Pub Date : 2022-11-08DOI: 10.1021/acsorginorgau.2c00051
Enzo Olivieri, and , Adrien Quintard*,
Dissipative systems are based on the supply of energy to a system by fuel pulses and dissipation of this energy through the fuel decomposition, resulting in repetition of a given physical or biological function. Such out of equilibrium processes are at the heart of all living organisms, and in the past decade, researchers have attempted to transpose these principles to purely synthetic systems. However, upon fuel decomposition, the resulting waste generated tends to accumulate in the system, rapidly inhibiting the machinery after a few cycles of fuel pulses. In order to solve this issue, trichloroacetic acid has appeared as a fuel of choice to reversibly change the acidity of a system, liberating volatile chloroform and CO2 upon fuel decomposition. In this Perspective, we present the advantages of this fuel and successful applications ranging from conformational switches to rotary motors to temporal control over crystallization or smart materials.
{"title":"Out of Equilibrium Chemical Systems Fueled by Trichloroacetic Acid","authors":"Enzo Olivieri, and , Adrien Quintard*, ","doi":"10.1021/acsorginorgau.2c00051","DOIUrl":"https://doi.org/10.1021/acsorginorgau.2c00051","url":null,"abstract":"<p >Dissipative systems are based on the supply of energy to a system by fuel pulses and dissipation of this energy through the fuel decomposition, resulting in repetition of a given physical or biological function. Such out of equilibrium processes are at the heart of all living organisms, and in the past decade, researchers have attempted to transpose these principles to purely synthetic systems. However, upon fuel decomposition, the resulting waste generated tends to accumulate in the system, rapidly inhibiting the machinery after a few cycles of fuel pulses. In order to solve this issue, trichloroacetic acid has appeared as a fuel of choice to reversibly change the acidity of a system, liberating volatile chloroform and CO<sub>2</sub> upon fuel decomposition. In this Perspective, we present the advantages of this fuel and successful applications ranging from conformational switches to rotary motors to temporal control over crystallization or smart materials.</p>","PeriodicalId":29797,"journal":{"name":"ACS Organic & Inorganic Au","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.acs.org/doi/epdf/10.1021/acsorginorgau.2c00051","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49768816","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}
Pub Date : 2022-10-31DOI: 10.1021/acsorginorgau.2c00040
Avik Bhattacharjee, Dayalis S. V. Brown, Trent E. Ethridge, Kristine M. Halvorsen, Alejandra C. Acevedo Montano and Theresa M. McCormick*,
This work demonstrates a strategy to fine-tune the efficiency of a photoredox water splitting Ni(II) tris-pyridinethiolate catalyst through heteroleptic ligand design using computational investigation of the catalytic mechanism. Density functional theory (DFT) calculations, supported by topology analyses using quantum theory of atoms in molecules (QTAIM), show that the introduction of electron donating (ED) −CH3 and electron withdrawing (EW) −CF3 groups on the thiopyridyl (PyS–) ligands of the same complex can tune the pKa and E0, simultaneously. Computational modeling of two heteroleptic nickel(II) tris-pyridinethiolate complexes with 2:1 and 1:2 ED and EW −CH3 and −CF3 group containing PyS– ligands, respectively, suggests that the ideal combination of EW to ED groups is 2:1. This work also outlines the possibility of formation of a large number of isomers after the protonation of one of the pyridyl N atoms and suggests that to acquire unambiguous computational results it is necessary to carefully account for all possible geometric isomers.
