Mesomeric Research Articles

AIM/NBO Analysis of the Geminal Coupling Constants in the Stabilization of A-Type Dimeric Proanthocyanidin: Angular Dependence.

The angular dependence of the indirect short-range spin-spin coupling constants (SSCC), the geminal , , and in A-type dimeric proanthocyanidin, was investigated using density functional theory. We studied the rotation of ring B around the bond. Therefore, we calculated hyperconjugative charge transfers and bond polarizations within the natural bond orbital (NBO) approach, performing a topological study based on Bader's theory, AIM (atoms in molecules), and analyzing the angular dependence of AIM/NBO parameters. The results describe a relationship between the geminal coupling that changes with angular variation and NBO charge transfers to the bonds involved in the coupling pathways that can explain the behavior of the former property. Based on AIM/NBO data, inductive and mesomeric effects were described and quantified, showing a clear correlation with the stabilization of the structure, demonstrating a resonance-assisted inductive effect. We also set out strong hyperconjugative interactions (anomeric effect) involving nonbonding electron pairs of oxygen atoms. This analysis of coupling constants supports previous models by other authors and shows the application in this particular case. Moreover, the SSCCs studied herein are used for identifying stable structures and conformational search analysis of flavonoids. Finally, our results show the relationship between SSCCs and the structure stabilization and charge delocalization effects.

Linear electronic relationship of surface functionalized fly ash and substituted phenols on bactericidal activity with the computational study

AbstractFly ash is a solid waste by‐product obtained from coal‐burning power plants. It is a silico‐aluminate material with an admixture of several metal oxides, which finds an application in geopolymers, zeolites, cement, catalysts, etc. The present article aims to assess the antibacterial activity of fly ash and substituted phenols against Escherichia coli and Staphylococcus in broth and agar cultures, respectively. High‐Temperature Activated Fly Ash (TAFA) shows significant bactericidal activity against gram positive (+) and negative (−) bacteria as compared to Mechanically Activated Fly Ash (MAFA) and Waste Polyethylene Coated Fly Ash (WPCFA), which attribute to the augmentation of mullite phase (lacking charge balancing cation) of fly ash at high temperature. These modified fly ash (TAFA, MAFA, and WPCFA) were characterized by Fourier Transform Infra Red (FT‐IR), Scanning Electron Microscope (SEM), and X‐Ray Diffraction (XRD) techniques. The substituted phenols further explored the significance of charge on the antibacterial properties. The para‐substituted phenols with groups having (+) mesomeric effect M > (−) I Inductive effect and ortho substituents with (+) I effect shows a linear electronic relationship with antibacterial properties with gram (+) bacteria, owing to charge augmentation at oxygen atom of phenoxide ion due to electronic effects. Further, the bactericidal efficacy was less significant on gram (−) bacteria. Small energy gap (Egap) values corroborated the chemical reactivity of phenols and substituted phenols. The antimicrobial potential of phenol/substituted phenols can be correlated with global descriptors. Molecular Electrostatic Potential (MEP) maps obtained through Density Functional Theory (DFT) indicate the nucleophilic centers in the molecular structure.

Effect of the cyano group in the HAVA mechanism for PAHs formation: a reaction force analysis for the reaction between benzonitrile (C6H5CN) and vinylacetylene

