{"title":"Band Alignment-Driven Space Charge Remodeling in NiFe LDH@CoOx-CNF Heterojunction for Efficient Alkaline Oxygen Evolution","authors":"Yuancong Luo, Jingjing Li, Yihui Shen, Huicheng Ge, Lingli Cheng, Zhen Li, Zheng Jiao","doi":"10.1039/d5qi00530b","DOIUrl":"https://doi.org/10.1039/d5qi00530b","url":null,"abstract":"While heterojunction engineering holds promise for enhancing NiFe-based oxygen evolution reaction (OER) catalysts, poorly matched interfacial Fermi levels often hinders the formation of high-valent Ni2+δ species critical for OER activity, creating a trade-off between charge-transfer efficiency and active-phase evolution. Herein, a band alignment strategy is proposed to resolve this conflict by controlled integration of Co nanodots (20 wt%) into electrospun carbon nanofibers (CoOx-CNF), followed by robust coupling NiFe LDH nanosheets. The presence of Co nanodots enhances CNF graphitization and tailors the interfacial Fermi level offset to 1.30 eV, thereby establishing directional electron transfer channels from NiFe LDH to CoOx-CNF. The resulting space charge remodeling induces selective electron depletion at Ni sites, which synergistically promotes the formation of catalytically active Ni2+δ species while accelerating charge transfer. Therefore, such an elaborately designed NiFe LDH@CoOx-CNF catalyst achieves an ultralow overpotential of 225 mV at 10 mA cm⁻² and exceptional stability for 100 h at 100 mA cm⁻². Operando electrochemical impedance spectroscopy directly tracks microscopic interfacial reactions and charge-transfer mechanisms, while DFT calculations reveal that the band alignment-mediated space charge effect improves the electronic structure and strengthens Ni 3d-O 2p hybridization, thus lowering the Gibbs free energy barrier of the rate-determining step (*O→*OOH). This work establishes a “band alignment→space charge remodeling→kinetic enhancement” paradigm for phase-selective electrocatalyst design.","PeriodicalId":79,"journal":{"name":"Inorganic Chemistry Frontiers","volume":"149 1","pages":""},"PeriodicalIF":7.0,"publicationDate":"2025-05-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144066342","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Rui Jian, Jie Wang, Pan Wang, Tiandong Qiu, Junjie Feng, Xiangyu He, Chuncheng Li, Zhichao Wang, Yufeng Zhang, Lianxin Gong, Luming Li, Hongmei Li, Si Chen, Yachao Zhu, Jie Deng
{"title":"Phosphoric Acid Passivation Layer-Induced Sacrificial Template Effect for Constructing S/P-modified self-supported NiFe Catalysts with Enhanced OER Performance","authors":"Rui Jian, Jie Wang, Pan Wang, Tiandong Qiu, Junjie Feng, Xiangyu He, Chuncheng Li, Zhichao Wang, Yufeng Zhang, Lianxin Gong, Luming Li, Hongmei Li, Si Chen, Yachao Zhu, Jie Deng","doi":"10.1039/d4qi03177f","DOIUrl":"https://doi.org/10.1039/d4qi03177f","url":null,"abstract":"The co-doping of sulfur (S) and phosphorus (P) into the mainstream NiFe catalysts can electronically modulate the Ni (or Fe) sites, thus kinetically augmenting the alkaline oxygen evolution reaction (OER) more prominently than unitary modifications. However, achieving this objective via an industrial-compatible synthetic route remains extremely challenging. Herein, an advantageous sacrificial template effect based on the phosphoric acid passivation layer can be easily realized, via a concise one-step binary molten salt inspiration, enabling the construction of the S/P co-decorated self-supported NiFe catalysts for superior OER performance. The prioritized pre-formed phosphoric acid passivation layer on the surface of commercial NiFe foam (NFF) can effectively prevent its over-corrosion by the sulphur salt and simultaneously promote the S doping. This interesting process ultimately produced an integrated electrode with OER-conductive features, such as the tuned valence state, enriched oxygen vacancies, ample crystalline-amorphous