Alexander A. Trifonov, Alexander N Selikhov, Yulia Nelyubina, Rinat R. Aysin
Metalation of bulky tris(2-(piperidin-1-yl-methyl)phenyl)methanol [(C5H10N)CH2C6H4-o]3COH with (Me3Si)2NK in Et2O results in a dimeric potassium alkoxide {[(C5H10N)CH2C6H4-o]3C(μ2-O)K(Et2O)}2(1). Et2O molecule can be removed from the K+ coordination sphere affording coordinatively unsaturated alkoxide species which readily traps π-donor molecules. In the presence of arene excess the reactions result in ηn-π-complexes retaining in crystal state a dimeric core {[(C5H10N)CH2C6H4-o]3C(μ2-O)K(ηn-arene)}2 (arene = C6H6 (2), CH3C6H5 (3), C10H8 (4)). With C6H5OMe and C6H5NMe2 molecules containing competing n- and π-donating sites the reactions proceed differently: the former coordinates to K+ through an oxygen lone pair resulting in {[(C5H10N)CH2C6H4-o]3C(μ2-O)K(κ1-O(Me)C6H5}2 (5) while for the latterπ-arene interaction turns out to be preferable {[(C5H10N)CH2C6H4-o]3C(μ2-O)K(η2-C6H5NMe2)}2 (6). The reactions with equimolar amounts of benzene or thiophene afford coordination polymers [{[(C5H10N)CH2C6H4-o]3C(μ2-O)K}2(μ-C6H6)]n (7) and [{[(C5H10N)CH2C6H4-o]3C(μ2-O)K}2(μ-C4H4S)]n (8), in which benzene and thiophene molecules are μ-bridging two K+ ions. The treatment of {[(C5H10N)CH2C6H4-o]3C(μ2-O)K(η2-CH3C6H5))}2 with Me3SiCH2Li or n-BuLi (1.2 eq) in hexane at 20 °C results in the facile metalation of Me-group of toluene, the formation of [PhCH2K]n and lithium alkoxide . This model reaction provides a deeper insight into the probable mechanism of metalation of CH bonds under Lochmann–Schlosser superbasic conditions, the role and the nature of the synergistic effect of two metals. The calculations and QTAIM analysis were performed for 1-8 and model molecules as well.
{"title":"Low coordinate potassium alkoxide - an efficient trap for arenes: the role of ηn non-covalent bonding in substrate activation for C-H bond metalation","authors":"Alexander A. Trifonov, Alexander N Selikhov, Yulia Nelyubina, Rinat R. Aysin","doi":"10.1039/d4dt03326d","DOIUrl":"https://doi.org/10.1039/d4dt03326d","url":null,"abstract":"Metalation of bulky tris(2-(piperidin-1-yl-methyl)phenyl)methanol [(C5H10N)CH2C6H4-o]3COH with (Me3Si)2NK in Et2O results in a dimeric potassium alkoxide {[(C5H10N)CH2C6H4-o]3C(μ2-O)K(Et2O)}2(1). Et2O molecule can be removed from the K+ coordination sphere affording coordinatively unsaturated alkoxide species which readily traps π-donor molecules. In the presence of arene excess the reactions result in ηn-π-complexes retaining in crystal state a dimeric core {[(C5H10N)CH2C6H4-o]3C(μ2-O)K(ηn-arene)}2 (arene = C6H6 (2), CH3C6H5 (3), C10H8 (4)). With C6H5OMe and C6H5NMe2 molecules containing competing n- and π-donating sites the reactions proceed differently: the former coordinates to K+ through an oxygen lone pair resulting in {[(C5H10N)CH2C6H4-o]3C(μ2-O)K(κ1-O(Me)C6H5}2 (5) while for the latterπ-arene interaction turns out to be preferable {[(C5H10N)CH2C6H4-o]3C(μ2-O)K(η2-C6H5NMe2)}2 (6). The reactions with equimolar amounts of benzene or thiophene afford coordination polymers [{[(C5H10N)CH2C6H4-o]3C(μ2-O)K}2(μ-C6H6)]n (7) and [{[(C5H10N)CH2C6H4-o]3C(μ2-O)K}2(μ-C4H4S)]n (8), in which benzene and thiophene molecules are μ-bridging two K+ ions. The treatment of {[(C5H10N)CH2C6H4-o]3C(μ2-O)K(η2-CH3C6H5))}2 with Me3SiCH2Li or n-BuLi (1.2 eq) in hexane