Rational Control of Maximum EMI/CPL Intensity and Wavelength of Bora[6]helicene via Polarity and Vibronic Effects.

Solvent polarity control as an efficient methodology to regulate the chiroptical properties, including spectral shape, width, intensity, wavelength, etc., has emerged as a novel frontier in optical materials design. However, the underling relationship connecting polarity to the optical property remains unclear. Herein, using state-of-the-art computations and the FC|VG model, the solvent effect on the chiroptical properties of bora[6]helicene was accurately and systematically computed to shed light on this issue. It is found that the vibronic coupling is crucial in explaining the spectral shape, width, and relative intensity of different peaks. Moreover, the intensity and position of the emission (EMI) and circularly polarized luminescence (CPL) are closely related to the polarity of the solvent. Intriguingly, we got a series of good linear relationships between polarity and EMI|CPL (|r| ≥ 0.95). Thus, this parameter can be used as a potential descriptor to estimate the intensity and position of EMI|CPL, leading to new strategies for designing fully colored fluorescent materials.

Theoretical study of excited state dynamics of a ratiometric fluorescent probe for detection of SO2 derivatives.

Sulfur dioxide (SO2), a toxic air pollutant, can have harmful effects on human health when inhaled or when it forms bisulfite in the body. In the present work, a ratiometric fluorescent probe, 2-(2'-hydroxyphenyl)benzothiazole-3-ethyl-1,1,2-trimethyl-1H-benzo[e]indolium (HBT-EMBI), was selected to study the mechanism of SO2 derivatives detection. This study provides insights into the attributions of ratiometric fluorescence through hydrogen bond dynamics, electronic excitation properties, radiation rates, and excited state intramolecular proton transfer (ESIPT) processes using the density functional theory (DFT) and the time-dependent density functional theory (TDDFT) level. The results confirm that the large Stokes shifts and broad emission spectra of the HBT-EMBI probe are associated with its intramolecular charge transfer (ICT) characteristics and hydrogen bonding-driven ESIPT processes, respectively. After the addition reaction between the probe and HSO3-/SO32-, the conformational populations of HBT-EMBI-HSO3- transfer abnormally from enol configurations to more stable keto configurations, which leads to a distinguished change in the visible color and the ratiometric fluorescence signal, and is not due to the blockage of the ICT process of HBT-EMBI-HSO3-, as previously reported. This work provides a new perspective on the mechanism of detection of SO2 derivatives by ESIPT fluorescent probes.

Wavelength-dependent photoisomerization of trans-4,4'-azopyridine: Nonadiabatic dynamics simulation.

The trans-cis photoisomerization processes of 4,4'-azopyridine upon S1 and S2 excitations have been investigated by nonadiabatic dynamics simulations based on multi-reference CASSCF calculations. 119 sampling trajectories were simulated starting from the trans form excited to the S1 (S2) state and the cis-isomer quantum yield is evaluated to be (3 ± 2)% ((18 ± 4)%), which is qualitatively in agreement with the recent experimental results in ethanol. We found that rotation around the central N-N bond accompanied by the N-N-C symmetrical bending vibrations is the main mechanism in photoisomerization of the target molecule excited to the S1 and S2 states. Upon S1 excitation, S1-S0 transition occurs earlier along the C-N-N-C torsional coordinate, leading to a low cis-isomer quantum yield. Upon S2 excitation, half of the simulated trajectories are trapped in a potential well on the S2 state, from which the twisted conical intersections are more easily reached in the internal conversion, resulting in a higher cis-isomer quantum yield.

Case report: Ectopic corpus cavernosum presented as bladder tumor in a 3-year-old boy.