{"title":"Computational Investigation into Heteroleptic Photoredox Catalysts Based on Nickel(II) Tris-Pyridinethiolate for Water Splitting Reactions","authors":"Avik Bhattacharjee, Dayalis S. V. Brown, Trent E. Ethridge, Kristine M. Halvorsen, Alejandra C. Acevedo Montano and Theresa M. McCormick*, ","doi":"10.1021/acsorginorgau.2c00040","DOIUrl":"https://doi.org/10.1021/acsorginorgau.2c00040","url":null,"abstract":"<p >This work demonstrates a strategy to fine-tune the efficiency of a photoredox water splitting Ni(II) tris-pyridinethiolate catalyst through heteroleptic ligand design using computational investigation of the catalytic mechanism. Density functional theory (DFT) calculations, supported by topology analyses using quantum theory of atoms in molecules (QTAIM), show that the introduction of electron donating (ED) −CH<sub>3</sub> and electron withdrawing (EW) −CF<sub>3</sub> groups on the thiopyridyl (PyS<sup>–</sup>) ligands of the same complex can tune the p<i>K</i><sub>a</sub> and <i>E</i><sup>0</sup>, simultaneously. Computational modeling of two heteroleptic nickel(II) tris-pyridinethiolate complexes with 2:1 and 1:2 ED and EW −CH<sub>3</sub> and −CF<sub>3</sub> group containing PyS<sup>–</sup> ligands, respectively, suggests that the ideal combination of EW to ED groups is 2:1. This work also outlines the possibility of formation of a large number of isomers after the protonation of one of the pyridyl N atoms and suggests that to acquire unambiguous computational results it is necessary to carefully account for all possible geometric isomers.</p>","PeriodicalId":29797,"journal":{"name":"ACS Organic & Inorganic Au","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.acs.org/doi/epdf/10.1021/acsorginorgau.2c00040","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49768905","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}
Pub Date : 2022-10-26DOI: 10.1021/acsorginorgau.2c00030
W. Ryan Osterloh, Jeanet Conradie, Abraham B. Alemayehu, Abhik Ghosh* and Karl M. Kadish*,
We have revisited the electrochemistry of metallocorrole dimers with low-temperature cyclic voltammetry and UV–visible–NIR spectroelectrochemistry, with the aim of determining the sites of the redox processes undergone by these compounds. The systems studied include the metal–metal triple-bonded complexes {Ru[TpOMePC]}2 and {Os[TpOMePC]}2 and the metal–metal quadruple-bonded complex {Re[TPC]}2, where TpOMePC and TPC refer to trianionic meso-tris(p-methoxyphenyl)corrole and meso-triphenylcorrole ligands. For all three compounds, the first oxidation potentials are found at 0.52 ± 0.04 V vs SCE in CH2Cl2/0.1 M TBAP and are accompanied by major changes in the optical spectra, especially the appearance of broad, low-energy bands, suggesting macrocycle-centered oxidation in each case. In contrast, the reduction potentials span an 800 mV range, occurring at E1/2 = −0.52 V for {Re[TPC]}2, −0.81 V for {Ru[TpOMePC]}2, and −1.32 V for {Os[TpOMePC]}2, with more modest changes in the optical spectra, implying a significant metal-centered character in the reduction process. Density functional theory (DFT) calculations largely (but not entirely) bear out these expectations. The combined experimental and theoretical data indicate that one-electron addition to the Re dimer involves the Re–Re δ* LUMO, while one-electron addition to the Ru dimer largely involves the Ru–Ru π* LUMO. In contrast, the calculations suggest that one-electron reduction of the Os dimer occurs largely on the corrole ligands, a phenomenon attributed to the relativistic destabilization of the Os–Os π* MOs.
