lectrical conductivity of the hybrid nanocomposite,p ossessing optimal K-PHI content, is reversibly modulated combining as eries of external stimuli ranging from visible light under inert conditions and to dark conditions under an O 2 atmosphere.Using aconductive polymer as the redoxactive substrate allows study of the photocatalytic processes mediated by semiconducting photocatalysts through electrical conductivity measurements.