Nondiffusion-Controlled Photoelectron Transfer Induced by Host–Guest Complexes to Initiate Cationic Photopolymerization

Charge-transfer inclusion complex formation of the tropylium cation with prism[6]arenes

Herein, we report that prism[6]arenes (PrS[6]R) can form charge-transfer (CT) inclusion complexes with tropylium tetrakis[3,5-bis(trifluoromethyl)-phenyl]borate (G) in chloroform solution with an obvious CT band at 560 nm. Moreover, the CT complex PrS[6]Et⊃G showed Cl-/Ag+ responsiveness which can be easily monitored by the naked eye.

Chirality Sensing of Cryptochiral Guests with Prism[n]arenes

Optical chirality sensing has gained significant attention in recent years. Within this field, the quest for stereodynamic chiroptical probes capable of detecting cryptochiral guests presents a formidable challenge. Macrocycles exhibiting planar chirality have emerged as promising candidates for amplifying the chirality of cryptochiral guests. In this study, we demonstrate that the formation of host-guest complexes between cryptochiral molecules and planar chiral prismarenes triggers electronic circular dichroism (ECD) signals via host-guest complexation-induced chirality amplification. The absolute configuration of the most stable chiral macrocyclic host-guest complex has been established by resorting to both exciton model and DFT computations. Furthermore, we demonstrated that this supramolecular chirality sensing system can be employed to determine the enantiomeric composition of scalemic mixtures by measuring the ECD bands intensity. The information described here opens the way for the use of prismarenes as stereodynamic probes for sensing of cryptochiral guests.

Recent Advances and Challenges in Long Wavelength Sensitive Cationic Photoinitiating Systems

With the advantages offered by cationic photopolymerization (CP) such as broad wavelength activation, tolerance to oxygen, low shrinkage and the possibility of "dark cure", it has attracted extensive attention in photoresist, deep curing and other fields in recent years. The applied photoinitiating systems (PIS) play a crucial role as they can affect the speed and type of the polymerization and properties of the materials formed. In the past few decades, much effort has been invested into developing cationic photoinitiating systems (CPISs) that can be activated at long wavelengths and overcome technical problems and challenges faced. In this article, the latest developments in the long wavelength sensitive CPIS under ultraviolet (UV)/visible light-emitting diodes (LED) lights are reviewed. The objective is, furthermore, to show differences as well as parallels between different PIS and future perspectives.

Supramolecular host-guest interaction-driven electrochemical recognition for pyrophosphate and alkaline phosphatase analysis

Herein, we report an electrochemical biosensor based on the supramolecular host-guest recognition between cucurbit[7]uril (CB[7]) and L -Phenylalanine-Cu(II) Complex for pyrophosphate (PPi) and alkaline phosphatase (ALP) analysis. First, L -Phe-Cu(II) Complex is simply synthesized by the complexation of Cu(II) (metal node) with L -Phe (bioorganic ligand), which can be immobilized onto CB[7] modified electrode via host-guest interaction of CB[7] and L -Phe. In this process, the signal of the Complex triggered electro-catalytic reduction of H 2 O 2 can be captured. Next, in the view of strong chelation between PPi and Cu(II), a biosensing system of the model "PPi and Cu(II) premixing, then adding L -Phe" is designed and the platform can be applied for PPi analysis well by hampering the formation of L -Phe-Cu(II) Complex. Along with ALP introduction, PPi can be hydrolyzed into orthophosphate (Pi), where abundant Cu(II) ions are released to form L -Phe-Cu(II) Complex, which gives rise to the catalytic reaction of Complex to H 2 O 2 reduction. The quantitative analysis of H 2 O 2 , PPi and ALP activity is achieved successfully and the detection of limits are 0.067 μM, 0.42 μM and 0.09 mU/mL ( S / N =3), respectively. With the merits of high sensitivity and selectivity, cost-effectiveness, and simplification, our developed analytical system has great potential to act on diagnosis and treatment of ALP-related diseases.

per-Hydroxylated Prism[n]arenes: Supramolecularly Assisted Demethylation of Methoxy-Prism[5]arene

Methoxy-prism[5]arene PrS[5]^Me is demethylated by a supramolecularly assisted reaction. In the presence of a tetramethylammonium cation, PrS[5]^Me is demethylated by BBr₃ in high yield, while in its absence a 55/40 mixture of PrS[5]^OH/PrS[6]^OH is formed. The dealkylation of prismarenes, such as PrS[6]^R (R = Et, nPr) and c-PrS[5]^Me, can be easily obtained in high yields in the presence of BBr₃.