Background: Ectopic tissue is rarely found in the bladder for adults. Currently, there have been reports of ectopic prostate and colon tissue in the bladder. These ectopic tissues are manifested as a bladder mass and cause lower urinary tract symptoms. However, the ectopic corpus cavernosum in the bladder has never been reported, and its clinical characteristics and treatment have not been explored yet. Case summary: A 3-year-old boy was admitted to the hospital due to 1 month of urinary frequency. The physical examination was unremarkable. Urine analysis from other hospitals showed an elevated urine white blood cell count of 17.9/ul. In addition, ultrasound indicated a possible bladder mass. CT and MRI showed a well-margined lesion (1.9×1.9 cm) in the bladder trigone. Through preoperative imaging, we diagnosed a bladder tumor (inclined towards benign). The transurethral resection of the bladder tumor was performed. Unfortunately, the surgery was unsuccessful due to the difficulty in removing the excised tissue through the urethra. Subsequently, bladder incision and tumor resection were performed. The tumor was successfully removed. Surprisingly, the postoperative pathology showed that the tumor tissue was corpus cavernosum. The pathological diagnosis was ectopic corpus cavernosum in the bladder. No complications were found after the operation, and no recurrence was observed during follow-up. Conclusion: The ectopic corpus cavernosum in the bladder has never been reported for children, which is presented as a benign tumor with rapid proliferation and large size. Surgery is recommended. However, the transurethral resection of bladder tumors is difficult to perform due to narrow urethra and limited surgical instruments. Bladder incision and tumor resection may be preferred.

Vacuum-Assisted vs Conventional Minimally Invasive Percutaneous Nephrolithotomy for the Treatment of Two-to-Four-Centimeter Stones: A Multicenter Prospective and Randomized Trial.

Introduction: Percutaneous nephrolithotomy (PCNL) is the recommended treatment for 2-4-cm renal stones. Minimally invasive PCNL (MPCNL) with ≤22F sheath was frequently used instead of standard PCNL. MPCNL uses pressurized irrigation to flush out stone fragments through a conventional nephrostomy sheath (cNS), which may result in higher intrarenal pressure (IRP) and longer operating time. The novel vacuum-assisted nephrostomy sheath (vaNS) was developed to mitigate higher IRP and to facilitate stone removal. It might improve the performance of MPCNL. This prospective and randomized trial compares these two sheaths. Materials and Methods: In total, 120 patients with 2-4-cm renal stones were accrued in six tertiary medical centers with equal numbers in 2021. In total, 120 patients underwent mPCNL, 60 using 18F cNS and 60 using 18F vaNS, in a prospective and randomized assignment. The primary outcome measurement is decrease in IRP. The secondary outcome is efficacy in stone retrieval. Results: The IRP was lower with vaNS than with cNS: mean IRP during lithotripsy was 12.0 ± 2.7 mm Hg with vaNS vs 20.4 ± 6.0 mm Hg with cNS, p = 0.000. IRP duration ≥30 mm Hg was shorter with vaNS than with cNS (6.7 ± 7.4 seconds vs 113.4 ± 222.7 seconds, p = 0.001). vaNS has shorter stone removal time (26.9 ± 14.3 minutes vs 35.7 ± 11.8 minutes, p = 0.000). Stone extraction rate was higher (166.4 ± 88.1 mm3/min vs 90.4 ± 31.7 mm3/min, p = 0.000). Stone grasper usage was less (1.4 ± 2.6 vs 11.9 ± 9.7, p = 0.000). vaNS maintained the safety profile. Blood loss, creatinine changes, perioperative complications, and hospital stays were the same in both groups, all p > 0.05. Conclusion: MPCNL for stones 2-4 cm using vaNS has shorter stone removal time, higher stone extraction rate, and less use of stone extractor. vaNS is superior to cNS at reducing IRP and is associated with improved stone free rates at 3 days but not at 30 days postoperatively. The trial was registered with Chinese Clinical Trial Registry (ClinicalTrials.gov, NCT ChiCTR2000039681).

The effect of the CPP size on the nonlinear optical properties of the new necklace-type molecules formed by carborane and [n]Cycloparaphenylenes(n = 8-11).

The new necklace-type molecules were formed by [8-13]CPP and carborane, which further manipulated the size of the macroring, revealing the effect of size on its luminescence behavior. In this work, the effects of ring size on the absorption spectrum, electron excitation and nonlinear optical properties of the compounds were investigated in detail, aiming to reveal an effective way to improve the optical properties of these necklace-type compounds. The absorption spectra of the compounds showed that the size of the CPP ring had little effect on the spectral shape and position, but the electron transition information showed that there were the significant charge transfer within the CPP ring and a gradual enhancement of interfragment charge transfer from the CPP ring to carborane. The increasing order of polarizability, first and second hyperpolarizability values of these compounds with the increase of CPP size indicated that increasing the size of the CPP ring was an effective way to increase the nonlinear optical properties of necklace-type molecules. Among the frequency dependent hyperpolarizability values, the γ(-ω;ω,0,0) value increased by a factor of 4 from complex 1 to 6 with the increase of CPP ring size, which indicated that increasing the size of the CPP ring was an effective way to increase the optical Kerr effect of necklace-type molecules. Therefore, these the new necklace-type nolecules formed by carborane and [n]Cycloparaphenylenes would be excellent nonlinear optical materials in the field of the all-optical switch.

