The C=N bond is a critical structural piece of many N-donor ligand scaffolds and is central to the properties and reactivity of important coordination complexes. For example, C=N units play a key role in the ‘redox non-innocence’ of α-diimine complexes and in making charge-transfer excited-state character available to complexes of N-heterocyclic ligands such as bipyridine. In N-heterocycles like pyridine, benzannulation can be used to extend the conjugated C=N containing π-system to quinoline (2,3-benzopyridine) to acridine (2,3-benzoquinoline). This stabilizes the lowest unoccupied molecular orbital (LUMO) of the molecule and boosts its electron-accepting properties, but the position of the benzannulation matters. For example, phenanthridine (3,4-benzoquinoline), an asymmetric isomer of acridine, bears a similarly electronically accessible extended π-system but more chemically isolated, ‘imine-like’ C=N moiety. This Award Paper presents an overview of our work investigating the impact of such site-selective benzannulation on the chemistry and properties of phenanthridine as a molecule and ligand.
{"title":"When is a Pyridine Not a Pyridine? Benzannulated N-Heterocyclic Ligands in Molecular Materials Chemistry","authors":"David E. Herbert","doi":"10.1139/cjc-2022-0314","DOIUrl":"https://doi.org/10.1139/cjc-2022-0314","url":null,"abstract":"The C=N bond is a critical structural piece of many N-donor ligand scaffolds and is central to the properties and reactivity of important coordination complexes. For example, C=N units play a key role in the ‘redox non-innocence’ of α-diimine complexes and in making charge-transfer excited-state character available to complexes of N-heterocyclic ligands such as bipyridine. In N-heterocycles like pyridine, benzannulation can be used to extend the conjugated C=N containing π-system to quinoline (2,3-benzopyridine) to acridine (2,3-benzoquinoline). This stabilizes the lowest unoccupied molecular orbital (LUMO) of the molecule and boosts its electron-accepting properties, but the position of the benzannulation matters. For example, phenanthridine (3,4-benzoquinoline), an asymmetric isomer of acridine, bears a similarly electronically accessible extended π-system but more chemically isolated, ‘imine-like’ C=N moiety. This Award Paper presents an overview of our work investigating the impact of such site-selective benzannulation on the chemistry and properties of phenanthridine as a molecule and ligand.","PeriodicalId":9420,"journal":{"name":"Canadian Journal of Chemistry","volume":"12 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2023-04-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75352258","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The synthesis of gem-difluoroalkenes by photocatalytic desulfonylative coupling of alkylsulfones with α-(trifluoromethyl)styrenes is described. Photoredox Ir complex was found to be an effective catalyst for this transformation through single electron reduction of alkyl 1-phenyltetrazolyl sulfones, providing structurally diverse gem-difluoroalkene products in good yields. The resulting alkenes could be further converted into fluorinated derivatives, highlighting the potential utility of this method in synthesis of organofluorine compounds.
{"title":"Visible-Light Photoredox-catalyzed Coupling of Alkylsulfones with α-(Trifluoromethyl)styrenes","authors":"Yasuyo Tahara, Koushik Ghosh, Masakazu Nambo","doi":"10.1139/cjc-2022-0271","DOIUrl":"https://doi.org/10.1139/cjc-2022-0271","url":null,"abstract":"The synthesis of gem-difluoroalkenes by photocatalytic desulfonylative coupling of alkylsulfones with α-(trifluoromethyl)styrenes is described. Photoredox Ir complex was found to be an effective catalyst for this transformation through single electron reduction of alkyl 1-phenyltetrazolyl sulfones, providing structurally diverse gem-difluoroalkene products in good yields. The resulting alkenes could be further converted into fluorinated derivatives, highlighting the potential utility of this method in synthesis of organofluorine compounds.","PeriodicalId":9420,"journal":{"name":"Canadian Journal of Chemistry","volume":"178 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2023-04-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79978453","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This journal (Canadian Journal of Chemistry) published a while ago a set of seminal studies revealing the underlying mechanisms supporting the then widely used analytical technique for detecting phenols at low levels in domestic water supply using 4-aminoantipyrine (4-AAP). The current paper revisits these studies with a primary focus on the dimension of this reaction that synthesizes 6- and 7-membered heterocyclic rings containing both N and O in a single step. Here we report a rather unusual outcome of the reaction in which, while the oxidative coupling of 4-AAP to 1-naphthol in aqueous solution at high pH (or condensation with 1,4-naphthoquinone in chloroform) leads to the same naphthoquinonimide product, a similar set of reactions with 2-naphthol and 1,2-naphthoquinone produces two isomeric forms of an oxazepine instead. In one isomer, the 4-AAP/naphthol C-N and the C-O linkages are at positions 1 and 2 of naphthyl ring, respectively and in the other form, these linkages are at positions 2 and 1, respectively. This unexpected difference in a one-pot reaction at ambient temperature is potentially the flexibility needed to synthesize families of pharmaceutically relevant oxazepines. Spectroscopic features useful for identifying 12 heterocyclic compounds, nine of which are new, are also provided.