at 20 °C results in the facile metalation of Me-group of toluene, the formation of [PhCH2K]n and lithium alkoxide . This model reaction provides a deeper insight into the probable mechanism of metalation of CH bonds under Lochmann–Schlosser superbasic conditions, the role and the nature of the synergistic effect of two metals. The calculations and QTAIM analysis were performed for 1-8 and model molecules as well.","PeriodicalId":71,"journal":{"name":"Dalton Transactions","volume":"17 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2025-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143050603","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
We investigated in this work the strength of metal–ligand bonding in complexes formed between Fe(III)- , Mn(III)- and Co(III)-myoglobin and methanol, water, nitrite, and azide, serving as neutral and ionic prototype ligands, for the ε and δ protonation forms of the myoglobin distal histidine. In total, 24 complexes and 12 associated gas phase models were investigated combining a QM/MM protocol with our local vibrational mode analysis at the PBE0/6-31g(d,p)/AMBER level of theory. According to our results, complexes with methanol and water ligands form weaker metal–ligand bonds than those with nitrite and azide ligands. Furthermore, the strength of the metal–ligand bonds depends on the protonation form of the distal histidine. Among the three metals investigated in this study, Fe, the metal found in native myoglobin, turned out to be the most versatile candidate, providing the broadest range of metal–ligand bond strengths. We also analyzed potential hydrogen bonds formed between the ligand and the distal histidine of the heme pocket. The ε tautomer of histidine forms weaker O· · · H type hydrogen bonds whereas the δ tautomer forms stronger N· · · H type hydrogen bonds. Overall, our findings identify the strength of both metal–ligand and hydrogen bonds (fully captured by our local vibrational mode analysis) as a key parameter determining the catalytic activity and function of myoglobins This is particularly relevant when considering neutral versus ionic ligands and other metals such as Mn or Co as alternatives to Fe. The insights gained through our investigation offer valuable guidance for strategically fine-tuning existing artificial myoglobins and designing new, versatile variants. We hope that our QM/MM - local mode analysis protocol will become a valuable addition to the research community’s toolkit.
{"title":"Metal-ligand and Hydrogen Bonding in the Active Site of Fe(III)-, Mn(III)- and Co(III)-myoglobins","authors":"Marek Freindorf, Elfi Kraka","doi":"10.1039/d4dt03246b","DOIUrl":"https://doi.org/10.1039/d4dt03246b","url":null,"abstract":"We investigated in this work the strength of metal–ligand bonding in complexes formed between Fe(III)- , Mn(III)- and Co(III)-myoglobin and methanol, water, nitrite, and azide, serving as neutral and ionic prototype ligands, for the ε and δ protonation forms of the myoglobin distal histidine. In total, 24 complexes and 12 associated gas phase models were investigated combining a QM/MM protocol with our local vibrational mode analysis at the PBE0/6-31g(d,p)/AMBER level of theory. According to our results, complexes with methanol and water ligands form weaker metal–ligand bonds than those with nitrite and azide ligands. Furthermore, the