ACS Catalysis 最新文献

{"title":"Clarifying the Methanol Synthesis Mechanism via CO2 Hydrogenation on the Cu(111) Surface: Insights from Accurate Doubly Hybrid Density Functionals","authors":"Zheng Chen,&nbsp;Zhangyun Liu and Xin Xu*,&nbsp;","doi":"10.1021/acscatal.5c0109910.1021/acscatal.5c01099","DOIUrl":"https://doi.org/10.1021/acscatal.5c01099https://doi.org/10.1021/acscatal.5c01099","url":null,"abstract":"<p >Methanol synthesis via CO₂ hydrogenation on copper-based catalysts is an emerging industrial process that has a growing importance in chemical production. Yet, the elucidation of the reaction mechanisms and the identification of active sites remain subjects of ongoing debate. Due to experimental challenges, experiments alone are insufficient to provide a complete picture of the energy landscape. Meanwhile, the proposed reaction mechanisms often rely on density functional theory calculations at the generalized gradient approximation (GGA) level, which can introduce considerable uncertainty. Here, we employ an advanced hybrid method, XYG3:GGA, that combines the doubly hybrid XYG3 functional with the periodic GGA to investigate the methanol synthesis on the Cu(111) surface. This hybrid method yields results that align well with the available energy landscape in the experiment while resolving the controversy between the experimental observation of the H₂COO* intermediate and the GGA-predicted pathway from the HCOOH* intermediate. It further clarifies that the Cu(111) site makes such an insignificant contribution that it cannot be considered the active site for the methanol formation on copper catalysts. These findings highlight the importance of using more accurate methods, such as XYG3:GGA, to elucidate the reaction mechanism and identify the active site, thereby bridging the gap between the experiment and theory.</p>","PeriodicalId":9,"journal":{"name":"ACS Catalysis ","volume":"15 6","pages":"5039–5045 5039–5045"},"PeriodicalIF":11.3,"publicationDate":"2025-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143667004","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":"The Molecular Basis of the β-Ketoacyl-ACP Synthase FabH in Catalyzing C–C Bond Formation of Acetoacetyl-ACP","authors":"Chang Cai, Yuzhou Huang, Lin Zhang, Liang Zhang","doi":"10.1021/acscatal.5c01167","DOIUrl":"https://doi.org/10.1021/acscatal.5c01167","url":null,"abstract":"β-Ketoacyl-ACP synthases (KAS) catalyze carbon skeleton extension in numerous metabolic routes such as the fatty acid biosynthesis pathway (FAS), among which FabH is the only known member that links the initiation stage to the elongation cycle of type-II FAS (FAS-II) by catalyzing condensation between acetyl-CoA and malonyl-ACP for the first β-keto-ACP intermediate acetoacetyl-ACP formation. Here, we reveal the substrate selection and condensation mechanisms of FabH from <i>Escherichia coli</i>. We demonstrate that <i>Ec</i>FabH binds CoA and ACP using distinct regions in an irreversible compulsory order. The malonyl moiety is then delivered to a hydrophobic cage near the catalytic triad residues through front and middle door residues in the tunnel, and the substrate length is selected by a backdoor residue Phe87, ensuring the preferential recognition of <i>Ec</i>FabH on acetyl moiety carried by CoA rather than longer substrates. Moreover, the malonyl moiety is locked in the cage by the acetylated Cys112 from the transacylation reaction, triggering the subsequent decarboxylation and condensation catalysis. Our study provides fundamental mechanistic insights into the initial extension of carbon skeletons catalyzed by FabH and homologues in FAS, PKS, and biotin biosynthesis pathways and may facilitate protein engineering and optimization for synthetic biological and pharmaceutical industry, as well as antibacterial drug development.","PeriodicalId":9,"journal":{"name":"ACS Catalysis ","volume":"19 1","pages":""},"PeriodicalIF":12.9,"publicationDate":"2025-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143589874","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":"Benzophenothiazine/Boronic Acid Cooperative Photocatalysis Enables the Synthesis of γ-Lactones via the [3 + 2] Cycloaddition of α,β-Unsaturated Carboxylic Acids with Olefins","authors":"Taichi Yumura,&nbsp;Takeshi Nanjo and Yoshiji Takemoto*,&nbsp;","doi":"10.1021/acscatal.5c0076410.1021/acscatal.5c00764","DOIUrl":"https://doi.org/10.1021/acscatal.5c00764https://doi.org/10.1021/acscatal.5c00764","url":null,"abstract":"<p >The radical-mediated [3 + 2] cycloaddition between α-carboxy radicals and olefins is an efficient method for the synthesis of γ-lactones. Here, we report a [3 + 2]-type lactonization via the reductive single-electron transfer (SET) and subsequent protonation of α,β-unsaturated carboxylic acids (UCAs), which are ideal α-carboxy radical precursors in terms of atom economy. The cooperative catalysis of benzophenothiazine and boronic acid efficiently promotes the formation of α-carboxy radicals from UCAs in the presence of appropriate Brønsted acids such as benzoic acid, leading to a practical synthetic method without the need for strong acids or reductants. The chemoselective activation of UCAs provides access to a wide range of alkenes, including α,β-unsaturated amides, to be used as radical acceptors. Mechanistic studies revealed that the thermodynamic stability of the α-carboxy radicals and the charge distribution of the radical anion intermediates have a significant impact on the reaction rate and regioselectivity of the protonation.</p>","PeriodicalId":9,"journal":{"name":"ACS Catalysis ","volume":"15 6","pages":"4975–4983 4975–4983"},"PeriodicalIF":11.3,"publicationDate":"2025-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143666894","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":"Unraveling the Roles of the ZnO Surface Structure and Second Metal Doping in Tuning the Catalytic Performance of Ethane Dehydrogenation","authors":"Lixing Zhang, Bingying Han, Baojun Wang, Maohong Fan, Lixia Ling, Riguang Zhang","doi":"10.1021/acscatal.4c08002","DOIUrl":"https://doi.org/10.1021/acscatal.4c08002","url":null,"abstract":"The ZnO surface is easily reduced during alkane dehydrogenation owing to the formation of surface hydrogen species, resulting in poor catalytic performance. Aiming at revealing ZnO surface structure evolution, the degree of surface reduction, catalyst stability, and the type of key species contributing to surface reduction in the ethane dehydrogenation (EDH) reaction, this work fully investigated the mechanism of the EDH reaction over ZnO and a series of ZnO-based catalysts by using DFT calculations and kMC simulations. The results show that ZnO surface reduction is mainly caused by the interaction of surface H* species from EDH with surface lattice oxygen to generate H₂O(g), leading to surface oxygen vacancy (O_v) formation over ZnO. As the EDH reaction proceeds, the number of O_v increases, and the active center gradually shifts from the Zn–O site to the Zn–Zn_cus site, decreasing the C₂H₄(g) formation activity and ultimately deactivating the ZnO catalyst. Furthermore, the second metal M is introduced into the ZnO surface to construct M/ZnO catalysts, and the Mn/ZnO catalyst is screened out to present better catalytic performance, which is not easily reduced. This work is of great significance in laying a solid foundation for optimizing the catalytic performance of the EDH reaction over ZnO-based catalysts.","PeriodicalId":9,"journal":{"name":"ACS Catalysis ","volume":"40 1","pages":""},"PeriodicalIF":12.9,"publicationDate":"2025-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143589873","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":"The Molecular Basis of the β-Ketoacyl-ACP Synthase FabH in Catalyzing C–C Bond Formation of Acetoacetyl-ACP","authors":"Chang Cai,&nbsp;Yuzhou Huang,&nbsp;Lin Zhang* and Liang Zhang*,&nbsp;","doi":"10.1021/acscatal.5c0116710.1021/acscatal.5c01167","DOIUrl":"https://doi.org/10.1021/acscatal.5c01167https://doi.org/10.1021/acscatal.5c01167","url":null,"abstract":"<p >β-Ketoacyl-ACP synthases (KAS) catalyze carbon skeleton extension in numerous metabolic routes such as the fatty acid biosynthesis pathway (FAS), among which FabH is the only known member that links the initiation stage to the elongation cycle of type-II FAS (FAS-II) by catalyzing condensation between acetyl-CoA and malonyl-ACP for the first β-keto-ACP intermediate acetoacetyl-ACP formation. Here, we reveal the substrate selection and condensation mechanisms of FabH from <i>Escherichia coli</i>. We demonstrate that <i>Ec</i>FabH binds CoA and ACP using distinct regions in an irreversible compulsory order. The malonyl moiety is then delivered to a hydrophobic cage near the catalytic triad residues through front and middle