Linking Group Research Articles

Stabilization Strategies of Buried Interface for Efficient SAM-based Inverted Perovskite Solar Cells.

In recent years, self-assembled monolayers (SAMs) anchored on metal oxides (MO) have greatly boosted the performance of inverted (p-i-n) perovskite solar cells (PVSCs) by serving as hole-selective contacts due to their distinct advantages in transparency, hole-selectivity, passivation, cost-effectiveness, and processing efficiency. While the intrinsic monolayer nature of SAMs provides unique advantages, it also makes them highly sensitive to external pressure, posing a significant challenge for long-term device stability. At present, the stability issue of SAM-based PVSCs is gradually attracting attention. In this review, we discuss the fundamental stability issues arising from the structural characteristics, operating mechanisms, and roles of SAMs, and highlight representative works on improving their stability. We identify the buried interface stability concerns in three key aspects: 1) SAM/MO interface, 2) SAM inner layer, and 3) SAM/perovskite interface, corresponding to the anchoring group, linker group, and terminal group in the SAMs, respectively. Finally, we have proposed potential strategies for achieving excellent stability in SAM-based buried interfaces, particularly for large-scale and flexible applications. We believe this review will deepen understanding of the relationship between SAM structure and their device performance, thereby facilitating the design of novel SAMs and advancing their eventual commercialization in high-efficiency and stable inverted PVSCs.

Stabilization Strategies of Buried Interface for Efficient SAM‐based Inverted Perovskite Solar Cells

In recent years, self‐assembled monolayers (SAMs) anchored on metal oxides (MO) have greatly boosted the performance of inverted (p‐i‐n) perovskite solar cells (PVSCs) by serving as hole‐selective contacts due to their distinct advantages in transparency, hole‐selectivity, passivation, cost‐effectiveness, and processing efficiency. While the intrinsic monolayer nature of SAMs provides unique advantages, it also makes them highly sensitive to external pressure, posing a significant challenge for long‐term device stability. At present, the stability issue of SAM‐based PVSCs is gradually attracting attention. In this review, we discuss the fundamental stability issues arising from the structural characteristics, operating mechanisms, and roles of SAMs, and highlight representative works on improving their stability. We identify the buried interface stability concerns in three key aspects: 1) SAM/MO interface, 2) SAM inner layer, and 3) SAM/perovskite interface, corresponding to the anchoring group, linker group, and terminal group in the SAMs, respectively. Finally, we have proposed potential strategies for achieving excellent stability in SAM‐based buried interfaces, particularly for large‐scale and flexible applications. We believe this review will deepen understanding of the relationship between SAM structure and their device performance, thereby facilitating the design of novel SAMs and advancing their eventual commercialization in high‐efficiency and stable inverted PVSCs.

Lewis-Acid Mediated Reactivity in Single-Molecule Junctions.

While chemical reactions at a gold electrode can be monitored using molecular conductance and driven by extrinsic stimuli, the intrinsic properties of the nanostructured interface may perform important additional functions that are not yet well understood. Here we evaluate these properties in studies of single-molecule junctions formed from components comprising 4,4'-biphenyl backbones functionalized with 12 different sulfur-based linker groups. With some linkers, we find evidence for in situ S-C(sp3) bond breaking, and C(sp2)-C(sp3) bond forming, reactions consistent with the ex situ transformations expected for those groups in the presence of a Lewis acid. Notably, we also approach the limits of substituent influence on the conductance of physisorbed sulfur-linked junctions. As an illustrative example, we show that a tert-butylthio-functionalized precursor can form both chemisorbed (Au-S) junctions, consistent with heterolytic S-C(sp3) bond cleavage and generation of a stable tert-butyl carbocation, as well as physisorbed junctions that are >1 order of magnitude lower conductance than analogous junctions comprising cyclic "locked" thioether contacts. These findings are supported by a systematic analysis of model thioether components comprising different simple hydrocarbon substituents of intermediate size, which do not form chemisorbed contacts and further clarify the inverse relationship between conductance and substituent steric bulk. First-principles calculations confirm that bulky sulfur-substituents increase the probability of forming junction geometries with reduced electronic coupling between the electrode and π-conjugated molecular backbone. Together, this work helps to rationalize the dual roles that linker chemical structure and metal electrode Lewis character can play in mediating interfacial reactions in break-junction experiments.