ABSTRACT Due to the importance and fascination that arises from processes involving Polycyclic Aromatic Hydrocarbon (PAHs) in the interstellar medium (ISM), in this work quantum calculations were used to study the HAVA mechanism (Hydrogen Abstraction Vinylacetylene Addition) involved in the PAHs formation from the benzonitrile (${\rm C_6H_5CN}$), molecule recently discovered in the ISM, and vinylacetylene (${\rm C_4H_4}$). The reaction force analysis was used to obtain information about the mechanisms in terms of structural and electronic rearrangements presents in the formation of naphthalene, 1-naphthonitrile, 2-naphthonitrile, and 3-ethynylisoquinoline. Due to the presence of the cyano group on the aromatic ring for the formation of 1-naphthonitrile and 2-naphthonitrile, these reactions: (a) follow the HAVA mechanism, showing the same structural nature of the submerged energy barriers and (b) result consistent with the fact that both molecules have recently been found in TMC-1, where benzonitrile and vinylacetylene are also present. The mesomeric and inductive effect of the cyano group on the aromatic ring contributes to lowering the energy barrier when the radical is in the ortho position on the aromatic ring with respect to the cyano group. This decrease contributes greatly to the work of electronic reordering. Although the formation of 3-ethynylisoquinoline (N-Heterocycle) does not follow the HAVA mechanism and involves positive barriers at the conditions of TMC-1, important astrochemical and astrobiological implications can be derived from this result, since N-containing heterocycles, have been detected in carbonaceous chondrites would be providing interesting connection between chemistry in space and the origin of life on Earth.

The relationship between sleep disturbance and aggressive behaviour among community-dwelling schizophrenia patients: a moderated mesomeric effect model

ObjectiveSleep disturbance is the most common concern of patients with schizophrenia and can lead to a poor prognosis, a low survival rate and aggressive behaviour, posing a significant threat to social security and stability. The aim of this study was to explore the mediating role of depression in the relationship between sleep disturbance and aggressive behaviour in people with schizophrenia living in the community, as well as the regulatory role of family intimacy and adaptability. These findings, in turn, may provide a theoretical basis and constructive suggestions for addressing the physical and mental health problems of these patients.MethodFrom September 2020 to August 2021, a convenience sampling method was used to select schizophrenia patients from the community attending follow-up appointments at the Fourth People’s Hospital of Pengzhou City, China. The researchers conducted a survey in the form of a star questionnaire. The survey included questions about general demographic data and disease-related questionnaires: the Pittsburgh Sleep Quality Index (PSQI), the revised Chinese version of the Modified Over Aggression Scale (MOAS), the Self-Rating Depression Scale (SDS), and the Family Adaptability and Cohesion Scale, Second Edition. FACES-II and SPSS 21.0 were used to organize and analyse the data.ResultsA total of 818 schizophrenia patients living in the community participated in the survey, and 785 valid questionnaires were ultimately collected, for a response rate of 95.97%. The results of multivariate analysis indicated that sex, number of psychiatric medications used, outpatient follow-up, history of hospitalization for mental disorders and sleep disturbances were factors influencing aggressive behaviour. Depression played a partial mediating role between sleep disturbance and aggressive behaviour, and the indirect effect size was 0.043 (57.33% of the total). In addition to sleep disturbance, family intimacy (β=-0.009, P < 0.01) and adaptability (β=-0.145, P < 0.001) can significantly predict depression.ConclusionThe findings indicate that sleep disturbance in schizophrenia patients in the community is a risk factor for aggressive behaviour, and depression plays a partial mediating role in the relationship among sleep disturbance, aggressive behaviour and family intimacy. In addition, adaptability plays a regulatory role in the relationship between depression and sleep disturbance.

Interaction between depression and insomnia under acupuncture treatment: a secondary analysis of a randomized controlled trial

