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Dual‐atom catalysts (DACs) with two adjacent atomic centers can operate together, offering complementary or synergistic effects or both, outperforming single‐atom catalysts (SACs). However, their rational design and precise synthesis remain significant challenges. Herein, atomically dispersed Fe and Se dual atomic sites are reported with asymmetric coordination supported on porous nitrogen‐doped carbon nanofibers (Fe/Se─N─C), engineered for highly efficient CO2 electroreduction. The asymmetrically coordinated catalyst achieves an impressive CO Faradaic efficiency of 95.6% at −0.45 V versus reversible hydrogen electrode. When assembled in a gas diffusion electrode, Fe/Se─N─C exhibits an exceptionally high CO partial current density of 272 mA cm‒2 in flow‐cell. Furthermore, Fe/Se─N─C‐based membrane electrode assembly (MEA) presents a remarkable 99% faradaic efficiency for CO2‐to‐CO conversion at an industrial‐level current density of 250 mA cm−2. Both in situ characterizations and theoretical calculations prove that the electronic hybridization effect induced by asymmetrically coordinated Fe‐Se dual sites effectively regulates the adsorption/desorption kinetic process of key intermediates on the active centers, breaks the linear scaling relationship between COOH* and CO* intermediates, and enhances the activation of CO2 and the desorption of CO. [ABSTRACT FROM AUTHOR]

It is still a challenge to construct single‐atom level reduction and oxidation sites in single‐component photocatalyst by manipulating coordination configuration for photocatalytic water splitting. Herein, the atomically dispersed asymmetric configuration of six‐coordinated Co‐S2O4 (two exposed S atoms, two OH groups, and two Co─O─Zn bonds) suspending on ZnIn2S4 nanosheets verified by combining experimental analysis with theoretical calculation, is applied into photocatalytic water splitting. The Co‐S2O4 site immobilized by Vs acts as oxidation sites to guide electrons transferring to neighboring independent S atom, achieving efficient separation of reduction and oxidation sites. It is worth mentioning that stabilized Co‐S2O4 configuration show dynamic structure evolution to highly active Co‐S1O4 configuration (one exposed S atom, one OH group, and three Co─O─Zn bonds) in reaction, which lowers energy barrier of transition state for H2O activization. Ultimately, the optimized photocatalyst exhibits excellent photocatalytic activity for water splitting (H2: 80.13 µmol g−1 h−1, O2: 37.81 µmol g−1 h−1) and outstanding stability than that of multicomponent photocatalysts due to dynamic and reversible evolution between stable Co‐S2O4 configuration and active Co‐S1O4 configuration. This work demonstrates new cognitions on immobilized strategy through vacancy inducing, manipulating coordination configuration, and dynamic evolution mechanism of single‐atom level catalytic site in photocatalytic water splitting. [ABSTRACT FROM AUTHOR]

Asymmetric coordination has emerged as a promising approach to enhance the oxygen evolution reaction (OER) activity, yet achieving a controlled synthesis of asymmetric structures to comprehensively understand the structure‐activity relationship remains challenging. In this study, a facile and effective symmetry‐breaking strategy is reported for tailoring the asymmetric MO5S1‐type metal–organic frameworks (MOFs) catalyst, establishing the correlation between the sulfur (S)‐mediated electron rearrangement and the adsorption/desorption dynamics of oxygen‐related intermediates in OER. Experimental and theoretical calculations reveal that a well‐designed asymmetric structure can effectively lower the d‐band center, optimizing the adsorption behavior of OH* and significantly decreasing the reaction energy barrier for the rate‐determining step (OH* → O*) with enhanced O–H bond cleavage process. The S‐NiFe‐MOF/CFP catalyst demonstrates a remarkable OER performance in an alkaline electrolyte environment. More importantly, the self‐assembled anion exchange membrane water electrolysis cell showcases a low voltage of 1.84 V to deliver the current density of 1 A cm−2, maintaining long‐term stability for over 100 h. This study unveils a precise asymmetric synthesis strategy employing S, highlighting the critical role of manipulating electron redistribution through asymmetric coordination to promote catalytic activity and develop advanced MOF‐based catalysts. [ABSTRACT FROM AUTHOR]

In the quest to boost the intrinsic activity of single‐atom catalysts (SACs), optimizing the electronic properties of metal centers and maximizing active sites play a pivotal role. Here, a facile surface molten salt‐assisted approach for fabricating porous iron‐nitrogen‐carbon catalysts enriched with catalytically accessible single‐atom motifs is reported. Multiple characterization analyses prove that abundant intrinsic defects are generated at the edge sites, resulting in the formation of thermally stable unstitched Fe‐N3 motif. Theoretical investigations unveil that the transition from Fe‐N4 to Fe‐N3 induces structural alteration, resulting in the convergence of Fe‐3d orbital energy to Fermi energy. The low‐coordinated Fe‐N3 motif exhibits higher activation ability, reinforcing its interaction with O3 and weakening the O‐O bond. This leads to a reduction in the reactivity of surface atomic oxygen barriers (O3‐to‐*O/*OO), ultimately achieving efficient catalytic oxidation of methyl mercaptan and its intermediates, achieving performance 20‐fold higher than intact Fe‐N4 catalysts and 625‐fold higher than commercial MnO2. These findings present a comprehensive approach for synthesizing SACs with fully accessible active sites and boosted electronic configurations to advance catalytic ozonation activity. [ABSTRACT FROM AUTHOR]

