RESUMEN
Radioiodine (mainly 129I and 131I) is known to be dangerous nuclear waste due to its high toxicity, fast mobility and long radioactive half-life. As an emerging class of novel porous organic polymers, covalent organic frameworks (COFs) have demonstrated tremendous application potential in the field of radioactive iodine capture because of their high specific surface area and tunable pore structure. Herein, three π-conjugated pyrene-based COFs, namely PyTTA-BPDA-COF, PyTTA-BPY-COF, and PyTTA-BT-COF, have been successfully prepared and used as highly efficient adsorbents for iodine capture. The experimental results show that the three COFs displayed excellent adsorption performance, with adsorption capacity of 5.03, 4.46, and 3.97 g g-1 for PyTTA-BPDA-COF, PyTTA-BPY-COF, and PyTTA-BT-COF, respectively. Additionally, the release rate of iodine-loaded COFs in methanol solution and recyclability were also impressive, demonstrating their potential for practical applications. The mechanism investigation reveals that both imine linkage and π-conjugated structure of the COFs may contribute to their high iodine adsorption capability. This work is instructive as a guide for designing and synthesizing COFs as a solid-phase adsorbent for iodine uptake.
RESUMEN
Carbon dioxide (CO2) coupled with epoxide to generate cyclic carbonate stands out in carbon neutrality due to its 100% atom utilization. In this work, the mechanism of CO2 cycloaddition with propylene oxide (PO) cocatalyzed by windmill-shaped polyoxovanadate, [(C2N2H8)4(CH3O)4VIV4VV4O16]·4CH3OH (V8-1), and n-Bu4NX (X = Br, I) was thoroughly investigated using density functional theory (DFT) calculations. The ring-opening, CO2-insertion, and ring-closing steps of the process were extensively studied. Our work emphasizes the synergistic effect between V8-1 and n-Bu4NX (X = Br, I). Through the analysis of an independent gradient model based on Hirshfeld partition (IGMH), it was found that the attack of n-Bu4NX (X = Br, I) on Cß of PO triggers a distinct attractive interaction between the active fragment and the surrounding framework, serving as the primary driving force for the ring opening of PO. Furthermore, the effect of different cocatalysts was explored, with n-Bu4NI being more favorable than n-Bu4NBr. Moreover, the role of V8-1 in the CO2 cycloaddition reaction was clarified as not only acting as Lewis acid active sites but also serving as "electron sponges". This work is expected to advance the development of novel catalysts for organic carbonate formation.
RESUMEN
Photodynamic therapy (PDT) is an emerging treatment but often restricted by the availability of oxygen. Enhancing the lifespan of singlet oxygen (1O2) by fractionated generation is an effective approach to improve the efficacy of PDT. Herein, an imine-based nanoscale COF (TpDa-COF) has been synthesized and functionalized with a pyridone-derived structure (Py) to create a 1O2-storing nanoplatform TpDa-COF@Py, which can reversibly capture and release 1O2. Under 660 nm laser exposure, Py interacts with 1O2 produced by the porphyrin motif in COF backbones to generate 1O2-enriched COF (TpDa-COF@Py + hv), followed by the release of 1O2 through retro-Diels-Alder reactions at physiological temperatures. The continuous producing and releasing of 1O2 upon laser exposure leads to an "afterglow" effect and a prolonged 1O2 lifespan. In vitro cytotoxicity assays demonstrates that TpDa-COF@Py + hv exhibits an extremely low half-maximal inhibitory concentration (IC50) of 0.54 µg/mL on 4T1 cells. Remarkably, the Py-mediated TpDa-COF@Py nanoplatform demonstrates enhanced cell-killing capability under laser exposure, attributed to the sustained 1O2 cycling, compared to TpDa-COF alone. Further in vivo assessment highlights the potential of TpDa-COF@Py + hv as a promising strategy to enhance phototheronostics and achieve effective tumor regression. Accordingly, the study supplies a generalized 1O2 "afterglow" nanoplatform to improve the effectiveness of PDT.