Recalibrating R$\mathbb {R}$‐order trees and Homeo+(S1)$\mbox{Homeo}_+(S^1)$‐representations of link groups

AbstractIn this paper, we study the left‐orderability of 3‐manifold groups using an enhancement, called recalibration, of Calegari and Dunfield's ‘flipping’ construction, used for modifying ‐representations of the fundamental groups of closed 3‐manifolds. The added flexibility accorded by recalibration allows us to produce ‐representations of hyperbolic link exteriors so that a chosen element in the peripheral subgroup is sent to any given rational rotation. We apply these representations to show that the branched covers of families of links associated to epimorphisms of the link group onto a finite cyclic group are left‐orderable. This applies, for instance, to fibred hyperbolic strongly quasi‐positive links. Our result on the orderability of branched covers implies that the degeneracy locus of any pseudo‐Anosov flow on an alternating knot complement must be meridional, which generalises the known result that the fractional Dehn twist coefficient of any hyperbolic fibred alternating knot is zero. Applications of these representations to order detection of slopes are also discussed in the paper.

Analysis of the third class mechanism using the modeling method in the Mathcad software environment

Purpose. To carry out a kinematic analysis of a flat twelve-link hinged mechanism with three leading links, the basis of which is a structural group of links of the third class of the fourth order with rotational kinematic pairs, which is used in technological equipment. Methodology. The kinematic study of a flat complex mechanism of the third class with three leading links was performed using the mathematical modeling method in the Mathcad software environment. Findings. Using the method of mathematical modeling, the mechanism was presented in the form of free vectors built on its links, for which, taking into account the presence of three leading links, three vector contours were selected, which made it possible to draw up a system of vector equations of their closedness with further solving by a numerical method in the Mathcad software environment. The functions of the rotation angles of the mechanism links, their angular velocities and accelerations were obtained in analytical and graphical form depending on the rotation angle of the first driving crank of the mechanism, the calculation of the angular velocities and accelerations of all the driven links of the mechanism was performed. Originality. A sequence was developed and a kinematic study of a complex planar mechanism of the third class with three leading links was done, the basis of which is a structural group of links of the third class of the fourth order. Schematic modeling of the mechanism with three leading links was performed, a visualization schedule of its kinematic scheme was built, and a valid version of its assembly was obtained from many possible ones, for which the values of kinematic parameters of all its links were determined. Practical value. An analysis of the effect of the kinematic parameters of the three leading links of the third-class mechanism on the movement of the working body of the technological equipment was carried out. From the analysis of the obtained research results for the cycle of the mechanism the reason was found for the incomplete technological stoppage of the link, which should provide the working body of the machine for the required period of time. Recommendations of the elimination were made to identify the deficiency and proposals for the need to improve the drive of this equipment.

Construction of Mesoporous Aluminosilicate Thin Films on ITO Electrodes for Immobilizing a Cationic Ru(II) Water Oxidation Catalyst

AbstractAluminosilicate (Al‐SiO2) thin films with vertically aligned mesochannels were successfully synthesized on Indium Tin Oxide (ITO) electrodes and employed for the immobilization of a cationic Ru(II) water oxidation catalyst without requiring linker groups. Optimal synthesis conditions yielded uniform mesoporous Al‐SiO2 films with tunable Al content, high surface area (568 m2/g), 3.94 nm pore size, and 155 nm thickness. Electrochemical studies confirmed the presence of the immobilized Ru complex undergoing diffusion‐controlled Ru(III/II) and Ru(IV/III) electron transfer. The Ru loading reached 4.71 nmol/cm2 at Si/Al=9.6, with higher Al content enhancing loading amounts via cation exchange. The Ru‐modified electrode exhibited high electrocatalytic water oxidation activity, achieving 75.3 % Faradaic efficiency and a turnover number of 298.6 for O2 evolution for 1 hour. This work provides a new approach to construct porous environments on an electrode surface to immobilize positively charged transition‐metal complexes as catalysts, offering potential applications in the development of electrocatalytic systems for energy conversion.