我们用低温循环伏安法和紫外-可见-近红外光谱电化学重新研究了金属吡咯二聚体的电化学,目的是确定这些化合物所经历的氧化还原过程的位点。所研究的体系包括金属-金属三键合物{Ru[TpOMePC]}2和{Os[TPOMEP]}2,以及金属-金属四键合物{Re[TPC]}2,其中TpOMePC和TPC指的是三元meso-tris(对甲氧基苯基)corrole和meso-triphenyl corrole配体。对于所有三种化合物,在CH2Cl2/0.1M TBAP中,第一氧化电位在0.52±0.04V vs SCE处发现,并且伴随着光谱的重大变化,特别是出现宽的低能带,表明在每种情况下都存在以大环为中心的氧化。相反,还原电位跨越800 mV的范围,在E1/2=−0.52 V的{Re[TPC]}2、−0.81 V的{Ru[TPOMEP]}2和−1.32 V的{Os[TpOMePC]}2中发生,光谱变化更为温和,这意味着还原过程中具有显著的金属中心特征。密度泛函理论(DFT)的计算在很大程度上(但并非完全)证明了这些期望。综合实验和理论数据表明,向Re二聚体的一个电子添加涉及Re–Reδ*LUMO,而向Ru二聚体添加一个电子主要涉及Ru–Ruπ*LUMO。相反,计算表明,Os二聚体的单电子还原主要发生在corrole配体上,这一现象归因于Os–Osπ*MO的相对论不稳定。
{"title":"The Question of the Redox Site in Metal–Metal Multiple-Bonded Metallocorrole Dimers","authors":"W. Ryan Osterloh, Jeanet Conradie, Abraham B. Alemayehu, Abhik Ghosh* and Karl M. Kadish*, ","doi":"10.1021/acsorginorgau.2c00030","DOIUrl":"https://doi.org/10.1021/acsorginorgau.2c00030","url":null,"abstract":"<p >We have revisited the electrochemistry of metallocorrole dimers with low-temperature cyclic voltammetry and UV–visible–NIR spectroelectrochemistry, with the aim of determining the sites of the redox processes undergone by these compounds. The systems studied include the metal–metal triple-bonded complexes {Ru[T<i>p</i>OMePC]}<sub>2</sub> and {Os[T<i>p</i>OMePC]}<sub>2</sub> and the metal–metal quadruple-bonded complex {Re[TPC]}<sub>2</sub>, where T<i>p</i>OMePC and TPC refer to trianionic <i>meso</i>-tris(<i>p</i>-methoxyphenyl)corrole and <i>meso</i>-triphenylcorrole ligands. For all three compounds, the first oxidation potentials are found at 0.52 ± 0.04 V vs SCE in CH<sub>2</sub>Cl<sub>2</sub>/0.1 M TBAP and are accompanied by major changes in the optical spectra, especially the appearance of broad, low-energy bands, suggesting macrocycle-centered oxidation in each case. In contrast, the reduction potentials span an 800 mV range, occurring at <i>E</i><sub>1/2</sub> = −0.52 V for {Re[TPC]}<sub>2</sub>, −0.81 V for {Ru[T<i>p</i>OMePC]}<sub>2</sub>, and −1.32 V for {Os[T<i>p</i>OMePC]}<sub>2</sub>, with more modest changes in the optical spectra, implying a significant metal-centered character in the reduction process. Density functional theory (DFT) calculations largely (but not entirely) bear out these expectations. The combined experimental and theoretical data indicate that one-electron addition to the Re dimer involves the Re–Re δ* LUMO, while one-electron addition to the Ru dimer largely involves the Ru–Ru π* LUMO. In contrast, the calculations suggest that one-electron reduction of the Os dimer occurs largely on the corrole ligands, a phenomenon attributed to the relativistic destabilization of the Os–Os π* MOs.</p>","PeriodicalId":29797,"journal":{"name":"ACS Organic & Inorganic Au","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-10-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.acs.org/doi/epdf/10.1021/acsorginorgau.2c00030","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49768649","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}
Pub Date : 2022-10-11DOI: 10.1021/acsorginorgau.2c00050
Jordi Ballesteros-Soberanas, Cristina Bilanin and Antonio Leyva-Pérez*,
Quantification is essential to fairly compare between synthetic reactions in chemistry. Here we propose two new parameters called “adapted sensitivity constant” (ρadap) and “substrate electronics adaptability” (SEA), easily obtainable from Hammett plots, to assess the ability of a (catalytic) reaction to transform substrates with opposing electronics. These new parameters allow one to list reactions, catalyzed or not, as a function of substrate scope.
