Radical Character Research Articles

Investigating the effect of radical-based strategies on improving foreign Chinese learners' radical awareness and character meaning production: a meta-analysis

This meta-analysis reviewed 11 articles regarding radical-based instruction strategies and synthesized their results to investigate the effect of radical-based strategies on improving radical awareness and character meaning production among CFL (Chinese as a Foreign Language) learners. The overall results demonstrated that radical-based instruction strategies had a significant effect associated with character meaning production. Furthermore, the differences of the effectiveness were also examined between beginning-level CFL learners and intermediate-level CFL learners.

Metal-Stabilized Thiyl Radicals Design Inspired by Elemental Periodic Extension Notion for Ligand-Based Alkene Addition.

Inspired by alkene addition to the Ru and Re tris(thiolate) complexes via carbon-sulfur bond formation/cleavage reactions along with a periodic extension catalysis notion, a comparative study of the electronic structures, mechanisms, and reactivities for ethylene addition to the Os and Tc tris(thiolate) complexes was performed by DFT and high-level ab initio quantum calculations. The oxidized Os and Tc complexes were revealed to exhibit sufficient radical characters on the ligands to support their reaction with ethylene, whereas neutral Tc tris(thiolate) complex featuring little thiyl radical character renders no reactivity toward ethylene. Differential reactivities of these tris(thiolate) complexes was deemed to derive from the synergy of the thiyl radical character, the electronegativity, the row, and the charge. Extending from Ru and Re tris(thiolate) complexes to their Os and Tc counterparts can help us to get insightful rationales that would promote further research on alkene addition to metal-stabilized thiyl radicals.

Creating, Preserving, and Directing Carboxylate Radicals in Ni-Catalyzed C(sp3)–H Acyloxylation of Ethers, Ketones, and Alkanes with Diacyl Peroxides

The reaction of Ni(II) acetate with diacyl peroxides produces high-valence Ni-species capable of catalytic oxidative acyloxylation of C(sp3)–H bonds in ethers, ketones, and alkanes. The desired esters were obtained in 20–82% yields. Computational analysis suggests that activation of the peroxide moiety produces a dynamically interconverting mixture of catalytic Ni-species in the formal Ni(III) state. Remarkably, in these species, coordination of the RCO2 group at Ni preserves radical character at the carboxylate moiety (i.e., carboxylate radical acts as an “L-ligand”), so the latter can induce fast C–H abstraction. The spirocyclopropyl moiety prevents premature radical decarboxylation via a combination of hybridization factors and stereoelectronic effects. A variety of viable C–H activation patterns were identified experimentally and computationally.

Controlling π-π Interactions of Highly Soluble Naphthalene Diimide Derivatives for Neutral pH Aqueous Redox Flow Batteries.

Organic redox-active molecules are a promising platform for designing sustainable, cheap, and safe charge carriers for redox flow batteries. However, radical formation during the electron-transfer process causes severe side reactions and reduces cyclability. This problem is mitigated by using naphthalene diimide (NDI) molecules and regulating their π-π interactions. The long-range π-stacking of NDI molecules, which leads to precipitation, is disrupted by tethering four ammonium functionalities, and the solubility approaches 1.5m in water. The gentle π-π interactions induce clustering and disassembling of the NDI molecules during the two-electron transfer processes. When the radical anion forms, the antiferromagnetic coupling develops tetramer and dimer and nullifies the radical character. In addition, short-range-order NDI clusters at 1m concentration are not precipitated but inhibit crossover. They are disassembled in the subsequent electron-transfer process, and the negatively charged NDI core strongly interacts with ammonium groups. These behaviors afford excellent RFB performance, demonstrating 98% capacity retention for 500 cycles at 25mA cm-2 and 99.5% Coulombic efficiency with 2m electron storage capacity.

Catalyst-Free Formal Conjugate Addition/Aldol or Mannich Multicomponent Reactions of Mixed Aliphatic Organozinc Reagents, π-Electrophiles and Michael Acceptors.