A promising platform for the rapid and sensitive sensing of mercury ion and its applications in biological and environmental system

Mercury ion (Hg2+) is one of harmful heavy metal ions that can accumulate inside the human organism and cause some health problems. Herein, a novel NBD derivative, 1-(2-((7-nitrobenzo[c] [1,2,5] oxadiazol-4-yl) amino) ethyl)-3-phenylthiourea (NBD-SCN), has been reasonably designed, which was simply synthesized by introducing NBD moiety as the fluorophore, phenyl-isothionitrate as the reaction site and ethylenediamine as a linker group, resulting in intense fluorescence emission with high fluorescence quantum yields. Intriguingly, probe NBD-SCN provides a dual-mode colorimetric and fluorescence response pattern for the sensing of mercury ion with great limit of detections (3.6 nM) and rapid response time (4 s). The strong combination of mercury ions and sulfur atoms leads to intramolecular cyclization, causing the color of probe solution changed from orange to pale yellow as well as a complete vanishing of fluorescence intensity. The proposed reaction mechanism was verified by fluorescence and UV titration, 1H NMR, FTIR, HRMS analyses and DFT studies. Motivated by an impressive chromatic variation, test strip sensing platform are facilely constructed for real-time and on-site measurement of Hg2+ levels. Furthermore, confocal imaging experiments verify that this probe can be used for monitoring mercury ion in living mung bean sprouts and in biological systems in real time.

Carbocyclic setmelanotide analogs maintain biochemical potency at melanocortin 4 receptors.

The melanocortin 4 receptor (MC4R) plays a critical role in satiety and energy homeostasis, and its dysregulation is implicated in numerous hyperphagic and obese disease states. Setmelanotide, a disulfide-based cyclic peptide, can rescue MC4R activity and treat obesities caused by genetic defects in MC4R signaling. But this peptide has moderate blood-brain barrier penetrance and metabolic stability, which can limit its efficacy in practice. Based on the cryo-electron microscopy structure of setmelanotide-bound MC4R, we hypothesized that replacing its lone disulfide bond with more metabolically stable and permeability-enhancing carbon-based linker groups could improve pharmacokinetic properties without abolishing activity. To test this, we used chemistry developed by our lab to prepare 11 carbocyclic (alkyl, aryl, perfluoroalkyl, and ethereal) analogs of setmelanotide and determined their biochemical potencies at MC4R in vitro. Ten analogs displayed full agonism, showing that disulfide replacement is tolerant of linkers ranging in size, rigidity, and functional groups, with heteroatom- or aryl-rich linkers displaying superior potencies.

In silico Approaches for Exploring the Pharmacological Activities of Benzimidazole Derivatives: A Comprehensive Review.

