JACS AuPub Date : 2024-10-16DOI: 10.1021/jacsau.4c0074510.1021/jacsau.4c00745
Kai Hua, Fei Xie, Shengfa Ye* and Ming-Tian Zhang*,
{"title":"Three Distinct Oxidation States (II/II, II/III, and III/III) of Diorganocopper Complexes","authors":"Kai Hua, Fei Xie, Shengfa Ye* and Ming-Tian Zhang*, ","doi":"10.1021/jacsau.4c0074510.1021/jacsau.4c00745","DOIUrl":"https://doi.org/10.1021/jacsau.4c00745https://doi.org/10.1021/jacsau.4c00745","url":null,"abstract":"<p >In this report, we present a structurally and spectroscopically characterized diorganocopper system in three distinct oxidation states: [Cu<sup>II</sup>Cu<sup>II</sup>] (<b>1</b>), [Cu<sup>II</sup>Cu<sup>III</sup>] (<b>2</b>), and [Cu<sup>III</sup>Cu<sup>III</sup>] (<b>3</b>). These states are stabilized by a macrocyclic ligand scaffold featuring two square-planar coordination {C<sub>2</sub><sup>NHC</sup>N<sub>2</sub><sup>pyrazole</sup>}. We have analyzed the geometric and electronic structures using X-ray diffraction (XRD) and multiple spectroscopic methods including nuclear magnetic resonance (NMR), UV–vis, and electron paramagnetic resonance (EPR) spectroscopies, in combination with density functional theory (DFT) calculations. Remarkably, this study provides a structural determination of mixed-valence diorganocopper(II,III) complex <b>2</b>, which is at the borderline between valence-trapped or charge-localized class I systems and charge moderately delocalized class II systems in Robin and Day classification. These findings enhance our understanding of the systematic structural and electronic changes that occur in diorganocopper complexes in response to redox transformations.</p>","PeriodicalId":94060,"journal":{"name":"JACS Au","volume":"4 11","pages":"4406–4414 4406–4414"},"PeriodicalIF":8.5,"publicationDate":"2024-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.acs.org/doi/epdf/10.1021/jacsau.4c00745","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142694568","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
JACS AuPub Date : 2024-10-14DOI: 10.1021/jacsau.4c0079510.1021/jacsau.4c00795
Laura Díaz-Casado, Enrique Mann, Ester Jiménez-Moreno, Alejandro Villacampa, Laura Montalvillo-Jiménez, Claudia Sánchez-García, Francisco Corzana, Jesús Jiménez-Barbero, Ana María Gómez, Andrés G. Santana and Juan Luis Asensio*,
{"title":"Opposed Aromatic Surfaces Behave as Independent Binding Sites for Carbohydrate Stacking: Analysis of Sandwich-like CH/π/CH Complexes","authors":"Laura Díaz-Casado, Enrique Mann, Ester Jiménez-Moreno, Alejandro Villacampa, Laura Montalvillo-Jiménez, Claudia Sánchez-García, Francisco Corzana, Jesús Jiménez-Barbero, Ana María Gómez, Andrés G. Santana and Juan Luis Asensio*, ","doi":"10.1021/jacsau.4c0079510.1021/jacsau.4c00795","DOIUrl":"https://doi.org/10.1021/jacsau.4c00795https://doi.org/10.1021/jacsau.4c00795","url":null,"abstract":"<p >CH/π bonds are versatile elements for the construction of complex molecular architectures, thus playing key roles in many biomolecular recognition processes. Although seldom acknowledged, aromatic units are inherently bivalent and can participate in CH/π bonds through either face simultaneously, leading to the formation of <i>ternary</i> stacking complexes. This sandwich-like arrangement is by far the most common in natural complexes and could potentially lead to negative cooperativity due to unfavorable polarization or electrostatic effects, especially when polarized CH fragments are involved. To evaluate the energetics of such interaction modes, we selected a biologically relevant model, <i>carbohydrate/aromatic stacking</i>, and conducted an experimental analysis comparing <i>binary</i> CH/π interactions to <i>ternary</i> CH/π/CH stacking. Our approach utilized a dynamic combinatorial strategy, which is well-suited to reveal minor stability differences among aromatic complexes. Our results showed that carbohydrate/aromatic stacking is relatively insensitive to molecular recognition events occurring on the opposite side of the aromatic platform, whether exposed to water or involved in additional CH/π contacts, with free energy fluctuations lower than 10%. Based on these data, for all practical purposes, the two opposing aromatic surfaces can be considered independent, noninteracting binding sites, making aromatic platforms optimal connecting elements for supramolecular cross-linking.</p>","PeriodicalId":94060,"journal":{"name":"JACS Au","volume":"4 11","pages":"4466–4473 4466–4473"},"PeriodicalIF":8.5,"publicationDate":"2024-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.acs.org/doi/epdf/10.1021/jacsau.4c00795","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142694535","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
