Correction for ‘A combined crystallography and DFT study on ring-shaped Cucurbit[ n ]urils: structures, surface character, and host–guest recognition’ by Guoxun Zhu et al. , RSC Adv. , 2022, 12 , 10014–10019, https://doi.org/10.1039/D2RA00797E.

Correction for 'A theoretical study on the on-off phosphorescence of novel Pt(ii)/Pt(iv)-bisphenylpyridinylmethane complexes' by Guoxun Zhu et al., RSC Adv., 2022, 12, 18238-18244, https://doi.org/10.1039/D2RA03060H

Correction for ‘A theoretical study on the on–off phosphorescence of novel Pt( ii )/Pt( iv )–bisphenylpyridinylmethane complexes’ by Guoxun Zhu et al. , RSC Adv. , 2022, 12 , 18238–18244, https://doi.org/10.1039/D2RA03060H

A combined experimental and density functional theory (DFT) study on the UV-Vis spectra of o-methoxyaniline-terminated mono azo dyes was conducted. By applying time-dependent-DFT calculations, details of excitation processes were determined and visualization by hole-electron analysis was undertaken. Fragment-divided analysis revealed the contributions of different parts of the structures for the UV-Vis spectra, that richer/poorer electron density on aromatic rings lead to greater/less maximum absorption wavelengths (λmax) and larger/smaller half peak width (W1/2). Combining theoretical prediction with experimental verification, we answered the question of how the electronegativities of substituents affected the electron densities and how it affected the spectra. In addition, a linear model connecting the λmax and W1/2 to the chemical shifts obtained by NMR spectroscopy was constructed, which laid the foundation for construction of a spectral library.

有机光转换材料可以将太阳能电池不能吸收的波段的光转换为太阳能电池可利用的可见光,从而拓宽太阳能电池的光谱响应范围,提高太阳能电池的光电转换效率.但是,这类光转换材料普遍存在着光稳定性差的问题,极大限制了其推广应用.选择了一种新型有机光转换材料,将其与乙烯-醋酸乙烯共聚物(EVA)树脂混合,制备了具有光转换功能的EVA胶膜.通过荧光光谱和紫外可见光谱测试了光转换EVA胶膜的发光性能和透明性,结果显示当光转换材料BL-3的质量分数为1.5％时,转光EVA胶膜具有最佳的发光性能,其在可见光区域的透过率与纯EVA胶膜相当.TG测试结果表明,光转换材料BL-3的加入不会对EVA胶膜的热稳定性造成明显影响.将BL-3质量分数1.5％的光转换EVA膜覆盖在太阳能标准电池表面,太阳能电池的光电转换效率(PCE)可从空白电池的14.03％提升至14.35％,相对增幅达到2.28％.紫外线加速老化测试结果表明,光转换EVA膜在加速老化500 h后,其相对荧光强度仍保持在初始荧光强度的85％以上.因此,该光转换EVA胶膜能够有效提升太阳能电池的光电转换效率,同时还具有优异的耐紫外线老化性能,有望应用于高效长寿命太阳能电池组件.

A combined crystallography and DFT study of cucurbit[n]urils (n = 5-8, 10) was carried out, and PBE0 was certified to be the most rational density functional method for optimization task. Steric hindrance and electronic effect of the hindered lone pair electrons in cucurbit[n]urils were qualitatively measured by bond order analysis, lone pair electron (LP) visualization and electrostatic potential (ESP) study. Together with energy decomposition analysis of some selected host-guest systems, we quantitatively verified the effect of size/cavity and noncovalent interaction in host-guest recognition. This solid study revealed that lone pairs electrons affect not only on host-guest identification mode but also on geometry stability, which pave the avenue for further sophisticated applications.

An in-depth theoretical study on the Pt(ii)/Pt(iv)-bisphenylpyridinylmethane complexes was carried out, which focused on the geometric/electronic structures, excitation procedures, on-off phosphorescence mechanisms, and structure-optical performance relationships. The key roles of the linkages (LK) connected in the middle of phenylpyridines were carefully investigated using multiple wavefunction analysis methods, such as non-covalent interaction (NCI) visualizations and natural bond orbital (NBO) studies. The phosphorescence-off phenomenon was considered by hole-electron analysis and visualizations, spin-orbit coupling (SOC) studies, and NBO analysis. Through these investigations, the relationship of the substituents in LK and the optical performances were revealed, as well as the fundamental principles of the phosphorescence-quenching mechanism in Pt(iv) complexes, which pave the way for further performance/structural renovation works. In addition, an intuitive visualization method was developed using a heatmap to quantitatively express the SOC matrix elementary (SOCME), which is helpful for big data simplification for phosphorescence analysis.

An efficient and practical reductive rearrangement reaction has been developed for the stereoselective synthesis of diverse piperidinones. This transformation features mild conditions, good substrate/functional group compatibility and large-scale synthetic potential. Subsequent combined DFT and experimental studies revealed a reduction triggered cascade pathway in which the active imine species was involved as the key intermediate. The biological application of the products has also been demonstrated by acting as the potent antitumor agents, which further strengthens the synthetic utility of this approach.