strength of the metal–ligand bonds depends on the protonation form of the distal histidine. Among the three metals investigated in this study, Fe, the metal found in native myoglobin, turned out to be the most versatile candidate, providing the broadest range of metal–ligand bond strengths. We also analyzed potential hydrogen bonds formed between the ligand and the distal histidine of the heme pocket. The ε tautomer of histidine forms weaker O· · · H type hydrogen bonds whereas the δ tautomer forms stronger N· · · H type hydrogen bonds. Overall, our findings identify the strength of both metal–ligand and hydrogen bonds (fully captured by our local vibrational mode analysis) as a key parameter determining the catalytic activity and function of myoglobins This is particularly relevant when considering neutral versus ionic ligands and other metals such as Mn or Co as alternatives to Fe. The insights gained through our investigation offer valuable guidance for strategically fine-tuning existing artificial myoglobins and designing new, versatile variants. We hope that our QM/MM - local mode analysis protocol will become a valuable addition to the research community’s toolkit.","PeriodicalId":71,"journal":{"name":"Dalton Transactions","volume":"34 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2025-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143044311","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Xiedong Cheng, Feifan Li, Qingqing Huang, Laura C J Pereira, Rui Cui, Yaping Li, Minfeng Lü
Five alkali metal manganese(III) fluorophosphates, K2Mn(PO3F)F3 (I), Rb2Mn(PO3F)F3 (II), Rb2Mn2(PO3F)(PO4)F3 (III), Rb3Mn3(PO3F)2(PO4)F5 (IV), and CsMn(PO3F)F2 (V), were successfully synthesized using a hydrothermal method. The monofluorophosphate anion (PO3F)2- groups work as "chemical scissors" to promote low-dimensional spin structures with the aid of alkali metal cations. I and II had an S = 2 uniform chain structure formed by corner-sharing trans-MnO2F4 octahedra. III contained a quasi one-dimensional S = 2 spin chain composed of trans-MnO4F2 octahedra and trans-MnO2F4 octahedra through vertex-sharing fluorine atoms running along the [1-10] direction, whereas V exhibited a zigzag S = 2 spin chain built from the facial-MnO3F3 octahedron. In contrast, IV constitutes weakly coupled S = 2 spin trimers, where the three-dimensional (3D) framework contains two-dimensional {Mn3O4F4(PO3F)2}2- layers formed by trinuclear Mn-octahedral units via corner-sharing fluorine atoms separated by PO3F tetrahedra. Magnetic measurements confirmed that I and II possess antiferromagnetic (AFM) long-range ordering at low temperature, with intrachain exchange couplings Jintra/kB = -12.1(1) K for I and Jintra/kB = -8.1(2) K for II. The magnetic behaviour of IV was very complex, with three successive magnetic transitions owing to weak AFM coupling among S = 2 spin trimers. V shows an alternating S = 2 one-dimensional (1D) chain with canted AFM ordering at 16.5 K.