{"title":"Parametrization of Catalytic Organic Reactions with Convex Hammett Plots","authors":"Jordi Ballesteros-Soberanas, Cristina Bilanin and Antonio Leyva-Pérez*, ","doi":"10.1021/acsorginorgau.2c00050","DOIUrl":"https://doi.org/10.1021/acsorginorgau.2c00050","url":null,"abstract":"<p >Quantification is essential to fairly compare between synthetic reactions in chemistry. Here we propose two new parameters called “adapted sensitivity constant” (ρ<sub>adap</sub>) and “substrate electronics adaptability” (SEA), easily obtainable from Hammett plots, to assess the ability of a (catalytic) reaction to transform substrates with opposing electronics. These new parameters allow one to list reactions, catalyzed or not, as a function of substrate scope.</p>","PeriodicalId":29797,"journal":{"name":"ACS Organic & Inorganic Au","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.acs.org/doi/epdf/10.1021/acsorginorgau.2c00050","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49768832","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}
Pub Date : 2022-10-03DOI: 10.1021/acsorginorgau.2c00027
Manishkumar S. Tiwari, Dipti Wagh, Jennifer Sarah Dicks, John Keogh, Michela Ansaldi, Vivek V. Ranade and Haresh G. Manyar*,
The manufacture of high-value products from biomass derived platform chemicals is becoming an integral part of the biorefinery industry. In this study, we demonstrate a green catalytic process using solvent free conditions for the synthesis of hydroxymethylfurfural (HMF) levulinate from HMF and levulinic acid (LA) over tin exchanged tungstophosphoric acid (DTP) supported on K-10 (montmorillonite K-10 clay) as the catalyst. The structural properties of solid acid catalysts were characterized by using XRD, FT-IR, UV–vis, titration, and SEM techniques. Partial exchange of the H+ of DTP with Sn (x = 1) resulted in enhanced acidity of the catalyst and showed an increase in the catalytic activity as compared to the unsubstituted DTP/K-10 as the catalyst. The effects of different reaction parameters were studied and optimized to get high yields of HMF levulinate. The kinetic model was developed by considering the Langmuir–Hinshelwood–Hougen–Watson (LHHW) mechanism, and the activation energy was calculated to be 41.2 kJ mol–1. The prepared catalysts were easily recycled up to four times without any noticeable loss of activity, and hot filtration test indicated the heterogeneous nature of the catalytic activity. The overall process is environmentally benign and suitable for easy scale up.
{"title":"Solvent Free Upgrading of 5-Hydroxymethylfurfural (HMF) with Levulinic Acid to HMF Levulinate Using Tin Exchanged Tungstophosphoric Acid Supported on K-10 Catalyst","authors":"Manishkumar S. Tiwari, Dipti Wagh, Jennifer Sarah Dicks, John Keogh, Michela Ansaldi, Vivek V. Ranade and Haresh G. Manyar*, ","doi":"10.1021/acsorginorgau.2c00027","DOIUrl":"10.1021/acsorginorgau.2c00027","url":null,"abstract":"<p >The manufacture of high-value products from biomass derived platform chemicals is becoming an integral part of the biorefinery industry. In this study, we demonstrate a green catalytic process using solvent free conditions for the synthesis of hydroxymethylfurfural (HMF) levulinate from HMF and levulinic acid (LA) over tin exchanged tungstophosphoric acid (DTP) supported on K-10 (montmorillonite K-10 clay) as the catalyst. The structural properties of solid acid catalysts were characterized by using XRD, FT-IR, UV–vis, titration, and SEM techniques. Partial exchange of the H<sup>+</sup> of DTP with Sn (<i>x</i> = 1) resulted in enhanced acidity of the catalyst and showed an increase in the catalytic activity as compared to the unsubstituted DTP/K-10 as the catalyst. The effects of different reaction parameters were studied and optimized to get high yields of HMF levulinate. The kinetic model was developed by considering the Langmuir–Hinshelwood–Hougen–Watson (LHHW) mechanism, and the activation energy was calculated to be 41.2 kJ mol<sup>–1</sup>. The prepared catalysts were easily recycled up to four times without any noticeable loss of activity, and hot filtration test indicated the heterogeneous nature of the catalytic activity. The overall process is environmentally benign and suitable for easy scale up.</p>","PeriodicalId":29797,"journal":{"name":"ACS Organic & Inorganic Au","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.acs.org/doi/epdf/10.1021/acsorginorgau.2c00027","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9222491","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}
Pub Date : 2022-09-28DOI: 10.1021/acsorginorgau.2c00038
Ulises Carrillo, Antonio Francés-Monerris, Anil Reddy Marri, Cristina Cebrián* and Philippe C. Gros*,
The stereoselective synthesis of geometrical iron(II) complexes bearing azine-NHC ligands is described. Facial and meridional selectivity is achieved as a function of the steric demand of the azine unit, with no remarkable influence of the carbene nature. More specifically, meridional complexes are obtained upon selecting bulky 5-mesityl-substituted pyridyl coordinating units. Unexpectedly, increase of the steric hindrance in the α position with respect to the N coordinating atom results in an exclusive facial configuration, which is in stark contrast to the meridional selectivity induced by other reported α-substituted bidentate ligands. Investigation of the structure and the optical and electrochemical properties of the here-described complexes has revealed the non-negligible effect of the fac/mer ligand configuration around the metal center.