{"title":"Revisiting the Coupling Reaction Between 4-Aminoantipyrine and Phenols: A Potential One-Pot Reaction Pathway to 4,11- and 5,12-Naphthoxazepine Isomers","authors":"O. Otim","doi":"10.1139/cjc-2022-0239","DOIUrl":"https://doi.org/10.1139/cjc-2022-0239","url":null,"abstract":"This journal (Canadian Journal of Chemistry) published a while ago a set of seminal studies revealing the underlying mechanisms supporting the then widely used analytical technique for detecting phenols at low levels in domestic water supply using 4-aminoantipyrine (4-AAP). The current paper revisits these studies with a primary focus on the dimension of this reaction that synthesizes 6- and 7-membered heterocyclic rings containing both N and O in a single step. Here we report a rather unusual outcome of the reaction in which, while the oxidative coupling of 4-AAP to 1-naphthol in aqueous solution at high pH (or condensation with 1,4-naphthoquinone in chloroform) leads to the same naphthoquinonimide product, a similar set of reactions with 2-naphthol and 1,2-naphthoquinone produces two isomeric forms of an oxazepine instead. In one isomer, the 4-AAP/naphthol C-N and the C-O linkages are at positions 1 and 2 of naphthyl ring, respectively and in the other form, these linkages are at positions 2 and 1, respectively. This unexpected difference in a one-pot reaction at ambient temperature is potentially the flexibility needed to synthesize families of pharmaceutically relevant oxazepines. Spectroscopic features useful for identifying 12 heterocyclic compounds, nine of which are new, are also provided.","PeriodicalId":9420,"journal":{"name":"Canadian Journal of Chemistry","volume":"23 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2023-04-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72936679","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Carmofur, a 5-fluorouracil derivative, was initially developed as an antineoplastic agent to treat colorectal cancer. Through drug repurposing efforts, it has been identified as a potent covalent inhibitor of the main protease of SARS-CoV-2 (Mpro), making it a promising therapeutic agent against COVID-19. However, previous synthetic procedures suffer from low yields, or long reaction times. In this study, benchtop 19F nuclear magnetic resonance spectroscopy (NMR) enables the real-time quantitative monitoring and characterization of the synthesis of carmofur by providing kinetic insight. Furthermore, its proton lock capabilities no longer require the use of deuterated solvents, and has enabled convenient, and rapidly scalable synthesis of our compound. Here, we present the application of benchtop 19F NMR as an efficient method for optimizing the synthesis of carmofur and its future application in the synthesis of related 5-FU analogs.