Accelerating sulfur conversion catalysis to alleviate the shuttle effect has become a novel paradigm for effective Li−S batteries. Although nitrogen‐coordinated metal single‐atom (M−N4) catalysts have been investigated, further optimizing its utilization rate and catalytic activities is urgently needed for practical applications. Inspired by the natural alveoli tissue with interconnected structure and well‐distributed enzyme catalytic sites on the wall for the simultaneously fast diffusion and in situ catalytic conversion of substrates, here, we proposed the controllable synthesis of bioinspired carbon cathode with interconnected porous structure and asymmetric coordinated V−S1N3 sites for efficient and stable Li−S batteries. The enzyme‐mimetic V−S1N3 shows asymmetric electronic distribution and high tunability, therefore enhancing in situ polysulfide conversion activities. Experimental and theoretical results reveal that the high charge asymmetry degree and large atom radius of S in V−S1N3 result in sloping adsorption for polysulfide, thereby exhibiting low thermodynamic energy barriers and long‐range stability (0.076 % decay over 600 cycles). [ABSTRACT FROM AUTHOR]

Single‐atom nanozymes (SAzymes) hold great promise in tumor therapy due to their maximized atomic utilization and well‐defined electronic structures. However, they still face challenges of activity, specificity, and targeting that impede therapeutic efficacy. Herein, a practical strategy is reported to construct asymmetric N, S‐coordinated Fe SAzymes (Fe‐S/N‐C). Benefiting from the regulatory influence of S atoms on the disruption of local charge symmetry of center Fe atoms, the Fe‐S/N‐C SAzymes exhibit significantly enhanced peroxidase (POD)‐ and glutathione oxidase (GSHOx)‐like activities, with catalytic efficiencies being 6.33 and 47.88 times higher than their symmetric Fe‐N4 counterparts, respectively. Theoretical calculations demonstrate that the asymmetric atomic interface configuration increases electron localization around center Fe sites, thus facilitating the adsorption and activation of H2O2 and O2. By camouflaging with macrophage membranes, the tumor‐targeting nanocatalytic agents (M@Fe‐S/N‐C) trigger enhanced self‐cascade catalysis in the tumor microenvironment for ferroptosis‐based tumor‐specific therapy. These results open up a promising avenue for addressing the limitations associated with current SAzymes‐based tumor therapies. [ABSTRACT FROM AUTHOR]

Exploring unique single‐atom sites capable of efficiently reducing O2 to H2O2 while being inert to H2O2 decomposition under light conditions is significant for H2O2 photosynthesis, but it remains challenging. Herein, we report the facile design and fabrication of polymeric carbon nitride (CN) decorated with single‐Zn sites that have tailorable local coordination environments, which is enabled by utilizing different Zn salt anions. Specifically, the O atom from acetate (OAc) anion participates in the coordination of single‐Zn sites on CN, forming asymmetric Zn−N3O moiety on CN (denoted as CN/Zn−OAc), in contrast to the obtained Zn−N4 sites when sulfate (SO4) is adopted (CN/Zn−SO4). Both experimental and theoretical investigations demonstrate that the Zn−N3O moiety exhibits higher intrinsic activity for O2 reduction to H2O2 than the Zn−N4 moiety. This is attributed to the asymmetric N/O coordination, which promotes the adsorption of O2 and the formation of the key intermediate *OOH on Zn sites due to their modulated electronic structure. Moreover, it is inactive for H2O2 decomposition under both dark and light conditions. As a result, the optimized CN/Zn−OAc catalyst exhibits significantly improved photocatalytic H2O2 production activity under visible light irradiation. [ABSTRACT FROM AUTHOR]

Addressing the limitations arising from the consistent catalytic behavior observed for various intermediates during the electrochemical carbon dioxide reduction reaction (CO2RR) poses a significant challenge in the optimization of catalytic activity. In this study, we aimed to address this challenge by constructing an asymmetric coordination Fe single atom catalyst (SCA) with a dynamically evolved structure. Our catalyst, consisting of a Fe atom coordinated with one S atom and three N atoms (Fe−S1N3), exhibited exceptional selectivity (CO Faradaic efficiency of 99.02 %) and demonstrated a high intrinsic activity (TOF of 7804.34 h−1), and remarkable stability. Using operando XAFS spectra and Density Functional Theory (DFT) calculations, we elucidated the self‐relaxation of geometric distortion and dynamic evolution of bond lengths within the catalyst. These structure changes enabled independent regulation of the *COOH and *CO intermediate adsorption energies, effectively breaking the linear scale relationship and enhancing the intrinsic activity of CO2RR. This study provides valuable insights into the dynamic evolution of SACs and paves the way for targeted catalyst designs aimed to disrupt the linear scaling relationships. [ABSTRACT FROM AUTHOR]