Asunto(s)
Supervivencia Celular , Estructuras Metalorgánicas , Fotoquimioterapia , Fármacos Fotosensibilizantes , Oxígeno Singlete , Oxígeno Singlete/metabolismo , Oxígeno Singlete/química , Fármacos Fotosensibilizantes/química , Fármacos Fotosensibilizantes/farmacología , Fármacos Fotosensibilizantes/síntesis química , Animales , Ratones , Supervivencia Celular/efectos de los fármacos , Estructuras Metalorgánicas/química , Estructuras Metalorgánicas/farmacología , Estructuras Metalorgánicas/síntesis química , Antineoplásicos/farmacología , Antineoplásicos/química , Tamaño de la Partícula , Línea Celular Tumoral , Ensayos de Selección de Medicamentos Antitumorales , Estructura Molecular , Propiedades de Superficie , Humanos , Proliferación Celular/efectos de los fármacos , Femenino , Ratones Endogámicos BALB CRESUMEN
The effective capture and recovery of radioiodine species associated with nuclear fuel reprocessing is of significant importance in nuclear power plants. Porous materials have been proven to be one of the most effective adsorbents for the capture of radioiodine. In this work, we design and synthesize a series of conjugated microporous polymers (CMPs), namely, TPDA-TFPB CMP, TPDA-TATBA CMP, and TPDA-TECHO CMP, which are constructed based on a planar rectangular 4-connected organic monomer and three triangular 3-connected organic monomers, respectively. The resultant CMPs are characterized using various characterization techniques and used as effective adsorbents for iodine capture. Our experiments indicated that the CMPs exhibit excellent iodine adsorption capacities as high as 6.48, 6.25, and 6.37 g g-1 at 348 K and ambient pressure. The adsorption mechanism was further investigated and the strong chemical adsorption between the iodine and the imine/tertiary ammonia of the CMPs, 3D network structure with accessible hierarchical pores, uniform micromorphology, wide π-conjugated structure, and high-density Lewis-base sites synergistically contribute to their excellent iodine adsorption performance. Moreover, the CMPs demonstrated good recyclability. This work provides guidance for the construction of novel iodine adsorbent materials with high efficiency in the nuclear power field.
RESUMEN
The design and synthesis of organic photocatalysts remain a great challenge due to their strict structural constraints. However, this could be mitigated by achieving structural flexibility by constructing permanent porosity into the materials. Conjugated microporous polymers (CMPs) are an emerging class of porous materials with an amorphous, three-dimensional network structure, which makes it possible to integrate the elaborate functional groups to enhance photocatalytic performance. Here, we report the synthesis of a novel CMP, named TAPFc-TFPPy-CMP, constructed by 1,1'3,3'-tetra(4-aminophenyl)ferrocene (TAPFc) and 1,3,6,8-tetrakis(4-formylphenyl)pyrene (TFPPy) monomers. The integration of the p-type dopant 7,7,8,8-tetracyanoquinodimethane (TCNQ) into the TAPFc-TFPPy-CMP improved the light adsorption performance, leading to a decrease in the optical bandgap from 2.00 to 1.43 eV. The doped CMP (TCNQ@TAPFc-TFPPy-CMP) exhibited promising catalytic activity in photocatalytic CO2 reduction under visible light, yielding 546.8 µmol g-1 h-1 of CO with a selectivity of 96% and 5.2 µmol g-1 h-1 of CH4. This represented an 80% increase in the CO yield compared to the maternal TAPFc-TFPPy-CMP. The steady-state photoluminescence (PL) and fluorescence lifetime (FL) measurements reveal faster carrier separation and transport after the doping. This study provides guidance for the development of organic photocatalysts for the utilization of renewable energy.
RESUMEN
Objective: China has an aging society; the issue of aging is becoming increasingly serious. This study aimed to explore the factors influencing the demand for medical treatment and health care services among the elderly and offer countermeasures and suggestions. Methods: In this cross-sectional study, a questionnaire method was used to inquire about 386 elderly people in three communities from Bincheng District, Binzhou City, and Shandong Province. Results: The demand of community-dwelling elderly for chronic disease medication consultation services was 91.71%, with 53.88% in urgent need of the service. Their demand for dietary guidance was 91.19%, with 52.07% having a great demand for the guidance. The demand for medical expenses guarantee was 87.82%, and those in great need accounted for 47.93%. 84.98% required hospice care service, with 31.87% in great need of the service. The demand for psychological and spiritual services was 84.20% and 44.56% of them reported high demand for it. From multiple regression analysis, the factors influencing the demand of the elderly for medical treatment and health care services were identified as the sources of income, harmonious relationship with their children, medical expenses guarantee, and psychological and spiritual services, with statistical significance (P < .05). Conclusions: Chronic disease medication consultation service, dietary guidance, and medical expenses guarantee are listed as the top three demands among the elderly living in the community from medical treatment and health care services. This warrants an urgent need to establish a multi-level, personalized, and diversified medical treatment and health care model, with improved long-term care insurance system, and trained medical professionals to provide professional services in order to improve the quality of life and health level of the elderly.