{"title":"Benchtop 19F nuclear magnetic resonance spectroscopy enabled kinetic studies and optimization of the synthesis of carmofur","authors":"Xina Wang, Julia Vu, Charissa Luk, Edward Njoo","doi":"10.1139/cjc-2022-0266","DOIUrl":"https://doi.org/10.1139/cjc-2022-0266","url":null,"abstract":"Carmofur, a 5-fluorouracil derivative, was initially developed as an antineoplastic agent to treat colorectal cancer. Through drug repurposing efforts, it has been identified as a potent covalent inhibitor of the main protease of SARS-CoV-2 (Mpro), making it a promising therapeutic agent against COVID-19. However, previous synthetic procedures suffer from low yields, or long reaction times. In this study, benchtop 19F nuclear magnetic resonance spectroscopy (NMR) enables the real-time quantitative monitoring and characterization of the synthesis of carmofur by providing kinetic insight. Furthermore, its proton lock capabilities no longer require the use of deuterated solvents, and has enabled convenient, and rapidly scalable synthesis of our compound. Here, we present the application of benchtop 19F NMR as an efficient method for optimizing the synthesis of carmofur and its future application in the synthesis of related 5-FU analogs.","PeriodicalId":9420,"journal":{"name":"Canadian Journal of Chemistry","volume":"45 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2023-04-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76008660","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Cailum M K Stienstra, N. Coughlan, Alexander Haack, Patrick J. J. Carr, J. Crouse, Joshua Featherstone, Scott W. Hopkins
Although the krypton dimer, Kr2, is a prototypical weakly bound van der Waals complex in its ground electronic state, the excited states of Kr2 exhibit many and various interactions. Resonance enhanced multiphoton ionization and velocity map imaging provide an avenue to explore the electronic structure and photofragmentation dynamics of Kr2 in the vacuum ultraviolet region. By monitoring photofragmentation product channels and recoil anisotropy distributions, one can gain insights into excited state symmetries and lifetimes, which can aid in interpreting spectroscopy. Here, we study the spectroscopy and photodissociation dynamics of Kr2 in the 91,000 – 94,500 cm-1 region. We record and assign photofragment product channels for 32 vibronic bands corresponding to seven electronic transitions. We also identify two previously unobserved vibronic band systems, which we assign as the Kr2 5p [5/2]3 1g ← X0g+ and 5p [3/2]2 0g+ ← X0g+ transitions. Velocity map images show photofragments arising from predissociation of the neutral Rydberg states and from dissociative photoionization at the n > 2 photon level. We also observe variation in branching ratios between the predissociative and dissociative photoionization channels depending on the lifetime of the intermediate; longer lived states favour higher dissociative photoionization yields and exhibit β6 anisotropy parameters for predissociation product channels, indicating “rotational smearing” of the product angular distributions.
{"title":"Investigating the Rydberg States and Photodissociation Dynamics of Kr2 using Velocity Map Imaging","authors":"Cailum M K Stienstra, N. Coughlan, Alexander Haack, Patrick J. J. Carr, J. Crouse, Joshua Featherstone, Scott W. Hopkins","doi":"10.1139/cjc-2022-0283","DOIUrl":"https://doi.org/10.1139/cjc-2022-0283","url":null,"abstract":"Although the krypton dimer, Kr2, is a prototypical weakly bound van der Waals complex in its ground electronic state, the excited states of Kr2 exhibit many and various interactions. Resonance enhanced multiphoton ionization and velocity map imaging provide an avenue to explore the electronic structure and photofragmentation dynamics of Kr2 in the vacuum ultraviolet region. By monitoring photofragmentation product channels and recoil anisotropy distributions, one can gain insights into excited state symmetries and lifetimes, which can aid in interpreting spectroscopy. Here, we study the spectroscopy and photodissociation dynamics of Kr2 in the 91,000 – 94,500 cm-1 region. We record and assign photofragment product channels for 32 vibronic bands corresponding to seven electronic transitions. We also identify two previously unobserved vibronic band systems, which we assign as the Kr2 5p [5/2]3 1g ← X0g+ and 5p [3/2]2 0g+ ← X0g+ transitions. Velocity map images show photofragments arising from predissociation of the neutral Rydberg states and from dissociative photoionization at the n > 2 photon level. We also observe variation in branching ratios between the predissociative and dissociative photoionization channels depending on the lifetime of the intermediate; longer lived states favour higher dissociative photoionization yields and exhibit β6 anisotropy parameters for predissociation product channels, indicating “rotational smearing” of the product angular distributions.","PeriodicalId":9420,"journal":{"name":"Canadian Journal of Chemistry","volume":"1 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2023-04-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90290566","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. Soliman, N. Mahmoud, Aml B. Mohamed, Howayda E. Khaled
A series of 2-(arylidenehydrazono)-5-(2-oxo-2-arylethyl)thiazolidin-4-one derivatives were synthesized, characterized by spectral analyses and evaluated for their in vitro antitumor activity. The IC50 determination of compounds was investigated on the human breast cancer cell line MCF-7. Among the series, compounds 3, 6, 10, 16, 17 and 24 showed remarkable anticancer activity with mean IC50 values 2.34, 0.73, 2.69, 3.40, 1.18 and 1.76 μg/ml respectively, against MCF-7 cancer cells. Compound 16 enhanced the concentration of caspase-9, inhibited the concentration of KI67 and showed a profound reduction in the amount of MMP9 secreted into the medium of MCF-7 treated cells. Furthermore, compound 16 revealed anti-angiogenic activity through down-regulation the concentration of VEGF in the medium of MCF-7 treated cells. Compound 16 exerted cytotoxic effects on MCF-7 tumor cells via anti-proliferative, apoptotic, antiangiogenic and antimetastatic activities. Molecular docking methodology was performed for the most effective anticancer compounds to rationalize the possible interactions with active site of VEGFR-2 enzyme.