boundaries, copious pores, and strong material-substrate binding. The as-synthesized electrode can deliver the ultra-low OER overpotential of 157.6 mV at a current density of 10 mA cm<small><sup>-2</sup></small> and ultralong stability of 1400 h to maintain an industrial-level current of 1 A cm<small><sup>-2</sup></small>, outperforming the recent peers. Results of isotope, TMA<small><sup>+</sup></small> probe and pH-dependent measurements further demonstrate that S/P co-doping profoundly alters proton exchange performance, thereby altering the OER mechanism and activity. This sacrificial template effect induced by phosphoric acid passivation layer may be extended to develop other binder-free transition metal compounds for broader electrocatalytic fields.","PeriodicalId":79,"journal":{"name":"Inorganic Chemistry Frontiers","volume":"55 1","pages":""},"PeriodicalIF":7.0,"publicationDate":"2025-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143980053","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Four-in-one multifunctional iron(III) complex for cancer theranostics: unique integration of targeted delivery, photodynamic therapy, and dual imaging modalities","authors":"Tukki Sarkar, Serena Rizzuti, Isorchand Chongtham, Rajesh Kushwaha, Arnab Bhattacharyya, Samya Banerjee, Eliana Gianolio, Akhtar Hussain","doi":"10.1039/d5qi00623f","DOIUrl":"https://doi.org/10.1039/d5qi00623f","url":null,"abstract":"3d transition metal complexes are increasingly valued for their theranostic roles in cancer, owing to their biocompatibility, cost-effectiveness, and multifunctional capabilities. We report a glucose-conjugated Fe(III) complex, Fe2, designed as a cancer theranostic agent by uniquely integrating four distinct functionalities: glucose-driven targeting, photodynamic therapy, optical imaging, and MRI contrast enhancement. Fe2 selectively targets cervical and breast cancer cells by capitalizing on the overexpression of glucose transporter-1 (GLUT-1) transmembrane protein. Its distinct ligand-to-metal charge transfer (LMCT) absorption band in the red region enables effective red-light photodynamic therapy for deep-tissue penetration, while its emission band supports optical cellular imaging. Additionally, its high-spin paramagnetic Fe(III) center facilitates T1-weighted MRI contrast enhancement. Fe2 demonstrates good water solubility and high aqueous stability under dark and irradiated conditions and in reducing environments, such as in the presence of reduced glutathione (GSH). Fe2 shows significant red-light phototoxicity in cervical (HeLa) and breast (MCF-7) cancer cells (IC50 ~ 14.1 and 9.2 µM, respectively) while being non-toxic in the dark or healthy breast epithelial cells (MCF-10A, IC50 > 200 µM). Cytotoxicity and cellular uptake studies confirm GLUT-1-mediated selective uptake of Fe2 in cancer cells over normal cells. Fe2 induces apoptosis via oxidative stress, activating both type-I and type-II photophysical pathways upon irradiation. Optical imaging studies confirm Fe2’s mitochondrial localization in HeLa and MCF-7 cells. Fe2 exhibits impressive relaxivity (r1p = 5.2 mM–1 s–1), attributed to interactions with human serum, and MRI phantom studies confirm significant contrast enhancement in MCF-7 cells. To our knowledge, Fe2 is the first complex to uniquely integrate these four functionalities, establishing it as a promising theranostic candidate and paving the way for designing carbohydrate-conjugated, photoactive paramagnetic complexes for targeted cancer theranostics.","PeriodicalId":79,"journal":{"name":"Inorganic Chemistry Frontiers","volume":"9 1","pages":""},"PeriodicalIF":7.0,"publicationDate":"2025-05-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143945588","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
David Fabra Escribano, Theresa Mendrina, Ana Isabel Matesanz, Angeles Medrano, Rastislav Pitek, Walter Berger, Isabella Poetsch, Petra Heffeter, Adoracion Gomez Quiroga