JACS AuPub Date : 2024-10-14eCollection Date: 2024-11-25DOI: 10.1021/jacsau.4c00795
Laura Díaz-Casado, Enrique Mann, Ester Jiménez-Moreno, Alejandro Villacampa, Laura Montalvillo-Jiménez, Claudia Sánchez-García, Francisco Corzana, Jesús Jiménez-Barbero, Ana María Gómez, Andrés G Santana, Juan Luis Asensio
{"title":"Opposed Aromatic Surfaces Behave as Independent Binding Sites for Carbohydrate Stacking: Analysis of Sandwich-like CH/π/CH Complexes.","authors":"Laura Díaz-Casado, Enrique Mann, Ester Jiménez-Moreno, Alejandro Villacampa, Laura Montalvillo-Jiménez, Claudia Sánchez-García, Francisco Corzana, Jesús Jiménez-Barbero, Ana María Gómez, Andrés G Santana, Juan Luis Asensio","doi":"10.1021/jacsau.4c00795","DOIUrl":"10.1021/jacsau.4c00795","url":null,"abstract":"<p><p>CH/π bonds are versatile elements for the construction of complex molecular architectures, thus playing key roles in many biomolecular recognition processes. Although seldom acknowledged, aromatic units are inherently bivalent and can participate in CH/π bonds through either face simultaneously, leading to the formation of <i>ternary</i> stacking complexes. This sandwich-like arrangement is by far the most common in natural complexes and could potentially lead to negative cooperativity due to unfavorable polarization or electrostatic effects, especially when polarized CH fragments are involved. To evaluate the energetics of such interaction modes, we selected a biologically relevant model, <i>carbohydrate/aromatic stacking</i>, and conducted an experimental analysis comparing <i>binary</i> CH/π interactions to <i>ternary</i> CH/π/CH stacking. Our approach utilized a dynamic combinatorial strategy, which is well-suited to reveal minor stability differences among aromatic complexes. Our results showed that carbohydrate/aromatic stacking is relatively insensitive to molecular recognition events occurring on the opposite side of the aromatic platform, whether exposed to water or involved in additional CH/π contacts, with free energy fluctuations lower than 10%. Based on these data, for all practical purposes, the two opposing aromatic surfaces can be considered independent, noninteracting binding sites, making aromatic platforms optimal connecting elements for supramolecular cross-linking.</p>","PeriodicalId":94060,"journal":{"name":"JACS Au","volume":"4 11","pages":"4466-4473"},"PeriodicalIF":8.5,"publicationDate":"2024-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11600182/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142752670","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
JACS AuPub Date : 2024-10-14eCollection Date: 2024-11-25DOI: 10.1021/jacsau.4c00777
Tian-Jiao Han, Qiu-Le Yang, Jiaen Hu, Min-Can Wang, Guang-Jian Mei
{"title":"Divergent Synthesis of Chiroptical Molecular Switches Based on 1,2-Diaxial Atropisomers.","authors":"Tian-Jiao Han, Qiu-Le Yang, Jiaen Hu, Min-Can Wang, Guang-Jian Mei","doi":"10.1021/jacsau.4c00777","DOIUrl":"10.1021/jacsau.4c00777","url":null,"abstract":"<p><p>The development of chiroptical molecular switches for chiral sensing, data communication, optical displays, chiral logic gates, and asymmetric catalysis is currently a vibrant frontier of science and technology. Herein, we report a practical artificial dynamic system based on a 1,2-diaxial atropisomer. Organocatalytic parallel kinetic resolution allows the divergent synthesis of two sets of stereoisomers with vicinal C-C and N-N axes from the same racemic single-axis substrates. By simply varying the configuration of the single catalyst, all four stereoisomers are accessible. The successive conduction of covalent unlocking/locking and thermal-isomerization processes enables sequential switching between all four atropisomeric states with electronic circular dichroism signal reversal, providing an example of multistate chiroptical molecular switches.</p>","PeriodicalId":94060,"journal":{"name":"JACS Au","volume":"4 11","pages":"4445-4454"},"PeriodicalIF":8.5,"publicationDate":"2024-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11600187/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142752521","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
JACS AuPub Date : 2024-10-14DOI: 10.1021/jacsau.4c0077710.1021/jacsau.4c00777
