Subsequent Dissociation Research Articles

Permeable TAD boundaries and their impact on genome-associated functions.

TAD boundaries are genomic elements that separate biological processes in neighboring domains by blocking DNA loops that are formed through Cohesin-mediated loop extrusion. Most TAD boundaries consist of arrays of binding sites for the CTCF protein, whose interaction with the Cohesin complex blocks loop extrusion. TAD boundaries are not fully impermeable though and allow a limited amount of inter-TAD loop formation. Based on the reanalysis of Nano-C data, a multicontact Chromosome Conformation Capture assay, we propose a model whereby clustered CTCF binding sites promote the successive stalling of Cohesin and subsequent dissociation from the chromatin. A fraction of Cohesin nonetheless achieves boundary read-through. Due to a constant rate of Cohesin dissociation elsewhere in the genome, the maximum length of inter-TAD loops is restricted though. We speculate that the DNA-encoded organization of stalling sites regulates TAD boundary permeability and discuss implications for enhancer-promoter loop formation and other genomic processes.

Identifying Highly Active and Selective Cobalt X-Ides for Electrocatalytic Hydrogenation of Quinoline.

Earth-abundant Co X-ides are emerging as promising catalysts for the electrocatalytic hydrogenation of quinoline (ECHQ), yet challenging due to the limited fundamental understanding of ECHQ mechanism on Co X-ides. This work identifies the catalytic performance differences of Co X-ides in ECHQ and provides significant insights into the catalytic mechanism of ECHQ. Among selected Co X-ides, the Co3O4 presents the best ECHQ performance with a high conversion of 98.2% and 100% selectivity at ambient conditions. The Co3O4 sites present a higher proportion of 2-coordinated hydrogen-bonded water at the interface than other Co X-ides at a low negative potential, which enhances the kinetics of subsequent water dissociation to produce H*. An ideal 1,4/2,3-H* addition pathway on Co3O4 surface with a spontaneous desorption of 1,2,3,4-tetrahydroquinoline is demonstrated through operando tracing and theoretical calculations. In comparison, the Co9S8 sites display the lowest ECHQ performance due to the high thermodynamic barrier in the H* formation step, which suppresses subsequent hydrogenation; while the ECHQ on Co(OH)F and CoP sites undergo the 1,2,3,4- and 4,3/1,2-H* addition pathway respectively with the high desorption barriers and thus low conversion of quinoline. Moreover, the Co3O4 presents a wide substrate scope and allows excellent conversion of other quinoline derivatives and N-heterocyclic substrates.

Electronic coupling of iron-cobalt in Prussian blue towards improved peroxydisulfate activation

Prussian blue analogs (PBAs) have attracted extensive attention in the field of aqueous organic degradation due to the tremendous potential for peroxydisulfate (PDS) activation. However, the relationship between the d-band center of the catalyst and the activation behavior of PDS remained largely unexplored. Herein, a series of Fe-Co PBAs-based catalysts with different Fe/Co ratios (Fe-Co PBAs-1 = 1: 0.52; Fe-Co PBAs-2 = 1: 1.21, and Fe-Co PBAs-3 = 1: 1.48) have been prepared by a facile hydrothermal procedure and subsequent acid treatment (Fe-Co PBAs-xH). The as-prepared Fe-Co PBAs-xH exhibited superior PDS activation performance and excellent recyclability in the degradation of methylene blue (MB). Density functional theory calculations revealed that the electron-occupied state of the Fe-Co PBAs was shifted to the Fermi level, indicating a strong interaction and easier electron transfer. Moreover, the d-band center of Fe-Co PBAs was upshifted relative to that of Fe PBAs, suggesting easier adsorption of MB and PDS, which was beneficial to enhancing catalytic activation and subsequent dissociation. Radicals such as •OH, 1O2, O2•−, and SO4•− were determined by the radical quenching experiment and electron paramagnetic resonance (EPR) testing in the Fe-Co PBAs-3H/PDS system, and the order of MB degradation by the free active radical is •OH > 1O2 > O2•− > SO4•−. The degradation pathway and potential ecotoxicity of MB and its intermediates were also studied. This work can provide new insights to construct the efficient catalysts for the activation of PDS and the degradation of organic pollutants.