Rational design of the proximal coordination of an active site to achieve its optimum catalytic activity is the ultimate goal in single‐atom catalysis, but still challenging. Here, we report theoretical prediction and experimental realization of an asymmetrically coordinated iridium single‐atom catalyst (IrN3O) for the formic acid oxidation reaction (FAOR). Theoretical calculations reveal that the substitution of one or two nitrogen with more electronegative oxygen in the symmetric IrN4 motif splits and downshifts the Ir 5d orbitals with respect to the Fermi level, moderating the binding strength of key intermediates on IrN4−xOx (x=1, 2) sites, especially that the IrN3O motif shows ideal activity for FAOR with a near‐zero overpotential. The as‐designed asymmetric Ir motifs were realized by pyrolyzing Ir precursor with oxygen‐rich glucose and nitrogen‐rich melamine, exhibiting a mass activity of 25 and 87 times greater than those of state‐of‐the‐art Pd/C and Pt/C, respectively. [ABSTRACT FROM AUTHOR]

Owing to the unique coordination environment and high atom utilization efficiency, single atom catalysts have been considered as an ideal artificial enzyme to mimic natural enzymes. Herein, single-atom Fe nanozyme anchored on N-doped Ti3C2Tx (Fe SA/N-Ti3C2Tx) with asymmetrically coordinated Fe-N1C2 configuration is synthesized by vacancy capture and heteroatom doping strategy, which exhibits excellent peroxidase-like activity. Based on the results of peroxidase catalytic kinetics and X-ray adsorption fine spectroscopy, the Fe-N1C2 active sites in Fe SA/N-Ti3C2Tx are responsible for the excellent performance. Furthermore, the developed Fe SA/N-Ti3C2Tx can be employed to quantitative detection of melatonin (MT), which shows a wide linear detection range (0.01–100 µM) and an excellent detection limit (7.3 nM) in buffer, 0.01–100 µM and 7.8 nM in serum samples. Our work proves that MXene-based single atoms can be promising nanozyme in the field of bioassays. [ABSTRACT FROM AUTHOR]

The atomic-level interfacial regulation of single metal sites through heteroatom doping can significantly improve the characteristics of the catalyst and obtain surprising activity. Herein, nickel single-site catalysts (SSCs) with dual-coordinated phosphorus and nitrogen atoms were developed and confirmed (denoted as Ni-PxNy, x = 1, 2 and y = 3, 2). In CO2 reduction reaction (CO2RR), the CO current density on Ni-PxNy was significantly higher than that of Ni-N4 catalyst without phosphorus modification. Besides, Ni-P1N3 performed the highest CO Faradaic efficiency (FECO) of 85.0%–98.0% over a wide potential range of −0.65 to −0.95 V (vs. the reversible hydrogen electrode (RHE)). Experimental and theoretical results revealed that the asymmetric Ni-P1N3 site was beneficial to CO2 intermediate adsorption/desorption, thereby accelerating the reaction kinetics and boosting CO2RR activity. This work provides an effective method for preparing well-defined dual-coordinated SSCs to improve catalytic performance, targetting to CO2RR applications. [ABSTRACT FROM AUTHOR]

Dual atomic nanozymes (DAzymes) are promising for applications in the field of tumor catalytic therapy. Here, integrating with ultrasmall Fe 5 C 2 nanoclusters, asymmetric coordination featuring Janus Zn-Fe dual-atom sites with an O 2 N 2 -Fe-Zn-N 4 moiety embedded in a carbon vacancy-engineered hollow nanobox (Janus ZnFe DAs-Fe 5 C 2 ) was elaborately developed. Theoretical calculation revealed that the synergistic effects of Zn centers acting as both adsorption and active sites, oxygen-heteroatom doping, carbon vacancy, and Fe 5 C 2 nanoclusters jointly downshifted the d-band center of Fe 3d orbitals, optimizing the desorption behaviors of intermediates *OH, thereby significantly promoting catalytic activity. Upon 1064 nm laser irradiation, Janus ZnFe DAs-Fe 5 C 2 with superior photothermal conversion efficiency (η = 62.5%) showed thermal-augmented catalytic therapy. Fascinatingly, Janus ZnFe DAs-Fe 5 C 2 with multienzymatic properties can suppress the expression of glutathione peroxidase 4 and accelerate the accumulation of lipid peroxides, through which ferroptosis is triggered. Overall, tannin-involved asymmetric Janus ZnFe DAs-Fe 5 C 2 will inspire more inventions of biodegradable DAzymes for tumor therapy application.