Molecular Understanding of the Interfacial Interaction and Corrosion Resistance between Epoxy Adhesive and Metallic Oxides on Galvanized Steel.

The epoxy adhesive-galvanized steel adhesive structure has been widely used in various industrial fields, but achieving high bonding strength and corrosion resistance is a challenge. This study examined the impact of surface oxides on the interfacial bonding performance of two types of galvanized steel with Zn-Al or Zn-Al-Mg coatings. Scanning electron microscopy and X-ray photoelectron spectroscopy analysis showed that the Zn-Al coating was covered by ZnO and Al2O3, while MgO was additionally found on the Zn-Al-Mg coating. Both coatings exhibited excellent adhesion in dry environments, but after 21 days of water soaking, the Zn-Al-Mg joint demonstrated better corrosion resistance than the Zn-Al joint. Numerical simulations revealed that metallic oxides of ZnO, Al2O3, and MgO had different adsorption preferences for the main components of the adhesive. The adhesion stress at the coating-adhesive interface was mainly due to hydrogen bonds and ionic interactions, and the theoretical adhesion stress of MgO adhesive system was higher than that of ZnO and Al2O3. The corrosion resistance of the Zn-Al-Mg adhesive interface was mainly due to the stronger corrosion resistance of the coating itself, and the lower water-related hydrogen bond content at the MgO adhesive interface. Understanding these bonding mechanisms can lead to the development of improved adhesive-galvanized steel structures with enhanced corrosion resistance.

Molecular structure and spectroscopic properties of two radicals of C4H2N: a DFT study.

CONTEXT: The cyano propargyl radical (CH2C3N and HC3HCN) is important reaction intermediate in both combustion flames and extraterrestrial environments such as cold molecular clouds and circumstellar envelopes of carbon stars. The acquisition of spectroscopic constants and anharmonic effect facilitates a more in-depth study of this radical. However, the data available in the literature do not allow the precise predictions for it in the interstellar medium. In this work, complete spectroscopic parameters as well as anharmonic constants of two radicals of C4H2N have been evaluated by different DFT methods. The calculated results show that it is reasonable to study the molecular spectroscopic properties of C4H2N by wB97XD/6-311++G theoretical level. On this basis, the sextic centrifugal distortion constants, anharmonic constants, vibration-rotation interaction constants, and so on are predicted for the study of high-precision rovibrational spectrum. In addition, the relationship between the anharmonic effect and vibration mode of CH2C3N and HC3HCN and their infrared spectroscopic characteristics are discussed. METHODS: The calculation of the anharmonic force fields and spectroscopy properties was performed using B3LYP, B3PW91, CAM-B3LYP, and wB97XD methods combined with the 6-311++G and aug-ccpVTZ basis sets, respectively, by the Gaussian16 program suite. The IR spectra were performed with Multiwfn3.8.

First-principles study of CO2 hydrogenation to formic acid on single-atom catalysts supported on SiO2.

The hydrogenation of CO2 into valuable chemical fuels reduces the atmospheric CO2 content and also has broad economic prospects. Support is essential for catalysts, but many of the reported support materials cannot meet the requirements of accessibility and durability. Herein, we theoretically designed a series of single-atom noble metals anchored on a SiO2 surface for CO2 hydrogenation using density functional theory (DFT) calculations. Through theoretical evaluation of the formation energy, hydrogen dissociation capacity, and activity of CO2 hydrogenation, we found that Ru@SiO2 is a promising candidate for CO2 hydrogenation to formic acid. The energy barrier of the rate-determining step of the entire conversion process is 23.9 kcal mol-1; thus, the reaction can occur under mild conditions. In addition, active and stable origins were revealed through electronic structure analysis. The charge of the metal atom is a good descriptor of the catalytic activity. The Pearson correlation coefficient (PCC) between metal charge and its CO2 hydrogenation barrier is 0.99. Two solvent models were also used to investigate hydrogen spillover processes and the reaction path was searched by the climbing image nudged-elastic-band (CI-NEB) method. The results indicated that the explicit solvent model could not be simplified into a few solvent molecules, leading to a large difference in the reaction paths. This work will serve as a reference for the future design of more efficient catalysts for CO2 hydrogenation.