Catalyst-free multicomponent reactions of mixed alkylzinc reagents with Michael acceptors and aldehydes, ketones or activated imines are described. Primary, secondary and tertiary alkylzinc reagents, pre-generated in acetonitrile from the corresponding iodoalkanes, were used in the process, leading to the very efficient formation of a variety of β-hydroxycarbonyl compounds. The imines showed more contrasting results, due to the direct addition of the organozinc compound to the C=N bond. Mechanistic assays involving TEMPO account for a polar instead of a radical character of the reaction.

Theoretical Understanding of Reactions of Rhenium and Ruthenium Tris(thiolate) Complexes with Unsaturated Hydrocarbons: Noninnocent Nature of the Ligand, Mechanism, and Origin of Differential Reactivity

In retrospect to the complexity induced by the noninnocent ligands in identifying the transition metal's oxidation state and correlating the ligand's noninnocence with reactivity, the reactions of alkene/alkyne addition to rhenium/ruthenium tris(thiolate) complexes are particularly good cases for shedding light on the chemistry of the dppbt ligand, including its noninnocent nature, ligand-centered mechanism, and origin of differential reactivity. Density functional theory (DFT) combined with the high-level ab initio calculations performed herein demonstrates that, upon alkene/alkyne addition, the orbital symmetry properly regulates the reaction to form ligand-centered cis-interligand dithioethers as the most favorable pathway. The neutral and cationic Re and Ru dithioethers are revealed via DFT calculations to be in a low-spin ground state; on the contrary, high-level ab initio methods confirm that the dicationic Re-dithioethers exhibit obvious multireference character with antiferromagnetic coupling between Re-dyz and S1-py. The metal-stabilized thiyl radicals play a pivotal role in delivering the reactivity of [RuL3]+ and [ReL3]+/2+ toward alkene/alkyne rather than [ReL3], where [RuL3]+ and [ReL3]+/2+ present significant radical characters on ligand S2, yet neutral [ReL3] has little such feature, from which differential reactivity arises. Faster styrene addition to Ru tris(thiolate) in contrast to Re tris(thiolate) has been properly interpreted using DFT calculations with major products assigned. The deeper understanding gained in this work would illuminate further experimental exploration in adding alkene/alkyne to other metal-stabilized thiyl radicals.

Electron-Coupled Proton Transfer Governed Magnetic Spin Couplings and Switching in Defect Nano Silicon Carbide

The formation mechanism, defect characterization, and potential applications of the Si vacancy (VSi) with internal H atoms in the silicon carbide (SiC) materials have been widely investigated. However, the inherent electronic properties and related phenomena induced by internal H dynamics in VSi, especially the C-radical spin interaction dynamics, are still poorly understood in such nano SiC. In this work, using the density functional calculations, we explore the magnetic coupling characteristics and dynamic behaviors induced by H-motion in nano SiC with four different types of H-doped VSi defect centers, (VSi + H)−, (VSi + H)+, (VSi + 2H), and NVH [i.e., (NCVSi + H)0 in which one of C-radical sites in VSi is replaced by N]. Our results reveal their unique ferromagnetic (FM) or antiferromagnetic (AFM) spin coupling characteristics and H-motion-induced interconversion. In general, the internal H-motion goes through the electron-coupled proton transfer (ECPT) in a C–H···C unit which has great impact on molecular orbitals, spin densities, and thus spin couplings among the C-radicals, allowing the VSi center to undergo magnetic switching between FM and AFM coupling. Interestingly, as in the (VSi + H)− center, such ECPT can further drive the excess electron delocalized on three C-radicals to gather at the ECPT unit, forming a three-center-four-electron (3c–4e) [C···H···C]− covalent H-bond with the switching of magnetic coupling. This work provides the dynamics insights into the spin coupling characteristics and its regulation by internal H-motion and multiple radical characters of such defect materials and the formation of a 3c–4e H-bond assisted by excess electron, and also provides inspired information for the design of inorganic magnetic materials and logic devices which can be controlled by interior doping and dopant dynamics.

