Closing the Gap Between Gas Phase and Condensed Phase: Fragmentation Studies of the Thiomethoxymethyl Complex [(bipy)Pt(CH3)2(CH2SCH3)]+

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Collision-induced dissociation (CID) of the mass-selected cation [(bipy)Pt(CH3)2(CH2SCH3)]+ in an ion-trap mass-spectrometer results in the losses of the neutrals ethane, ethene, dimethyl sulfide, methane, ethyl methyl sulfide, and propane. The generation of the first four neutrals is also observed, when the isolated, dimeric complex [(bipy)Pt(CH3)2(CH2SCH3)]2[SbF6]2 is heated in the condensed phase. While the product distribution is very similar regardless of whether the complex is heated in the solid state or in solution, ethane loss, i.e. the quite rare event of an sp3-sp3 C–C reductive elimination from a platinum(IV) complex, dominates in the gas-phase experiment. However, when the counter anion [SbF6]- is exchanged by the more weakly coordinating anion [BAr4F]-, the amounts of ethane and ethene are increased also in the condensed phase. These sum of observations indicates the similarities of the fragmentation of [(bipy)Pt(CH3)2(CH2SCH3)]+ in both phases. Thus, a correlation of processes in both environments is possible for selected systems (and particularly for unimolecular processes), but the choice of the proper conditions is crucial for a meaningful comparison.

Immobilization of  Prussian blue nanoparticles onto Au‐modified ZnIn2S4 photoanode for efficient photoelectrochemical water splitting

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ZnIn2S4 has been regarded as a promising photoanode material for photoelectrochemical (PEC) water splitting. However, its severe charge recombination and low carrier transport efficiency limit practical applications in PEC water separation. A novel ZnIn2S4/Au/PB photoanode was prepared by in situ photodeposition and electrodeposition. The photocurrent density of the ternary photoanode reached 0.42 mA/cm2 at 1.23 VRHE, which is 6 times higher than that of pure ZnIn2S4. The introduction of Au nanoparticles remarkably improved the efficiency of carrier transport and separation. Additionally, the application of PB onto ZnIn2S4 resulted in an extended spectrum of light absorption. The incident photon-to-current efficiency (IPCE) value recorded was 24.6% at 350 nm. This improvement can be attributed to the formation of a Z-type heterojunction.

The role of the terminal benzene derivatives in triphenylamine‐based oxime esters for free radical photopolymerization

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In this study, we investigate the effect of terminal benzene derivatives in triphenylamine-based oxime esters on their photoreactivity. Five novel oxime esters ( Miko series) that containing different benzene derivatives as terminal groups, were synthesized. The electronic properties of the substituents on the benzene ring range from electron-donating to electron-withdrawing. Specifically, a methoxy benzene for Miko-MOB, tert-butyl benezene for Miko-t-Bu, chloro benzene for Miko-CB, trifluoromethyl benzene for Miko-TFM, and nitro benzene for Miko-NB. Additionally, a compound with benzene only as the terminal substituent (TP-1) was selected for comparision. All the new compounds exhibited higher molar extinction coefficients than TP-1. Additionally, the steady-state photolysis and electron spin resonance (ESR) properties would decrease from the electron-donating substitutes to electron-withdrawing substitutes. Finally, these oxime esters are utilized in Type I photoinitiating systems for the free radical polymerization of trimethylolpropane triacrylate (TMPTA) under UV or LED@405 nm light irradiation conditions. Among all formulations, Miko-MOB demonstrated the highest double bond conversion efficiency under both UV and LED@405 nm light irradiation. Thus, terminal benzene derivatives in oxime esters play an important role in tuning the optical and photochemical reaction performance, offering significant value for the design strategy of such photoinitiators.

Investigation on Fluorescence Origins and Spectral heterogeneity in Carbon Dots: A Dynamic Perspective

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Heterogeneity in the fluorescence of carbon dots (CDs) has been hard to figure out so far. This could potentially be related to structural factors, size or intermediate fluorophores, especially when employing the bottom-up synthesis. Herein, we unveil the origin of fluorescence and spectral heterogeneity of CDs using a simple dynamic method. This work reports the room light-excited green fluorescence and dual-emissive N-doped CDs synthesized using a hydrothermal method. Studies were carried out considering the factors of fluorescence phenomena, such as excitation-independent emission, fluorescent impurities, aggregation and solvation dynamics. The new steady-state, Excitation-resolved area-normalized emission spectroscopy (ERANES) and ensemble measurements, including time-resolved studies reveal that a heterogeneous environment exists in the ground state. Eventually, the results show the existence of core, edge and surface states in the CDs. Additionally, the fluorescence characteristics depend on the structural functionalization that occurs in both the intrinsic and extrinsic states of the CDs and it is proven that this does not violate the Kasha-Vavilov rule. Although a highly purified material could still exhibit heterogeneity due to the ensemble emissive states and structural variations. Our results provide insights into the enduring debates about fluorescence and a deeper understanding of the structure- property relationship of CDs.