Rational design of a small organic photosensitizer for NIR-I imaging-guided synergistic photodynamic and photothermal therapy.

Developing a small molecular photosensitizer to achieve multimodal phototherapy has recently garnered attention as a promising strategy for efficient cancer treatment. However, synthesis of a multifunctional small molecular photosensitizer has remained challenging. Here we report an aggregation-induced-emission (AIE)-featured luminogen (AIEgen) TPA-BTZ decorated with long and branched alkyl chains. TPA-BTZ shows long-wavelength emission at ca. 800 nm in the NIR-I region. Moreover, upon laser irradiation, TPA-BTZ could produce O2˙- and 1O2via both type I and type II mechanisms for enhanced photodynamic therapy (PDT). The propeller-like structure triphenylamine (TPA) rotators not only endow TPA-BTZ with AIE characteristics but also facilitate heat generation by intramolecular rotation for photothermal therapy (PTT). More importantly, long and branched alkyl chains can create intermolecular spatial isolation in the fabricated TPA-BTZ@PEG2000 nanoparticles (NPs) to allow sufficient intramolecular motion for photothermal conversion. Due to these unique features, in vitro and in vivo evaluations demonstrate that the TPA-BTZ@PEG2000 NPs exhibited long-term NIR-imaging ability, superior tumoricidal activity, and suppressed tumor growth. This research provides new insights for developing new AIEgens for NIR imaging-guided multimodal phototherapy.

A biomass-derived Schiff base material composited with polylactic acid nanofiber membrane as selective fluorescent 'turn off/on' platform for Pb2+ quantitative detection and characterization.

Herein, a biomass-derived compound Z1 is synthesized via 'one pot' method for detection Pb2+ using fluorescence and visual dual-mode in aqueous solution. Z1 shows good response to Pb2+ with a limit of detection (LOD) of 13.4 nM. Importantly, the coordination mode of Z1 with Pb2+ is further evaluated by UV-vis and NMR spectroscopy and a 1:1 stoichiometry is identified. Furthermore, Z1 can be applied to detection Pb2+ in practical samples with satisfactory recoveries in range of 96.0 %-112.0 % in real samples. Besides, Z1 is added into polylactic acid (PLA) solution and made as portable fluorescence nanofiber membrane for Pb2+ detection. Further, Z1 responds to Pb2+ with high selectivity and sensitivity and has been applied for tracking Pb2+ changes in soil samples, zebrafish, and plant tissues. These results indicated that Z1 had great application potential in accurate detection Pb2+.

Colorimetric/spectral dual-mode analysis of sensitive fluorescent probe based on 2,3,3-trimethyl-3H-benzo[e]indole detection of acid pH.

Herein, a high-performance fluorescence probe, namely H4, based on intramolecular charge transfer (ICT) mechanism was developed. H4 could serve as fluorescent probe for detection acidic pH change in environment with outstanding sensitivity, short response time (<10 s), low hemolysis effect (<0.3%) and excellent photostability (>120 min). H4 exhibits a good linear relationship (R2 = 0.9901, Y = 22.0409X-58.3397) characteristics in range of pH 2.2-7.4 with pKa 4.3. In addition, the probe can be also made as fluorescent test sheets and further used as a portable sensor to enhance the screening speed to achieve detection of H+ in real-time. Further, H4 determined H+ in real food samples (milk, shrimps, and scallops) has excellent recoveries (98-105%), which making it of great potential use in food freshness evaluation. Initially, its favorable behavior for detecting H+ change is successfully illustrated in living onion tissues and zebrafish, which allows qualitative visualization of acid pH changes in in biological systems.