To explore the interaction between emotional and insomnia symptom improvement in comorbid depression and insomnia patients treated with optimized acupuncture. A secondary analysis was conducted on a multicenter randomized controlled trial of acupuncture treatment for comorbid depression and insomnia. One hundred and forty patients with comorbid depression and insomnia were randomly assigned to an optimized acupuncture group (70 cases, 8 cases dropped out) and a conventional acupuncture group (70 cases, 8 cases dropped out). The patients in the conventional acupuncture group were treated with acupuncture at Yintang (GV 24+), Baihui (GV 20), bilateral Hegu (LI 4) and Taichong (LR 3); the patients in the optimized acupuncture group were treated with additional acupuncture at bilateral Lieque (LU 7), Zhaohai (KI 6), and intradermal needling was applied alternately at bilateral Xinshu (BL 15) and Danshu (BL 19), Shenshu (BL 23) and Anmian (Extra). Both groups received treatments twice a week for six weeks. The Hamilton depression scale-24 (HAMD-24) and Pittsburgh sleep quality index (PSQI) scores were observed before and after treatment for both groups. Mediation analysis was used to assess the mesomeric effect of PSQI and HAMD-24 emotional factors, and latent profile analysis categorized patients into subgroups based on HAMD-24 scores, followed by between-group efficacy comparisons. The indirect effect of the optimized acupuncture on improving depression emotions through PSQI was 3.052 (95%CI [1.407, 4.697]), accounting for 77.5% of the total effect. Conversely, the indirect effect of improving PSQI through the optimized protocol on depression emotions was 0.479 (95%CI [0.024, 0.935]), representing 14.8% of the total effect. Latent profile analysis identified 3 categories based on emotional and insomnia symptoms, and statistically significant differences in efficacy favoring the optimized acupuncture protocol over the conventional acupuncture protocol were observed only in the subgroup with relatively mild depression and insomnia symptoms (PSQI: 95%CI [-10.98, -5.44], P<0.001; HAMD-24: 95%CI [-12.31, -3.73], P =0.001). The optimized acupuncture protocol primarily improves insomnia symptoms and further improves depression emotions. Its efficacy advantages are more evident in patients with mild symptoms compared with the conventional acupuncture protocol.

Resilience provides mediating effect of resilience between fear of progression and sleep quality in patients with hematological malignancies.

Hematological tumors are common malignant tumors, with high morbidity and mortality rates. Most patients with hematological malignancies develop sleep disorders that seriously affect their life and health because of acute onset of disease, rapid progression, high recurrence rates, complex treatment methods, and treatment costs. To explore the mediating effect of resilience on fear of disease progression and sleep quality in patients with hematological malignancies. A cross-sectional analysis of 100 patients with hematological malignancies, treated in the First Affiliated Hospital of Jinzhou Medical University between August 2022 and August 2023, was conducted. Patients were assessed using a general data survey, a simplified scale for the fear of progression (FoP) of disease, a resilience scale, and the Pittsburgh Sleep Quality Index. Statistical analysis was conducted to determine the relationship between various patient characteristics and FoP, resilience, and sleep quality. Spearman's correlation analysis was used to examine the correlations between mental resilience, FoP, and sleep quality. The total FoP score mean value in patients with hematological malignancies was 38.09 ± 5.16; the total resilience score mean value was 40.73 ± 7.04; and the Pittsburgh Sleep Quality Index score mean value was 10.72 ± 1.90. FoP, resilience, and sleep quality of the patients were associated with family per capita monthly income and patient education level (P < 0.05). Spearman correlation analysis revealed that FoP was negatively correlated with resilience and sleep quality scores (r = -0.560, -0.537, P < 0.01), respectively, and resilience was significantly associated with sleep quality scores (r = 0.688, P < 0.01). Mediation analysis showed that the mediating effect of resilience between FoP and sleep quality in patients with hematological malignancies was -0.100 and accounted for 50.51% of the total effect. This indicated that FoP directly and indirectly affected sleep quality through the mesomeric effect of resilience. Resilience is an intermediary variable between FoP and sleep quality in patients with hematological malignancies. Medical staff should evaluate and follow-up FoP and resilience to implement measures to improve sleep quality.

Sulfur in Waste-Free Sustainable Synthesis: Advancing Carbon-Carbon Coupling Techniques.

This review explores the pivotal role of sulfur in advancing sustainable carbon-carbon (C-C) coupling reactions. The unique electronic properties of sulfur, as a soft Lewis base with significant mesomeric effect make it an excellent candidate for initiating radical transformations, directing C-H-activation, and facilitating cycloaddition and C-S bond dissociation reactions. These attributes are crucial for developing waste-free methodologies in green chemistry. Our mini-review is focused on existing sulfur-directed C-C coupling techniques, emphasizing their sustainability and comparing state-of-the-art methods with traditional approaches. The review highlights the importance of this research in addressing current challenges in organic synthesis and catalysis. The innovative use of sulfur in photocatalytic, electrochemical and metal-catalyzed processes not only exemplifies significant advancements in the field but also opens new avenues for environmentally friendly chemical processes. By focusing on atom economy and waste minimization, the analysis provides broad appeal and potential for future developments in sustainable organic chemistry.