{"title":"Structural variations in the trans-carboxylate/chlorido axis that impact on the mode of action of Pt(II) complexes","authors":"David Fabra Escribano, Theresa Mendrina, Ana Isabel Matesanz, Angeles Medrano, Rastislav Pitek, Walter Berger, Isabella Poetsch, Petra Heffeter, Adoracion Gomez Quiroga","doi":"10.1039/d5qi00674k","DOIUrl":"https://doi.org/10.1039/d5qi00674k","url":null,"abstract":"The design of trans-platinum(II) complexes marked a significant turning point in the design of unconventional anticancer metallodrugs. Compared to cisplatin, these complexes exhibit distinctly different cellular responses and are often active against cisplatin-resistant cell lines. In this study, we synthesized and fully characterized two new Pt(II) complexes introducing one acetate (-OCOCH3) ligand (X) into the trans-PtXX’ axis where X’ is either acetate or chlorido. We evaluated their cytotoxicity across a panel of malignant (Capan-1, B16, MCF7, HCT-116, CT26 and P31) and non-malignant (HaCaT, HUVEC, BEC, MCF10A) cell lines, finding that the complex with only one acetate in trans to a chlorido group is more active and selective than the complex with two acetates (X=X’). Furthermore, the two complexes differ in their cellular uptake route as well as mode of action from cisplatin by inducing cancer cell death via non-DNA-associated mechanisms.","PeriodicalId":79,"journal":{"name":"Inorganic Chemistry Frontiers","volume":"69 1","pages":""},"PeriodicalIF":7.0,"publicationDate":"2025-05-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143933099","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Metal Selection Tactic in Nitronyl Nitroxide Biradical-3d-4f Macrocycle for Boosting Photothermal Conversion and Application of Solar-Driven Water Evaporation","authors":"Hongdao Li, Chaoyi Jin, Lu Xi, Lifeng Ding, Jing Han, Pei Jing","doi":"10.1039/d5qi00727e","DOIUrl":"https://doi.org/10.1039/d5qi00727e","url":null,"abstract":"Metal-organic photothermal conversion materials is vital for efficient utilization of renewable energy to relieve freshwater shortage. Driven by the aspiration to pursue performant photothermal conversion materials, extensive efforts are committed to regulating the photothermal effect. Decoration of the molecular skeleton represents the traditional design idea for adjusting the photophysical features. Distinctively, here, we introduce a more easy-to-operate heterometallic selection tactic that allows for fine adjustment of photothermal conversion ability as exemplified by a series of nitronyl nitroxide biradical-based 3d-4f macrocycles, namely DyCo-1, YbCo-2, DyZn-3 and GdCo-4. The comparative investigation of DyCo-1/YbCo-2 and DyCo-1/DyZn-3 reveals that photothermal conversion efficiency follows the trend of DyCo-1 (75.5 %) > YbCo-2 (71.9 %) > DyZn-3 (57.3 %) on account of 3d/4f metal modulation, suggesting Dy-Co combination achieves the optimization of photothermal performance. Furthermore, DyCo-1 is successfully applied to solar-driven water evaporation with efficiency of 53.1 %. To the best of our knowledge, macrocyclic compounds 1-3 represent the first example of nitronyl nitroxide-3d-4f photothermal materials. The work not only offers a feasible heterometallic modulation strategy to elaborately design molecular photothermal agents, but also a new material selection for solar-driven water evaporation and freshwater production with the intention of alleviating water scarcity.","PeriodicalId":79,"journal":{"name":"Inorganic Chemistry Frontiers","volume":"124 1","pages":""},"PeriodicalIF":7.0,"publicationDate":"2025-05-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143933096","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Frederico Henrique do Carmo Ferreira, Nicholas P. Farrell, Luiz Antônio Sodré Costa