{"title":"Synthesis, anticancer evaluation and molecular docking study of some Arylidenehydrazono analogues","authors":"M. Soliman, N. Mahmoud, Aml B. Mohamed, Howayda E. Khaled","doi":"10.1139/cjc-2022-0276","DOIUrl":"https://doi.org/10.1139/cjc-2022-0276","url":null,"abstract":"A series of 2-(arylidenehydrazono)-5-(2-oxo-2-arylethyl)thiazolidin-4-one derivatives were synthesized, characterized by spectral analyses and evaluated for their in vitro antitumor activity. The IC50 determination of compounds was investigated on the human breast cancer cell line MCF-7. Among the series, compounds 3, 6, 10, 16, 17 and 24 showed remarkable anticancer activity with mean IC50 values 2.34, 0.73, 2.69, 3.40, 1.18 and 1.76 μg/ml respectively, against MCF-7 cancer cells. Compound 16 enhanced the concentration of caspase-9, inhibited the concentration of KI67 and showed a profound reduction in the amount of MMP9 secreted into the medium of MCF-7 treated cells. Furthermore, compound 16 revealed anti-angiogenic activity through down-regulation the concentration of VEGF in the medium of MCF-7 treated cells. Compound 16 exerted cytotoxic effects on MCF-7 tumor cells via anti-proliferative, apoptotic, antiangiogenic and antimetastatic activities. Molecular docking methodology was performed for the most effective anticancer compounds to rationalize the possible interactions with active site of VEGFR-2 enzyme.","PeriodicalId":9420,"journal":{"name":"Canadian Journal of Chemistry","volume":"25 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2023-04-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81589343","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Organic chemistry is one of the most feared and failed courses due to its complex and fast-paced nature. Investigating affective metrics that relate to achievement in these courses can be worthwhile, particularly when these metrics show predictive relationships to achievement. Attitude toward chemistry has been investigated utilizing a variety of instruments. We present herein an instrument related to the well-established ASCIv2. This new instrument was developed utilizing The Standards of Psychological and Educational Measurement which describe five aspects of validity evidence that should be gathered when using instruments in research. Content validity was gathered through consultation with experts. Response process validity was gathered through student interviews. Internal structure validity was collected through confirmatory factor analysis. Relations to other variables were investigated through correlation analysis and structural equation modeling. Consequential validity was studied through measurement invariance testing before comparing scores for subgroups (high- and low-achieving students). Additionally, reliability evidence was tested with Omega coefficients for each of the factors. We showed that all tests and analyses were done with high rigor, and that this new instrument, ASCI-UE, measuring Utility and Emotional Satisfaction, can provide interesting results and implications for research and practice.