{"title":"Synthesis, structures, and magnetic properties of alkali metal manganese(III) fluorophosphates containing low-dimensional <i>S</i> = 2 spin structures.","authors":"Xiedong Cheng, Feifan Li, Qingqing Huang, Laura C J Pereira, Rui Cui, Yaping Li, Minfeng Lü","doi":"10.1039/d4dt02768j","DOIUrl":"https://doi.org/10.1039/d4dt02768j","url":null,"abstract":"<p><p>Five alkali metal manganese(III) fluorophosphates, K<sub>2</sub>Mn(PO<sub>3</sub>F)F<sub>3</sub> (I), Rb<sub>2</sub>Mn(PO<sub>3</sub>F)F<sub>3</sub> (II), Rb<sub>2</sub>Mn<sub>2</sub>(PO<sub>3</sub>F)(PO<sub>4</sub>)F<sub>3</sub> (III), Rb<sub>3</sub>Mn<sub>3</sub>(PO<sub>3</sub>F)<sub>2</sub>(PO<sub>4</sub>)F<sub>5</sub> (IV), and CsMn(PO<sub>3</sub>F)F<sub>2</sub> (V), were successfully synthesized using a hydrothermal method. The monofluorophosphate anion (PO<sub>3</sub>F)<sup>2-</sup> groups work as \"chemical scissors\" to promote low-dimensional spin structures with the aid of alkali metal cations. I and II had an <i>S</i> = 2 uniform chain structure formed by corner-sharing <i>trans</i>-MnO<sub>2</sub>F<sub>4</sub> octahedra. III contained a quasi one-dimensional <i>S</i> = 2 spin chain composed of <i>trans</i>-MnO<sub>4</sub>F<sub>2</sub> octahedra and <i>trans</i>-MnO<sub>2</sub>F<sub>4</sub> octahedra through vertex-sharing fluorine atoms running along the [1-10] direction, whereas V exhibited a zigzag <i>S</i> = 2 spin chain built from the <i>facial</i>-MnO<sub>3</sub>F<sub>3</sub> octahedron. In contrast, IV constitutes weakly coupled <i>S</i> = 2 spin trimers, where the three-dimensional (3D) framework contains two-dimensional {Mn<sub>3</sub>O<sub>4</sub>F<sub>4</sub>(PO<sub>3</sub>F)<sub>2</sub>}<sup>2-</sup> layers formed by trinuclear Mn-octahedral units <i>via</i> corner-sharing fluorine atoms separated by PO<sub>3</sub>F tetrahedra. Magnetic measurements confirmed that I and II possess antiferromagnetic (AFM) long-range ordering at low temperature, with intrachain exchange couplings <i>J</i><sub>intra</sub>/<i>k</i><sub>B</sub> = -12.1(1) K for I and <i>J</i><sub>intra</sub>/<i>k</i><sub>B</sub> = -8.1(2) K for II. The magnetic behaviour of IV was very complex, with three successive magnetic transitions owing to weak AFM coupling among <i>S</i> = 2 spin trimers. V shows an alternating <i>S</i> = 2 one-dimensional (1D) chain with canted AFM ordering at 16.5 K.</p>","PeriodicalId":71,"journal":{"name":"Dalton Transactions","volume":" ","pages":""},"PeriodicalIF":3.5,"publicationDate":"2025-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143044961","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Robert Boothe, Julian Oppelt, Alicja Franke, Jamonica L. Moore, Andrea Squarcina, Achim Zahl, Laura Senft, Ina Kellner, Akudo L. Awalah, Alisabeth Bradford, Segun V. Obisesan, Dean D. Schwartz, Ivana Ivanović-Burmazović, Christian R. Goldsmith
Although nickel is found in the active sites of a class of superoxide dismutase (SOD), nickel complexes with non-peptidic ligands normally do not catalyze superoxide degradation, and none has displayed activity comparable to those of the best manganese-containing SOD mimics. Here, we find that nickel complexes with polydentate quinol-containing ligands can exhibit catalytic activity comparable to those of the most efficient manganese-containing SOD mimics. The nickel complexes retain a significant portion of their activity in phosphate buffer and under operando conditions and rely on ligand-centered redox processes for catalysis. Although nickel SODs are known to cycle through Ni(II) and Ni(III) species during catalysis, cryo-mass spectrometry studies indicate that the nickel atoms in our catalysts remain in the +2 oxidation state throughout SOD mimicry.