Mobility-Assisted Pseudo-MS3 Sequencing of Protein Ions.

The sequencing of intact proteins within a mass spectrometer has many benefits but is frequently limited by the fact that tandem mass spectrometry (MS/MS) techniques often generate poor sequence coverages when applied to protein ions. To overcome this limitation, exotic MS/MS techniques that rely on lasers and radical chemistry have been developed. These techniques generate high sequence coverages, but they require specialized instrumentation, create products through multiple dissociation mechanisms, and often require long acquisition times. Recently, we demonstrated that protein ions can be dissociated in a trapped ion mobility spectrometry (TIMS) device prior to mobility separation in a commercial timsTOF. All generated product ions were distributed throughout the mobility dimension, and this separation enabled deconvolution of complex tandem mass spectra and could enable facile pseudo-MS3 interrogation of generated product ions with the downstream quadrupole and collision cell. A second activation step improves sequence coverage because the most labile bonds have been depleted during the first dissociation and subsequent dissociation events are more evenly distributed throughout the product ion backbone. In this work, we explore the potential of this mobility-assisted pseudo-MS3 (MAP) method on a commercial timsTOF and timsTOF Pro 2. We demonstrate that while MAP only generates 92% of the sequence coverage of the most effective MS/MS technique, it accomplished this feat in 1.5 min and could be facilely integrated with liquid chromatographic separations.

A modified method for isolating sinoatrial node myocytes from adult mice.

Sinoatrial node (SAN) is the pacemaker of the heart in charge of initiating spontaneous electronical activity and controlling heart rate. Myocytes from SAN can generate spontaneous rhythmic action potentials, which propagate through the myocardium, thereby triggering cardiac myocyte contraction. Acutely, the method for isolating sinoatrial node myocytes (SAMs) is critical in studying the protein expression and function of myocytes in SAN. Currently, the SAMs were isolated by transferring SAN tissue directly into the digestion solution, but it is difficult to judge the degree of digestion, and the system was unstable. Here, we present a modified protocol for the isolation of SAMs in mice, based on the collagenase II and protease perfusion of the heart using a Langendorff apparatus and subsequent dissociation of SAMs. The appearance and droplet flow rate of the heart could be significantly changed during enzymatic digestion via perfusion, which allowed us to easily judge the degree of digestion and avoid incomplete or excessive digestion. The SAMs with stable yield and viability achieved from our optimized approach would facilitate the follow-up experiments.

Inhalation of ferrate-disinfected Escherichia coli caused lung injury via endotoxin-induced oxidative stress and inflammation response

Ferrate (Fe(VI)) is an environmentally friendly disinfectant that is widely used to eradicate microbes in reclaimed water. However, the potential health risks associated with inhalation of Fe(VI)-treated bacteria-laden reclaimed water remains uncertain. We aimed to explore the inhalation hazards and potential mechanisms of K2FeO4-treated Escherichia coli (E. coli, ATCC 25922). Our findings indicated that Fe(VI) disinfection induced a dose- and time-dependent E. coli inactivation, accompanied by a rapid release of the bacterial endotoxin, lipopolysaccharide (LPS). Scanning electron microscopy (SEM) observations indicate that Fe(VI)-induced endotoxin production consists of at least two stages: initial binding of endotoxin to bacteria and subsequent dissociation to release free endotoxin. Furthermore, Fe(VI) disinfection was not able to effectively eliminate pure or E. coli-derived endotoxins. The E. coli strain used in this study lacks lung infection capability, thus the inhalation of bacteria alone failed to induce severe lung injury. However, mice inhaled exposure to Fe(VI)-treated E. coli showed severe impairment of lung structure and function. Moreover, we observed an accumulation of neutrophil/macrophage recruitment, cell apoptosis, and ROS generation in the lung tissue of mice subjected to Fe(VI)-treated E. coli. RNA sequencing (RNA-seq) and PCR results revealed that genes involved with endotoxin stimuli, cell apoptosis, antioxidant defence, inflammation response, chemokines and their receptors were upregulated in response to Fe(VI)-treated E. coli. In conclusion, Fe(VI) is ineffective in eliminating endotoxins and can trigger secondary hazards owing to endotoxin release from inactivated bacteria. Aerosol exposure to Fe(VI)-treated E. coli causes considerable damage to lung tissue by inducing oxidative stress and inflammatory responses.