{"title":"Gathering Validity Evidence in the Development of a New Version of the Attitude Toward the Subject of Chemistry Inventory (ASCI-UE)","authors":"","doi":"10.1139/cjc-2022-0162","DOIUrl":"https://doi.org/10.1139/cjc-2022-0162","url":null,"abstract":"Organic chemistry is one of the most feared and failed courses due to its complex and fast-paced nature. Investigating affective metrics that relate to achievement in these courses can be worthwhile, particularly when these metrics show predictive relationships to achievement. Attitude toward chemistry has been investigated utilizing a variety of instruments. We present herein an instrument related to the well-established ASCIv2. This new instrument was developed utilizing The Standards of Psychological and Educational Measurement which describe five aspects of validity evidence that should be gathered when using instruments in research. Content validity was gathered through consultation with experts. Response process validity was gathered through student interviews. Internal structure validity was collected through confirmatory factor analysis. Relations to other variables were investigated through correlation analysis and structural equation modeling. Consequential validity was studied through measurement invariance testing before comparing scores for subgroups (high- and low-achieving students). Additionally, reliability evidence was tested with Omega coefficients for each of the factors. We showed that all tests and analyses were done with high rigor, and that this new instrument, ASCI-UE, measuring Utility and Emotional Satisfaction, can provide interesting results and implications for research and practice.","PeriodicalId":9420,"journal":{"name":"Canadian Journal of Chemistry","volume":"21 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2023-04-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91139967","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yuheng Song, Derek H. G. von Eppinghoven, Yang Zhou, Hanxiao Zhang, Juewen Liu
Tetracyclines are a group of very important antibiotics that are still in use to date. To extract, detect and remove tetracyclines from the environment, various nanomaterials have been employed. Although gold nanoparticles (AuNPs) are a commonly cited material for these purposes, fundamental understanding of these tetracycline-AuNP systems are still limited. In this work, the adsorption of tetracycline, oxytetracycline and doxycycline to AuNPs was studied. The effect on the colloidal stability of AuNPs, adsorption kinetics, and the resulting adsorption isotherms were measured. While millimolar concentrations of the tetracyclines can cause aggregation of AuNPs, saturated monolayer adsorption was achieved with low micromolar concentrations of the tetracyclines. Adsorption was instantaneous, and adsorption to AuNPs enhanced their intrinsic fluorescence instead of quenching. With the assumption of aptamer/target complexes cannot be easily adsorbed by AuNPs compared to free aptamers, a label-free colorimetric detection method was tested. While the label-free sensor showed target-dependent aggregation of AuNPs, a non-binding mutant aptamer showed the same trend, suggesting that the color change did not reflect aptamer adsorption but other events such as target adsorption. This study indicates the importance of fundamental understanding of target/AuNP interactions to correctly design aptamer and AuNP-based label-free biosensors.
{"title":"Adsorption of tetracycline antibiotics to gold nanoparticles and feasibility of aptamer-based label-free colorimetric detection","authors":"Yuheng Song, Derek H. G. von Eppinghoven, Yang Zhou, Hanxiao Zhang, Juewen Liu","doi":"10.1139/cjc-2022-0253","DOIUrl":"https://doi.org/10.1139/cjc-2022-0253","url":null,"abstract":"Tetracyclines are a group of very important antibiotics that are still in use to date. To extract, detect and remove tetracyclines from the environment, various nanomaterials have been employed. Although gold nanoparticles (AuNPs) are a commonly cited material for these purposes, fundamental understanding of these tetracycline-AuNP systems are still limited. In this work, the adsorption of tetracycline, oxytetracycline and doxycycline to AuNPs was studied. The effect on the colloidal stability of AuNPs, adsorption kinetics, and the resulting adsorption isotherms were measured. While millimolar concentrations of the tetracyclines can cause aggregation of AuNPs, saturated monolayer adsorption was achieved with low micromolar concentrations of the tetracyclines. Adsorption was