{"title":"SI-PPC-induced modulation of heparin/heparanase binding affinity: a steered molecular dynamics approach","authors":"Frederico Henrique do Carmo Ferreira, Nicholas P. Farrell, Luiz Antônio Sodré Costa","doi":"10.1039/d5qi00461f","DOIUrl":"https://doi.org/10.1039/d5qi00461f","url":null,"abstract":"We report a steered molecular dynamics (SMD) investigation into how substitution-inert polynuclear platinum complexes (SI-PPCs) influence the binding affinity between heparan sulphate (HS) and the enzyme heparanase. By simulating the forced dissociation of HS from the enzyme's active site, we demonstrate that the presence of cationic SI-PPCs substantially reduces the work required to pull the HS substrate away. Compared to the unmodified system, this work decreases by an average of 35.6% in the presence of these platinum complexes, highlighting their “metalloshielding” effect. Detailed analysis of hydrogen bonding and the formation of cyclic sulphate clamps and forks revealed that SI-PPCs stabilize the anionic HS moieties, effectively masking them from enzymatic cleavage. Among the complexes tested, those with greater charge and hydrogen-bonding capacity formed more stable noncovalent interactions. These findings provide mechanistic insight into the experimentally observed inhibition of HS-degrading enzymes by SI-PPCs and offer a pathway for the rational design of new agents to hinder tumour cell invasion and metastasis.","PeriodicalId":79,"journal":{"name":"Inorganic Chemistry Frontiers","volume":"26 1","pages":""},"PeriodicalIF":7.0,"publicationDate":"2025-05-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143933100","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Mohamed Saber Lassoued, Kun Wang, FAIZAN AHMAD, Bai Sun, Yan-Zhen Zheng
{"title":"Exploring the Potential of Two-Dimensional Bismuth-Copper Hybrid Double Perovskites for Memristor Applications","authors":"Mohamed Saber Lassoued, Kun Wang, FAIZAN AHMAD, Bai Sun, Yan-Zhen Zheng","doi":"10.1039/d5qi00670h","DOIUrl":"https://doi.org/10.1039/d5qi00670h","url":null,"abstract":"Hybrid double perovskites (HDPs) have attracted considerable attention due to their potential in optoelectronics. However, the exploration of their properties for memristor devices has not yet been touched. In this study, we introduce a novel two-dimensional HDPs, (H2MPP)2BiCuI8, where H2MPP = 1-methylpiperidinium-4-amine, characterized by its structured layering, narrow bandgap of 1.65 eV, and enhanced stability. More importantly, this HDPs was utilized as a functional layer to prepare a memristor device with an Ag/(H2MPP)2BiCuI8/ITO sandwich structure, which exhibits pronounced RS behavior. In particular, the device exhibits a gradual increase in conductance, followed by a distinct transition at voltages above approximately 0.37 V. Building on this observation, we revealed that the charge conduction mechanism is primarily driven by space charge limited current (SCLC) model, which provides significant insights into charge transport dynamics in HDPs memristors. We believe that this work will provide useful information for the development of high-performance HDPs memristor devices.","PeriodicalId":79,"journal":{"name":"Inorganic Chemistry Frontiers","volume":"54 1","pages":""},"PeriodicalIF":7.0,"publicationDate":"2025-05-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143939972","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Heting Hou, Christian Cerezo-Navarrete, Didac Fenoll, Matilda Kraft, C. Marini, Luis Rodríguez-Santiago, Xavier Solans-Monfort, Luis Miguel Martínez-Prieto, Nuria Romero, Jordi García-Antón, Xavier Sala