In situ photodeposition of platinum clusters on a covalent organic framework for photocatalytic hydrogen production.

Photocatalytic hydrogen production has been considered a promising approach to obtain green hydrogen energy. Crystalline porous materials have arisen as key photocatalysts for efficient hydrogen production. Here, we report a strategy to in situ photodeposit platinum clusters as cocatalyst on a covalent organic framework, which makes it an efficient photocatalyst for light-driven hydrogen evolution. Periodically dispersed adsorption sites of platinum species are constructed by introducing adjacent hydroxyl group and imine-N in the region of the covalent organic framework structural unit where photogenerated electrons converge, leading to the in situ reduction of the adsorbed platinum species into metal clusters by photogenerated electrons. The widespread platinum clusters on the covalent organic framework expose large active surface and greatly facilitate the electron transfer, finally contributing to a high photocatalytic hydrogen evolution rate of 42432 µmol g-1 h-1 at 1 wt% platinum loading. This work provides a direction for structural design on covalent organic frameworks to precisely manipulate cocatalyst morphologies and positions at the atomic level for developing efficient photocatalysts.

In silico design of metal-free hydrophosphate catalysts for hydrogenation of CO2 to formate.

CO2 reduction by H2 using metal-free catalysts is highly challenging. Frustrated Lewis pairs (FLPs) have been considered potential metal-free catalysts for this reaction. However, most FLPs are unstable, which limits their practical applications. In this study, a class of novel metal-free catalysts composed of K3-nHnPO4 (n = 0, 1, 2) and B(C6F5-mHm)3 (m = 0, 3, 5) were prepared and identified as effective catalysts for CO2 hydrogenation to formate by density functional theory (DFT) calculations. The simulations show that the B-H bond formation is the rate-determining step (RDS). The acid/base strength and repulsive steric interactions affect the corresponding energy barrier. Therefore, the catalytic performance can be improved by choosing a suitable Lewis acid or base. Among these catalysts, the B(C6H5)3-KH2PO4 pair, with the lowest barrier height (26.3 kcal mol-1) in RDS, is suggested as a promising metal-free catalyst for CO2 hydrogenation. This study may provide strategies for designing new LP-based metal-free catalysts.

Digital-intellectual design of microporous organic polymers.

Microporous organic polymers (MOPs) are a new class of microporous materials. Due to their high porosity, large pore volume, and large surface area, MOPs exhibit excellent performance in gas adsorption and storage, membrane separation, ion capture, heterogeneous catalysis, light energy conversion and storage, capacitance, and other fields. However, selecting high-performance materials for specific applications from thousands of candidate MOPs is a key problem. Traditional design strategies for new materials with targeted properties, including trial-and-error and relying on the experiences of domain experts, are time- and cost-consuming. With the rapid development of computation technology and theoretical chemistry, the discovery of new materials is no longer a purely experimental subject. Breaking away from the traditional trial-and-error strategy for materials discovery, materials design is emerging and gaining increasing attention. In addition, the ability to collect "big data" has greatly improved and has further stimulated the development of new methods for materials design and discovery. In this perspective, we examine how data-driven techniques combine artificial intelligence (AI) and human expertise, playing a significant role in the design of MOPs. Such analytics can significantly reduce time-to-insight and accelerate the cost-effective materials discovery, which is the goal for designing future MOPs.

Stacking Engineering: A Boosting Strategy for 2D Photocatalysts.

Two-dimensional (2D) photocatalytic material is a vital project for modern solar energy conversion and storage. Despite a vast family of potential 2D photocatalysts that is demonstrated, their commercial applications are severely limited because of fast photogenerated electron-hole recombination. Here, based on first-principles, we propose a general paradigm to boost the separation of photoexcited charge carriers in 2D photocatalysts by stacking engineering. Taking the emerging water splitting photocatalyst MoSi2N4 as an example, we show that specific interlayer stacking-induced electric polarization plays a significant role in altering the electronic properties and thus the suppressed recombination rate of photoexcited carriers. Moreover, we find that the catalytic performance can be further controlled by vertical strain. These generalized findings not only highlight the importance of stacking-induced electric polarization but also offer new prospects for the design and application of 2D photocatalysts.