This article reviews computational research on benzimidazole derivatives. Cytotoxicity for all compounds against cancer cell lines was measured and the results revealed that many compounds exhibited high inhibitions. This research examines the varied pharmacological properties like anticancer, antibacterial, antioxidant, anti-inflammatory and anticonvulsant activities of benzimidazole derivatives. The suggested method summarises In silico research for each activity. This review examines benzimidazole derivative structure-activity relationships and pharmacological effects. In silico investigations can anticipate structural alterations and their effects on these derivative's pharmacological characteristics and efficacy through many computational methods. Molecular docking, molecular dynamics simulations and virtual screening help anticipate pharmacological effects and optimize chemical design. These trials will improve lead optimization, target selection, and ADMET property prediction in drug development. In silico benzimidazole derivative studies will be assessed for gaps and future research. Prospective studies might include empirical verification, pharmacodynamic analysis, and computational methodology improvement. This review discusses benzimidazole derivative In silico research to understand their specific pharmacological effects. This will help scientists design new drugs and guide future research. Latest, authentic and published reports on various benzimidazole derivatives and their activities are being thoroughly studied and analyzed. The overview of benzimidazole derivatives is more comprehensive, highlighting their structural diversity, synthetic strategies, mechanisms of action, and the computational tools used to study them. In silico studies help to understand the structure-activity relationship (SAR) of benzimidazole derivatives. Through meticulous alterations of substituents, ring modifications, and linker groups, this study identified the structural factors influencing the pharmacological activity of benzimidazole derivatives. These findings enable the rational design and optimization of more potent and selective compounds.

Highly Reversible "On-Off-On" Fluorescence Switch Governed by pH, Utilizing Bis(Benzimidazole) Derivatives with Varied Link Groups.

In this work, a series of dibenzimidazole derivatives 1-4, act as highly reversible colorimetric and fluorescent pH chemosensor, were designed and synthesized. Excellent reversible pH response of these sensors could be found by a specific pH change through obvious fluorescent color changes. The response is not affected by common cations (including Al3+, Cu2+, Ca2+, Cd2+, Co2+, Cr3+, Mg2+, Na+, K+, Ni2+, Pb2+ and Zn2+) and anions (including F-, Cl-, Br-, I-, ClO4-, H2PO4-, HSO4-, HCO3- and CH3COO-). Notably, these sensors can be reused more than 10 times without losing functionality. Unlike previous reports, the distinct properties of 1-4 are attributed to the varied link groups. Based on comprehensive experimental data and mechanistic analyses, it is concluded that sensors 1-4 are promising candidates for use as highly reversible "on-off-on" fluorescence switches under precise pH control.

Light-induced H2 generation in a photosystem I-O2-tolerant [FeFe] hydrogenase nanoconstruct

The fusion of hydrogenases and photosynthetic reaction centers (RCs) has proven to be a promising strategy for the production of sustainable biofuels. Type I (iron-sulfur-containing) RCs, acting as photosensitizers, are capable of promoting electrons to a redox state that can be exploited by hydrogenases for the reduction of protons to dihydrogen (H2). While both [FeFe] and [NiFe] hydrogenases have been used successfully, they tend to be limited due to either O2 sensitivity, binding specificity, or H2 production rates. In this study, we fuse a peripheral (stromal) subunit of Photosystem I (PS I), PsaE, to an O2-tolerant [FeFe] hydrogenase from Clostridium beijerinckii using a flexible [GGS]4 linker group (CbHydA1-PsaE). We demonstrate that the CbHydA1 chimera can be synthetically activated in vitro to show bidirectional activity and that it can be quantitatively bound to a PS I variant lacking the PsaE subunit. When illuminated in an anaerobic environment, the nanoconstruct generates H2 at a rate of 84.9 ± 3.1 µmol H2 mgchl-1 h-1. Further, when prepared and illuminated in the presence of O2, the nanoconstruct retains the ability to generate H2, though at a diminished rate of 2.2 ± 0.5 µmol H2 mgchl-1 h-1. This demonstrates not only that PsaE is a promising scaffold for PS I-based nanoconstructs, but the use of an O2-tolerant [FeFe] hydrogenase opens the possibility for an in vivo H2 generating system that can function in the presence of O2.