RESUMEN
Radioactive iodine from nuclear waste poses a huge threat to public safety and raises concerns about environmental pollution. There is thus a growing demand for developing novel adsorbents for highly effective iodine capture. In this work, we design and synthesize three novel conjugated microporous polymers, namely, TPE-PyTTA-CMP, TPE-TAPP-CMP, and TPE-TPDA-CMP, which are constructed by an imidization reaction based on octet and tetratopic linkers. The iodine vapor adsorption experiments show that the three CMPs have an excellent iodine adsorption capacity as high as 3.10, 3.67, and 4.68 g·g-1 under 348 K and ambient pressure conditions, respectively. The adsorbed iodine in the CMPs can be released into methanol in a dramatically rapid manner, and their excellent iodine adsorption performance can still be maintained after multiple cycles. In addition, the CMPs demonstrate good adsorption performance in an n-hexane solution of iodine, and the kinetic experimental data follow the pseudo-second-order model. The hierarchical porosity, extended π-conjugated skeleton, and rich electron-donor nitrogen sites of the CMPs could contribute to their excellent iodine adsorption performance. The knowledge information obtained in this work could open up new possibilities for designing novel CMPs targeting a wide range of environment-related applications.
RESUMEN
Polyoxometalates (POMs) have a broad array of applied platforms with well-characterized catalysis to achieve N-H bond activation. Herein, the mechanism of the Anderson-type POM-based catalyst [FeIIIMoVI6O18{(OCH2)3CNH2}2]3- ([TrisFeIIIMoVI6O18]3-, Tris = {(OCH2)3CNH2}2) for the N-H bond activation of hydrazine (PhHNNHPh) was investigated by density functional theory calculations. The results reveal that [TrisFeIIIMoVI6O18]3- as the active species is responsible for the continuous abstraction of two electrons and two protons of PhHNNHPh via a proton-coupled electron transfer pathway, resulting in the activation of two N-H bonds in PhHNNHPh and thus the product PhNNPh. H2O2 acts as an oxidant to regulate catalyst regeneration. Based on the proposed catalytic mechanism, the key role of the heteroatom FeIII in [TrisFeIIIMoVI6O18]3- was disclosed. The d-orbital of FeIII in [TrisFeIIIMoVI6O18]3- acts as an electron receptor to promote the electron transfer (ET) in the rate-determining step (RDS) of the catalytic cycle. The substitution of the heteroatom FeIII of [TrisFeIIIMoVI6O18]3- with CoIII, RuIII, or MnIII is expected to improve the catalytic activity for several reasons: (i) the unoccupied molecular orbitals of POM-based compounds containing CoIII or RuIII are low, which is beneficial for the ET of RDS; (ii) For N-H bond activation catalyzed by the MnIII-containing POM-based compound, the transition state of RDS is stable because the d-orbital of its active site is half-filled, which results in a low free-energy barrier.
RESUMEN
Precise control of the structure and spatial distance of Lewis acid (LA) and Lewis base (LB) sites in a porous system to construct efficient solid frustrated Lewis pair (FLP) catalyst is vital for industrial application but remains challenging. Herein, we constructed FLP sites in a polyoxometalate (POM)-based metal-organic framework (MOF) by introducing coordination-defect metal nodes (LA) and surface-basic POM with abundant oxygen (LB). The well-defined and unique spatial conformation of the defective POM-based MOF ensure that the distance between LA and LB is at ~4.3â Å, a suitable distance to activate H2 . This FLP catalyst can heterolytically dissociate H2 into active Hδ- , thus exhibiting high activity in hydrogenation, which is 55 and 2.7â times as high as that of defect-free POM-based MOF and defective MOF without POM, respectively. This work provides a new avenue toward precise design multi-site catalyst to achieve specific activation of target substrate for synergistic catalysis.