Constructing the coordination environment of single-atom catalysts (SACs) can be an attractive technical strategy to regulate the generation of reactive oxygen species for Fenton-like reactions. Herein, we have constructed an asymmetric coordination of Fe single-atom catalyst (Fe SA -NS-PCNS) with abundant N-Fe-S bridge (Fe SA -N 3 S 1) for robust Fenton-like reactions. 82.5 % of singlet oxygen (1O 2) selectivity and high turnover frequency of bisphenol A degradation (0.568 min−1) were achieved at mild conditions. Experimental works and theoretical analyses illustrated that S doping breaks the inert environment of the original N-Fe-N symmetric coordination equilibrium and modulates the electron density of the atomic Fe center, which is beneficial for boosting PMS adsorption and reducing the energy barriers of vital *OH and *O intermediates. The coupling between the Fe SA -N 3 S 1 interface and peroxymonosulfate molecule boosts in-situ electron transfer through the N-Fe-S bridge, which induces more electron flow from the low valence Fe to OH* on the surface of Fe-*O-H, forming a high yield of 1O 2. Moreover, we designed the Fenton-like reactions by Fe SA -NS-PCNS membrane reactor for an efficient contaminant removal rate of over 90 % even after 11 cycles. This work provides a novel perspective on developing SACs with asymmetric coordination to regulate reactive oxygen species for the treatment of organic contaminants in water bodies. [Display omitted] • N, S-coordinated Fe single-atom catalysts are successfully fabricated with abundant N-Fe-S bridge. • The obtained Fe SA -NS-PCNS can effectively degrade typical bisphenols. • The N-Fe-S bridge boosts in-situ electron transfer to form a high yield of 1O 2. • *OH and *O reaction intermediates are vital during the generation of 1O 2. • Fe SA -NS-PCNS membrane removes over 90 % of contaminants after 11 cycles. [ABSTRACT FROM AUTHOR]

Electrochemical reduction of CO 2 (CO 2 RR) to value-added liquid fuels is a highly attractive solution for carbon-neutral recycling, especially for C 2+ products. However, the selectivity control to preferable products is a great challenge due to the complex multi-electron proton transfer process. In this work, a series of Cu atomic dispersed catalysts are synthesized by regulating the coordination structures to optimize the CO 2 RR selectivity. Cu 2 -SNC catalyst with a uniquely asymmetrical coordinated CuN 2 -CuNS site shows high ethanol selective with the FE of 62.6% at -0.8 V versus RHE and 60.2% at 0.9 V versus RHE in H-Cell and Flow-Cell test, respectively. Besides, the nest-like structure of Cu 2 -SNC is beneficial to the mass transfer process and the selection of catalytic products. In situ experiments and theory calculations reveal the reaction mechanisms of such high selectivity of ethanol. The S atoms weaken the bonding ability of the adjacent Cu to the carbon atom, which accelerates the selection from *CHCOH to generate *CHCHOH, resulting in the high selectivity of ethanol. This work indicates a promising strategy in the rational design of asymmetrically coordinated single, dual, or tri-atom catalysts and provides a candidate material for CO 2 RR to produce ethanol., (© 2024 Wiley‐VCH GmbH.)

A certain class of predicates in German optionally allows for their complement clause to appear as coordinated with the matrix clause rather than embedded into it. This construction, which I will call Implicational Complement Coordination, exhibits all the hallmark properties of Asymmetric Coordination: Despite technically being in a conjunct position, the clause in question behaves like a subordinate clause with respect to asymmetric binding, asymmetric scope of negation and adverbs as well as asymmetric extraction. Based on the detailed description of the phenomenon by Reis (1993), it can be shown that this coordinate construction mimics its infinitival counterpart with respect to these syntactic tests. In this paper, I argue that this can be accounted for by saying that the coordinate construction is derived on the basis of its subordinate counterpart by means of movement. The subordinate properties of the second conjunct then derive from its derivational history as a subordinate clause. Further, I will show that even though other cases of Asymmetric Coordination (in German) lack a minimally different infinitival counterpart, they can and should still be derived from an underlyingly subordinate syntax.

Ruthenium single-atom catalysts have great potential in ammonia-selective catalytic oxidation (NH 3 -SCO); however, the stable sp 3 hybrid orbital of NH 3 molecules makes N(sp 3 )-H dissociation a challenge for conventional symmetrical metallic oxide catalysts. Herein, we propose a heterogeneous interface reverse atom capture strategy to construct Ru with unique asymmetric Ru 1 N 2 O 1 coordination. Ru 1 N 2 O 1 /CeO 2 exhibits intrinsic low-temperature conversion ( T 100 at 160 °C) compared to symmetric coordinated Ru-based (280 °C), Ir-based (220 °C), and Pt-based (200 °C) catalysts, and the TOF is 65.4 times that of Ag-based catalysts. The experimental and theoretical studies show that there is a strong d-p orbital interaction between Ru and N atoms, which not only enhances the adsorption of ammonia at the Ru 1 N 2 O 1 position but also optimizes the electronic configuration of Ru. Furthermore, the affinity of Ru 1 N 2 O 1 /CeO 2 to water is significantly weaker than that of conventional catalysts (the binding energy of the Pd 3 Au 1 catalyst is -1.19 eV, but it is -0.39 eV for our material), so it has excellent water resistance. Finally, the N(sp 3 )-H activation of NH 3 requires the assistance of surface reactive oxygen species, but we found that asymmetric Ru 1 N 2 O 1 can directly activate the N(sp 3 )-H bond without the involvement of surface reactive oxygen species. This study provides a novel principle for the rational design of the proximal coordination of active sites to achieve its optimal catalytic activity in single-atom catalysis.