{"title":"Nickel(II) complexes with covalently attached quinols rely on ligand-derived redox couples to catalyze superoxide dismutation","authors":"Robert Boothe, Julian Oppelt, Alicja Franke, Jamonica L. Moore, Andrea Squarcina, Achim Zahl, Laura Senft, Ina Kellner, Akudo L. Awalah, Alisabeth Bradford, Segun V. Obisesan, Dean D. Schwartz, Ivana Ivanović-Burmazović, Christian R. Goldsmith","doi":"10.1039/d4dt03331k","DOIUrl":"https://doi.org/10.1039/d4dt03331k","url":null,"abstract":"Although nickel is found in the active sites of a class of superoxide dismutase (SOD), nickel complexes with non-peptidic ligands normally do not catalyze superoxide degradation, and none has displayed activity comparable to those of the best manganese-containing SOD mimics. Here, we find that nickel complexes with polydentate quinol-containing ligands can exhibit catalytic activity comparable to those of the most efficient manganese-containing SOD mimics. The nickel complexes retain a significant portion of their activity in phosphate buffer and under operando conditions and rely on ligand-centered redox processes for catalysis. Although nickel SODs are known to cycle through Ni(<small>II</small>) and Ni(<small>III</small>) species during catalysis, cryo-mass spectrometry studies indicate that the nickel atoms in our catalysts remain in the +2 oxidation state throughout SOD mimicry.","PeriodicalId":71,"journal":{"name":"Dalton Transactions","volume":"188 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2025-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143044313","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Harapriya Rath, Anirban Panua, Gunasekaran Velmurugan, Peter Comba
Retrosynthetically designed and synthesis of three unprecedented doubly N-confused porphyrinoids with tunable aromaticity are reported. Controlled modification of types of oxidants (chloranil vs. DDQ) has led to the isolation of cross-conjugated doubly N-confused porphyrinoid 7 (upon chloranil oxidation) and Hϋckel aromatic porphyrinoid 8, while DDQ oxidation has led to the 16 Hϋcckel-antiaromatic porphyrinoid 9. All three hybrid N-confused porphyrinoids 7-9 have been thoroughly characterized via solution state spectroscopic measurements and in-depth DFT studies. While 7 and 8 could form respective Cu(III) organometallic complexes, porphyrinoid 9 remained unsusceptible to Cu metallation.
{"title":"Copper(III) organometallic complexes of non (anti)aromatic and aromatic doubly N-confused porphyrinoids: syntheses and characterization","authors":"Harapriya Rath, Anirban Panua, Gunasekaran Velmurugan, Peter Comba","doi":"10.1039/d4dt03265a","DOIUrl":"https://doi.org/10.1039/d4dt03265a","url":null,"abstract":"Retrosynthetically designed and synthesis of three unprecedented doubly N-confused porphyrinoids with tunable aromaticity are reported. Controlled modification of types of oxidants (chloranil vs. DDQ) has led to the isolation of cross-conjugated doubly N-confused porphyrinoid 7 (upon chloranil oxidation) and Hϋckel aromatic porphyrinoid 8, while DDQ oxidation has led to the 16 Hϋcckel-antiaromatic porphyrinoid 9. All three hybrid N-confused porphyrinoids 7-9 have been thoroughly characterized via solution state spectroscopic measurements and in-depth DFT studies. While 7 and 8 could form respective Cu(III) organometallic complexes, porphyrinoid 9 remained unsusceptible to Cu metallation.","PeriodicalId":71,"journal":{"name":"Dalton Transactions","volume":"114 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2025-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143044838","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ningning Yuan, Tingchun Zhu, Jianping Ma, Yunsheng Xue, Yirui Liu
The isolation of a stable persistent carbazole-stabilized boron-centered monoradical anion 1˙−, which has a high spin density at the B atom, has been reported. It is characterized using the crystal structure and UV-vis absorption spectrum, as well as electron paramagnetic resonance spectroscopy. Interestingly, the B–N bond was activated by the boron-centered radical anion 1˙−, which had not been reported before.