RESUMEN
Injury to the anterior talofibular ligament (ATFL) is a common acute injury of the lateral foot ligament. Untimely and improper treatment significantly affects the quality of life and rehabilitation progress of patients. The purpose of this paper is to review the anatomy and the current methods of diagnosis and treatment of acute injury to the ATFL. The clinical manifestations of acute injury to the ATFL include pain, swelling, and dysfunction. At present, non-surgical treatment is the first choice for acute injury of the ATFL. The standard treatment strategy involves the "peace and love" principle. After initial treatment in the acute phase, personalized rehabilitation training programs can be followed. These may involve proprioception training, muscle training, and functional exercise to restore limb coordination and muscle strength. Static stretching and other techniques to loosen joints, acupuncture, moxibustion massage, and other traditional medical treatments can relieve pain, restore range of motion, and prevent joint stiffness. If the non-surgical treatment is not ideal or fails, surgical treatment is feasible. Currently, arthroscopic anatomical repair or anatomical reconstruction surgery is commonly used in clinical practice. Although open Broström surgery provides good results, the modified arthroscopic Broström surgery has many advantages, such as less trauma, rapid pain relief, rapid postoperative recovery, and fewer complications, and is more popular with patients. In general, when treating acute injury to the ATFL, treatment management and methods should be timely and reasonably arranged according to the specific injury scenario and attention should be paid to the timely combination of multiple therapies to achieve the best treatment results.
RESUMEN
BACKGROUND: Lung cancer is the most common cancer-related death worldwide. In 2022, the number of daily deaths of lung cancer was estimated to reach around 350 in the United States. Lung adenocarcinoma is the main subtype of lung cancer and patients with malignant pleural effusion (MPE) suffer from poor prognosis. Microbiota and its metabolites are associated with cancer progression. However, the effect of pleural microbiota on pleural metabolic profile of MPE in lung adenocarcinoma patients remains largely unknown. METHODS: Pleural effusion samples collected from lung adenocarcinoma patients with MPE (n = 14) and tuberculosis pleurisy patients with benign pleural effusion (BPE group, n = 10) were subjected to microbiome (16S rRNA gene sequencing) and metabolome (liquid chromatography tandem mass spectrometry [LC-MS/MS]) analyses. The datasets were analyzed individually and integrated for combined analysis using various bioinformatic approaches. RESULTS: The metabolic profile of MPE in lung adenocarcinoma patients were clearly distinguished from BPE with 121 differential metabolites across six significantly enriched pathways identified. Glycerophospholipids, fatty and carboxylic acids, and derivatives were the most common differential metabolites. Sequencing of microbial data revealed nine significantly enriched genera (i.e., Staphylococcus, Streptococcus, Lactobacillus) and 26 enriched ASVs (i.e., species Lactobacillus_delbrueckii) in MPE. Integrated analysis correlated MPE-associated microbes with metabolites, such as phosphatidylcholine and metabolites involved in the citrate cycle pathway. CONCLUSION: Our results provide substantial evidence of a novel interplay between the pleural microbiota and metabolome, which was drastically perturbed in MPE in lung adenocarcinoma patients. Microbe-associated metabolites can be used for further therapeutic explorations.
Asunto(s)
Adenocarcinoma del Pulmón , Neoplasias Pulmonares , Microbiota , Derrame Pleural Maligno , Derrame Pleural , Humanos , Derrame Pleural Maligno/patología , Cromatografía Liquida , ARN Ribosómico 16S/genética , Espectrometría de Masas en Tándem , Adenocarcinoma del Pulmón/complicaciones , Adenocarcinoma del Pulmón/genética , Neoplasias Pulmonares/complicaciones , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/metabolismo , Biomarcadores de Tumor/metabolismoRESUMEN
Covalent organic frameworks (COFs) hold the potential in converting CO2 with water into value-added fuels and O2 to save the deteriorating ecological environment. However, reaching high yield and selectivity is a grand challenge under metal-, photosensitizer-, or sacrificial reagent-free conditions. Here, inspired by microstructures of natural leaves, we designed triazine-based COF membranes with the integration of steady light-harvesting sites, efficient catalytic center, and fast charge/mass transfer configuration to fabricate a novel artificial leaf for the first time. Significantly, a record high CO yield of 1240 µmol g-1 in a 4 h reaction, approximately 100% selectivity, and a long lifespan (at least 16 cycles) were achieved under gas-solid conditions without using any metal, photosensitizer, or sacrificial reagent. Unlike the existing knowledge, the chemical structural unit of triazine-imide-triazine and the unique physical form of the COF membrane are predominant for such a remarkable photocatalysis. This work opens a new pathway to simulating photosynthesis in leaves and may motivate relevant research in the future.