The nature of π-hole interactions between iodide anions and quinoid rings in the crystalline state.

The investigated co-crystal of 3-chloro-N-methylpyridinium iodide with tetrabromoquinone (3-Cl-N-MePy·I·Br4Q) reveals a π-hole interaction between an iodide anion and a quinoid ring involving an n → π* charge transfer. The quinoid ring has a partial negative charge (estimated to be in the range 0.08-0.11e) and a partial radical character, which is related to the black colour of the crystals (crystals of neutral tetrabromoquinone are yellow). A detailed X-ray charge density study revealed two symmetry-independent bond critical points between the iodide anions and carbon atoms of the ring. Their maximum electron density of 0.065 e Å-3 was reproduced by quantum chemical modelling. The energy of the interaction is estimated to be -11.16 kcal mol-1, which is comparable to the strength of moderate hydrogen bonding (about -10 kcal mol-1); it is dominantly electrostatic in nature, with a considerable dispersion component.

SOCIAL CONSTRUCTION OF LEADERS AT INTEGRATED MADRASAH ALIYAH (MA) OF DARUL AMAL KARANGANYAR CONCERNING RELIGIOUS MODERATION POLICIES

This study aims to analyze the leadership's understanding of religious moderation and the way madrasah leaders construct their students to become moderate Muslims. This research was phenomenological qualitative research. The results of this study are that the leadership's thinking greatly influences the character of the santri. If the leader has a radical understanding, then the santri (students) will have a radical character, while the leader who has a moderate understanding will also become a moderate Muslim. The leadership of the Darul Amal Integrated Supreme Court has a good understanding of religious moderation. From this understanding, madrasa leaders implement indicators of religious moderation through habituation, curricula, and extracurricular learning. So that students have moderate character and become a habit in everyday life.

C4-Selective C–H Borylation of Pyridinium Derivatives Driven by Electron Donor–Acceptor Complexes

The photoinduced C4-selective C-H borylation of pyridines was achieved using electron donor-acceptor complexes derived from a Lewis base and N-amidopyridinium salts under external oxidant- and photocatalyst-free conditions. Notably, the nucleophilic character of phosphite-ligated boryl radicals enables addition of a radical to position C4 of pyridinium salts to afford C4-borylated heteroarenes that are otherwise difficult to obtain. This approach provides a versatile platform for the installation of both phosphite- and amine-coordinated boron groups on a series of pyridines under mild conditions, demonstrating excellent C4-positional selectivity for the pyridine scaffolds.

Paramagnetic Semiconducting Se–Mn Clusters: A Mn3Se4-Stabilized Selenide Radical Intermediate and Its Aggregated Derivatives

