K. Chow, Ronald J. Quinn, Ian D. Jenkins, E. Krenske
{"title":"The mechanism of cleavage of Evans chiral auxiliaries by LiOOH: origins of the different regioselectivities obtained with LiOH, LiOOH, LiOBn and LiSBn","authors":"K. Chow, Ronald J. Quinn, Ian D. Jenkins, E. Krenske","doi":"10.1071/ch23086","DOIUrl":"https://doi.org/10.1071/ch23086","url":null,"abstract":"","PeriodicalId":8575,"journal":{"name":"Australian Journal of Chemistry","volume":"25 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78930150","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}
Sigma complexes containing η2-H2 ligands, with both hydrogen atoms interacting with the metal center and with each other, are well known nowadays. The possibility of η1-H2 coordination, with only one hydrogen atom interacting with the metal center, remains an intriguing, but unreported, possibility. In this study, we used the hidden descriptors (HD) strategy previously developed in our group to investigate the capacity of well-established metal fragments to achieve stable LnM(η1-H2) metal complexes. Computational techniques, including low-cost density functional theory (DFT) calculations and the BDE Matrix App are used. The results confirm that the search for stable LnM(η1-H2) complexes is challenging, as no obvious candidate can be identified. Hints are obtained about what the properties of this hypothetic metal fragment should be, such as a strong tendency to covalent association with ligands. The outcomes of this research provide a comprehensive framework for comparing and investigating atypical candidates for this type of bonding and serve as a valuable resource for future explorations in this field.
{"title":"A computational search of the ideal metal fragment for monohapto coordination of dihydrogen","authors":"Lucía Morán-González, Feliu Maseras","doi":"10.1071/ch23121","DOIUrl":"https://doi.org/10.1071/ch23121","url":null,"abstract":"Sigma complexes containing η2-H2 ligands, with both hydrogen atoms interacting with the metal center and with each other, are well known nowadays. The possibility of η1-H2 coordination, with only one hydrogen atom interacting with the metal center, remains an intriguing, but unreported, possibility. In this study, we used the hidden descriptors (HD) strategy previously developed in our group to investigate the capacity of well-established metal fragments to achieve stable LnM(η1-H2) metal complexes. Computational techniques, including low-cost density functional theory (DFT) calculations and the BDE Matrix App are used. The results confirm that the search for stable LnM(η1-H2) complexes is challenging, as no obvious candidate can be identified. Hints are obtained about what the properties of this hypothetic metal fragment should be, such as a strong tendency to covalent association with ligands. The outcomes of this research provide a comprehensive framework for comparing and investigating atypical candidates for this type of bonding and serve as a valuable resource for future explorations in this field.","PeriodicalId":8575,"journal":{"name":"Australian Journal of Chemistry","volume":"85 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135599916","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 torsional constant (F) is a parameter extracted from spectroscopic analyses of molecules possessing a methyl group. Its value depends primarily on the methyl structure. Widely varying F values have been reported for substituted toluenes in their ground electronic state, first excited singlet electronic state or the ground electronic state of the cation. Conventionally, this variability is assumed to indicate significant changes in the methyl structure with substituent, its position on the ring and the electronic state. However, when the large amplitude methyl torsion interacts with other, small amplitude vibrations, this interpretation is misleading as the torsional states are shifted to lower energy, resulting in a reduced, ‘effective’ F being determined. We have observed coupling between methyl torsion and the low frequency, methyl group out-of-plane wag vibration in toluene, p-fluorotoluene, m-fluorotoluene and N-methylpyrrole, leading us to postulate that, since such motion will be present whenever the methyl group is attached to a planar frame, this type of interaction is widespread. This is tested for a series of substituted toluenes by comparing the methyl group structure calculated by quantum chemistry with the experimental torsional constants. The quantum chemistry calculations predict little variation in the methyl structure across a wide range of substituents, ring positions and electronic state. The wide variation in F values observed in experimental analyses is attributed to the torsion–vibration interaction affecting the torsional band structure, so that measured F values become ‘effective constants’. Comparisons between calculated and experimental torsional constants need to be cognisant of this effect.