instantaneous, and adsorption to AuNPs enhanced their intrinsic fluorescence instead of quenching. With the assumption of aptamer/target complexes cannot be easily adsorbed by AuNPs compared to free aptamers, a label-free colorimetric detection method was tested. While the label-free sensor showed target-dependent aggregation of AuNPs, a non-binding mutant aptamer showed the same trend, suggesting that the color change did not reflect aptamer adsorption but other events such as target adsorption. This study indicates the importance of fundamental understanding of target/AuNP interactions to correctly design aptamer and AuNP-based label-free biosensors.","PeriodicalId":9420,"journal":{"name":"Canadian Journal of Chemistry","volume":"67 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2023-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83162831","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Celebrating the life of Suning Wang","authors":"Z. Hudson, B. Blight","doi":"10.1139/cjc-2023-0024","DOIUrl":"https://doi.org/10.1139/cjc-2023-0024","url":null,"abstract":"","PeriodicalId":9420,"journal":{"name":"Canadian Journal of Chemistry","volume":"13 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2023-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83905068","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Tony Nguyen, Tyler Hannah, Warren E. Piers, Benjamin Gelfand
We have recently reported the synthesis and application of boron–nitrogen dihydroindeno[1,2-b]fluorene derivatives as acceptors in organic photovoltaic devices. Their modest observed efficiencies may be related to the properties of their reduced congeners. In this work, we report two new members of this family of compounds prepared via the electrophilic borylation of 2,5-di- p-tolylpyrazine followed by an arylation of the boron center with ZnAr 2 reagents. Two derivatives, 1 (Ar = 2,4,6-F 3 C 6 H 2 ) and 2 (Ar = C 6 F 5 ) were synthesized, and their radical anions, 1 •− and 2 •− , were formed via chemical reductions with CoCp* 2 and CoCp 2 , respectively. Through comparison of structural parameters, as well as spectroscopic and computational data, the unpaired electron in the radical anions is localized in the planar core of the molecule, and dimerization is disfavored as a result. However, unlike the neutral starting materials, 1 •− and 2 •− are reactive toward ambient atmosphere. These observations suggest that the reduced compounds are stable toward intrinsic degradation pathways but subject to extrinsic degradation in device operation.
我们最近报道了硼氮二氢茚[1,2-b]芴衍生物作为受体在有机光伏器件中的合成和应用。它们所观察到的适度效率可能与它们的还原同系物的性质有关。在这项工作中，我们报告了该家族化合物的两个新成员，它们是通过2,5-二对甲基吡嗪的亲电硼化，然后用ZnAr 2试剂将硼中心进行芳化而制备的。合成了两个衍生物1 (Ar = 2,4,6- f3c6h 2)和2 (Ar = c6f 5)，它们的自由基阴离子1•−和2•−分别由CoCp* 2和CoCp 2化学还原形成。通过结构参数的比较，以及光谱和计算数据的比较，发现自由基阴离子中的未配对电子定位在分子的平面核心，不利于二聚化。然而，与中性起始材料不同的是，1•−和2•−对周围大气具有反应性。这些观察结果表明，减少的化合物是稳定的内在降解途径，但受制于外在的降解装置操作。
{"title":"Stable, π-conjugated radical anions of boron–nitrogen dihydroindeno[1,2-b]fluorenes","authors":"Tony Nguyen, Tyler Hannah, Warren E. Piers, Benjamin Gelfand","doi":"10.1139/cjc-2022-0039","DOIUrl":"https://doi.org/10.1139/cjc-2022-0039","url":null,"abstract":"We have recently reported the synthesis and application of boron–nitrogen dihydroindeno[1,2-b]fluorene derivatives as acceptors in organic photovoltaic devices. Their modest observed efficiencies may be related to the properties of their reduced congeners. In this work, we report two new members of this family of compounds prepared via the electrophilic borylation of 2,5-di- p-tolylpyrazine followed by an arylation of the boron center with ZnAr 2 reagents. Two derivatives, 1 (Ar = 2,4,6-F 3 C 6 H 2 ) and 2 (Ar = C 6 F 5 ) were synthesized, and their radical anions, 1 •− and 2 •− , were formed via chemical reductions with CoCp* 2 and CoCp 2 , respectively. Through comparison of structural parameters, as well as spectroscopic and computational data, the unpaired electron in the radical anions is localized in the planar core of the molecule, and dimerization is disfavored as a result. However, unlike the neutral starting materials, 1 •− and 2 •− are reactive toward ambient atmosphere. These observations suggest that the reduced compounds are stable toward intrinsic degradation pathways but subject to extrinsic degradation in device operation.","PeriodicalId":9420,"journal":{"name":"Canadian Journal of Chemistry","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135742783","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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