The transition metal-stabilized heavy main group radicals are extremely scarce due to their highly reactive natures, making them difficult to be isolated and identified. We report here a rare class of the Se radical-containing manganese carbonyl anionic cluster, [(μ-Se)(μ3-Se2)2Mn3(CO)9]•2- (1), which was successfully obtained from the one-pot reaction of Se powder and Mn2(CO)10 in concentrated KOH/MeOH/MeCN solutions at 90 °C. Dianion 1 and its dimeric cluster, [(μ4-Se2){(μ3-Se2)2Mn3(CO)9}2]4- [(1)2], could undergo the reversible Se-Se bond breakage or reformation by the thermal cracking of (1)2 or self-dimerization of 1, showing the μ-Se•- radical character of 1. Complex 1 could react with (2,2,6,6-tetramethylpiperidin-1-yl)oxyl (TEMPO) to form the Se radical-captured complex [(μ-Se(TEMPO)) (μ3-Se2)2Mn3(CO)9]2- (1-TEMPO) or could react with alkylene bromides (CH2)nBr2 (n = 1, 2) to give the Mn4-based oxidative coupling products, [(μ4-Se2)(μ-Se2LSe)2Mn4(CO)12]2- (L = CH2, 2-CH2; Se, 2-Se). In addition, dianion 1 and its aggregated derivatives (1)2, 1-TEMPO, 2-CH2, and 2-Se exhibited unusual paramagnetic properties with the spin-state switching from S = 1 (Mn) + 1/2 (Se) to S = 1 (Mn), in which their magnetic centers were proved to be mixed-valent Mn atoms and the μ-Se•- radical, as evidenced by Evans method, superconducting quantum interference device, X-ray photoelectron spectra, electron paramagnetic resonance, and density functional theory calculations. Importantly, these clusters showed semiconducting behaviors with low and tunable energy gaps (1.50-2.01 eV) and varied electrical conductivities (2.52 × 10-8-4.58 × 10-9 S/cm), where efficient electron transports mainly arose from C-H(phenyl)···O(carbonyl) interactions within the solid-state frameworks.

Exploring soot inception rate with stochastic modelling and machine learning

A diverse range of polycyclic aromatic compounds (PACs) is thought to exist in flame environments before and during soot inception. This work seeks to develop a machine learning (ML)-based soot inception model that considers detailed and diverse PAC properties such as oxygenation, aliphatic content, radical character, size, and shape. To this end, temporal rates of change of PAC properties were computed by the stochastic modelling code SNapS2 and used as input to an ML model that predicts soot inception rate. The model is trained using experimentally-derived soot inception rates for three atmospheric pressure laminar premixed ethylene/air flames. An ML model (kernel ridge regression with a linear kernel) was developed to predict the soot inception rate in the three premixed flames. The soot inception rate predictions from this SNapS2-informed ML model outperformed the predictions from both the advanced soot modelling CFD code CoFlame and an ML model which used CFD-determined inputs (temperature and species concentrations). The final model had an R2 value of approximately 0.71 and a mean absolute error approximately 25% of the target values. The performance of the SNapS2-informed model suggests that detailed PAC properties are important to consider in inception modelling. While expanding this approach to other types of flames and fuels is crucial for future improvement to the model’s accuracy and generality, this methodology provides a successful framework for the current system. The success of this method demonstrates that ML can offer improvements in accuracy compared to current CFD inception models and the highlights the potential for ML in soot predictions.

Defect-engineered WO3-x@MoS2 hollow tube exhibiting enhanced Fenton-like and photocatalytic activities via electric field rearrangement and band alignment

Here we report a defect-engineered WO3−x @MoS2 hollow tube that exhibits not only enhanced Fenton-like activity but also improved photoactivity in a wide range of pH as a versatile platform for water purification. Its successful performance was achieved by tuning oxygen defect and band position and investigated using tetracycline degradation and E. coli inactivation experiments as concept demonstration. The activity of WO3−x @MoS2 can reach one to two orders of magnitude higher than that of other materials used in this work and the ecotoxicity of intermediates was largely reduced. It exhibits an intrinsic radical character for H2O2 decomposition under dark condition and an efficient photon utilization under visible light irradiation, which is clearly different from the conventional photocatalysts and Fenton reagents. The present strategy of combing the dark Fenton-like and photocatalytic activities extends the applications of the conventional photocatalysts and should be an efficient way of energy utilization.

Role of "S" Substitution on C-H Activation Reactivity of Iron(IV)-Oxo Cyclam Complexes: a Computational Investigation.