door residues in the tunnel, and the substrate length is selected by a backdoor residue Phe87, ensuring the preferential recognition of <i>Ec</i>FabH on acetyl moiety carried by CoA rather than longer substrates. Moreover, the malonyl moiety is locked in the cage by the acetylated Cys112 from the transacylation reaction, triggering the subsequent decarboxylation and condensation catalysis. Our study provides fundamental mechanistic insights into the initial extension of carbon skeletons catalyzed by FabH and homologues in FAS, PKS, and biotin biosynthesis pathways and may facilitate protein engineering and optimization for synthetic biological and pharmaceutical industry, as well as antibacterial drug development.</p>","PeriodicalId":9,"journal":{"name":"ACS Catalysis ","volume":"15 6","pages":"5028–5038 5028–5038"},"PeriodicalIF":11.3,"publicationDate":"2025-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143666958","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":"Unraveling the Roles of the ZnO Surface Structure and Second Metal Doping in Tuning the Catalytic Performance of Ethane Dehydrogenation","authors":"Lixing Zhang,&nbsp;Bingying Han*,&nbsp;Baojun Wang,&nbsp;Maohong Fan,&nbsp;Lixia Ling and Riguang Zhang*,&nbsp;","doi":"10.1021/acscatal.4c0800210.1021/acscatal.4c08002","DOIUrl":"https://doi.org/10.1021/acscatal.4c08002https://doi.org/10.1021/acscatal.4c08002","url":null,"abstract":"<p >The ZnO surface is easily reduced during alkane dehydrogenation owing to the formation of surface hydrogen species, resulting in poor catalytic performance. Aiming at revealing ZnO surface structure evolution, the degree of surface reduction, catalyst stability, and the type of key species contributing to surface reduction in the ethane dehydrogenation (EDH) reaction, this work fully investigated the mechanism of the EDH reaction over ZnO and a series of ZnO-based catalysts by using DFT calculations and kMC simulations. The results show that ZnO surface reduction is mainly caused by the interaction of surface H* species from EDH with surface lattice oxygen to generate H₂O(g), leading to surface oxygen vacancy (O_v) formation over ZnO. As the EDH reaction proceeds, the number of O_v increases, and the active center gradually shifts from the Zn–O site to the Zn–Zn_cus site, decreasing the C₂H₄(g) formation activity and ultimately deactivating the ZnO catalyst. Furthermore, the second metal M is introduced into the ZnO surface to construct M/ZnO catalysts, and the Mn/ZnO catalyst is screened out to present better catalytic performance, which is not easily reduced. This work is of great significance in laying a solid foundation for optimizing the catalytic performance of the EDH reaction over ZnO-based catalysts.</p>","PeriodicalId":9,"journal":{"name":"ACS Catalysis ","volume":"15 6","pages":"5014–5027 5014–5027"},"PeriodicalIF":11.3,"publicationDate":"2025-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143666891","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":"Designing Ruthenium Phthalocyanine with Chiral Pockets Formed by (1R,2S,5R)-Menthoxy Groups for Enantioselective Catalysis","authors":"Andrey P. Kroitor,&nbsp;Alexander A. Dmitrienko,&nbsp;Gayane A. Kirakosyan,&nbsp;Chantal Lorentz,&nbsp;Alexander G. Martynov*,&nbsp;Yulia G. Gorbunova*,&nbsp;Aslan Yu. Tsivadze and Alexander B. Sorokin*,&nbsp;","doi":"10.1021/acscatal.4c0769610.1021/acscatal.4c07696","DOIUrl":"https://doi.org/10.1021/acscatal.4c07696https://doi.org/10.1021/acscatal.4c07696","url":null,"abstract":"<p >Unprecedented chiral ruthenium(II) complexes with phthalocyanines having chiral motifs near the catalytic metal site have been prepared by cross condensation of the chiral 3,6-bis-aryloxy-phthalonitrile (<b>α-Ar*O</b>)₂<b>Pn</b> bearing two (1<i>R</i>,2<i>S</i>,5<i>R</i>)-menthoxy groups orthogonal to the aromatic plane and (15-crown-5)phthalonitrile. Four complexes containing chiral menthyl groups (<b>M</b>) and 15-crown-5 units (<b>C</b>), notably <b>RuPc[MC</b>_<b>3</b><b>](CO)</b>, <b>RuPc[</b><i>opp</i><b>-M</b>_<b>2</b><b>C</b>_<b>2</b><b>](CO)</b>, <b>RuPc[</b><i>adj</i><b>-M</b>_<b>2</b><b>C</b>_<b>2</b><b>](CO)</b>, and <b>RuPc[M</b>_<b>3</b><b>C](CO)</b>, were isolated in pure form and fully characterized by UV–vis, circular dichroism, HRMS, and various ¹H NMR and ¹³C NMR techniques. Their evaluation in the benchmark asymmetric cyclopropanation reaction