Nonstatistical Unimolecular Decay of the CH2OO Criegee Intermediate in the Tunneling Regime.

Unimolecular decay of the formaldehyde oxide (CH2OO) Criegee intermediate proceeds via a 1,3 ring-closure pathway to dioxirane and subsequent rearrangement and/or dissociation to many products including hydroxyl (OH) radicals that are detected. Vibrational activation of jet-cooled CH2OO with two quanta of CH stretch (17-18 kcal mol-1) leads to unimolecular decay at an energy significantly below the transition state barrier of 19.46 ± 0.25 kcal mol-1, refined utilizing a high-level electronic structure method HEAT-345(Q)Λ. The observed unimolecular decay rate of 1.6 ± 0.4 × 106 s-1 is 2 orders of magnitude slower than that predicted by statistical unimolecular reaction theory using several different models for quantum mechanical tunneling. The nonstatistical behavior originates from excitation of a CH stretch vibration that is orthogonal to the heavy atom motions along the reaction coordinate and slow intramolecular vibrational energy redistribution due to the sparse density of states.

Kinetics and Mechanism of the Singlet Oxygen Atom Reaction with Dimethyl Ether.

We combine in situ laser spectroscopy, quantum chemistry, and kinetic calculations to study the reaction of a singlet oxygen atom with dimethyl ether. Infrared laser absorption spectroscopy and Faraday rotation spectroscopy are used for the detection and quantification of the reaction products OH, H2O, HO2, and CH2O on submillisecond time scales. Fitting temporal profiles of products with simulations using an in-house reaction mechanism allows product branching to be quantified at 30, 60, and 150 Torr. The experimentally determined product branching agrees well with master equation calculations based on electronic structure data and transition state theory. The calculations demonstrate that the dimethyl peroxide (CH3OOCH3) generated via O-insertion into the C-O bond undergoes subsequent dissociation to CH3O + CH3O through energetically favored reactions without an intrinsic barrier. This O-insertion mechanism can be important for understanding the fate of biofuels leaking into the atmosphere and for plasma-based biofuel processing technologies.

Regulating the d-band center of Cu nanoparticles for efficient photo-driven catalytic CO2 reduction

The conversion of CO2 into solar fuels via photo-driven catalytic reduction presents a promising avenue toward achieving carbon neutrality. Herein, copper-based catalysts are prepared and explored for photo-driven photothermal CO2 reduction reaction. The optimized catalyst exhibits a consistent CO production rate of 165.9 mmol g−1 h−1 and 100% CO selectivity at ambient pressure. We unveil the intricate adsorption dynamics at play: H2 molecules predominantly interact with and activate at Cu sites, while CO2 molecules preferentially adsorb and activate at interfacial sites within the composites. Furthermore, we elucidate how the positive shift of the d-band center (εd) for Cu 3d orbitals significantly enhances H2 adsorption and activation. Crucially, the subsequent dissociation of H2 molecules at Cu sites drives the efficient conversion of adsorbed CO2 molecules at interfacial sites into CO. Overall, our findings not only advance the theoretical understanding but also offer practical insights for realizing photothermal catalytic CO2 reduction reactions.

Dissociation As a Mechanism of Risk for Interpersonal Victimization Among Adolescent Girls.