Sulfur in Waste‐Free Sustainable Synthesis: Advancing Carbon–Carbon Coupling Techniques

AbstractThis review explores the pivotal role of sulfur in advancing sustainable carbon‐carbon (C−C) coupling reactions. The unique electronic properties of sulfur, as a soft Lewis base with significant mesomeric effect make it an excellent candidate for initiating radical transformations, directing C−H‐activation, and facilitating cycloaddition and C−S bond dissociation reactions. These attributes are crucial for developing waste‐free methodologies in green chemistry. Our mini‐review is focused on existing sulfur‐directed C−C coupling techniques, emphasizing their sustainability and comparing state‐of‐the‐art methods with traditional approaches. The review highlights the importance of this research in addressing current challenges in organic synthesis and catalysis. The innovative use of sulfur in photocatalytic, electrochemical and metal‐catalyzed processes not only exemplifies significant advancements in the field but also opens new avenues for environmentally friendly chemical processes. By focusing on atom economy and waste minimization, the analysis provides broad appeal and potential for future developments in sustainable organic chemistry.

PHOTOCATALYTIC DEGRADATION OF 3-CHLOROPHENOL USING Pd/Ag DOPED ON P25 DEGUSSA TiO2 NANOPARTICLE WITH UV RADIATION

Photocatalytic degradation of 3-chlorophenol was investigated using Pd/Ag doped on P25 Degussa TiO2. The Pd/AgTiO2 photocatalysts were prepared by sol immobilization method. A fabricated photo-reactor was used in photocatalytic degradation of 3-chlorophenol and monitored using HPLC. The experimental results indicates that doping of Pd/Ag on TiO2 increases the photocatalytic efficiency of TiO2. The experimental results indicates that Pd/ TiO2 has a photodegradation efficiency of 40.44% while Ag/TiO2 has a photodegradation efficiency of 60.44%. The dried catalysts were subsequently used again under the same experimental condition with a fresh 3-chlorophenol up to four (4) times. The result indicates that the re-used catalysts remain active for up to four (4) times of usage with minor reduction in activity, which is attributed to metal leaching. Ag/TiO2 has higher rate constant of - 0.019 than Pd/TiO2 which is -0.031, the rate constant for the degradation followed first-order reaction kinetics. The photocatalytic degradation of 3-chlorophenol indicates unstable degradation due to effect of inductive and mesomeric effect which is less on meta-position. The use of nanotechnology in wastewater treatment plants to curtail the environmental and health consequences of a widespread of organic pollutants should be encouraged.

Towards the 4 V-class n-type organic lithium-ion positive electrode materials: the case of conjugated triflimides and cyanamides.

Organic electrode materials have garnered a great deal of interest owing to their sustainability, cost-efficiency, and design flexibility metrics. Despite numerous endeavors to fine-tune their redox potential, the pool of organic positive electrode materials with a redox potential above 3 V versus Li+/Li0, and maintaining air stability in the Li-reservoir configuration remains limited. This study expands the chemical landscape of organic Li-ion positive electrode chemistries towards the 4 V-class through molecular design based on electron density depletion within the redox center via the mesomeric effect of electron-withdrawing groups (EWGs). This results in the development of novel families of conjugated triflimides and cyanamides as high-voltage electrode materials for organic lithium-ion batteries. These are found to exhibit ambient air stability and demonstrate reversible electrochemistry with redox potentials spanning the range of 3.1 V to 3.8 V (versus Li+/Li0), marking the highest reported values so far within the realm of n-type organic chemistries. Through comprehensive structural analysis and extensive electrochemical studies, we elucidate the relationship between the molecular structure and the ability to fine-tune the redox potential. These findings offer promising opportunities to customize the redox properties of organic electrodes, bridging the gap with their inorganic counterparts for application in sustainable and eco-friendly electrochemical energy storage devices.