Synthesis, Structures, Thermal stability and optical spectroscopy of Pt(II) di‑yne and poly‑yne incorporating 2,2′-Bipyridine-4,4′-diyl spacer

In platinum(II) di-ynes and poly-ynes the optical properties are influenced by the pattern of conjugation in the functionalised acetylide linker groups. We report the synthesis and characterisation of new Pt(II) di‑yne trans-[(Ph)(Et₃P)₂Pt–CC–Ar–CC–Pt(PEt₃)₂(Ph)] (Pt-M) and Pt(II) poly‑yne trans-[Pt(nBu3P)2Pt–CC–Ar–CC–]n (Pt-P) (Ar = 2,2′-bipyridine-4,4′-diyl) materials using analytical and spectroscopic techniques. The solid-state structure of the protected ligand precursor 4,4′-bis(trimethylsilylethynyl)-2,2′-bipyridine (LP1) and the dinuclear Pt(II) di‑yne (Pt-M) have been determined by the single-crystal X-ray diffraction (SC-XRD) while the number average molecular weight (Mn), weight average molecular weight (Mw) and polydispersity index (PDI) of the Pt(II) poly‑yne (Pt-P) have been determined by the gel permeation chromatography/light-scattering (GPC/LS) methods (Mn/Mw/PDI = 55,210/88,560/1.6). The thermal stability of the protected and di-terminal alkynyl ligands, Pt(II) di‑yne (Pt-M) and Pt(II) poly‑yne (Pt-P) have been evaluated and are discussed. To delineate the impact of incorporating the heavy Pt(II) ion along the polymer backbone, optical absorption studies have been performed and are discussed in detail. The results of optical absorption studies, especially (Pt-M) have been compared to their 5,5′- and 6,6′-bis(ethynyl) substituted analogues to better understand the effect of ligand topology on the effective conjugation.

An enhanced consensus algorithm for blockchain

Consensus plays a crucial role in blockchain technology, with the delegated proof of stake (DPoS) consensus mechanism commonly utilized in both public and hybrid chains. However, the current DPoS mechanism faces challenges such as low node engagement in voting and potential security risks posed by malicious nodes. In response, we propose the DL-DPoS (deep link–delegated proof of stake) mechanism, which builds upon the DPoS framework. The DL-DPoS incorporates the LINK incentive mechanism to encourage inactive nodes to participate in voting and leader selection. Furthermore, a comprehensive credit scoring system based on wealth, performance, and stability is introduced to enhance the security of elected nodes. The verification process is optimized to involve all nodes except the leader node, and mechanisms are in place to handle malicious attacks by degrading or removing offending nodes and redistributing their responsibilities to the LINK group. Performance testing of the DL-DPoS mechanism, conducted through blockchain simulation tests using the GO language, shows a 23% increase in throughput compared to DPoS, with over 95% node participation and improved distribution of rights and equity. These results indicate the enhanced performance, security, and stability of the DL-DPoS consensus mechanism.

Enhancing Response Rates in Web-Based Surveys: The Impact of Direct Participant Contact.

Achieving a high participation rate is a common challenge in healthcare research based on web-based surveys. A study on local anesthetic systemic toxicity awareness and usage among medical practitioners at two Swiss university hospitals encountered resistance in obtaining personal email addresses from Heads of Departments. Participants were therefore divided into two groups: those who were directly invited via email (personal invitation group) and those who received a generic link through intermediaries (generic link group). The latter group was eventually excluded from survey data analysis. To determine whether one method of survey administration was more effective than another, we carried out a retrospective analysis of response rates and the proportion of new questionnaires completed after initial invitation and subsequent reminders. The results showed significantly higher response rates in the personal invitation group (40.2%, 313/779) compared to the generic link group (25.3%, 22/87), emphasizing the effectiveness of personal invitations on response rate (+14.9%, p = 0.007). The personal invitation group consistently yielded a higher number of completed questionnaires following the initial invitation and each reminder. The method of survey administration can greatly influence response rates and should be acknowledged as a quality criterion when conducting web-based surveys.

Signaling Modulation Mediated by Ligand Water Interactions with the Sodium Site at μOR.