Childhood interpersonal violence exposure (IVE) is associated with repeated victimization in adolescence and adulthood. Research suggests dissociation, a psychological phenomenon characterized by alterations and disruptions to consciousness, memory, and perceptions of the environment, and out-of-body experiences, increases the risk of revictimization. Self-report data from a longitudinal study of 92 violence-exposed adolescent girls from a large, urban area were analyzed to assess whether dissociation predicts polyvictimization or exposure to multiple types of interpersonal violence across adolescence. Participants' mental and interpersonal health was assessed at four in-person laboratory visits scheduled across 3.5 years (i.e., T1-T4). IVE included direct or indirect victimization experienced at home, school, the neighborhood, or town, such as child maltreatment, domestic violence, peer victimization, dating aggression, and community violence. Polyvictimization was operationalized as a composite score of the different types of IVE endorsed by the participant or caregiver. A random-intercept cross-lagged panel model was used to test the bidirectional relationships between dissociation and polyvictimization longitudinally. Cross-lagged regressions were analyzed to determine whether dissociation and polyvictimization predicted subsequent dissociation symptoms and polyvictimization. Concurrent and previous dissociation significantly accounted for polyvictimization at T2, T3, and T4. Polyvictimization did not significantly predict future dissociation symptoms. The results from this study provide support for dissociation's unique contribution to polyvictimization among violence-exposed girls, making it an important target for clinical assessment and treatment.

Dissecting the mechanism of atlastin-mediated homotypic membrane fusion at the single-molecule level

Homotypic membrane fusion of the endoplasmic reticulum (ER) is mediated by dynamin-like GTPase atlastin (ATL). This fundamental process relies on GTP-dependent domain rearrangements in the N-terminal region of ATL (ATLcyto), including the GTPase domain and three-helix bundle (3HB). However, its conformational dynamics during the GTPase cycle remain elusive. Here, we combine single-molecule FRET imaging and molecular dynamics simulations to address this conundrum. Different from the prevailing model, ATLcyto can form a loose crossover dimer upon GTP binding, which is tightened by GTP hydrolysis for membrane fusion. Furthermore, the α-helical motif between the 3HB and transmembrane domain, which is embedded in the surface of the lipid bilayer and self-associates in the crossover dimer, is required for ATL function. To recycle the proteins, Pi release, which disassembles the dimer, activates frequent relative movements between the GTPase domain and 3HB, and subsequent GDP dissociation alters the conformational preference of the ATLcyto monomer for entering the next reaction cycle. Finally, we found that two disease-causing mutations affect human ATL1 activity by destabilizing GTP binding-induced loose crossover dimer formation and the membrane-embedded helix, respectively. These results provide insights into ATL-mediated homotypic membrane fusion and the pathological mechanisms of related disease.

Metal-facilitated, sustainable nitroarene hydrogenation under ambient conditions

Hydrogenation is a critical reaction in the chemical industry, yielding a range of important compounds such as fine chemicals, pharmachemicals and agrochemicals. However, conventional hydrogenation typically requires pressurized hydrogen, high temperatures and involves noble metal catalysts. We proposed a two-step hydrogenation process, utilizing water as the hydrogen source for the industrially important reduction of nitroarenes to anilines. A metal or reduced metal oxide, which can be obtained from solar thermal or electrochemical reduction, acts as the active site for nitrobenzene adsorption, H2O dissociation and in-situ hydrogen generation. Among the 15 metal and reduced metal oxides investigated, Zn and Sn emerged as highly efficient catalysts for the reduction of a broad range of organic nitro compounds under mild conditions, with H2 utilization efficiency 1–2 orders of magnitude above the state-of-the-art. The presented protocol provides extra dimensions for designing and optimizing conventional hydrogenation process with an alternative pathway. The reactive hydrogen atoms generated in-situ effectively overcome the barriers associated with hydrogen gas dissolution and its subsequent dissociation on the catalyst surface, thereby greatly enhancing the overall effectiveness for the hydrogenation reaction. This research potentially establishes a sustainable, generally applicable alternative to conventional hydrogenation methods, simultaneously presenting a viable solution for renewable energy storage.

Gas-Phase Ion/Ion Reactions to Enable Radical-Directed Dissociation of Fatty Acid Ions: Application to Localization of Methyl Branching.