DFT Study of a Series of Nicotinic Acid Benzylidenehydrazide Derivatives: Structure, Stability and Reactivity

Hydrazones especially nicotinic acid benzylidenehydrazide derivatives constitute an important class of compounds that has received much interest in recent years, due to their diverse biological characteristics, such as antimicrobial, anticonvulsant, analgesic, anti-inflammatory, antiplatelet, antituberculous and antitumor activities. These compounds have donor sites such as N and O which have non-bonding doublets which allow them to coordinate with metal ions. For this purpose, ten hydrazones structures were optimized in the DFT method, using the B3LYP functional, with the basis 6-31G** for all atoms, in the gas phase using the Gaussian 09 program. The structural, energetic (energies, EHOMO-LUMO gaps), electronic (dipolar moments, atomic charges) parameters were determined. A study of the stability of the ligands was carried out based on the relative energies to study the chemical reactivity of the optimized structures, we calculated the global reactivity parameters (ionization potential, electronic affinity, electronic chemical potential, absolute hardness, overall softness and overall electrophilicity). The results obtained show that All the systems considered are stabilized by two types of electronic effect. Either; an inductive attractor effect, with a coexistence of mesomeric effects. Analysis of chemical hardness values indicates that the most stable isomers found are the hardest, with larger HOMO/LUMO gaps, and therefore less reactive. As a result, charge transfer will be predominant. The most nucleophilic systems are also determined based on the calculation of the eletrophicity and nucleophilicity indices.

The impact of vocational college students' professional identity on academic achievement: Self-efficacy as a mediator

To understand the current situation of the academic achievement of Chinese vocational college students in China. A questionnaire survey was conducted among 1560 students; the University Student Professional Identity Scale, General Self-Efficacy Scale, and Academic Achievement Scale were used as research tools. The responses were recorded using 5-point Likert-type scales. Propose research hypotheses based on structural models. We tested reliability and validity, difference analyses, correlation analyses, regression analyses, and mesomeric effect analysis. There are significant differences in academic achievement among students of different grades, but there is no significant difference in academic achievement among student cadres. The professional identity of vocational college students is significantly and positively predicted academic achievement; self-efficacy partially mediates between professional identity and academic achievement. Professional identity of vocational college students significantly and positively predicted. Academic achievement: self-efficacy partially mediates between professional identity and academic achievement. (1) There is a certain imbalance in the subjects and majors of the study in terms of gender; (2) The exploration of this study is mainly quantitative research, lacking qualitative research; (3) Due to the limitations of research time and method, this study only investigated the real situation for a certain period and lacked the process of long-term follow-up research. University administrators and professional teachers should improve the professional identity of vocational college students to enhance their self-efficacy, promote their academic achievement development, and enhance the vocational, educational, and technical nature of vocational education.

Molecular hybrids of substituted phenylcarbamoylpiperidine and 1,2,4-triazole methylacetamide as potent 15-LOX inhibitors: Design, synthesis, DFT calculations and molecular docking studies