{"title":"Enhanced Electrocatalytic Hydrogen Evolution with Bimetallic Ru/Pt Nanoparticles Supported on Nitrogen-Doped Reduced Graphene Oxide","authors":"Heting Hou, Christian Cerezo-Navarrete, Didac Fenoll, Matilda Kraft, C. Marini, Luis Rodríguez-Santiago, Xavier Solans-Monfort, Luis Miguel Martínez-Prieto, Nuria Romero, Jordi García-Antón, Xavier Sala","doi":"10.1039/d5qi00451a","DOIUrl":"https://doi.org/10.1039/d5qi00451a","url":null,"abstract":"The electrocatalytic hydrogen evolution reaction (HER) has been explored using mono- and bimetallic Pt-Ru nanoparticles (NPs) deposited onto nitrogen-doped reduced graphene oxide (NH2-rGO) in acidic media. In this contribution, monometallic and bimetallic nanoparticles with three different Pt/Ru ratios (1/5, 1/1, and 5/1) have been used, yielding five different materials denoted as PtxRuy@NH2-rGO (x = 0, y = 1; x = 1, y = 0; x = 1, y = 5; x = 1, y = 1; x = 5, y = 1). The materials were characterized using a variety of state-of-the-art techniques, including high-angle annular dark field scanning transmission electron microscopy (HAADF-STEM), energy dispersive X-Ray spectroscopy (EDX) and X-Ray absorption spectroscopy (XAS), enabling the investigation of differences in morphology, coordination environment and oxidation state as a function of the metal composition of the graphene-supported NPs. The materials exhibited HER activity and demonstrated competitive overpotentials close to the thermodynamic limit. The initial catalytic activity of the as-synthesized materials enhances as the Pt/Ru ratio increases. Chronopotentiometry cathodic experiments showed that under reductive conditions the electrocatalytic performance is drastically impacted. Ru-rich materials were activated, whereas Pt-rich materials showed poor stability. Upon applying a reducing potential for 58 h, Pt1Ru5@NH2-rGO reached the best catalytic activity with outstanding overpotentials of h0 = 0 mV and h10 = 3 mV and no signs of deactivation even after 12 additional hours of electrolysis. According to DFT calculations, all nanoparticles present surface sites whose hydrogen adsorption energy is optimal for HER. In agreement with the experimental data, the Pt1Ru5 model shows the highest number of highly active sites, especially those involving Ru centres close to the Pt-Ru interface. Combining thorough characterization and computational modelling, this work reveals that the synergy between the two metals, structural features, and their affinity for the support are responsible for the observed differences in catalytic activities and stabilities.","PeriodicalId":79,"journal":{"name":"Inorganic Chemistry Frontiers","volume":"39 1","pages":""},"PeriodicalIF":7.0,"publicationDate":"2025-05-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143933103","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Regulating Band Gap of ZnxCd1-xS in 3DOM CaTiO3 for High Hydrogen Evolution and Gluconic Acid Selectivity","authors":"Ting-Ting Shen, Jing Liu, Fang-Yuan Bai, Wei-Wei Xu, Xue Yong, Zhi-Rong Li, Jing-Ru Han, Jun Chen, Heng Zhao, Zhi-Yi Hu, Yu Li, Bao-Lian Su","doi":"10.1039/d5qi00824g","DOIUrl":"https://doi.org/10.1039/d5qi00824g","url":null,"abstract":"Biomass photoreforming to coproduce sustainable hydrogen and valuable chemicals is a potential strategy for alleviating energy and environmental issues. However, the lack of bifunctional catalysts to efficiently achieve the “one stone kills two birds” scenario greatly limits its practical application. Herein, we rationally design a three-dimensionally ordered macro-porous structure (3DOM) CaTiO3 (CTO) to address the mass diffusion and light harvesting and to load ZnxCd1-xS (ZxC1-xS) quantum dots (QDs) realizing the selective glucose photoreforming process. The regulatable band gap of ZxC1-xS endows 3DOM CTO-ZxC1-xS composites with sufficient light absorbance and adjustable redox potentials. As a result, the optimized 3DOM CTO-Z0.5C0.5S delivers the best performance for sustainable hydrogen evolution from glucose photoreforming with the rate of 4.05 mmol g-1 h-1 and the apparent quantum efficiency (AQY) of 6.48% under monochromatic light of 365 nm. In particular, the well-developed photocatalysts simultaneously