This paper presents a study of French Sign Language (LSF) temporal constructions. While we know from spoken language research that temporal constructions can be expressed through a variety of syntactic strategies such as subordination, juxtaposition, and coordination, finding their equivalent in sign languages is often a challenge due to the absence of overt complementizers and other function words such as coordinators. This study explores temporal constructions in LSF and frames them within a broad typological perspective. We show that LSF temporal clauses are very different from those of Italian Sign language (LIS) studied by Aristodemo (2017). Specifically, LSF temporal constructions are composed of two coordinated clauses and the temporal marker is integrated into the second conjunct. LIS temporal clauses, on the other hand, are composed of a main and a subordinated clause. This finding shows that the typological categories found in spoken language are also relevant for sign language studies.

Asymmetric coordination effect is an important concept in heterogeneous catalysis where both catalytic activity and product selectivity are serious influenced. However, this effect has rarely been understood because of the difficult in characterizing detailed coordination information. Here, by employing a theoretical study on electrocatalytic CO 2 reduction reaction (ECO 2 RR) towards HCOOH over Ti 3 C 2 O 2 -based NS/NN co-coordinated transition metal single atom catalysts (TM-NS/NN-Ti 3 C 2 O 2 SACs), we show that asymmetric coordination environments have great impact on the electronic structure of the active center. Both electron transferring ability and spin polarization of the active center are vital to optimize the adsorption and hydrogenation of key intermediates. As a result, both catalytic activity and product selectivity can be maximized. V-NN-Ti 3 C 2 O 2 are predicted to promote high-throughput HCOOH generation process at operation applied potential of −0.32 with considerable electrochemical stability, surpassing most reported catalysts. This work demonstrates V-NN-Ti 3 C 2 O 2 as high-performance ECO 2 RR catalysts, and highlights that the introduction of the concept of asymmetric coordination effect may offer a new insight into the rational design of more efficient SACs. [Display omitted] [ABSTRACT FROM AUTHOR]

The advancement of rechargeable zinc-air batteries (RZABs) faces challenges from the pronounced polarization and sluggish kinetics of oxygen reduction and evolution reactions (ORR and OER). Single-atom catalysts offer an effective solution, yet their insufficient or singular catalytic activity hinders their development. In this work, a dual single-atom catalyst, FeCo-SAs, was fabricated, featuring atomically dispersed N 3 -Fe-Co-N 4 sites on N-doped graphene nanosheets for bifunctional activity. Introducing Co into Fe single-atoms and secondary pyrolysis altered Fe coordination with N, creating an asymmetric environment that promoted charge transfer and increased the density of states near the Fermi level. This catalyst achieved a narrow potential gap of 0.616 V, with a half-wave potential of 0.884 V for ORR (vs the reversible hydrogen electrode) and a low OER overpotential of 270 mV at 10 mA cm -2 . Owing to the superior activity of FeCo-SAs, RZABs exhibited a peak power density of 203.36 mW cm -2 and an extended cycle life of over 550 h, exceeding the commercial Pt/C + IrO 2 catalyst. Furthermore, flexible RZABs with FeCo-SAs demonstrated the promising future of bimetallic pairs in wearable energy storage devices.

Anode materials with excellent properties have become the key to develop sodium-ion hybrid capacitors (SIHCs) that combine the advantages of both batteries and capacitors. Amorphous modulation is an effective strategy to realize high energy/power density in SIHCs. Herein, atomically amorphous Nb-O/N clusters with asymmetric coordination are in situ created in N-doped hollow carbon shells (Nb-O/N@C). The amorphous clusters with asymmetric Nb-O 3 /N 1 configurations have abundant charge density and low diffusion energy barriers, which effectively modulate the charge transport paths and improve the reaction kinetics. The clusters are also enriched with unsaturated vacancy defects and isotropic ion-transport channels, and their atomic disordering exhibits high structural stress buffering, which are strong impetuses for realizing bulk-phase-indifferent ion storage and enhancing the storage properties of the composite. Based on these features, Nb-O/N@C achieves notably improved sodium-ion storage properties (reversible capacity of 240.1 mAh g -1 at 10.0 A g -1 after 8000 cycles), and has great potential for SIHCs (230 Wh Kg -1 at 4001.5 W Kg -1 ). This study sheds new light on developing high-performance electrodes for sodium-ion batteries and SIHCs by designing amorphous clusters and asymmetric coordination., (© 2023 Wiley‐VCH GmbH.)