Tian-Jiao Han, Qiu-Le Yang, Jiaen Hu, Min-Can Wang and Guang-Jian Mei*,
{"title":"Divergent Synthesis of Chiroptical Molecular Switches Based on 1,2-Diaxial Atropisomers","authors":"Tian-Jiao Han, Qiu-Le Yang, Jiaen Hu, Min-Can Wang and Guang-Jian Mei*, ","doi":"10.1021/jacsau.4c0077710.1021/jacsau.4c00777","DOIUrl":"https://doi.org/10.1021/jacsau.4c00777https://doi.org/10.1021/jacsau.4c00777","url":null,"abstract":"<p >The development of chiroptical molecular switches for chiral sensing, data communication, optical displays, chiral logic gates, and asymmetric catalysis is currently a vibrant frontier of science and technology. Herein, we report a practical artificial dynamic system based on a 1,2-diaxial atropisomer. Organocatalytic parallel kinetic resolution allows the divergent synthesis of two sets of stereoisomers with vicinal C–C and N–N axes from the same racemic single-axis substrates. By simply varying the configuration of the single catalyst, all four stereoisomers are accessible. The successive conduction of covalent unlocking/locking and thermal-isomerization processes enables sequential switching between all four atropisomeric states with electronic circular dichroism signal reversal, providing an example of multistate chiroptical molecular switches.</p>","PeriodicalId":94060,"journal":{"name":"JACS Au","volume":"4 11","pages":"4445–4454 4445–4454"},"PeriodicalIF":8.5,"publicationDate":"2024-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.acs.org/doi/epdf/10.1021/jacsau.4c00777","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142694536","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Selective [3 + 2] C–H/C–H Alkyne Annulation via Dual (Distal) C(β, δ)–H Bond Activation Relay: A Novel Therapeutic Quinazolone-Tethered Benzofulvenes for Oral Cancer","authors":"Dinesh Parshuram Satpute, Garvita Narang, Harshal Rohit, Jagdish Manjhi, Divita Kumar, Sangita Dattatray Shinde, Shyam Kumar Lokhande, Priyanka Patel Vatsa, Vinal Upadhyay, Shivkanya Madhavrao Bhujbal, Amit Mandoli* and Dinesh Kumar*, ","doi":"10.1021/jacsau.4c0080210.1021/jacsau.4c00802","DOIUrl":"https://doi.org/10.1021/jacsau.4c00802https://doi.org/10.1021/jacsau.4c00802","url":null,"abstract":"<p >In contrast to proximal C–H bond activations, distal C–H bond activation is fundamentally more challenging and requires distinctly specialized directing partners or techniques. In this context, we report an unprecedented dual (distal) β-C(benzylic)–H and δ-C(aryl)–H bond activation relay protocol for the chemo-, regio-, and stereoselective construction of heterocycle-tethered benzofulvenes via [3 + 2] CH/CH-alkyne annulation under palladium catalysis. The protocol overrides the more favorable [4 + 2] CH/NH annulation and does not follow the vinylic C–H bond activation pathway. Mechanistic studies provide insight into the favored cyclopalladation of key intermediates (resulting from β-C(benzylic)–H bond cleavage) through relay δ-C(aryl)–H cleavage (vs N–H cleavage) prior to reductive elimination, which is the key to desired annulation. The synthesized new chemical entities (NCEs) constitute a novel scaffold with favorable anticancer activity against oral squamous cell carcinoma (OSCC). Detailed biomolecular studies, including RNA-sequencing and analysis, indicate that these compounds (<b>4e</b> and <b>4w</b>) arrest the cell cycle at the S-phase and target multiple cancer hallmarks, such as the activation of apoptotic pathways and impairment of mitochondrial activity simultaneously, suggesting their chemotherapeutic potential for oral cancer by addressing the complexity and adaptability of cancer cells in chorus.</p>","PeriodicalId":94060,"journal":{"name":"JACS Au","volume":"4 11","pages":"4474–4487 4474–4487"},"PeriodicalIF":8.5,"publicationDate":"2024-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.acs.org/doi/epdf/10.1021/jacsau.4c00802","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142694533","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
JACS AuPub Date : 2024-10-11DOI: 10.1021/jacsau.4c0070110.1021/jacsau.4c00701
Jieyi Liu, Nan Wang, Sibao Liu* and Guozhu Liu*,
