{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,18]],"date-time":"2026-08-18T14:21:47Z","timestamp":1787062907197,"version":"build-2736575974"},"reference-count":47,"publisher":"MDPI AG","issue":"5","license":[{"start":{"date-parts":[[2026,3,6]],"date-time":"2026-03-06T00:00:00Z","timestamp":1772755200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100012166","name":"National Key R&D Program of China","doi-asserted-by":"publisher","award":["2022YFA1505400"],"award-info":[{"award-number":["2022YFA1505400"]}],"id":[{"id":"10.13039\/501100012166","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100001809","name":"National Natural Science Foundation of China","doi-asserted-by":"publisher","award":["22488101"],"award-info":[{"award-number":["22488101"]}],"id":[{"id":"10.13039\/501100001809","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100001809","name":"National Natural Science Foundation of China","doi-asserted-by":"publisher","award":["21933005"],"award-info":[{"award-number":["21933005"]}],"id":[{"id":"10.13039\/501100001809","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100001809","name":"National Natural Science Foundation of China","doi-asserted-by":"publisher","award":["22473014"],"award-info":[{"award-number":["22473014"]}],"id":[{"id":"10.13039\/501100001809","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100012226","name":"Fundamental Research Funds for the Central Universities","doi-asserted-by":"publisher","award":["2023ZYGXZR002"],"award-info":[{"award-number":["2023ZYGXZR002"]}],"id":[{"id":"10.13039\/501100012226","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Molecules"],"abstract":"<jats:p>In conventional low-viscosity solvents, magnetic field effects (MFEs) in photoredox catalysis are often negligible because photogenerated radical ion pairs (RIPs) diffuse apart before significant spin evolution occurs. This study reports using ionic liquids (ILs) as a tunable homogeneous \u201csolvent cage\u201d to observe distinct low-field MFEs in the phenothiazine-mediated photoinduced reductive dechlorination of aryl chlorides. Experimental results demonstrate that MFEs increase significantly with bulk viscosity, reaching saturation at approximately 1000 Gs with a maximum enhancement of about 15%, consistent with the hyperfine coupling mechanism (HFCM). Femtosecond transient absorption spectroscopy (fs-TA) reveals that the ionic liquid environment effectively reduces the radical cage escape rate, matching it with the spin evolution rate. This allows the external magnetic field to intervene in the back electron transfer (BET) process. However, unlike strongly confined micellar systems, the contribution of the triplet charge recombination (TCR) pathway here is moderate, intrinsically limiting the magnetic enhancement amplitude. These findings establish that MFE magnitude is determined by both viscosity-controlled cage dynamics and the efficiency of the TCR channel, providing a mechanistic basis for designing spin-modulated homogeneous photoredox systems.<\/jats:p>","DOI":"10.3390\/molecules31050886","type":"journal-article","created":{"date-parts":[[2026,3,6]],"date-time":"2026-03-06T14:43:07Z","timestamp":1772808187000},"page":"886","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":1,"title":["Viscosity-Controlled Magnetic Field Effects in Homogeneous Photoredox Catalysis Enabled by Ionic Liquids"],"prefix":"10.3390","volume":"31","author":[{"given":"Mingli","family":"Sun","sequence":"first","affiliation":[{"name":"Spin-X Institute, South China University of Technology, Guangzhou 511442, China"},{"name":"School of Chemistry and Chemical Engineering, South China University of Technology, Guangzhou 510641, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jie","family":"Cheng","sequence":"additional","affiliation":[{"name":"Spin-X Institute, South China University of Technology, Guangzhou 511442, China"},{"name":"School of Chemistry and Chemical Engineering, South China University of Technology, Guangzhou 510641, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Chenli","family":"Chen","sequence":"additional","affiliation":[{"name":"College of Chemistry, Beijing Normal University, Beijing 100875, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jialong","family":"Jie","sequence":"additional","affiliation":[{"name":"College of Chemistry, Beijing Normal University, Beijing 100875, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Hongmei","family":"Su","sequence":"additional","affiliation":[{"name":"College of Chemistry, Beijing Normal University, Beijing 100875, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-0039-6346","authenticated-orcid":false,"given":"Song","family":"Gao","sequence":"additional","affiliation":[{"name":"Spin-X Institute, South China University of Technology, Guangzhou 511442, China"},{"name":"Key Laboratory of Bioinorganic and Synthetic Chemistry of Ministry of Education, School of Chemistry, LIFM, IGCME, GBRCE for Functional Molecular Engineering, Sun Yat-Sen University, Guangzhou 510275, China"},{"name":"Beijing National Laboratory of Molecular Science, Beijing Key Laboratory of Magnetoelectric Materials and Devices, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2989-1535","authenticated-orcid":false,"given":"Linan","family":"Zhou","sequence":"additional","affiliation":[{"name":"Spin-X Institute, South China University of Technology, Guangzhou 511442, China"},{"name":"School of Chemistry and Chemical Engineering, South China University of Technology, Guangzhou 510641, China"},{"name":"State Key Laboratory of Luminescent Materials and Devices, South China University of Technology, Guangzhou 510641, China"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,3,6]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"4926","DOI":"10.1039\/D3CS01129A","article-title":"Visible photons as ideal reagents for the activation of coloured organic compounds","volume":"53","author":"Nicchio","year":"2024","journal-title":"Chem. 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