Methyl branching on the carbon chains of fatty acids and fatty esters is among the structural variations encountered with fatty acids and fatty esters. Branching in fatty acid/ester chains is particularly prominent in bacterial species and, for example, in vernix caseosa and sebum. The distinction of branched chains from isomeric straight-chain species and the localization of branching can be challenging to determine by mass spectrometry (MS). Condensed-phase derivatization strategies, often used in conjunction with separations, are most commonly used to address the identification and characterization of branched fatty acids. In this work, a gas-phase ion/ion strategy is presented that obviates condensed-phase derivatization and introduces a radical site into fatty acid ions to facilitate radical-directed dissociation (RDD). The gas-phase approach is also directly amenable to fatty acid anions generated via collision-induced dissociation from lipid classes that contain fatty esters. Specifically, divalent magnesium complexes bound to two terpyridine ligands that each incorporate a ((2,2,6,6-tetramethyl-1-piperidine-1-yl)oxy) (TEMPO) moiety are used to charge-invert fatty acid anions. Following the facile loss of one of the ligands and the TEMPO group of the remaining ligand, a radical site is introduced into the complex. Subsequent collision-induced dissociation (CID) of the complex exhibits preferred cleavages that localize the site(s) of branching. The approach is illustrated with iso-, anteiso-, and isoprenoid branched-chain fatty acids and an intact glycerophospholipid and is applied to a mixture of branched- and straight-chain fatty acids derived from Bacillus subtilis.

Styrene thermal decomposition and its reaction with acetylene under shock tube pyrolysis conditions: An experimental and kinetic modeling study

Styrene is an important compound for polymer production and a key intermediate in gas-phase kinetics of polycyclic aromatic hydrocarbons (PAHs). For the first time, the pyrolysis of styrene with and without the presence of acetylene is investigated in a single-pulse shock tube coupled to gas chromatography and mass spectrometry. For each reaction system, quantitative speciation profiles are probed within the temperature range of 1100–1730 K, nominal pressure of 20 bar, and reaction duration of ∼ 4 ms. A kinetic model is built to simulate the results. The model explains how styrene is consumed under high-pressure pyrolytic conditions, how the secondary chemistry of intermediate products affect subsequent PAH formation, and how acetylene addition alters the reaction pathways. Throughout the temperature range, styrene breakdown is dominated by the bimolecular interaction between styrene and hydrogen atom, which produces benzene+vinyl or phenyl and ethylene through the stabilization of 2-phenylethyl and its subsequent dissociation. As a result, large amounts of phenyl accumulate, which react with styrene to form C14H12 species while simultaneously releasing H atoms through addition/elimination reactions. The reactivity of fuel consumption is preserved by the regeneration of H atoms as chain carriers. Several C14H10 compounds are formed as a result of the following breakdown of the C14H12 isomers, particularly stilbene, 1,1-diphenyl ethylene, and 9-methyl-9H-fluorene. The presence of acetylene as a co-reactant with styrene allows the Hydrogen-Abstraction-Acetylene-Addition (HACA) pathway to proceed from phenyl radical to enhance the production of phenylacetylene at very low temperatures and acenaphthylene. This hinders the formation of C14H12 isomers, exclusive products from pure styrene dissociation by competing with the styrene+phenyl routes.

CO2 activation by copper oxide clusters: size, composition, and charge state dependence.

The interaction of CO2 with copper oxide clusters of different size, composition, and charge is investigated via infrared multiple-photon dissociation (IR-MPD) spectroscopy and density functional theory (DFT) calculations. Laser ablation of a copper target in the presence of an O2/He mixture leads to the preferred formation of oxygen-rich copper oxide cluster cations, CuxOy+ (y > x; x ≤ 8), while the anionic cluster distribution is dominated by stoichiometric (x = y) and oxygen-deficient (y < x; x ≤ 8) species. Subsequent reaction of the clusters with CO2 in a flow tube reactor results in the preferred formation of near-stoichiometric CuxOy(CO2)+/- complexes. IR-MPD spectroscopy of the formed complexes reveals the non-activated binding of CO2 to all cations while CO2 is activated by all anions. The great resemblance of spectra for all sizes investigated demonstrates that CO2 activation is largely independent of cluster size and Cu/O ratio but mainly determined by the cluster charge state. Comparison of the IR-MPD spectra with DFT calculations of the model systems Cu2O4(CO2)- and Cu3O4(CO2)- shows that CO2 activation exclusively results in the formation of a CO3 unit. Subsequent CO2 dissociation to CO appears to be unfavorable due to the instability of CO on the copper oxide clusters indicating that potential hydrogenation reactions will most likely proceed via formate or bicarbonate intermediates.