{"title":"Evidence for widespread torsion–vibration interaction in substituted toluenes","authors":"Jason R. Gascooke, Warren D. Lawrance","doi":"10.1071/ch23122","DOIUrl":"https://doi.org/10.1071/ch23122","url":null,"abstract":"The torsional constant (F) is a parameter extracted from spectroscopic analyses of molecules possessing a methyl group. Its value depends primarily on the methyl structure. Widely varying F values have been reported for substituted toluenes in their ground electronic state, first excited singlet electronic state or the ground electronic state of the cation. Conventionally, this variability is assumed to indicate significant changes in the methyl structure with substituent, its position on the ring and the electronic state. However, when the large amplitude methyl torsion interacts with other, small amplitude vibrations, this interpretation is misleading as the torsional states are shifted to lower energy, resulting in a reduced, ‘effective’ F being determined. We have observed coupling between methyl torsion and the low frequency, methyl group out-of-plane wag vibration in toluene, p-fluorotoluene, m-fluorotoluene and N-methylpyrrole, leading us to postulate that, since such motion will be present whenever the methyl group is attached to a planar frame, this type of interaction is widespread. This is tested for a series of substituted toluenes by comparing the methyl group structure calculated by quantum chemistry with the experimental torsional constants. The quantum chemistry calculations predict little variation in the methyl structure across a wide range of substituents, ring positions and electronic state. The wide variation in F values observed in experimental analyses is attributed to the torsion–vibration interaction affecting the torsional band structure, so that measured F values become ‘effective constants’. Comparisons between calculated and experimental torsional constants need to be cognisant of this effect.","PeriodicalId":8575,"journal":{"name":"Australian Journal of Chemistry","volume":"135 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135749639","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":"Synthesis of hydrogels incorporating core–shell structured Fe3O4@ZIF-8 as bio-nanocomposite carriers for drug delivery","authors":"Pagasukon Mekrattanachai, Naruemon Setthaya, Chakkresit Chindawong, Bunlawee Yotnoi, Wei Song, C. Manaspon","doi":"10.1071/ch22224","DOIUrl":"https://doi.org/10.1071/ch22224","url":null,"abstract":"","PeriodicalId":8575,"journal":{"name":"Australian Journal of Chemistry","volume":"8 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87294154","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}
Nicole McNamara, Anitha Kopinathan, Helen Wolff, T. Spurling, Greg Simpson, K. Locock
{"title":"Breaking down barriers: standing on the shoulders of Australia’s early female chemists","authors":"Nicole McNamara, Anitha Kopinathan, Helen Wolff, T. Spurling, Greg Simpson, K. Locock","doi":"10.1071/ch22235","DOIUrl":"https://doi.org/10.1071/ch22235","url":null,"abstract":"","PeriodicalId":8575,"journal":{"name":"Australian Journal of Chemistry","volume":"94 5 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83349278","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}
MXene is a novel two-dimensional material that exhibits excellent competitive performance in energy storage and conversion applications due to its high electrical conductivity, good dispersibility, and abundant surface functional groups. However, the van der Waals interactions between MXene nanosheets tend to lead to stacking, which limits the number of active sites and ion dynamics. Constructing MXene materials into three-dimensional (3D) porous structures is an effective strategy to improve energy storage performance by increasing specific surface area and porosity, and decreasing ion transport distance. This review provides an overview of four novel design strategies for preparing three-dimensional MXene materials, including template-based, 3D printing, electrospinning, and gas-assisted methods, over the last 5 years (2019–2023), and explores the potential applications of 3D MXene structures in the new-type energy storage systems of metal-ion hybrid capacitors. Finally, the authors provide prospects for the future development of 3D MXene structures.
{"title":"Novel design strategies of three-dimensional MXene structures and their applications in metal-ion hybrid capacitors","authors":"Lingfang Li, Bin Zeng, Chuang Xiang, Wen Liu","doi":"10.1071/ch23090","DOIUrl":"https://doi.org/10.1071/ch23090","url":null,"abstract":"MXene is a novel two-dimensional material that exhibits excellent competitive performance in energy storage and conversion applications due to its high electrical conductivity, good dispersibility, and abundant surface functional groups. However, the van der Waals interactions between MXene nanosheets tend to lead to stacking, which limits the number of active sites and ion dynamics. Constructing MXene materials into three-dimensional (3D) porous structures is an effective strategy to improve energy storage performance by increasing specific surface area and porosity, and decreasing ion transport distance. This review provides an overview of four novel design strategies for preparing three-dimensional MXene materials, including template-based, 3D printing, electrospinning, and gas-assisted methods, over the last 5 years (2019–2023), and explores the potential applications of 3D MXene structures in the new-type energy storage systems of metal-ion hybrid capacitors. Finally, the authors provide prospects for the future development of 3D MXene structures.","PeriodicalId":8575,"journal":{"name":"Australian Journal of Chemistry","volume":"29 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135551466","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":"‘Renovation of old drugs’ – can peptide drug conjugates lead the post-ADC era?","authors":"Chaowei Hao, Peng Chen, Hui Zhang, Sarra Setrerrahmane, Hanmei Xu","doi":"10.1071/ch22252","DOIUrl":"https://doi.org/10.1071/ch22252","url":null,"abstract":"","PeriodicalId":8575,"journal":{"name":"Australian Journal of Chemistry","volume":"22 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81051027","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":"A review of psilocybin: chemistry, clinical uses and future research directions","authors":"Eliza Milliken, P. Galettis, J. Martin","doi":"10.1071/ch23010","DOIUrl":"https://doi.org/10.1071/ch23010","url":null,"abstract":"","PeriodicalId":8575,"journal":{"name":"Australian Journal of Chemistry","volume":"24 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76717771","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":"Polyadenine complexed to polyglutamine suggests the peptide backbone has a cis conformation","authors":"Anthony B. Bransgrove, Louise Anderson","doi":"10.1071/ch23084","DOIUrl":"https://doi.org/10.1071/ch23084","url":null,"abstract":"","PeriodicalId":8575,"journal":{"name":"Australian Journal of Chemistry","volume":"98 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86494494","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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