Inflammation is a multifaceted phenomenon triggered by potentially active mediators acutely released arachidonic acid metabolites partially in lipoxygenase (LOX) pathway which are primarily accountable for causing several diseases in humans. It is widely believed that an inhibitor of the LOX pathway represents a rational approach for designing more potent antiinflammatory leads with druggable super safety profiles. In our continual efforts in search for anti-LOX molecules, the present work was to design a new series of N-alkyl/aralkyl/aryl derivatives (7a-o) of 4-phenyl-5-(1-phenylcarbamoylpiperidine)-4H-1,2,4-triazole-3-thiol which was commenced in seriate formation of phenylcarbamoyl derivative (1), hydrazide (2), semicarbazide (3) and 4-phenyl-5-(1-phenylcarbamoylpiperidine)-4H-1,2,4-triazole-3-thiol (4). The aimed compounds were obtained by reacting 4-phenyl-5-(1-phenylcarbamoylpiperidine)-4H-1,2,4-triazole-3-thiol with assorted N-alkyl/aralkyl/aryl electrophiles. All compounds were characterized by FTIR, 1H-, 13C-NMR spectroscopy, EI-MS and HR-EI-MS spectrometry and screened against soybean 15-LOX for their inhibitory potential using chemiluminescence method. All the compounds except 7m and 7h inhibited the said enzyme remarkably. Compounds 7c,7l, 7j and 7a displayed potent inhibitions ranging from IC50 1.92 ± 0.13 µM to 7.65 ± 0.12 µM. Other analogues 7g, 7o, 7e, 7b, 7d, 7k and 7n revealed excellent inhibitory values ranging from IC50 12.45 ± 0.38 µM to 24.81 ± 0.47 µM. All these compounds did not reveal DPPH radical scavenging activity. Compounds 7i-o maintained > 90 % human blood mononuclear cells (MNCs) viability at 0.125 mM as assayed by MTT whilst others were found toxic. Pharmacokinetic profiles predicted good oral bioavailability and drug-likeness properties of the active scaffolds. SAR investigations showed that phenyl substituted analogue on amide side decreased inhibitory activity due to inductive and mesomeric effects while the mono-alkyl substituted analogues were more active than disubstituted ones and ortho substituted analogues were more potent than meta substituted ones. MD simulation predicted the stability of the 7c ligand and receptor complex as shown by their relative RMSD (root mean square deviation) values. Molecular docking studies displayed hydrogen bonding between the compounds and the enzyme with Arg378 which was common in 7n, 7g, 7h and baicalein. In 7a and quercetin, hydrogen bonding was established through Asn375. RMSD values exhibited good inhibitory profiles in the order quercetin (0.73 Å) < 7 g < baicalein < 7a < 7n < 7 h (1.81 Å) and the binding free energies followed similar pattern. Density functional theory (DFT) data established good correlation between the active compounds and significant activity was associated with more stabilized LUMO (lowest unoccupied molecular orbitals) orbitals. Nevertheless, the present studies declare active analogues like 7c, 7 l, 7a, 7j as leads. Work is ongoing in derivatizing active molecules to explore more effective leads as 15-LOX inhibitors as antiinflammatory agents.

Determining the Quintet Lifetimes in Side-ring Substituted [Fe(terpy)2]2+ Complexes

We previously studied the effect of 4' substitution in iron(II)-bis-terpyridine complexes, showing that the photoexcited high-spin quintet-state is stabilized by electron-donating substituents. In this paper we explore the effects of electron-donating ( X = NH2 , Cl ) and withdrawing ( X = NO2 ) substituents in the 5,5" positions on the stability and lifetime of the quintet-state. We used a simple densitiy-functional theory (DFT) based method that had been proven fairly accurate in the case of 4' substitution to estimate the energy barrier of the quintet-singlet transition and thereby predict the quintet state lifetime. We synthetized the complexes and used ultrafast transient optical absorption spectroscopy to experimentally determine the quintet lifetimes, in order to test the applicability of these quantum-chemistry based predictive methods for these side-ring substitution cases. UV-Visible spectra of the complexes have shown that the metal-to-li­gand charge transfer (MLCT) and ligand-localized transitions of these complexes change according to the previous observations. We have shown that in the 5,5" positions, electron withdrawing groups stabilize the quintet state, while donating groups destabilize it. This is in stark contrast to the effects previously observed for the 4' case, and indicates that unlike the latter case, the simple concept of inductive and mesomeric effects may not be adequate to describe the changes due to 5,5" substitution, warranting further study of the area.

The Impact of the Digital Economy on the Optimization of Industrial Structure: An Empirical Study Based on the Intermediary Role of Technological Innovation

The digital economy has become an important path for the transformation and upgrading of industrial structure. Technological innovation, as the primary driving force for development, is a key entry point in analyzing this issue. This paper conducts empirical analysis based on Panel data of 31 provinces in China from 2011-2021, and constructs Mesomeric effect and moderating effect models. Research has found that the development of the digital economy has a significant promoting effect on the rationalization of industrial structure; The digital economy can promote the improvement of technological innovation level; From a national perspective, the level of technological innovation reflects the masking effect in the process of promoting industrial structure rationalization in the digital economy, and this conclusion is still valid after robustness testing.Based on this, we need to strengthen the construction of digital infrastructure, rely on the digital economy to stimulate independent innovation and technological transformation level, and promote the upgrading of industrial structure.