A comprehensive density functional theory (DFT) investigation has been presented in this article to address the role of equatorial sulfur ligation in C-H activation. A non-heme iron-oxo compound with four nitrogen atoms constituting the equatorially connected macrocyclic framework (represented as N4) [Fe(IV)═O(THC)(CH3CN)]2+(THC = 1,4,8,11-tetrahydro1,4,8,11-tetraazacyclotetradecane) has been considered as the base compound. Other complexes have been anticipated by the sequential replacement of this nitrogen by sulfur, that is, N4, N3S1, N2S2, N1S3, and S4. Counterions, as always, have been considered to avoid the self-interaction error in DFT. Generally, the anti-conformers (with respect to equatorial N-H and Fe═O) turned out to be the most stable. It was found that with the enrichment of the equatorial sulfur atom, reactivity increases successively, that is, we get the trend N4 < N3S1 < N2S2 < N1S3 < S4. Our investigations have also verified the available experimental results where it has been reported that N2S2 is more reactive than N4 in their mixed conformation. In search of insights into this typical pattern of reactivity, the interplay of several factors has been recognized, such as the distortion energy which decreases for the transition states with the addition of sulfur; the spin density on the oxygen atom which increases implying that the radical character of abstractor increases on sulfur ligation; the energy of the electron acceptor orbital (the lowest unoccupied molecular orbital (σz2*)) which decreases continuously with the sulfur substitution; and the triplet-quintet oxidant energy gap which decreases consistently with S enrichment in the equatorial position. The computational predictions reported here, if further validated by experiments, will definitely encourage the synthesis of sulfur-ligated bio-inspired complexes instead of the ones constituting nitrogen exclusively.

Role of radical position and character configuration in Chinese handwritten production

Role of radical position and character configuration in Chinese handwritten production

The Making(s) of an Alternative Urban Policy: What Happens When Free Fares Come to Town?

AbstractWhile many urban policies and practices claim to offer an “alternative” to the “mainstream” of urban entrepreneurialism, they remain under‐theorised and prone to alignment with entrepreneurial agendas. In this paper I examine fare‐free public transport (FFPT) as a salient example of an alternative urban policy. Looking at Aubagne (France) and Tallinn (Estonia), I explore what happens when an alternative policy “comes to town”. I detect how FFPT enters local urban regimes, and study the (non‐)participation of public transport passengers and workers in the decision‐making process about whether and how to abolish public transport fares. My analysis reveals that albeit alternative policies such as FFPT seem to oppose entrepreneurialism, they may hinge on urban regimes that span across institutions, leave the local configurations of power unchallenged, and strenghten local elites. The adaptability of alternatives to diverse political and intellectual positions explains their resilience. Consequently, their radical character cannot be taken for granted and remains an object of political struggle.

Crystalline Germanium‐Dipyrromethene Radicals: from a Delocalized Neutral to a Localized Cation

Comprehensive SummaryBoth dipyrromethene complexes and radicals of heavier main group elements have been of high interest. However, cationic germanium radicals and dipyrromethene‐based radicals of heavier main group elements are still escaped to be isolated. Herein, we report the isolation and full characterization of a neutral Ge(I)‐masked dipyrromethene‐based radical 3 and the first cationic Ge(III)‐centered radical 5·+ as stable crystalline solids. 3 behaves as a germanium(I) radical in its reaction with diphenyl disulfide to form the Ge—S bond, although X‐ray crystallographic, EPR spectroscopic, computational studies revealed that the unpaired electron of 3 is mainly delocalized over the C9N2Ge backbone and the allylic radical character is also significant in 3. In contrast to 3, the spin density of 5·+ is mainly localized at the Ge center with minor contribution from the dipyrromethene ligand. Moreover, reduction of 5·+ with potassium graphite quantitatively regenerates 5, illustrating a reversible one‐electron redox pair.