RESUMEN
Achalasia cardia, type of esophageal dynamic disorder, is a relatively rare primary motor esophageal disease characterized by the functional loss of plexus ganglion cells in the distal esophagus and lower esophageal sphincter. Loss of function of the distal and lower esophageal sphincter ganglion cells is the main cause of achalasia cardia, and is more likely to occur in the elderly. Histological changes in the esophageal mucosa are considered pathogenic; however, studies have found that inflammation and genetic changes at the molecular level may also cause achalasia cardia, resulting in dysphagia, reflux, aspiration, retrosternal pain, and weight loss. Currently, the treatment options for achalasia focus on reducing the resting pressure of the lower esophageal sphincter, helping to empty the esophagus and relieve symptoms. Treatment measures include botulinum toxin injection, inflatable dilation, stent insertion, and surgical myotomy (open or laparoscopic). Surgical procedures are often subject to controversy owing to concerns about safety and effectiveness, particularly in older patients. Herein, we review clinical epidemiological and experimental data to determine the prevalence, pathogenesis, clinical presentation, diagnostic criteria, and treatment options for achalasia to support its clinical management.
RESUMEN
Metal-nitrogen-carbon catalysts, as promising alternative to platinum-based catalysts for oxygen reduction reaction (ORR), are still highly expected to achieve better performance by modulating the composition and spatial structure of active site. Herein, we constructed the non-planar nest-like [Fe2 S2 ] cluster sites in N-doped carbon plane. Adjacent double Fe atoms effectively weaken the O-O bond by forming a peroxide bridge-like adsorption configuration, and the introduction of S atoms breaks the planar coordination of Fe resulting in greater structural deformation tension, lower spin state, and downward shifted Fe d-band center, which together facilitate the release of OH* intermediate. Hence, the non-planar [Fe2 S2 ] cluster catalyst, with a half-wave potential of 0.92â V, displays superior ORR activity than that of planar [FeN4 ] or [Fe2 N6 ]. This work provides insights into the co-regulation of atomic composition and spatial configuration for efficient oxygen reduction catalysis.
RESUMEN
Cobalt coordinated covalent organic frameworks have attracted increasing interest in the field of CO2 photoreduction to CO, owing to their high electron affinity and predesigned structures. However, achieving high conversion efficiency is challenging since most Co related coordination environments facilitate fast recombination of photogenerated electron-hole pairs. Here, we design two kinds of Co-COF catalysts with oxygen coordinated Co atoms and find that after tuning of coordination environment, the reported Co framework catalyst with Co-O4 sites exhibits a high CO production rate of 18000 µmol g-1 h-1 with selectivity as high as 95.7% under visible light irradiation. From in/ex-situ spectral characterizations and theoretical calculations, it is revealed that the predesigned Co-O4 sites significantly facilitate the carrier migration in framework matrixes and inhibit the recombination of photogenerated electron-hole pairs in the photocatalytic process. This work opens a way for the design of high-performance catalysts for CO2 photoreduction.
RESUMEN
Highly efficient removal of Hg(ii) has been previously achieved through the adsorption by functionalized covalent organic frameworks (COFs). Among these COFs, thioether groups need to be deliberately introduced into the pores of COFs through either a bottom-up synthesis or post-synthesis strategy. Herein, we report a simple mercury removal strategy that used a stable alkynyl (-C[triple bond, length as m-dash]C-) based covalent organic framework (TP-EDDA COF) as an adsorbent for Hg(ii) removal. Sulfur vapor was first adsorbed by the TP-EDDA COF due to the van der Waals interaction between adsorbed sulfur and alkynyl groups. The Hg(ii) removal capability was then evaluated for the sulfur loaded TP-EDDA COF. Our results exhibited a good Hg(ii) removal performance for the sulfur loaded TP-EDDA COF. It was deduced that sâ¯π interaction between sulfur atom and the alkynyl groups of the COF skeleton caused an increase in the electron density of sulfur and the electronegative sulfur atoms acted as a soft acid to accept soft-basic Hg(ii). This strategy provides a convenient platform for COFs to cope with environmental issues.