The mu opioid receptor (μOR) is a target for clinically used analgesics. However, adverse effects, such as respiratory depression and physical dependence, necessitate the development of alternative treatments. Recently we reported a novel strategy to design functionally selective opioids by targeting the sodium binding allosteric site in μOR with a supraspinally active analgesic named C6guano. Presently, to improve systemic activity of this ligand, we used structure-based design, identifying a new ligand named RO76 where the flexible alkyl linker and polar guanidine guano group is swapped with a benzyl alcohol, and the sodium site is targeted indirectly through waters. A cryoEM structure of RO76 bound to the μOR-Gi complex confirmed that RO76 interacts with the sodium site residues through a water molecule, unlike C6guano which engages the sodium site directly. Signaling assays coupled with APEX based proximity labeling show binding in the sodium pocket modulates receptor efficacy and trafficking. In mice, RO76 was systemically active in tail withdrawal assays and showed reduced liabilities compared to those of morphine. In summary, we show that targeting water molecules in the sodium binding pocket may be an avenue to modulate signaling properties of opioids, and which may potentially be extended to other G-protein coupled receptors where this site is conserved.

Core groups

The core group of a classical link was introduced independently by Kelly in 1991 and Wada in 1992. It is a link invariant defined by a presentation involving the arcs and crossings of a diagram, related to Wirtinger’s presentation of the fundamental group of a link complement. Two close relatives of the core group are defined by presentations involving regions rather than arcs; one of them is related to Dehn’s presentation of a link group. The definitions are extended to virtual link diagrams and properties of the resulting invariants are discussed.

Photoactivated Controlled Dnazyme Platform for on-Demand Activation Sensitive Electrochemiluminescence mRNA Analysis.

Programming ultrasensitive and stimuli-responsive DNAzyme-based probes holds great potential for on-demand biomarker detection. Here, an optically triggered DNAzyme platform was reported for on-demand activation-sensitive electrochemiluminescence (ECL) c-myc mRNA analysis. In this design, the sensing and recognition function of the split DNAzyme (SDz) probe was silent by engineering a blocking sequence containing a photocleavable linker (PC-linker) group at a defined site that could be indirectly cleaved by 302 nm ultraviolet (UV) light. When the SDz probes were assembled on the Au nanoparticles and potassium (K) element doped graphitic carbon nitride nanosheet (K-doped g-C3N4) covered electrode, UV light activation induces the configurational switching and consequently the formation of an active DNAzyme probe with the help of target c-myc mRNA, allowing the cleavage of the substrate strand by magnesium ions (Mg2+). Thus, the release of a ferrocene (Fc)-labeled DNAzyme 2 strand contributed to an extreme ECL signal recovery. In the meantime, the released target c-myc mRNA combined another inactive SDz motif to form active DNAzyme and repeat the cyclic cleavage reaction, resulting in the signal amplification. Furthermore, according to the responses toward two other designed nPC-SDz and m-SDz probes, we demonstrated that controlled UV light mediated photoactivation of the DNAzyme biosensor "on demand" effectively constrained the ECL signal to the mRNA of interest. Moreover, false positive signals could also be avoided due to such a photoactivation design with UV light. Therefore, this study provided a simple methodology that may be broadly applicable for investigating the mRNA-associated physiological events that were difficult to access using traditional DNAzyme probes.

Dielectric response of metal-organic frameworks as a function of confined guest species investigated by molecular dynamics simulations.

When using metal-organic frameworks (MOFs) as electric field-dependent sensor devices, understanding their dielectric response is crucial as the orientation of polar groups is largely affected by confinement. To shed light on this at the molecular level, the response to a static field was computationally investigated for two structurally related MOFs, depending on their loading with guest molecules. The pillared-layer MOFs differ in their pillar moiety, with one bearing a rotatable permanent dipole moment and the other being non-polar. Two guest molecules with and without polarity, namely, methanol and methane, were considered. A comprehensive picture of the response of the guest molecules could be achieved with respect to both the amount and polarity of the confined species. For both MOFs, the dielectric response is very sensitive to the introduction of methanol, showing an anisotropic and non-linear increase in the system's relative permittivity expressed by a strongly increasing polarization response to external electric fields scaling with the number of confined methanol molecules. As expected, the effect of methane in the non-dipolar MOF is negligible, whereas subtle differences can be observed for the dipolar response of the MOF with rotatable dipolar linker groups. Taking advantage of these anisotropic and guest-molecule-specific confinement effects may open pathways for future sensing applications. Finally, methanol-induced global framework dynamics were observed in both MOFs.