{"title":"Substituent-Induced Control of fac/mer Isomerism in Azine-NHC Fe(II) Complexes","authors":"Ulises Carrillo, Antonio Francés-Monerris, Anil Reddy Marri, Cristina Cebrián* and Philippe C. Gros*, ","doi":"10.1021/acsorginorgau.2c00038","DOIUrl":"https://doi.org/10.1021/acsorginorgau.2c00038","url":null,"abstract":"<p >The stereoselective synthesis of geometrical iron(II) complexes bearing azine-NHC ligands is described. Facial and meridional selectivity is achieved as a function of the steric demand of the azine unit, with no remarkable influence of the carbene nature. More specifically, meridional complexes are obtained upon selecting bulky 5-mesityl-substituted pyridyl coordinating units. Unexpectedly, increase of the steric hindrance in the α position with respect to the N coordinating atom results in an exclusive facial configuration, which is in stark contrast to the meridional selectivity induced by other reported α-substituted bidentate ligands. Investigation of the structure and the optical and electrochemical properties of the here-described complexes has revealed the non-negligible effect of the <i>fac</i>/<i>mer</i> ligand configuration around the metal center.</p>","PeriodicalId":29797,"journal":{"name":"ACS Organic & Inorganic Au","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-09-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.acs.org/doi/epdf/10.1021/acsorginorgau.2c00038","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71704802","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}
Pub Date : 2022-09-28DOI: 10.1021/acsorginorgau.2c00034
Fen Zhao, Wided Hagui, María Ballarín-Marión, Cyril Ollivier*, Virginie Mouriès-Mansuy* and Louis Fensterbank*,
A pathway for the synthesis of 3-sulfonylindoles has been devised. Upon blue LED irradiation, in the presence of a gold(I) or a silver(I) salt, ortho-alkynyl N-sulfonyl precursors readily undergo a 5-endo-dig cyclization concomitant with a 1,3-sulfonyl migration. While the gold-catalyzed reaction takes place in photocatalyst-free conditions, an iridium photocatalyst (Ir[dF(CF3)ppy]2(dtbbpy)PF6) is necessary with silver catalysis. Mechanistic studies featuring the generation of a sulfonyl radical support this dichotomy.