RESUMEN
Transforming CO2 into value-added chemicals has been an important subject in recent years. The development of a novel heterogeneous catalyst for highly effective CO2 conversion still remains a great challenge. As an emerging class of porous organic polymers, covalent organic frameworks (COFs) have exhibited superior potential as catalysts for various chemical reactions, due to their unique structure and properties. In this study, a layered two-dimensional (2D) COF, IM4F-Py-COF, was prepared through a three-component condensation reaction. Benzimidazole moiety, as an ionic liquid precursor, was integrated onto the skeleton of the COF using a benzimidazole-containing building unit. Ionization of the benzimidazole framework was then achieved through quaternization with 1-bromobutane to produce an ionic liquid-immobilized COF, i.e., BMIM4F-Py-COF. The resulting ionic COF shows excellent catalytic activity in promoting the chemical fixation of CO2 via reaction with epoxides under solvent-free and co-catalyst-free conditions. High porosity, the one-dimensional (1D) open-channel structure of the COF and the high catalytic activity of ionic liquid may contribute to the excellent catalytic performance. Moreover, the COF catalyst could be reused at least five times without significant loss of its catalytic activity.
RESUMEN
As one of the main nuclear wastes generated in the process of nuclear fission, radioactive iodine has attracted worldwide attention due to its harm to public safety and environmental pollution. Therefore, it is of crucial importance to develop materials that can rapidly and efficiently capture radioactive iodine. Herein, we report the construction of three electron-rich porous organic polymers (POPs), denoted as POP-E, POP-T and POP-P via Schiff base polycondensations reactions between Td-symmetric adamantane knot and four-branched "linkage" molecules. We demonstrated that all the three POPs showed high iodine adsorption capability, among which the adsorption capacity of POP-T for iodine vapor reached up to 3.94 g·g-1 and the removal rate of iodine in n-hexane solution was up to 99%. The efficient iodine capture mechanism of the POP-T was investigated through systematic comparison of Fourier transform infrared spectroscopy (FT-IR), Raman spectroscopy and X-ray photoelectron spectroscopy (XPS) before and after iodine adsorption. The unique π-π conjugated system between imine bonds linked aromatic rings with iodine result in charge-transfer complexes, which explains the exceptional iodine capture capacity. Additionally, the introduction of heteroatoms into the framework would also enhance the iodine adsorption capability of POPs. Good retention behavior and recycling capacity were also observed for the POPs.
Asunto(s)
Yodo , Neoplasias de la Tiroides , Electrones , Humanos , Yoduros , Yodo/química , Radioisótopos de Yodo , Polímeros/química , Porosidad , Bases de Schiff , Espectroscopía Infrarroja por Transformada de FourierRESUMEN
Covalent organic frameworks (COFs) are an emerging class of crystalline porous polymers that make these materials suitable for use as excellent scaffold in heterogeneous catalysis. Here we synthesize a layered two-dimensional (2D) COF (TADP-COF) through the condensation reaction between four-branched 5,10,15,20-tetrakis(4-aminophenyl)porphyrin (TAPP) and linear 2,5-dihydroxyterephthalaldehyde (Dha) and 1,4-phthalaldehyde (PA) building blocks. Porphyrin units, imine and hydroxyl groups together with imines can provide wide coordination sites for metal docking. Using a programmed synthetic procedure, Cu(ii) ions first coordinated with the imine groups in conjunction with their adjacent hydroxyl groups, and porphyrin units and subsequently added Pd(ii) ions occupied the remaining imine sites in the space between adjacent COF layers. The bimetallic Pd(ii)/Cu(ii)@TADP-COF showed high catalytic activity in a one-pot coupling/oxidation cascade reaction in water. The high surface area, one-dimensional (1D) open channel structure and predesigned catalytic active sites of this material make it ideal candidate for use as heterogeneous catalyst in a wide range of catalytic reactions.
RESUMEN
In this work, the mechanism of water oxidation catalyzed by an Ru-based complex [Ru(L)]+ (L = 5,5-chelated 2-carboxyl-phen, 2,2';6',2''-terpyridine) was studied by density functional theory (DFT) calculations. In [Ru(L)]+, a carboxyl group is included in the second coordination sphere and plays an important role in the catalytic process. In the oxidation activation stage of water oxidation catalysis, the carboxyl group is proposed as a promising proton acceptor to promote proton transfer, which results in active RuV[double bond, length as m-dash]O species. Then, O-O bond formation can proceed via water nucleophilic attack (WNA) or oxo-oxo coupling mechanisms. In the O2 release stage, similar to the oxidation activation process, the carboxyl group promotes proton transfer as a promising proton acceptor. In the present work, the favorable mechanism is WNA that involves proton transfer to the carboxyl group. It is expected that this work will provide meaningful information for synthesizing excellent water oxidation catalysts (WOCs).