{"title":"An isolable boron-centered radical anion stabilized by a carbazole moiety","authors":"Ningning Yuan, Tingchun Zhu, Jianping Ma, Yunsheng Xue, Yirui Liu","doi":"10.1039/d4dt03314k","DOIUrl":"https://doi.org/10.1039/d4dt03314k","url":null,"abstract":"The isolation of a stable persistent carbazole-stabilized boron-centered monoradical anion <strong>1</strong>˙<small><sup>−</sup></small>, which has a high spin density at the B atom, has been reported. It is characterized using the crystal structure and UV-vis absorption spectrum, as well as electron paramagnetic resonance spectroscopy. Interestingly, the B–N bond was activated by the boron-centered radical anion <strong>1</strong>˙<small><sup>−</sup></small>, which had not been reported before.","PeriodicalId":71,"journal":{"name":"Dalton Transactions","volume":"9 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2025-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143044314","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Xiaohai He, Bo Gao, Qingyuan Wu, Chengrui Xin, Junjie Xue, Fangwei Lu, Xin-Ping Qu, Simin Li, Fan Zhang, Hui Shen
Chemical mechanical polishing (CMP) represents one of the most important steps in the manufacturing of integrated circuits and high surface quality is always required for the CMP processes of shallow trench isolation (STI) structures. Herein, a new series of polydopamine (PDA)-coated cerium oxide core-shell nanoparticles has been developed as efficient and non-damaging abrasives for CMP of SiO2 on the surface of silicon wafers. The composite abrasives with the structure of SiO2@CeO2@PDA have been fabricated in a simple manner and thoroughly characterized using scanning electron microscopy, transmission electron microscopy, energy dispersive X-ray spectroscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. The SiO2 core enhances the content of Ce3+ in the abrasives, while the water-soluble PDA layer facilitates the interaction between the abrasives and SiO2 dielectrics. As a result, the wafers polished by SiO2@CeO2@PDA not only achieved a high polishing rate but also exhibited a high surface quality (Ra = 0.109). This study not only presents a new efficient and non-damaging type of cerium oxide abrasives for CMP, but also highlights the potential of the surface coordination strategy in the fabrication of advanced abrasives for the manufacturing of integrated circuits.
{"title":"Polydopamine-coated cerium oxide core-shell nanoparticles for efficient and non-damaging chemical-mechanical polishing","authors":"Xiaohai He, Bo Gao, Qingyuan Wu, Chengrui Xin, Junjie Xue, Fangwei Lu, Xin-Ping Qu, Simin Li, Fan Zhang, Hui Shen","doi":"10.1039/d4dt03546a","DOIUrl":"https://doi.org/10.1039/d4dt03546a","url":null,"abstract":"Chemical mechanical polishing (CMP) represents one of the most important steps in the manufacturing of integrated circuits and high surface quality is always required for the CMP processes of shallow trench isolation (STI) structures. Herein, a new series of polydopamine (PDA)-coated cerium oxide core-shell nanoparticles has been developed as efficient and non-damaging abrasives for CMP of SiO2 on the surface of silicon wafers. The composite abrasives with the structure of SiO2@CeO2@PDA have been fabricated in a simple manner and thoroughly characterized using scanning electron microscopy, transmission electron microscopy, energy dispersive X-ray spectroscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. The SiO2 core enhances the content of Ce3+ in the abrasives, while the water-soluble PDA layer facilitates the interaction between the abrasives and SiO2 dielectrics. As a result, the wafers polished by SiO2@CeO2@PDA not only achieved a high polishing rate but also exhibited a high surface quality (Ra = 0.109). This study not only presents a new efficient and non-damaging type of cerium oxide abrasives for CMP, but also highlights the potential of the surface coordination strategy in the fabrication of advanced abrasives for the manufacturing of integrated circuits.","PeriodicalId":71,"journal":{"name":"Dalton Transactions","volume":"28 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2025-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143044315","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Simon Dotzauer, Sourav Kar, Theresa Swoboda, Christoph Weidemann, Andreas Häfner, Rian David Dewhurst, Holger Braunschweig
Boriranes, highly strained three-membered cyclic organoboron heterocycles, have emerged as potential synthons for the synthesis of many organoboron species. However, the synthesis of boriranes with tricoordinate, sp2-hybridised boron and tetracoordinate, sp3-hybridised carbon atoms is very challenging owing to their high Lewis acidity. Herein we describe the isolation of base-free triaminoboriranes from the room-temperature reaction of diaminoalkynes with an aminodistannylborane. Further elimination of stannyl groups from these boriranes using potassium graphite afforded 2π-aromatic triaminoborirenes. To our knowledge, these are the first examples of conversions of alkanes to alkenes using reducing agents. Interestingly, the triaminoborirene underwent photolytic ring opening to afford a boryl- and amino-substituted acetylene featuring a polarised alkynyl group.