The paper develops a multi-priority control method of asymmetric coordination for a redundant dual-arm robot. A novel dual-arm coordination impedance is introduced to the multi-priority control, and then the performance of the object tracking and the redundant joints is improved by the regulation of the relative Cartesian errors between two arms. The control of asymmetric coordination is divided into the main task and the secondary task. The control of the main task can regulate the two end-effectors' errors and the relative errors by building the model of spatial parallel spring and damping (SPSDM), which establishes the dual-arm coordination impedance relation in Cartesian space. The control of the secondary task optimizes the performance of the redundant joint impedance and joint limit avoidance in null space. Finally, a typical asymmetric coordination experiment of peg-in-hole is carried out to verify the validity and feasibility of the proposed method. The results indicate that the proposed dual-arm coordination impedance can regulate the relative tracking errors between two objects directly, and in the context of the external impact force applied to the two end-effectors, the peg-in-hole dual-arm task can be achieved successfully. [ABSTRACT FROM AUTHOR]

Unsaturated benzylamines and arylamines are the key building blocks for the synthesis of organic pharmaceutical molecules, but their synthetic processes always suffer from low selectivity as a result of the excessive hydrogenation of unsaturated groups. Herein, the cobalt single-atom catalyst with an asymmetric Co 1 -N 3 -O 1 structure was designed and constructed on porous carbon nanospheres. It is found that the Co 1 -N 3 -O 1 catalyst showed excellent catalytic activity toward the synthesis of unsaturated benzylamines and arylamines. The results of characterization analysis and density functional theory (DFT) calculation further clarify that introducing oxygen into the Co single-atom coordination environment of Co 1 -N 3 -O 1 increased hydrogenation energy barrier of the terminal C=C double bond, which is beneficial to suppress competing hydrogenation reactions. Meanwhile, the Co 1 -N 3 -O 1 catalyst had the lower energy barrier for reduction of the C=N bond to amino group, boosting the yields of unsaturated benzylamines and arylamines. This study offers an attracting strategy for efficient and selective reductive amination reaction by making use of the asymmetrically structured Co single-atom catalyst. [ABSTRACT FROM AUTHOR]

Single-atom Fe catalysts are considered as the promising catalysts for oxygen reduction reaction (ORR). However, the high electronegativity of the symmetrical coordination N atoms around Fe site generally results in too strong adsorption of *OOH intermediates on the active site, severely limiting the catalytic performance. Herein, a "heteroatom pair synergetic modulation" strategy is proposed to tailor the coordination environment and spin state of Fe sites, enabling breaking the shackles of unsuitable adsorption of intermediate products on the active centers toward a more efficient ORR pathway. The unsymmetrically Co and B heteroatomic coordinated Fe single sites supported on an N-doped carbon (Fe─B─Co/NC) catalyst perform excellent ORR activity with high half-wave potential (E 1/2 ) of 0.891 V and a large kinetic current density (J k ) of 60.6 mA cm -2 , which is several times better than those of commercial Pt/C catalysts. By virtue of in situ electrochemical impedance and synchrotron infrared spectroscopy, it is observed that the optimized Fe sites can effectively accelerate the evolution of O 2 into the *O intermediate, overcoming the sluggish O─O bond cleavage of the *OOH intermediate, which is responsible for fast four-electron reaction kinetics., (© 2023 Wiley-VCH GmbH.)

• A novel asymmetric Pd 1 O 3 C 1 active site was conveniently constructed. • The Pd 1 O 3 C 1 site offers ultrahigh activity and durability in CO 2 electroreduction. • The Pd 1 O 3 C 1 -based tri-phase cathode exhibits high performance in Zn–CO 2 battery. Single-atom catalysts (SACs) have attracted great attention for electrocatalysis. The coordination configurations of heteroatoms surrounding the metal center have a significant influence on the catalytic performance. The construction of asymmetric coordination configurations has recently been found to be an efficient strategy to improve electrocatalytic performance. However, noble-metal-based SACs with an asymmetric coordination environment have seldom been achieved. Herein, we rationally design and construct single-atom Pd catalysts with asymmetric Pd 1 O 3 C 1 or Pd 1 N 3 C 1 sites anchored on oxidized mesoporous carbon with optimized porosity and hydrophobicity. The as-prepared catalyst (Pd1-O-CB) selectively produces CO with a high CO Faradaic efficiency (FE CO) of 99.6 % at a low potential of –0.6 V versus reversible hydrogen electrode (RHE). Furthermore, the Pd1-O-CB-based gas diffusion layer exhibits a high current density of 280.4 mA cm−2 and long-term stability over 48 h benefitted from the regulated porosity and hydrophobicity of the tri-interface. Finally, a rechargeable Zn–CO 2 battery is constructed with the optimal gas diffusion electrode to deliver a maximal power density of 1.72 mW cm−2. [ABSTRACT FROM AUTHOR]