CEO stability and enterprise total factor productivity from the perspective of dual carbon: a mechanism test based on green innovation

PurposeThrough this study, the aim is to provide reference for the improvement of CEO related theories, the reform of internal governance mechanisms and compensation systems in enterprises, and ultimately contribute to economic and social development and the achievement of dual carbon goals.Design/methodology/approachIn the context of accelerating the implementation of the “dual carbon” goal and promoting sustainable economic and social development, this paper builds a panel data model based on the panel data of 31 provinces in China from 2011 to 2019 to empirically test the impact of CEO stability on green innovation and total factor productivity of enterprises.FindingsThe results show that CEO stability has a positive role in promoting enterprise total factor productivity and green innovation and enterprise green innovation also has a positive role in promoting total factor productivity; Heterogeneity testing found that CEO stability has no significant impact on green innovation in state-owned enterprises. Corporate green innovation has a partial mesomeric effect between CEO stability and total factor productivity; The proportion of independent directors has a negative moderating effect on CEO stability and corporate green innovation, while equity incentive has a positive moderating effect on the relationship between CEO stability, corporate total factor productivity and green innovation.Originality/valueFirst, it develops the research on CEO stability and its economic consequences. Second, it expands the impact of CEO stability on heterogeneous enterprises. Third, provides new ideas for the reform of internal governance mechanism and salary system of enterprises.

Exploring the mesomeric effect of executive equity incentives on enterprise innovation: a study in the context of digital transformation

PurposeThe purpose of this study is to explain the following questions: First, whether the executive equity incentive has an impact on enterprise innovation and digital transformation; Second, if there is any influence, whether there is difference between state-owned enterprises and private enterprises in the research conclusions; Third, whether the digital transformation of enterprises has had an intermediary effect between executive equity incentive and enterprise innovation; Fourth, whether the proportion of independent directors in the corporate governance mechanism has a regulatory effect.Design/methodology/approachIn the context of China's promotion of “digital China” construction and high-quality development of economic innovation, this paper takes Shanghai and Shenzhen A-share listed companies in 2011–2019 as a sample, empirically studies the linear and nonlinear relationship between executive equity incentive and enterprise digital transformation and innovation, and further considers the regulatory effect of heterogeneous property rights and the proportion of independent directors, with a view to improving the reform of China's enterprise equity incentive system make contributions to enterprise innovation and digital transformation.FindingsThe results show that executive equity incentive has a positive role in promoting enterprise digital transformation and innovation, and enterprise digital transformation has a positive role in promoting enterprise innovation; Digital transformation of enterprises has a partial intermediary effect between executive equity incentive and enterprise innovation.Originality/valueFirst, it expands the research on the economic consequences of enterprise salary incentive system. Second, it expands the research on the specific role path of enterprise digital economy transformation. Third, provide new ideas for the reform of corporate governance mechanism.

N-Heterocyclic Carbenes with Polyfluorinated Groups at the 4- and 5-Positions from [3 + 2] Cycloadditions between Formamidinates and cis-1,2-Difluoroalkene Derivatives.