produce gluconic acid with the selectivity up to 83.8% from the targeted oxidation of terminal aldehyde group of glucose. The DFT calculations on Gibbs free energy change of HER and the energy difference between reactants and products of OER further reveal that the constructed Z-scheme heterojunction contributes to the spatial separation of photogenerated electrons and holes for a good quantum efficiency and liquid product selectivity. This work demonstrates a sustainable technology for the coproduction of hydrogen and value-added chemicals from photocatalytic biomass valorization.","PeriodicalId":79,"journal":{"name":"Inorganic Chemistry Frontiers","volume":"1 1","pages":""},"PeriodicalIF":7.0,"publicationDate":"2025-05-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143933098","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Selective aromatic halogenation by a manganese compound I model: A mimic of chloroperoxidase","authors":"Lina Zhang, Steiny Russelisaac Premakumari, Maggie Ng, Jisheng Zhang, Yong-Min Lee, Shunichi Fukuzumi, Kyung-Bin Cho, Wonwoo Nam","doi":"10.1039/d5qi00807g","DOIUrl":"https://doi.org/10.1039/d5qi00807g","url":null,"abstract":"A high-valent manganese(IV)-hydroxo porphyrin π-cation radical complex, [Mn<small><sup>IV</sup></small>(OH)(Por<small><sup>+·</sup></small>)(OTf)]<small><sup>+</sup></small> (a protonated manganese Compound I analogue), was studied in the halogenation of aromatic compounds. By replacing the triflate anion with Cl<small><sup>–</sup></small> or Br<small><sup>–</sup></small>, we were able to halogenate toluene with a high selectivity for C(sp<small><sup>2</sup></small>)–H bonds over C(sp<small><sup>3</sup></small>)–H bonds, such as chlorination with Cl<small><sup>–</sup></small> or bromination with Br<small><sup>–</sup></small> in the aromatic ring. We have also examined the halogenation of naphthalene and benzene derivatives with [Mn<small><sup>IV</sup></small>(OH)(Por<small><sup>+·</sup></small>)(X)]<small><sup>+</sup></small> (X = Cl<small><sup>–</sup></small> and Br<small><sup>–</sup></small>). In all of these reactions, halogenated products were formed dominantly and the source of the halogens in the products was found to be halides in the [Mn<small><sup>IV</sup></small>(OH)(Por<small><sup>+·</sup></small>)(X)]<small><sup>+</sup></small> complexes. In the absence of halides, naphthalene was found to undergo dimerization. Kinetic isotope effect (KIE) experiments on this reaction showed no isotopic effect in the halogenation reactions. DFT calculations on models with naphthalene substrate supported a mechanism involving an initial (rate-limiting) electron transfer from the substrate to [Mn<small><sup>IV</sup></small>(OH)(Por<small><sup>+·</sup></small>)(OTf)]<small><sup>+</sup></small>, coupled by the Cl<small><sup>–</sup></small> attachment to the C<small><sub>1</sub></small> position of naphthalene radical cation. This picture was also supported by Marcus theory of outer-sphere electron transfer. The so-formed [Mn<small><sup>IV</sup></small>(OH)(Por)(OTf)] (a manganese Compound II analogue) performed a hydrogen atom transfer from the C<small><sub>1</sub></small> position of the substrate to form the chlorinated naphthalene and [Mn<small><sup>III</sup></small>(H<small><sub>2</sub></small>O)(Por)(OTf)]. DFT calculations showed that [Mn<small><sup>IV</sup></small>(OH)(Por)(OTf)] can also perform direct OH-transfer to the substrate competitively, leaving open possibilities for side-reactions or alternative reactions in a different environment. This study provides a deeper understanding of chloroperoxidase-like reactions.","PeriodicalId":79,"journal":{"name":"Inorganic Chemistry Frontiers","volume":"54 1","pages":""},"PeriodicalIF":7.0,"publicationDate":"2025-05-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143933102","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}