of styrene derivatives by ethyl diazoacetate indicated that the <b>RuPc[</b><i>opp</i><b>-M</b>_<b>2</b><b>C</b>_<b>2</b><b>](CO)</b> complex was the most efficient in terms of diastereo- and enantioselectivity. Further study revealed the strong dependence of the stereoselectivity on the solvent nature and salt additives, which caused conformational rearrangement of the flexible chiral surrounding, as evidenced by multinuclear NMR and CD spectra. For instance, upon moving from commonly used CH₂Cl₂ to EtOH with the addition of NaPF₆, a significant enhancement of enantioselectivity (from 35 to 84% with <i>p</i>-methylstyrene) was obtained. Of particular importance is a very high diastereoselectivity of cyclopropanation of many substrates promoted by the incorporation of sodium cations into crown ether cavities of phthalocyanine to attain a <i>trans</i>/<i>cis</i> ratio up to 499:1. Such a regulating effect in chiral catalysis involving tetrapyrrolic complexes has not been previously observed, rendering this complex a prominent example of the phthalocyanine tunable catalyst. The developed synthetic strategy paves the way to phthalocyanine complexes with a chiral environment around the metal site and crown ether receptors to tune the catalytic properties.</p>","PeriodicalId":9,"journal":{"name":"ACS Catalysis ","volume":"15 6","pages":"4984–5001 4984–5001"},"PeriodicalIF":11.3,"publicationDate":"2025-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143666914","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":"Influence of Dihydrophenazine Photoredox Catalyst Excited State Character and Reduction Potentials on Control in Organocatalyzed Atom Transfer Radical Polymerization","authors":"Katherine O. Puffer, Brandon S. Portela, Alexis J. Olson-Gwin, Katherine A. Chism, Sylwia Dworakowska, Ethan J. Crace, Robert S. Paton, Garret M. Miyake","doi":"10.1021/acscatal.4c07204","DOIUrl":"https://doi.org/10.1021/acscatal.4c07204","url":null,"abstract":"The development of <i>N</i>,<i>N</i>-diaryl dihydrophenazine organic photoredox catalysts (PCs) has enabled numerous examples of organocatalyzed atom transfer radical polymerization (O-ATRP) of methyl methacrylate (MMA) monomer to polymers with low dispersity (<i>Đ</i> &lt; 1.30) and near-unity initiator efficiency (<i>I</i>* ∼ 100%), as well as small molecule synthesis. In this work, we investigate the influence of core substitution (CS) by alkyl, aryl, and heteroatom groups on singlet excited state reduction potential (<i>E</i>_S1°*). We observe that a highly reducing <i>E</i>_S1°* is in part a result of a locally excited (LE)-dominated hybridized local and charge transfer (HLCT) excited state in CS PCs, which is influenced by the identity of the core substituent. Additionally, the PCs that possess a LE-dominated HLCT character maintain a relatively oxidizing PC radical cation oxidation potential (<i>E</i>_1/2) for deactivation in O-ATRP compared to fully LE PCs reported in prior work. For example, a thiophenol core substituted (heteroatom CS, HetCS) PC shows the most negative <i>E</i>_S1°* (−2.07 V vs SCE), more LE character (Stokes shift = 124 nm), and has an oxidizing PC radical cation (<i>E</i>_1/2 = 0.30 V vs SCE). The CS PCs with improved properties, including more negative <i>E</i>_S1°*, perform best in O-ATRP of MMA with the HetCS PC showing the best control in both DMAc (<i>Đ</i> = 1.08, <i>I*</i> = 89%) and EtOAc (<i>Đ</i> = 1.06, <i>I*</i> = 97%). Additionally, the HetCS PC was found to mediate the controlled polymerization of <i>n</i>-butyl acrylate (<i>n</i>-BA) (<i>Đ</i> = 1.24, <i>I*</i> = 97%), which has remained challenging in O-ATRP without supplemental deactivation strategies. An aryl CS PC was found to have moderate control as low as 1 ppm PC, indicating facilitation of low PC loadings (<i>Đ</i> = 1.33, <i>I*</i> = 69%). The relationship between excited state character, <i>E</i>_S1°*, and polymerization control observed in this work provides a foundation for increasing the utility of phenazine PCs across photoredox catalysis.","PeriodicalId":9,"journal":{"name":"ACS Catalysis ","volume":"19 1","pages":""},"PeriodicalIF":12.9,"publicationDate":"2025-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143583062","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":"Benzophenothiazine/Boronic Acid Cooperative Photocatalysis Enables the Synthesis of γ-Lactones via the [3 + 