Theoretical study on the mechanism of tryptophan methylation catalyzed by the cobalamin-dependent radical enzyme TsrM

TsrM is a radical S-adenosylmethionine (SAM) methylase that catalyzes the C2 methylation of L-tryptophan to produce 2-methyltryptophan, an intermediate in the biosynthesis of the antibiotic thiostrepton A. The mechanism of TsrM is investigated through the quantum chemical cluster approach. The calculations suggested an expanded ‘ping-pong’ mechanism that requires the participation of two SAM molecules. In the first half-reaction, one SAM molecule binds to the active site of TsrM and delivers its methyl group to the CoI ion of the cobalamin, leading to the generation of methylcobalamin. With the subsequent dissociation of a SAH molecule, another SAM molecule binds into the active site, which facilitates the transfer of the methyl group from methylcobalamin to the C2 of tryptophan via a non-radical mechanism. The resulting carbon cation intermediate then readily undergoes facile deprotonation to yield the final product 2-methyltryptophan. Our proposed mechanism also rationalizes the reactivity trends observed among four substrates with different substitutions.

Roles of Re and Cs Promoters and Organochlorine Moderators in the Synthesis of Ethylene Oxide on Ag‐based Catalysts

AbstractC2H4−O2 reactions form ethylene oxide (EO) on Ag nanoparticles dispersed on α‐Al2O3 and promoted with alkali and other elements, with Re and Cs most frequently used in practice. Traces of alkyl chlorides (e. g., C2H5Cl) and alkanes in much larger amounts are added to reactants to balance the rate of deposition and removal (and the coverage) of Cl adatoms (Cl*) on Ag surfaces. Such Cl adlayers retain Ag surface ensembles that form O2‐derived intermediates that favor EO synthesis, but typically decrease O2 activation rates. A series of Ag/α‐Al2O3 catalysts (with and without Re or Cs) are used here to examine the role of promoters and Cl moderators through an analysis of the effects of reaction conditions and C2H5Cl levels using convection‐reaction constructs and a mechanistic formalism that considers O2 (as chemisorbed O2*) as the reactant in EO synthesis through one electrophilic O‐atom, with the second O‐atom (O*) acting as a unselective nucleophile that must be scavenged by a sacrificial reductant (C2H4 or EO); such channels are precluded by any intervening O2 dissociation events (that form two O*). O2 consumption rates in C2H4−O2 reactions decrease 10‐fold upon exposing Ag/α‐Al2O3 to C2H5Cl, evincing persistent Cl* species that block active sites and require &gt;104 C2H4 oxidation turnovers to be removed. Activation barriers do not change but relative rates of epoxidation versus combustion increase in the presence of this refractory Cl* adlayer, which reduces the number and shrinks the size of available site ensembles without altering their intrinsic reactivity for O2 activation to form O2* but attenuating rates of its subsequent dissociation. Refractory O* adlayers also form on Ag surfaces, as shown by the accumulation of persistent O* species upon exposing reduced Ag particles to N2O. Inter‐atom repulsive forces weaken O* binding and destabilize N2O decomposition transition states to eventually allow stable N2 and O2 evolution for catalytic N2O decomposition, which occurs at landing ensembles formed at interstices of refractory adlayers. Cl* forms denser adlayers than O*, as evidenced by a 10‐fold decrease not only to C2H4−O2 rates but also to N2O stoichiometric and catalytic rates and O* uptakes. The occasional evolution of O2, which forms larger landing ensembles that more readily form 2O* from O2, occurs with higher frequency from O* than mixed O*/Cl* adlayers, and this effect of Cl* to inhibit (O−O)* dissociation is demonstrated in CO probe reaction studies, which show that highly reactive bound dioxygen species are retained to a greater extent when adlayers comprise both Cl* and O*. Re and Cs do not influence the nature of such adlayers but increase and decrease, respectively, the number of acid sites and selectivity losses via EO combustion. Their respective domains may also block a modest fraction of Ag surfaces without consequences on intrinsic O2 activation rates or EO selectivities. The effects of Re beyond those reported here may emerge upon synthetic protocols that alter Re location and Ag−Re intimacy to enable channels which utilize both O‐atoms in epoxidation.