{"title":"Synthesis of Base-free Boriranes and their Conversion to Borirenes Using Strong Reductant","authors":"Simon Dotzauer, Sourav Kar, Theresa Swoboda, Christoph Weidemann, Andreas Häfner, Rian David Dewhurst, Holger Braunschweig","doi":"10.1039/d5dt00069f","DOIUrl":"https://doi.org/10.1039/d5dt00069f","url":null,"abstract":"Boriranes, highly strained three-membered cyclic organoboron heterocycles, have emerged as potential synthons for the synthesis of many organoboron species. However, the synthesis of boriranes with tricoordinate, <em>sp</em><small><sup>2</sup></small>-hybridised boron and tetracoordinate, <em>sp</em><small><sup>3</sup></small>-hybridised carbon atoms is very challenging owing to their high Lewis acidity. Herein we describe the isolation of base-free triaminoboriranes from the room-temperature reaction of diaminoalkynes with an aminodistannylborane. Further elimination of stannyl groups from these boriranes using potassium graphite afforded 2π-aromatic triaminoborirenes. To our knowledge, these are the first examples of conversions of alkanes to alkenes using reducing agents. Interestingly, the triaminoborirene underwent photolytic ring opening to afford a boryl- and amino-substituted acetylene featuring a polarised alkynyl group.","PeriodicalId":71,"journal":{"name":"Dalton Transactions","volume":"22 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2025-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143044312","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
AA mono-metallic MOF (Mn-FM) and r-GO composite of the MOF (rGO@Mn-FM) were synthesized with simple and cost-effective method. The MOF contains Mn2+ metal centre with in situ generated ligand from the decomposition of DMF used as a reaction medium under solvothermal condition. The unit cell also contains in situ generated dimethyl ammonium (DMA) cation entrapped inside the pores of the framework. Due to the presence of DMA cation, MOF exhibits selective adsorption of anionic dye (namely methyl blue, methyl orange) through ionic interaction. Again, upon removal of DMA cation, adsorption was significantly enhanced owing to the formation of higher charge density species in the framework. Water stability of the MOF was significantly improved through composite formation with r-graphene oxide (namely rGO@Mn-FM) which in turn improved the adsorption of methyl blue as well. The adsorption efficiency could be achieved up to 84% within 40 minutes. Moreover, the composite was found to be highly sensitive and capable of adsorbing trace amount of the MeB dye (upto 1 ppm) from aqueous solution. The composite follows pseudo-second order kinetics and Langmuir isotherm model signifying monolayer chemisorption with homogenous sites. The releasing/desorption of adsorbed methyl blue from rGO@Mn-FM surface establishes the reusability of dye and subsequently the stability and potential of the adsorbent to reuse for multiple cycles.