The efficient couplings of diverse N-arylureas and methyleneoxetanones have been realized via Rh(III)-catalyzed and solvent-controlled chemoselective C-H functionalization, which involved the tunable β-H elimination and β-O elimination processes, thereby giving divergent access to quinolin-2(1 H)-ones and ortho-allylated N-arylureas with broad substrate compatibility and good functional group tolerance. the divergent synthetic utilities of the transformations have also been exemplified by subsequently tandem C-H allylation, unsymmetrical C-H functionalization, alternative reaction mode, as well as removal of the carbamoyl group.

食品风味是评价食品品质特征的重要指标.食品风味物质分析通常采用一维气相色谱或气相色谱-质谱联用法,但由于某些食品风味成分组成和基质复杂,无法用一维气相色谱将其完全分离.全二维气相色谱将分离机理不同而又相互独立的两根色谱柱以正交方式组合,显著提升了色谱分离能力和分析速度,可满足食品中风味化学成分的二次分离.该文综述了全二维气相色谱技术在未经二次加工的食用农产品(如水果、蔬菜和肉类)和经过二次加工的食品(如乳制品、饮品和调味品)中风味化学成分分析中的应用,展现了全二维气相色谱技术的特点,并为食品风味的解析提供参考.

Photodynamic therapy (PDT) is a modern cancer therapy. But it is still difficult to obtain ideal photosensitizers. We synthesized six new peri-xanthenoxanthene derivatives rapidly and efficiently using solid-phase carbon-bath microwave irradiation technology, and investigated their in vitro photodynamic antitumor activity with 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Our results showed that all compounds exhibited extremely low dark cytotoxicity and good phototoxicity against four human cancer cell lines. In particular, compound 3c showed the best in vitro PDT activity against Hela cells and Bel-7402 cells with IC50 values of 91 and 74nmol/L, respectively. Its value of 1-octanol/water partition coefficient (log K-ow) was 0.5309, suggesting that it is a promising photosensitizer for PDT due to its low dark cytotoxicity, high phototoxicity, and potential water solubility.

In this work, we report a new fluorescent material for pentaerythritol tetranitrate (PETN) vapor detection. A series of fluorene substituted vinyl-SiO microspheres with different ratios has been designed and easily synthesized. Sensing films on quartz plates were obtained by a solid phase transfer method. With a specific diameter of SiO and a specific density of surrounding fluorene, the microspheres performed a rapid fluorescence color change via oxidation with highly selective PETN catalysis. The emission peak at 355 nm was rapidly quenched while an enhancement at 525 nm appeared under exposure to PETN saturated vapor. Herein, we present this fluorescent silica nanoparticle as an excellent sensing material towards vapor phase PETN, making contributions to many fields such as public security and military use.

A series of conjugated compounds containing imidazole structure units were designed and synthesized. Their structures were characterized by H-1 NMR, C-13 NMR, MS and elemental analysis. Their UV absorption wavelength (lambda(a)), fluorescence emission wavelength (lambda(e)), fluorescence quantum yield (Phi) and fluorescence lifetime (tau) were determined, and the relationships between the molecular structures and its spectral data were discussed. The results showed that these compounds possess strong luminescence characteristic, and the maximum value of Phi is 91%. 1,4- Bis-(2-(1-benzylbenzimidazole))benzene (5b) was selected to fabricate organic light-emitting diode (OLED). Its main luminous peak is at 448 nm, the maximum brightness is 6790 cd.m(-2) when the voltage is 23.8 V (875 mA.cm(-2)), the maximum current efficiency is 1.17 cd.A(-1), the maximum power efficiency is 0.96 lm.W-1, and the maximum external quantum efficiency is 0.92%, which indicate that these compounds have great potential application value as OLED materials.

Volatile components in Dalbergia cochinchinensis Pierre were analysed using a comprehensive two-dimensional gas chromatography with mass spectrometry method featuring a new solid-state modulator. Compared to one-dimensional gas chromatography, the number of detected peaks were significantly increased. A total of 45 major compounds were identified in this study and the forward and reverse match factors of these compounds were both above 800. The results showed that the volatile components in Dalbergia cochinchinensis Pierre were primarily aldehyde and ketone compounds such as benzaldehyde, cinnamaldehyde, 4-chromanone, 1-(2-hydroxyphenyl)ethanone and acetophenone. In addition, a semi-quantitative analysis was conducted to determine the contents of the detected compounds based on peak area percentage. Moreover, the repeatability of the comprehensive two-dimensional gas chromatography-mass spectrometry analysis in this study was quite satisfactory with relative standard deviations less than 12.7% for intraday and 17.3% for interday measurements.