We herein report the formation of fluorinated N-heterocyclic carbenes (NHCFs) that bear fluorine atoms at the 4- and 5-positions of the imidazol-2-ylidene ring. Treatment of sodium N,N'-bis(aryl)formamidinates with tetrafluoroethylene followed by the addition of LiBF4 induced a [3 + 2] cycloaddition to afford 4,5-difluorinated imidazolium salts, which served as the precursors for 4,5-difluorinated NHCs. A key feature of this procedure is its applicability to other perfluorinated compounds, which enabled us to incorporate polyfluorinated functional groups at 4- and 5-positions on the imidazol-2-ylidene skeleton. Thus, employing octafluorocyclopentene and hexafluorobenzene led to the formation of 4,4,5,5,6,6-hexafluoro-1,3-diaryl-3,4,5,6-tetrahydrocyclopenta[d]imidazolium (CypIPrF·HBF4) and 4,5,6,7-tetrafluoro-1,3-diarylbenzimidazolium (BIPrF·HBF4) salts, respectively. A thorough NMR analysis of these NHCFs, their selenium adducts, and their tricarbonyl nickel complexes, (NHCF)Ni(CO)3, demonstrated that the fluorine substituents, contrary to expectations, tend to act as electron donors owing to the considerable positive mesomeric effect, while the perfluorocyclopentene-fused and tetrafluorobenzo-fused rings are pure electron acceptors due to their strong negative inductive effect. The unique and increased π-accepting character of the perfluorocyclopentene-fused and tetrafluorobenzo-fused NHCFs in both stoichiometric and catalytic reactions is further demonstrated by employing (NHCF)Ni(CO)3 and (NHCF)AuCl species, respectively. Moreover, an analysis of the % buried volume (%Vbur) values clearly suggests that the modification of the NHC backbone with polyfluorinated groups can drastically alter the electronic properties of the NHC ligand without substantially changing its steric properties. Our experimental results were further corroborated by a series of computational calculations.

Spectroscopic, quantum chemical investigation and molecular docking studies on N-(2-benzoylamino) phenyl benzamide: A novel SARS-CoV-2 drug.

The present work describes the structural and spectral properties of N-(2-benzoylamino) phenyl benzamide (NBPB). The geometrical parameters of NBPB molecule such as bond lengths, bond angles and dihedral angles are calculated and compared with experimental values. The assigned vibrational wave numbers are in good agreement with the experimental FTIR and FT Raman spectra. The vibrational frequency of C=O stretching was downshifted to a lower wave number (red shift) due to mesomeric effect. The UV-Vis spectrum of the title compound was simulated and validated experimentally. The energy gap and charge transfer interaction of the title molecule were studied using frontier molecular orbital analysis. The electrophilic and nucleophilic reactivity sites of NBPB were investigated through the analysis of the molecular electrostatic potential surface and the Fukui function. An assessment of the intramolecular stabilization interactions of the molecule was performed using natural bond orbital analysis. The drug-likeness parameter was calculated. To investigate the inhibitory potential of the molecule, molecular docking analysis was conducted against SARS-CoV-2 proteins, revealing its capability to serve as a novel inhibitor against SARS-CoV-2. The high binding affinity of NBPB molecule was due to the presence of hydrogen bonds along with different hydrophobic interactions between the drug and the SARS-CoV-2 protein receptor. Hence, the title molecule is identified to be a potential candidate for SARS-CoV-2.

Molecular Control of Floquet Topological Phase in Non-adiabatic Thouless Pumping.

Non-adiabatic Thouless pumping of electrons is studied in the framework of topological Floquet engineering, particularly with a focus on how atomistic changes to chemical moieties control the emergence of the Floquet topological phase. We employ real-time time-dependent density functional theory to investigate the extent to which the topological invariant, the winding number, is impacted by molecular-level changes to trans-polyacetylene. In particular, several substitutions to trans-polyacetylene are studied to examine different effects on the electronic structure, including the mesomeric effect, inductive effect, and electron conjugation effect. Maximally localized Wannier functions are employed to relate the winding number to the valence bond description by expressing the topological pumping as the transport dynamics of the localized Wannier functions. By further exploiting the gauge invariance of the quantum dynamics in terms of the minimal particle-hole excitations, the topological pumping of electrons can be also represented as a cyclic transition among the bonding and antibonding orbitals. Having connected the topological invariant to the chemical concepts, we demonstrate molecular-level control of the emergence of the Floquet topological phase, presenting an exciting opportunity for the intuitive engineering of molecular systems with such an exotic topological phase.