Rhodium-Catalyzed and Chiral Zinc Carboxylate-Assisted Allenylation of Benzamides via Kinetic Resolution.

Enantioenriched allenes are important building blocks. While they have been accessed by other coupling methodologies, enantioenriched allenes have been rarely obtained via C-H activation. In this work, kinetic resolution of tertiary propargyl alcohols as an allenylating reagent has been realized via rhodium(III)-catalyzed C-H allenylation of benzamides. The reaction proceeded efficiently under mild conditions, and both the allenylated products and the propargyl alcohols were obtained in high enantioselectivities with an s-factor of up to 139. The resolution results from bias of the two propargylic substituents and is assisted by a chiral zinc carboxylate additive.

UV-fluorescence probe for detection Ni2+ with colorimetric/spectral dual-mode analysis method and its practical application.

Fluorescence probe combines with fluorescence imaging technology has become the most powerful analytical method with their great advantages of high sensitivity and selectivity and real-time monitoring. Ni2+ is widely distributed in food, environment and living animals, thereof, it is of great significance for detection Ni2+ with high selectivity. Herein, a simple strategy is proposed to design and synthesiz a small molecule fluorescent probe Y1 by using "one-pot" method. The spectroscopic behaviors including UV-Vis absorption and fluorescence emission spectrum have been used to verify the feasibility of probe towards Ni2+ in water/EtOH (v/v = 2:8) mixtures under neutral condition. As expected, Y1 offers high selectivity and sensitivity for detection Ni2+ in aqueous solution with a good linear relationship and low detection limit within Ni2+ concentration variation from 0 to 13 µM (DOL = 0.0038 µM, R2 = 0.9983). It is remarkable that Y1 can be applied for real-time visualization Ni2+ change in sprouted potato and zebrafish with great photo-stability, highlighting that the practicability and feasibility of Y1 to detect and monitor Ni2+ in the field of food industry and biomedical field.

"Turn-on" ratiometric fluorescent probe: Naked-eye detection of acidic pH and citric acid (CA) by using fluorescence spectrum and its application in real food samples and zebrafish.

Rapid, accurate and efficient detection of acidic pH and citric acid (CA) changes is of great significance for predicting environmental and food safety problems by fluorescence analysis technique. Herein, a small molecule ratiometric fluorescent probe (BICL) based on benzoindole derivatives is successfully synthesized and characterized and used for quantitatively and qualitatively "turn-on" detection acid pH and CA changes in solution and environment by ultraviolet spectrum and fluorescence emission spectrum. On the one hand, the probe has a good linear relation to acidic pH in the pH range 3.1-4.5 (I604/I550 = 13.088-2.3878pH, R2 = 0.9986). On the other hand, the probe has a good linear relationship in the range of CA concentration of 14.0-23.0 µM (I604/I550 = 0.5324 [CA]-5.2628, R2 = 0.9993) and a low detection limit of 2.967 µM. BICL has a good recovery rate in the range of 114.6 ~ 101.0% and a low relative standard deviation (RSD) (0.0011 ~ 0.0092) in the determination of CA in real samples (water, drinks and fruits), which holds great potential for application in determination of CA in real samples. Importantly, the probe has good blood compatibility, and it has been successfully applied to detect exogenously induced changes in acidic pH and CA in zebrafish with great time-stability by using fluorescence imaging technology, respectively.

Rhodium-Catalyzed C-H Activation-Based Construction of Axially and Centrally Chiral Indenes through Two Discrete Insertions.

Reported herein is asymmetric [3+2] annulation of arylnitrones with different classes of alkynes catalyzed by chiral rhodium(III) complexes, with the nitrone acting as an electrophilic directing group. Three classes of chiral indenes/indenones have been effectively constructed, depending on the nature of the substrates. The coupling system features mild reaction conditions, excellent enantioselectivity, and high atom-economy. In particular, the coupling of N-benzylnitrones and different classes of sterically hindered alkynes afforded C-C or C-N atropochiral pentatomic biaryls with a C-centered point-chirality in excellent enantio- and diastereoselectivity (45 examples, average 95.6 % ee). These chiral center and axis are disposed in a distal fashion and they are constructed via two distinct migratory insertions that are stereo-determining and are under catalyst control.