{"title":"Catalytic Hydrodeoxygenation of Mixed Plastic Wastes into Sustainable Naphthenes","authors":"Jieyi Liu, Nan Wang, Sibao Liu* and Guozhu Liu*, ","doi":"10.1021/jacsau.4c0070110.1021/jacsau.4c00701","DOIUrl":"https://doi.org/10.1021/jacsau.4c00701https://doi.org/10.1021/jacsau.4c00701","url":null,"abstract":"<p >The chemical upcycling of plastic wastes by converting them into valuable fuels and chemicals represents a sustainable approach as opposed to landfilling and incineration. However, it encounters challenges in dealing with mixed plastic wastes due to their complex composition and sorting/cleaning costs. Here, we present a one-pot hydrodeoxygenation (HDO) method for converting mixed plastic wastes containing poly(ethylene terephthalate) (PET), polycarbonate (PC), and poly(phenylene oxide) (PPO) into sustainable naphthenes under mild reaction conditions. To facilitate this process, we developed a cost-effective, contaminant-tolerant, and reusable Ni/HZSM-5 bifunctional catalyst through an ethylene glycol-assisted impregnation method. The metallic Ni site plays a pivotal role in catalyzing C–O and C–C cleavages as well as hydrogenation reactions, while the acidic site of HZSM-5 facilitates dehydration and isomerization reactions. The collaboration between metal and acid dual sites on Ni/HZSM-5 enabled efficient HDO of a wide range of substrates, including bottles, textile fibers, pellets, sheets, CDs/DVDs, and plastics without cleaning or pigments removal and even their various mixtures, into naphthenes with a high yield up to 99% at 250 °C and 4 MPa H<sub>2</sub> within 4–6 h. Furthermore, the metal-acid balance of the Ni/HZSM-5 catalyst is crucial for determining both HDO activity and product distribution. This proposed one-pot HDO process utilizing earth-abundant metal catalysts provides a promising avenue toward practical valorization of mixed plastic wastes.</p>","PeriodicalId":94060,"journal":{"name":"JACS Au","volume":"4 11","pages":"4361–4373 4361–4373"},"PeriodicalIF":8.5,"publicationDate":"2024-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.acs.org/doi/epdf/10.1021/jacsau.4c00701","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142694534","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Selective [3 + 2] C-H/C-H Alkyne Annulation via Dual (Distal) C<sub>(β, δ)</sub>-H Bond Activation Relay: A Novel Therapeutic Quinazolone-Tethered Benzofulvenes for Oral Cancer.","authors":"Dinesh Parshuram Satpute, Garvita Narang, Harshal Rohit, Jagdish Manjhi, Divita Kumar, Sangita Dattatray Shinde, Shyam Kumar Lokhande, Priyanka Patel Vatsa, Vinal Upadhyay, Shivkanya Madhavrao Bhujbal, Amit Mandoli, Dinesh Kumar","doi":"10.1021/jacsau.4c00802","DOIUrl":"10.1021/jacsau.4c00802","url":null,"abstract":"<p><p>In contrast to proximal C-H bond activations, distal C-H bond activation is fundamentally more challenging and requires distinctly specialized directing partners or techniques. In this context, we report an unprecedented dual (distal) β-C(benzylic)-H and δ-C(aryl)-H bond activation relay protocol for the chemo-, regio-, and stereoselective construction of heterocycle-tethered benzofulvenes via [3 + 2] CH/CH-alkyne annulation under palladium catalysis. The protocol overrides the more favorable [4 + 2] CH/NH annulation and does not follow the vinylic C-H bond activation pathway. Mechanistic studies provide insight into the favored cyclopalladation of key intermediates (resulting from β-C(benzylic)-H bond cleavage) through relay δ-C(aryl)-H cleavage (vs N-H cleavage) prior to reductive elimination, which is the key to desired annulation. The synthesized new chemical entities (NCEs) constitute a novel scaffold with favorable anticancer activity against oral squamous cell carcinoma (OSCC). Detailed biomolecular studies, including RNA-sequencing and analysis, indicate that these compounds (<b>4e</b> and <b>4w</b>) arrest the cell cycle at the S-phase and target multiple cancer hallmarks, such as the activation of apoptotic pathways and impairment of mitochondrial activity simultaneously, suggesting their chemotherapeutic potential for oral cancer by addressing the complexity and adaptability of cancer cells in chorus.</p>","PeriodicalId":94060,"journal":{"name":"JACS Au","volume":"4 11","pages":"4474-4487"},"PeriodicalIF":8.5,"publicationDate":"2024-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11600166/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142752728","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
JACS AuPub Date : 2024-10-11eCollection Date: 2024-11-25DOI: 10.1021/jacsau.4c00701
Jieyi Liu, Nan Wang, Sibao Liu, Guozhu Liu
