Two novel supramolecular photoinitiators (supra-photoinitiators) based on the host−guest complexation of macrocycles (pillar[6]arene, P6; prism[5]arene, NP5) and diphenyl-iodonium salt (Iod) were fabricated. Under light irradiation, macrocycle P6 or NP5 could donate electrons to the guest molecule Iod, which generated highly active free radicals and cationic fragments to achieve efficient polymerization. Compared to a commercial activator, the electron transfer between macrocycles and Iod were under nondiffusion control, endowing a much higher photopolymerization rate and epoxy resin final conversion. In addition, the host−guest complexation of NP5 extended the initiating wavelength of Iod from ultrashort ultraviolet to near-ultraviolet, which could better match the environment-friendly LED light source. It is anticipated that a supra-photoinitiator may open a new route for designing novel photoinitiators with high performance.

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In this work, a naphthalene-based macrocycle prism[5]arene (NP 5 OCH 3 ) is developed as a novel kind of photoinitiator. When NP 5 OCH 3 is irradiated under light, the bond between methylene and naphthalene can be quickly broken owning to the existence of ring tension. The macrocycle is cleaved to linear oligomer biradicals, which can effectively initiate the free radical photopolymerization of acrylate monomers. Compared with conventional photoinitiators, NP 5 OCH 3 has strong light absorption in the wavelength range of 365-405 nm, so it can well match the environment-friendly light-emitting diodes (LEDs) light source to realize highly efficient initiation. In addition, there is no small molecule fragment generated during NP 5 OCH 3 fracture, and the resulted linear oligomer biradicals can be immobilized in the polymer after initiating polymerization, so NP 5 OCH 3 photoinitiators show much lower migration rate and cytotoxicity. Cleavable macrocycle prismarene may provide a new idea for the design of safe and efficient photoinitiators matching long wavelength light.

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A novel class of agents is developed based on the core engineering of open‐shelled organic mixed‐valence (MV) systems, which enable tunable absorption and emission across the near infrared (NIR)‐I to III biowindow (700–1850 nm) by adjusting the number of central nitrogen oxidation sites and the length of the conjugated bridge. Organic mixed‐valence (MV) systems are synthesized through a one‐step partial chemical oxidation of starburst oligoarylamines, with varying nitrogen oxidation sites and conjugated bridge lengths, including tris(4‐[diethylamino]phenyl)aminen+ (T4EPAn+), N,N,N',N'‐tetrakis(4‐[diisobutylamino]phenyl)‐1,4‐phenylenediaminen+ (TPDAn+), and N,N,N',N'‐tetrakis(4‐methoxyphenyl)benzidinen+ (TMPBn+). The absorption wavelength of the MV systems redshifted clearly as the number of central nitrogen oxidation sites increased or the conjugated bridge length is prolonged. T4EPAn+ with one central nitrogen oxidation site exhibits fluorescence emission in the range of 900–1400 nm, while TPDAn+ with two central nitrogen oxidation sites demonstrate strong heat generation capabilities. Additionally, the absorption peak of TMPBn+ with a biphenyl conjugated bridge reaches up to 1610 nm. Especially, these MV systems are highly stable for biological applications due to their high steric hindrance and hyperconjugation effect. These characteristics make MV systems promising candidates for constructing NIR‐I/II/III emitters and photothermal agents, representing a significant advance toward developing the next generation of NIR‐I to III agents.