2] Cycloaddition of α,β-Unsaturated Carboxylic Acids with Olefins","authors":"Taichi Yumura, Takeshi Nanjo, Yoshiji Takemoto","doi":"10.1021/acscatal.5c00764","DOIUrl":"https://doi.org/10.1021/acscatal.5c00764","url":null,"abstract":"The radical-mediated [3 + 2] cycloaddition between α-carboxy radicals and olefins is an efficient method for the synthesis of γ-lactones. Here, we report a [3 + 2]-type lactonization via the reductive single-electron transfer (SET) and subsequent protonation of α,β-unsaturated carboxylic acids (UCAs), which are ideal α-carboxy radical precursors in terms of atom economy. The cooperative catalysis of benzophenothiazine and boronic acid efficiently promotes the formation of α-carboxy radicals from UCAs in the presence of appropriate Brønsted acids such as benzoic acid, leading to a practical synthetic method without the need for strong acids or reductants. The chemoselective activation of UCAs provides access to a wide range of alkenes, including α,β-unsaturated amides, to be used as radical acceptors. Mechanistic studies revealed that the thermodynamic stability of the α-carboxy radicals and the charge distribution of the radical anion intermediates have a significant impact on the reaction rate and regioselectivity of the protonation.","PeriodicalId":9,"journal":{"name":"ACS Catalysis ","volume":"68 1","pages":""},"PeriodicalIF":12.9,"publicationDate":"2025-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143583067","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":"Influence of Dihydrophenazine Photoredox Catalyst Excited State Character and Reduction Potentials on Control in Organocatalyzed Atom Transfer Radical Polymerization","authors":"Katherine O. Puffer,&nbsp;Brandon S. Portela,&nbsp;Alexis J. Olson-Gwin,&nbsp;Katherine A. Chism,&nbsp;Sylwia Dworakowska,&nbsp;Ethan J. Crace,&nbsp;Robert S. Paton* and Garret M. Miyake*,&nbsp;","doi":"10.1021/acscatal.4c0720410.1021/acscatal.4c07204","DOIUrl":"https://doi.org/10.1021/acscatal.4c07204https://doi.org/10.1021/acscatal.4c07204","url":null,"abstract":"<p >The development of <i>N</i>,<i>N</i>-diaryl dihydrophenazine organic photoredox catalysts (PCs) has enabled numerous examples of organocatalyzed atom transfer radical polymerization (O-ATRP) of methyl methacrylate (MMA) monomer to polymers with low dispersity (<i>Đ</i> &lt; 1.30) and near-unity initiator efficiency (<i>I</i>* ∼ 100%), as well as small molecule synthesis. In this work, we investigate the influence of core substitution (CS) by alkyl, aryl, and heteroatom groups on singlet excited state reduction potential (<i>E</i>_S1°*). We observe that a highly reducing <i>E</i>_S1°* is in part a result of a locally excited (LE)-dominated hybridized local and charge transfer (HLCT) excited state in CS PCs, which is influenced by the identity of the core substituent. Additionally, the PCs that possess a LE-dominated HLCT character maintain a relatively oxidizing PC radical cation oxidation potential (<i>E</i>_1/2) for deactivation in O-ATRP compared to fully LE PCs reported in prior work. For example, a thiophenol core substituted (heteroatom CS, HetCS) PC shows the most negative <i>E</i>_S1°* (−2.07 V vs SCE), more LE character (Stokes shift = 124 nm), and has an oxidizing PC radical cation (<i>E</i>_1/2 = 0.30 V vs SCE). The CS PCs with improved properties, including more negative <i>E</i>_S1°*, perform best in O-ATRP of MMA with the HetCS PC showing the best control in both DMAc (<i>Đ</i> = 1.08, <i>I*</i> = 89%) and EtOAc (<i>Đ</i> = 1.06, <i>I*</i> = 97%). Additionally, the HetCS PC was found to mediate the controlled polymerization of <i>n</i>-butyl acrylate (<i>n</i>-BA) (<i>Đ</i> = 1.24, <i>I*</i> = 97%), which has remained challenging in O-ATRP without supplemental deactivation strategies. An aryl CS PC was found to have moderate control as low as 1 ppm PC, indicating facilitation of low PC loadings (<i>Đ</i> = 1.33, <i>I*</i> = 69%). The relationship between excited state character, <i>E</i>_S1°*, and polymerization control observed in this work provides a foundation for increasing the utility of phenazine PCs across photoredox catalysis.</p>","PeriodicalId":9,"journal":{"name":"ACS Catalysis ","volume":"15 6","pages":"5002–5013 5002–5013"},"PeriodicalIF":11.3,"publicationDate":"2025-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143666959","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}