{"title":"Catalytic Hydrodeoxygenation of Mixed Plastic Wastes into Sustainable Naphthenes.","authors":"Jieyi Liu, Nan Wang, Sibao Liu, Guozhu Liu","doi":"10.1021/jacsau.4c00701","DOIUrl":"10.1021/jacsau.4c00701","url":null,"abstract":"<p><p>The chemical upcycling of plastic wastes by converting them into valuable fuels and chemicals represents a sustainable approach as opposed to landfilling and incineration. However, it encounters challenges in dealing with mixed plastic wastes due to their complex composition and sorting/cleaning costs. Here, we present a one-pot hydrodeoxygenation (HDO) method for converting mixed plastic wastes containing poly(ethylene terephthalate) (PET), polycarbonate (PC), and poly(phenylene oxide) (PPO) into sustainable naphthenes under mild reaction conditions. To facilitate this process, we developed a cost-effective, contaminant-tolerant, and reusable Ni/HZSM-5 bifunctional catalyst through an ethylene glycol-assisted impregnation method. The metallic Ni site plays a pivotal role in catalyzing C-O and C-C cleavages as well as hydrogenation reactions, while the acidic site of HZSM-5 facilitates dehydration and isomerization reactions. The collaboration between metal and acid dual sites on Ni/HZSM-5 enabled efficient HDO of a wide range of substrates, including bottles, textile fibers, pellets, sheets, CDs/DVDs, and plastics without cleaning or pigments removal and even their various mixtures, into naphthenes with a high yield up to 99% at 250 °C and 4 MPa H<sub>2</sub> within 4-6 h. Furthermore, the metal-acid balance of the Ni/HZSM-5 catalyst is crucial for determining both HDO activity and product distribution. This proposed one-pot HDO process utilizing earth-abundant metal catalysts provides a promising avenue toward practical valorization of mixed plastic wastes.</p>","PeriodicalId":94060,"journal":{"name":"JACS Au","volume":"4 11","pages":"4361-4373"},"PeriodicalIF":8.5,"publicationDate":"2024-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11600173/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142751931","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Effect of Thermal Stress on Morphology in High-Performance Organic Photovoltaic Blends.","authors":"Haoyu Zhao, Nathaniel Prine, Soumya Kundu, Guorong Ma, Xiaodan Gu","doi":"10.1021/jacsau.4c00631","DOIUrl":"10.1021/jacsau.4c00631","url":null,"abstract":"<p><p>Thermal stress is a critical factor causing long-term instability in bulk heterojunction (BHJ) layers of organic photovoltaic (OPV) devices. This study provides direct insights into the thermal properties of Y6, PM6, and their binary blends by employing fast differential scanning calorimetry (flash DSC) to analyze their chain dynamics. The glass transition temperatures (<i>T</i> <sub>g</sub>) of Y6 and PM6 were measured, with Y6 exhibiting a <i>T</i> <sub>g</sub> of 175.2 °C and PM6 showing two <i>T</i> <sub>g</sub>s at 39.7 and 107.6 °C. Our findings indicate that average OPVs' operational temperatures are lower than the blend's primary <i>T</i> <sub>g</sub> of 138.2 °C. Thus, the mobility of PM6 and Y6 is not the critical factor that results in drastic drifts in the device morphology. Instead, we discovered that the crystallization of small molecules Y6 in the BHJ film at elevated operation temperatures <i>significantly contributes</i> to the morphological instability of the BHJ layer, based on a flash DSC isotherm crystallization study. The crystallization of the acceptor leads to severe phase separation between donors and acceptors and results in device failure. The acceptor Y6's crystallization rate also increased when blended with donor PM6, compared to that of pure Y6 molecules. Furthermore, AFM-IR analysis of the morphology of the BHJ layer after high thermal stress of 200 °C revealed an apparent demixing of donor PM6 and acceptor Y6, revealing Y6 globules about 200 nm in diameter, with PM6 domains surrounding the Y6 regions. This crystallization-induced morphology change was later confirmed to correlate well with the device performance drop. This study offers valuable insights into the origin of BHJ layer instability in OPV devices containing nonfullerene small molecule acceptors and polymer donors. Additionally, it emphasizes the importance of addressing thermal stress to enhance the performance and durability of such devices and informs strategies for developing more stable organic solar cells.</p>","PeriodicalId":94060,"journal":{"name":"JACS Au","volume":"4 11","pages":"4334-4344"},"PeriodicalIF":8.5,"publicationDate":"2024-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11600174/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142752616","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}