{"title":"An anionic metal-organic framework and its r-graphene oxide composite for selective adsorption and separation of methyl blue from aqueous solution","authors":"Uddit Narayan Hazarika, Prithiviraj Khakhlary, Anisha Pegu, Shrutipriya Devi, Surajit Konwer, Moirangthem Kameshwor Singh, Simi Gogoi, Mintumoni Pegu","doi":"10.1039/d4dt03471f","DOIUrl":"https://doi.org/10.1039/d4dt03471f","url":null,"abstract":"AA mono-metallic MOF (Mn-FM) and r-GO composite of the MOF (rGO@Mn-FM) were synthesized with simple and cost-effective method. The MOF contains Mn2+ metal centre with in situ generated ligand from the decomposition of DMF used as a reaction medium under solvothermal condition. The unit cell also contains in situ generated dimethyl ammonium (DMA) cation entrapped inside the pores of the framework. Due to the presence of DMA cation, MOF exhibits selective adsorption of anionic dye (namely methyl blue, methyl orange) through ionic interaction. Again, upon removal of DMA cation, adsorption was significantly enhanced owing to the formation of higher charge density species in the framework. Water stability of the MOF was significantly improved through composite formation with r-graphene oxide (namely rGO@Mn-FM) which in turn improved the adsorption of methyl blue as well. The adsorption efficiency could be achieved up to 84% within 40 minutes. Moreover, the composite was found to be highly sensitive and capable of adsorbing trace amount of the MeB dye (upto 1 ppm) from aqueous solution. The composite follows pseudo-second order kinetics and Langmuir isotherm model signifying monolayer chemisorption with homogenous sites. The releasing/desorption of adsorbed methyl blue from rGO@Mn-FM surface establishes the reusability of dye and subsequently the stability and potential of the adsorbent to reuse for multiple cycles.","PeriodicalId":71,"journal":{"name":"Dalton Transactions","volume":"38 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2025-01-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143031189","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Karina Kurmanbayeva, Semyon Nikulaichev, Viktoriia Torbina, Nikolai A. Sokovikov, Olga Vodyankina
Dihydroxyacetone is a valuable waste-valorization compound, which is a main intermediate in lactic acid production from different recyclable sources. In the present work, the Sn incorporation into the Zr-based metal-organic framework is used to increase its acidity and facilitate dihydroxyacetone conversion to lactic acid through the minimization of side reactions. Three series of Sn-modified metal-organic frameworks with different synthetic conditions and Zr/Sn molar ratio are prepared and characterized by low-temperature nitrogen adsorption, XRD, XRF, TGA, FTIR of adsorbed CO, and NH3-TPD methods. The nature of the Sn species depends on both the Sn precursor and water amount in the liquid phase during the synthesis allowing the control of the SnClx hydrolysis. The Sn addition leads to an increase in the acidity of the MOF and mostly depends on the nature of the Sn species rather than the Sn loading. An insertion of the tin species directly inside the UiO-66 structure results in an almost quantitative yield of the target products. The material retains its structure after catalysis, but the deposition of the polycondensation products on the MOF surface slightly decreases the selectivity at consecutive runs.
{"title":"Sn-modified Zr-UiO-66 metal-organic frameworks for dihydroxyacetone conversion into lactic acid","authors":"Karina Kurmanbayeva, Semyon Nikulaichev, Viktoriia Torbina, Nikolai A. Sokovikov, Olga Vodyankina","doi":"10.1039/d4dt02975e","DOIUrl":"https://doi.org/10.1039/d4dt02975e","url":null,"abstract":"Dihydroxyacetone is a valuable waste-valorization compound, which is a main intermediate in lactic acid production from different recyclable sources. In the present work, the Sn incorporation into the Zr-based metal-organic framework is used to increase its acidity and facilitate dihydroxyacetone conversion to lactic acid through the minimization of side reactions. Three series of Sn-modified metal-organic frameworks with different synthetic conditions and Zr/Sn molar ratio are prepared and characterized by low-temperature nitrogen adsorption, XRD, XRF, TGA, FTIR of adsorbed CO, and NH3-TPD methods. The nature of the Sn species depends on both the Sn precursor and water amount in the liquid phase during the synthesis allowing the control of the SnClx hydrolysis. The Sn addition leads to an increase in the acidity of the MOF and mostly depends on the nature of the Sn species rather than the Sn loading. An insertion of the tin species directly inside the UiO-66 structure results in an almost quantitative yield of the target products. The material retains its structure after catalysis, but the deposition of the polycondensation products on the MOF surface slightly decreases the selectivity at consecutive runs.","PeriodicalId":71,"journal":{"name":"Dalton Transactions","volume":"3 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2025-01-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143031190","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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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