Kwon, Min Sang

Herein we report a rational design strategy for tailoring intermolecular interactions to enhance room-temperature phosphorescence from purely organic materials in amorphous matrices at ambient conditions. The built-in strong halogen and hydrogen bonding between the newly developed phosphor G1 and the poly(vinyl alcohol) (PVA) matrix efficiently suppresses vibrational dissipation and thus enables bright room-temperature phosphorescence (RTP) with quantum yields reaching 24%. Furthermore, we found

Metal-free organic phosphorescent materials are attractive alternatives to the predominantly used organometallic phosphors but are generally dimmer and are relatively rare, as, without heavy-metal atoms, spin-orbit coupling is less efficient and phosphorescence usually cannot compete with radiationless relaxation processes. Here we present a general design rule and a method to effectively reduce radiationless transitions and hence greatly enhance phosphorescence efficiency of metal-free organic

, photoinduced electron/energy transfer-RAFT (PET-RAFT), photoiniferter, and photomediated cationic RAFT polymerization). Among these, visible-light-driven RAFT polymerization has attracted particular attention in recent years due to its benefits, including low energy consumption and the safe reaction procedure. Moreover, the incorporation of visible-light photocatalysis in the polymerization has conferred attractive features, such as spatiotemporal control and oxygen tolerance; however, a clear

A novel donor-acceptor-donor triad that exhibits fluorescence on-off switching with high contrast ratio (ca. 10(3) ) in response to a mechanical stimulus in the solid state is reported. This system provides a very unique example of high-contrast fluorescence switching that is driven by a mechanical-force-controlled photo-induced electron transfer (eT) in molecular assemblies.

A lot of efforts have been made for the development of novel organic photoredox catalysts (PCs) due to their gratifying replacement for conventional transition metal‐based PCs in photoredox catalysis. In this minireview, we summarized and classified the recently reported organic PCs into several categories based on functional groups (e.g. cyanoarene, phenazine, xanthene, and others) with their applications to various organic transformations including polymerization reactions. The strategies used

Soft magnetic materials have shown promise in diverse applications due to their fast response, remote actuation, and large penetration range for various conditions. Herein, a new soft magnetic composite material capable of reprogramming its magnetization profile without changing intrinsic magnetic properties of embedded magnetic particles or the molecular property of base material is reported. This composite contains magnetic microspheres in an elastomeric matrix, and the magnetic microspheres a

The addition of chemical additives is considered as a promising approach for obtaining high-quality perovskite films under mild conditions, which is essential for both the efficiency and the stability of organic-inorganic hybrid perovskite solar cells (PeSCs). Although such additive engineering yields high-quality films, the inherent insulating property of the chemical additives prevents the efficient transport and extraction of charge carriers, thereby limiting the applicability of this approac

Abstract Herein we report a rational design strategy for tailoring intermolecular interactions to enhance room‐temperature phosphorescence from purely organic materials in amorphous matrices at ambient conditions. The built‐in strong halogen and hydrogen bonding between the newly developed phosphor G1 and the poly(vinyl alcohol) (PVA) matrix efficiently suppresses vibrational dissipation and thus enables bright room‐temperature phosphorescence (RTP) with quantum yields reaching 24 %. Furthermore

Abstract Cyanoarene-based photocatalysts (PCs) have attracted significant interest owing to their superior catalytic performance for radical anion mediated photoredox catalysis. However, the factors affecting the formation and degradation of cyanoarene-based PC radical anion (PC •‒ ) are still insufficiently understood. Herein, we therefore investigate the formation and degradation of cyanoarene-based PC •‒ under widely-used photoredox-mediated reaction conditions. By screening various cyanoaren

A highly efficient organic photocatalyst (OPC) for photoinduced electron/energy-transfer reversible addition–fragmentation chain-transfer (PET-RAFT) polymerization was identified through a systematic catalyst design and discovery. The devised OPC offers excellent control over PET-RAFT polymerizations of methyl methacrylate at very low catalyst loadings (5 ppm), that is, ca. 5–50 times lower loadings than other OPCs reported so far. Moreover, excellent oxygen tolerance was achieved using the disc

We report herein a new class of piezochromic luminescence (PCL) material with an acid stimulus response based on a donor (D)–acceptor (A)–donor (D) molecular triad, m-BHHDCS (1), synthesized via a rational design strategy. Acid-responsive harmane derivatives were rationally introduced into the unique D–A–D platform to obtain dual-stimuli responsive properties, i.e. acidochromic and piezochromic behaviors. Upon exposure to mechanical force and/or acid treatment, the pristine powders of 1 showed r

Current technological advances in the organic light-emitting diode panel design of foldable smartphones demand advanced adhesives with UV-blocking abilities, beyond their conventional roles of bonding objects and relieving deformation stress. However, optically clear adhesives (OCAs) with UV-blocking ability cannot be prepared using conventional UV-curing methods relying on a photoinitiator. Herein, a new acrylic resin that can be efficiently cured using visible light without oxygen removal is p

The unique 16-membered macrolide (+)-exiguolide (1) was the target of a total synthesis featuring radical and Prins cyclizations of β-alkoxyacrylates, along with ring-closing olefin metathesis. The structure incorporates two cis-2,6-disubstituted oxane rings where one of the rings has an exocyclic enoate group. The successful synthesis of 1, isolated from a marine sponge, led to the unambiguous determination of its absolute stereochemistry.

Metal-free organic phosphors can be an attractive smart optical sensing materials since, in such compounds, intersystem crossing (ISC) and the phosphorescence process are placed in subtle competition with fluorescence, internal conversion (IC), and non-radiative decay pathways. Here, we report a unique environment-dependent multi-luminescence switching behavior of metal-free organic phosphorescent materials. Through combined photophysical measurements and computational electronic structure analy