TÜRK FEMİNİZM HAREKETİ ÜZERİNE BİR DEĞERLENDİRME: “MİLLİ HASSASİYETLER” ve “BAŞARILI KADINLAR”

The Turkish feminism movement emerged with a manifesto published in April 2021 and organized its defenses on social media. It has been claimed that the Turkish feminism movement was started for women’s struggle for equality and freedom. It has been stated that it is aimed to eliminate the problems that continue to exist in Turkey and cause false perceptions to settle. It has been mentioned that these problems are caused by the manipulation of groups that are members or sympathizers of a terrorist organization and that this manipulation gains a more radical character with each passing day. A strict reaction has been developed towards the propaganda of the terrorist organization by using women’s actions and rallies, and the struggle for rights and freedom of women who are members of the terrorist organization to take place in these actions and rallies. The idea that women have problems arising from being a woman, especially inequality and discrimination, and that these problems can be solved by taking inspiration from Turkish history comes to the fore. For this reason, attention is drawn to the achievements of women who stand out and are the first in Turkish history. The Turkish emphasis is not an effort to strengthen the nationalist ideological background; it is emphasized the bond of citizenship. The Turkish feminism movement focuses on the problems of all women who are bound by citizenship; it is stated that only women who are members or sympathizers of a terrorist organization are excluded from this movement. Criticisms that women are divided and feminism is universal are also found to be unwarranted and meaningless. In this study, the main arguments of the Turkish feminism movement, which is a fairly new formation, are discussed and an analysis is made on the topics of which arguments the movement uses while reinforcing these arguments and what kind of perspective it develops on gender roles. The discursive framework that is tried to be created about Turkishness and Turkish womanhood is defined; how the bond that was tried to be established between the Ottoman women’s movement and the Kemalist women’s movement found its place within this framework is among the questions whose answers are sought throughout the study. In accordance with the purpose of the study, the statements and shares of the Turkish feminism movement on social media, as well as the statements and interviews of the founding members, constitute the data area of the study.

Shanghai Ladies and Lilong Housing: The Feminine Scene Permeating Urban Shanghai

In the Shanghai of the early twentieth century, rapid population growth and the consequent high density meant that, in much of the city, everyday life was condensed into a small and compact box-shaped row house. These houses were arranged along lanes which were also communities, called lilong. Shanghai’s lilong seem haunted by images of Shanghai ladies. This paper aims to explore the social ecology of the lilong by studying its spatial aspects and asking to what extent they influence and are influenced by the radical and creative character of Shanghai ladies, whether “New Women” or “Modern Girls.” Shanghai ladies’ modern femininity, which was architecturally, socially and historically conditioned, seems to have given them a particular attitude with which to approach the physical world, and which in turn pervaded the atmosphere and identity of the city as a whole.

Johannes Paul II. und der slowakische Katholizismus auf dem Weg zur politischen Wende 1989

John Paul II’s Ostpolitik and its influence on the erosion of the communist system rank among the most addressed topics in historical research on the pontificate. In international discourse, however, the focus is often placed on the Pope’s relations with the great powers or with Poland, while the then “stateless” Slovakia -although similar to Poland in its religious characteristics and of considerable importance within the Pope’s European concept of Christian renewal- is practically absent from scholarly discussion. Drawing from a wide variety of sources, the article aims to integrate the Slovak case into international reflection. It examines the complex relations between the Pope, Slovakia’s Catholicism - at home and in exile, within state-recognised and clandestine church structures- and Czechoslovakia’s communist regime, placing them in their international context. On the one hand, the study reconstructs the diplomatic activities of John Paul II, who continued the Ostpolitik of Paul VI, giving it a more radical character, often on the brink of an open conflict. On the other hand, it looks back at the vast mobilisation of Catholics and the moral and practical support given to the Church behind the Iron Curtain. The Marian and Cyrillo-Methodian spirituality of the Pope, the emphasis put on the rights of the nation and human rights -including the right to religious freedom- the valorisation of great historical figures and shrines rooted in Christianity, the lively communication across the barbed wire, the Pope’s policy of appointments and invitations, his public letters, speeches and gestures, as well as his frequent pronouncements encouraging Catholics to free themselves from fear and indifference, met with a broad response in Slovakia and contributed to the religious, national and social awakening of the country.