Mechanistic insights into the adsorption and dissociation of nitrogen oxides on nickel phosphide (Ni2P) catalysts

The escalating concern regarding nitrogen oxides (NOx) emissions, linked to environmental challenges like smog, acid rain, ozone depletion, and global warming, necessitates effective strategies for their mitigation. DeNOx processes, including selective catalytic reduction (SCR), offer potential solutions, but costly precious metal catalysts hinder a widespread implementation. Alternatively, earth-abundant element compounds, particularly transition metal phosphides (TMPs), such as nickel phosphides (Ni2P), have garnered interest due to their promising catalytic performance. This study employed first-principles density functional theory (DFT) methods to investigate the catalytic properties of the (0001) Ni2P surface concerning NOx adsorption and dissociation. Both NO and NO2 are found to exhibit strong reactivity towards Ni2P-(0001)’s surface at the hollow triple-Ni sites, forming stable conjugated structures. Bader charge analysis indicates significant charge transfers during NOx adsorption from the interacting surface to the NOx, resulting in elongated N–O bond lengths, confirmed by vibrational frequency analyses. The dissociation process of NO2 was found to be both thermodynamically and kinetically favorable, with more heat being released than the subsequent NO dissociation’s activation barrier, resulting in a self-sustaining overall reaction. These insights provide valuable knowledge for designing efficient and sustainable Ni2P-based catalytic systems to address NOx emissions in environmental and industrial applications.

Unraveling the Morphology‐Function Correlation of Mesoporous ZnO Films upon Water Exposure

AbstractUbiquitous moisture in synthetic conditions and ambient environments can strongly influence the conductivity of ZnO semiconductors via the chemisorption and physisorption of water molecules on the ZnO surface. Such an intrinsically water‐sensitive nature will become more evident in mesoporous ZnO films where a large surface area and active sites are created simultaneously. However, fundamental insights underlying water‐mediated ZnO surface chemistry and electrical conductivity and the factors affecting them remain ambiguous due to the complexity of ZnO surfaces and the difficulties of in situ characterizations at multi‐dimensions. Here, self‐assembling diblock copolymers are exploited as structure‐directing agents to achieve mesoporous ZnO thin films with highly tailorable structural characteristics ranging from nanomorphologies, over crystalline levels, to defect contents. As verified by theoretical calculations, the presence of oxygen vacancy will facilitate favorable water adsorption and subsequent dissociation on the polar ZnO surfaces. Upon humidity exposure with progressively increased levels, mesoporous ZnO films are revealed to follow an almost positive relationship between adsorption and electrical conductivity but show superior morphological stability. This work not only elucidates the water‐governed ZnO surface chemistry but may also promote a comprehensive understanding of the morphology‐function relationship on ZnO‐based electronics.

Cavity-Modified Chemiluminescent Reaction of Dioxetane.

Chemiluminescence is a thermally activated chemical process that emits a photon of light by forming a fraction of products in the electronic excited state. A well-known example of this spectacular phenomenon is the emission of light in the firefly beetle, where the formation of a four-membered cyclic peroxide compound and subsequent dissociation produce a light-emitting product. The smallest cyclic peroxide, dioxetane, also exhibits chemiluminescence but with a low quantum yield as compared to that of firefly dioxetane. Employing the strong light-matter coupling has recently been found to be an alternative strategy to modify the chemical reactivity. In the presence of an optical cavity, the molecular degrees of freedom greatly mix with the cavity mode to form hybrid cavity-matter states called polaritons. These newly generated hybrid light-matter states manipulate the potential energy surfaces and significantly change the reaction dynamics. Here, we theoretically investigate the effects of a strong light-matter interaction on the chemiluminescent reaction of dioxetane using the extended Jaynes-Cummings model. The cavity couplings corresponding to the electronic and vibrational degrees of freedom have been included in the interaction Hamiltonian. We explore how the cavity alters the ground- and excited-state path energy barriers and reaction rates. Our results demonstrate that the formation of excited-state products in the dioxetane decomposition process can be either accelerated or suppressed, depending on the molecular orientation with respect to the cavity polarization.