Selective electroreduction of CO 2 to C 1 feed gas provides an attractive avenue to store intermittent renewable energy. However, most of the CO 2 -to-CO catalysts are designed from the perspective of structural reconstruction, and it is challenging to precisely design a meaningful confining microenvironment for active sites on the support. Herein, we report a local sulfur doping method to precisely tune the electronic structure of an isolated asymmetric nickel-nitrogen-sulfur motif (Ni 1 -NSC). Our Ni 1 -NSC catalyst presents >99% faradaic efficiency for CO 2 -to-CO under a high current density of -320 mA cm -2 . In situ attenuated total reflection surface-enhanced infrared absorption spectroscopy and differential electrochemical mass spectrometry indicated that the asymmetric sites show a significantly weaker binding strength of *CO and a lower kinetic overpotential for CO 2 -to-CO. Further theoretical analysis revealed that the enhanced CO 2 reduction reaction performance of Ni 1 -NSC was mainly due to the effectively decreased intermediate activation energy.

High-valence metal species generated in peroxymonosulfate (PMS)-based Fenton-like processes are promising candidates for selective degradation of contaminants in water, the formation of which necessitates the cleavage of OH and OO bonds as well as efficient electron transfer. However, the high dissociation energy of OH bond makes its cleavage quite challenging, largely hampering the selective generation of reactive oxygen species. Herein, an asymmetrical configuration characterized by a single cobalt atom coordinated with boron and nitrogen (CoB 1 N 3 ) is established to offer a strong local electric field, upon which the cleavage of OH bond is thermodynamically favored via a promoted coupled electron-proton transfer process, which serves an essential step to further allow OO bond cleavage and efficient electron transfer. Accordingly, the selective formation of Co(IV)O in a single-atom Co/PMS system enables highly efficient removal performance toward various organic pollutants. The proposed strategy also holds true in other heteroatom doping systems to configure asymmetric coordination, thus paving alternative pathways for specific reactive species conversion by rationalized design of catalysts at atomic level toward environmental applications and more., (© 2023 The Authors. Advanced Materials published by Wiley-VCH GmbH.)

Electrochemical CO 2 reduction reaction (CO 2 RR) provides an effective solution to the problems of greenhouse effect and energy shortage. As one of the catalysts for CO 2 RR, symmetric M-N 4 atomic moieties still suffer from low product selectivity and high reaction overpotentials. The asymmetric coordination configurations are expected to modulate the adsorption/desorption behavior of key reaction intermediates, thereby suppressing the occurrence of side reactions and accelerating the reaction rate. This review discussed the recent progress of asymmetrically coordinated atomic site catalysts in electrocatalytic CO 2 RR. The asymmetric atomic sites, including low-coordination sites, heteroatom coordination sites and bi-metal sites were presented, which could be induced by the breakage of M-N bonds or/and the formation of M-X bonds. The regulation of electronic structure, the optimization of reaction paths and catalytic selectivity towards asymmetric configurations were discussed. At last, several research prospects were proposed, aiming to deepen and promote the development of asymmetric sites for electrochemical CO 2 RR. [Display omitted] • The characteristic of asymmetric coordination are generalized. • The modulation effects of asymmetric configurations for CO 2 RR are explored. • The challenges and prospects of asymmetric coordination are pointed out. [ABSTRACT FROM AUTHOR]

Main group single atom catalysts (SACs) are promising for CO 2 electroreduction to CO by virtue of their ability in preventing the hydrogen evolution reaction and CO poisoning. Unfortunately, their delocalized orbitals reduce the CO 2 activation to *COOH. Herein, an O doping strategy to localize electrons on p-orbitals through asymmetric coordination of Ca SAC sites (Ca-N 3 O) is developed, thus enhancing the CO 2 activation. Theoretical calculations indicate that asymmetric coordination of Ca-N 3 O improves electron-localization around Ca sites and thus promotes *COOH formation. X-ray absorption fine spectroscopy shows the obtained Ca-N 3 O features: one O and three N coordinated atoms with one Ca as a reactive site. In situ attenuated total reflection infrared spectroscopy proves that Ca-N 3 O promotes *COOH formation. As a result, the Ca-N 3 O catalyst exhibits a state-of-the-art turnover frequency of ≈15 000 per hour in an H-cell and a large current density of -400 mA cm -2 with a CO Faradaic efficiency (FE) ≥ 90% in a flow cell. Moreover, Ca-N 3 O sites retain a FE above 90% even with a 30% diluted CO 2 concentration., (© 2023 The Authors. Advanced Materials published by Wiley-VCH GmbH.)