PURPOSE:Tumor xenograft model is an indispensable animal cancer model. In esophageal squamous cell carcinoma (ESCC) research, orthotopic tumor xenograft model establishes tumor xenograft in the animal esophagus, which allows the study of tumorigenesis in its native microenvironment.MATERIALS AND METHODS:In this study,we described two simple and reproducible methods to develop tumor xenograft at the cervical or the abdominal esophagus in nude mice by direct injection of ESCC cells in the esophageal wall.RESULTS:In comparing these two methods, the cervical one presented with more clinically relevant features, i.e., esophageal stricture, body weight loss and poor survival. In addition, the derived tumor xenografts accompanied a rapid growth rate and a high tendency to invade into the surrounding structures. This model was subsequently used to study the anti-tumor effect of curcumin, which is known for its potential therapeutic effects in various diseases including cancers, and its analogue SSC-5. SSC-5 was selected among the eight newly synthesized curcumin analogues based on its superior anti-tumor effect demonstrated in an MTT cell proliferation assay and its effects on apoptosis induction and cell cycle arrest in cultured ESCC cells. Treatment of orthotopic tumor-bearing mice with SSC-5 resulted in an inhibition in tumor growth and invasion.CONCLUSION:Taken together, we have established a clinically relevant orthotopic tumor xenograft model that can serve as a preclinical tool for screening new anti-tumor compounds, e.g., SSC-5, in ESCC.

Multi-component reaction (MCR) is a powerful, versatile and step-economical approach in organic synthesis due to reducing reaction steps and simplifying operation. An ab initio study was carried out on the MCR of acetone, aniline and 4-hydro-coumarine, including wave function analysis of the reactant complexes, intermediates, and reaction mechanism. Meantime, the effect of the solvent and noncovalent interaction on the reaction was also discussed. The obtained result was well matched with experimental data and gave a deeper understanding of the reaction. It is found that the reaction went through several cascade-reaction steps, including Aldol reaction, imine rearrangement, Michael addition reaction, and the whole reactions were equilibrium. Based on the ab initio analysis, the reaction was improved by increasing the yield with 20%.

Herein, two versatile bran-new methods have been developed for building three new kinds of complicated-framework compounds including 2,4,4-trimethyl-2-(phenylamino)-3,4-dihydro-2H,5H-pyrano[3,2-c]chromen-5-ones, 4,4,4',4'-tetramethyl-1,3,3',4,4',5-hexahydro-5'H-spiro-[benzo[b][1,4]diazepine-2,2'-pyrano[3,2-c]-chromen]-5'-ones, and 2,2,4',4'-tetramethyl-2,3,3',4'-tetrahydro-5H,5'H-spiro[benzo[b][1,4]-oxazepine-4,2'-pyrano[3,2-c]chromen]-5'-ones in a one-pot manner via four-molecule and five-molecule cascade reactions of commercially available 4-hydroxychromen-2-one, substituted anilines, and acetone. In consideration of these impressive features including no need of additional catalysts and solvents, moderate to good yields, excellent site-selectivity, and broad substrate/functional group tolerance, we believe that the two present protocols should have the potential for broad synthetic utility.

52 Structure-based thiosemicarbazone compounds bearing various substituted-lipophilic part, including substituted-benzaldehyde, substituted-phenylalkan-1-one and their biphenyl-type thiosemicarbazone analogs, were designed, synthesized and evaluated as new tyrosinase inhibitors. The results demonstrated that 22 compounds have potent inhibitory activities against tyrosinase with the IC50 value of lower than 1.0 μM. On the basis of the obtained experimental data, the structure-activity relationships (SARs) were rationally derived. Besides, the inhibition mechanism and the inhibitory kinetics of selected compounds 3d and 6e were investigated, revealing that such type of compounds were belonged to the reversible and competitive tyrosinase inhibitors. To verify the safety of these developed thiosemicarbazone compounds, four randomly selected compounds 3d, 4e, 6a and 9a were also tested in 293T cell line for the evaluation of the cytotoxicity. Interestingly, all these compounds almost did not perform any toxicity to 293T cells even at a high concentration of 1000 μmol/L. Taken together, these results suggested that such compounds could serve as the highly efficient and more safe candidates for the treatment of tyrosinase-related disorders.

Dibenzoxanthenes were reported to possess antitumor biological activity.

In continuing our program aimed to search for potent compounds as highly efficient tyrosinase inhibitors, here a series of novel 4-alkoxy- and 4-acyloxy-phenylethylenethiosemicarbazone analogues were designed, synthesized and their biological activities on mushroom tyrosinase were evaluated. Notably, most of compounds displayed remarkable tyrosinase inhibitory activities with IC50 value of lower than 1.0 μM. Furthermore, the structure–activity relationships (SARs) were discussed and the inhibition mechanism and the inhibitory kinetics of selected compounds 7k and 8d were also investigated. Taken together, these results suggested that such compounds could serve as the promising candidates for the treatment of tyrosinase-related disorders and further development of such compounds might be of great interest.