Novel room-temperature synthesis of pioneering CsPbX3@(Ce)UiO-66-Y hybrid nanomaterials for boosted photocatalytic hydrogen evolution

Perovskites are attractive structures for photocatalytic hydrogen generation, but also are limited by low stability, which can be improved by combination with other materials. Perovskite structures have potential for photocatalytic hydrogen generation; however, their practical application is hindered by inherent low stability. This limitation can be effectively mitigated through strategic combinations with complementary materials. Therefore, hybrids consisting of the perovskite CsPbX3 (X = Br, I) and the metal–organic framework (Ce)UiO-66-Y (Y = H, Br, NH2) were successfully synthesized for the first time, using a straightforward ligand-assisted reprecipitation synthesis at room temperature. To develop a room temperature synthesis for CsPbX3@(Ce)UiO-66-Y hybrid nanomaterials, herein, we optimized the synthesis of perovskite firstly (considering factors such as the choice of solvents, the drying of stabilizers, and the purification) and then developed an efficient way to combine both materials. Six types of hybrid materials, differing in the type of perovskite and functional group in the MOFs linker, were synthesized by the introduction of MOFs powder into a solution containing perovskite precursors (CsX and PbX2 in DMF stabilized by oleyamine and oleic acid) followed by antisolvent addition. We demonstrated that the hybrids containing perovskite in combination with MOF (Ce)UiO-66-NH2 in a molar ratio of 13:1 exhibited significantly higher activity and twice as long reaction stability time compared to the individual components of the hybrids when tested separately. This outcome underscores the presence of a synergistic effect, highlighting the potential of these hybrid materials in catalyzing hydrogen generation.

Electronic structure and microenvironment modulation of Pd@UiO-66 enhances direct CO esterification to dimethyl carbonate

While the microenvironment around metal catalytic sites is recognized to be crucial in heterogeneous catalysis, its roles in CO esterification to dimethyl carbonate remain subtle. Herein, Pd nanoparticles are confined into the metal–organic frameworks with TiIV metal substitutions and functional linker groups, namely Pd@Ti-Zr-UiO-66-X (X = H, NH2, NO2). The partial substitution of metal nodes by Ti species can dramatically enhance the activity of CO, and synergistically improves catalytic performance with electron-withdrawing functionalized nitroxide linkers. As a result, Pd@Ti-Zr-UiO-66-NO2 exhibits superior conversion of CO (67.5%), selectivity for DMC (83.5%, based on all products) and WTY for DMC (1725 g·kgcat−1·h−1) much higher than those of Pd@Zr-UiO-66-H with conversion of CO (46.4%), selectivity for DMC (87%) and WTY for DMC (1175 g·kgcat−1·h−1). Based on results of experimental and DFT calculation, the synergistic effect of highly electronegative Ti species and nitro-functional linker groups with electron-withdrawing ability realizes the precise control of the electronic structure and microenvironment of Pd NPs. The number of charges transferred from Pd NPs to Zr-UiO-66 and Ti-Zr-UiO-66-NO2 increased from 1.83 to 2.69 e, respectively. The microenvironment of electron-deficient palladium species and Ti-Zr-UiO-66-NO2 promotes the activation of MN and CO, which exhibits a superior performance in direct CO esterification to dimethyl carbonate. This study not only provides a new approach for rational modulation of the chemical microenvironment of metal centers and optimization of catalytic performance but also offers important insights for the design of heterogeneous catalysts.