The ability to construct metal single-atom catalysts (SACs) asymmetrically coordinated with organic heteroatoms represents an important endeavor toward developing high-performance catalysts over symmetrically coordinated counterparts. Moreover, it is of key importance in creating supporting matrix with porous architecture for situating SACs as it greatly impacts the mass diffusion and transport of electrolyte. Herein, we report the crafting of Fe single atoms with asymmetrically coordinated nitrogen (N) and phosphorus (P) atoms scaffolded by rationally designed mesoporous carbon nanospheres (MCNs) with spoke-like nanochannels for boosting ring-opening reaction of epoxide to produce an array of pharmacologically important  β -amino alcohols. Notably, interfacial defects in MCN derived from the use of sacrificial template create abundant unpaired electrons, thereby stably anchoring N and P atoms and in turn Fe atoms on MCN. Importantly, the introduction of P atom promotes the symmetry-breaking of common four N-coordinated Fe sites, resulting in the Fe-N 3 P sites on MCN (denoted Fe-N 3 P-MCN) with an asymmetric electronic configuration and thus superior catalytic capability. As such, the Fe-N 3 P-MCN catalysts manifest a high catalytic activity for ring-opening reaction of epoxide (97% yield) over the Fe-N 3 P docked on nonporous carbon surface (91%) as well as the sole Fe-N 4  SACs grounded on the same MCN support (89%). Density functional theory calculations reveal that Fe-N 3 P SAC lowers the activation barrier for the C-O bond cleavage and the C-N bond formation, thus accelerating the ring-opening of epoxide. Our study provides fundamental and practical insights into developing advanced catalysts in a simple and controllable manner for multistep organic reactions.

In Culicover and Jackendoff (1997) , the Conditional Conjunction construction is cited as one example of a literal mismatch between syntax and semantics because it seems to exhibit syntactic properties of coordinate structures and semantic properties of subordinate structures at the same time. Hence, as they conclude, this construction cannot be derived in frameworks such as Minimalism where the semantics is derived from some syntactic level of representation such as LF. I want to argue that it is possible to derive the specific properties of this construction under Minimalist assumptions if one adheres to a strictly derivational model of Minimalism and subscribes to the assumption that a clause can be base-generated as an adjunct low in the tree and then be moved to the specifier of a coordination phrase as the regular first conjunct of a coordination. [ABSTRACT FROM AUTHOR]

Preparation and characterization of 2,6-diacetylpyridine bis(4N-p-chlorophenylthiosemicarbazone) ligand, H2L, and its palladium(II) and platinum(II) complexes [PdL] and [PtL], is described. The molecular structure of the two new complexes has been determined by single crystal X-ray diffraction. The ligand acts as dianionic tetradentate donor coordinating to the metal center in a square planar geometry through the pyridine nitrogen atom and the azomethine nitrogen and thione sulfur atoms from one thiosemicarbazone arm, the fourth coordination position is occupied by the hydrazine nitrogen atom of the other arm. New free ligand and its metal complexes have been evaluated for antiproliferative activity in vitro against NCI-H460, T-47D, A2780 and A2780cisR human cancer cell lines. The cytotoxicity data suggest that these compounds may be endowed with important antitumor properties, especially H2L and [PtL] since they are capable of not only circumvent cisplatin resistance in A2780cisR cells but also exhibit high antiproliferative activity in breast cancer T-47D cells. The interaction of H2L with calf thymus DNA was also investigated and its binding constant (Kb) determined. [ABSTRACT FROM AUTHOR]

In this paper, I argue on empirical grounds that (VL-initial) Asymmetric Coordination in German cannot be reduced to a syntactic structure of the form [if S1, then S2], but rather needs to be analyzed as some kind of adjunction to the if-clause, i.e., along the lines of [[if S1] and S2]. This conclusion gives rise to an apparent mismatch between syntactic structure (narrow scope of if) and semantic interpretation (wide scope of if). To resolve this paradoxical situation, I propose a compositional semantics for conditionals that is based on the idea that (indexed) if is to be construed as some kind of anaphor (variable) that ranges over objects of type modal base picking up a modal background in the actual context. Even though this analysis assigns a non-vacuous semantics to the complementizer if, it is still compatible with the syntax of Asymmetric Coordination in German, and, in contrast to alternative accounts, avoids the generation of non-existent distributive readings. [ABSTRACT FROM AUTHOR]

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Abstract: We propose an analysis in lfg of a particular asymmetric sentential coordination pattern in Welsh. In this construction, the main verb of the first clause is marked for tense and the remaining conjuncts have non-finite verb forms. This single instance of tense marking (occurring on the finite verb of the first conjunct) is semantically interpreted with respect to each conjunct. The coordinate structure also shares a single subject. In this paper we show how the approach to coordination in lfg can provide a simple and straightfoward analysis of this tense and subject asymmetric coordination pattern found in Welsh. The lfg approach to constituent coordination (a) posits an exocentric (or multiply-headed) coordinate schema at c-structure and (b) interprets coordinate structures as sets at f-structure. We extend the constituent coordination schema to permit the coordination of IP and VP, and postulate explicit “spreading” equations for the shared information. We show that the spreading analysis is also motivated by similar data from a range of typologically diverse languages. Finally, we show how the approach is superior to a structurally symmetric alternative involving VP level coordination, with the finite verb in I and the subject DP nodes outside the structural scope of coordination. [Copyright &y& Elsevier]