{"title":"3-Sulfonylindoles via Gold- or Silver-Catalyzed Cyclization─1,3-Sulfonyl Migration Sequences under Visible Light Irradiation","authors":"Fen Zhao, Wided Hagui, María Ballarín-Marión, Cyril Ollivier*, Virginie Mouriès-Mansuy* and Louis Fensterbank*, ","doi":"10.1021/acsorginorgau.2c00034","DOIUrl":"https://doi.org/10.1021/acsorginorgau.2c00034","url":null,"abstract":"<p >A pathway for the synthesis of 3-sulfonylindoles has been devised. Upon blue LED irradiation, in the presence of a gold(I) or a silver(I) salt, <i>ortho</i>-alkynyl <i>N</i>-sulfonyl precursors readily undergo a 5-<i>endo</i>-<i>dig</i> cyclization concomitant with a 1,3-sulfonyl migration. While the gold-catalyzed reaction takes place in photocatalyst-free conditions, an iridium photocatalyst (Ir[dF(CF<sub>3</sub>)ppy]<sub>2</sub>(dtbbpy)PF<sub>6</sub>) is necessary with silver catalysis. Mechanistic studies featuring the generation of a sulfonyl radical support this dichotomy.</p>","PeriodicalId":29797,"journal":{"name":"ACS Organic & Inorganic Au","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-09-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.acs.org/doi/epdf/10.1021/acsorginorgau.2c00034","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49768742","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}
Pub Date : 2022-09-20DOI: 10.1021/acsorginorgau.2c00014
Joscha Breibeck, Nadiia I. Gumerova and Annette Rompel*,
The presence of oxo-ligands is one of the main required characteristics for polyoxometalates (POMs), although some oxygen ions in a metallic environment can be replaced by other nonmetals, while maintaining the POM structure. The replacement of oxo-ligands offers a valuable approach to tune the charge distribution and connected properties like reducibility and hydrolytic stability of POMs for the development of tailored compounds. By assessing the reported catalytic and biological applications and connecting them to POM structures, the present review provides a guideline for synthetic approaches and aims to stimulate further applications where the oxo-replaced compounds are superior to their oxo-analogues. Oxo-replacement in POMs deserves more attention as a valuable tool to form chemically activated precursors for the synthesis of novel structures or to upgrade established structures with extraordinary properties for challenging applications.
{"title":"Oxo-Replaced Polyoxometalates: There Is More than Oxygen","authors":"Joscha Breibeck, Nadiia I. Gumerova and Annette Rompel*, ","doi":"10.1021/acsorginorgau.2c00014","DOIUrl":"10.1021/acsorginorgau.2c00014","url":null,"abstract":"<p >The presence of oxo-ligands is one of the main required characteristics for polyoxometalates (POMs), although some oxygen ions in a metallic environment can be replaced by other nonmetals, while maintaining the POM structure. The replacement of oxo-ligands offers a valuable approach to tune the charge distribution and connected properties like reducibility and hydrolytic stability of POMs for the development of tailored compounds. By assessing the reported catalytic and biological applications and connecting them to POM structures, the present review provides a guideline for synthetic approaches and aims to stimulate further applications where the oxo-replaced compounds are superior to their oxo-analogues. Oxo-replacement in POMs deserves more attention as a valuable tool to form chemically activated precursors for the synthesis of novel structures or to upgrade established structures with extraordinary properties for challenging applications.</p>","PeriodicalId":29797,"journal":{"name":"ACS Organic & Inorganic Au","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9732882/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10590517","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}
Pub Date : 2022-09-20DOI: 10.1021/acsorginorgau.2c00035
Betty Y.T. Lee, Andrew D. Phillips*, Muhammad Hanif, Tilo Söhnel and Christian G. Hartinger*,
Organometallic Rh(Cp*) (Cp* = η5-pentamethylcyclopentadienyl) complexes with monodentate N-heterocyclic carbene (NHC) ligands bearing a pendant anthracenyl substituent have been shown to undergo intramolecular C–C coupling reactions. Herein, two bidentate NHC ligands substituted with pyridyl or triazolyl donor groups were prepared along with the corresponding MII/III (M = RuII, OsII, RhIII, IrIII) complexes. While the Rh(Cp*) complex featuring an NHC-triazole bidentate ligand underwent the equivalent reaction as the monodentate Rh(NHC) complex, i.e., it formed a polydentate ligand, the pyridyl-pendant derivative was unequivocally shown to be unreactive. This contrasting behavior was further investigated by density functional theory (DFT) calculations that highlighted significant differences between the two types of Rh(III) complexes with pendant pyridyl or triazolyl N-coordinating groups. Modeling of the reaction pathways suggests that the initial formation of a dicationic Rh(III) species is unfavorable and that the internal ligand transformation proceeds first by dissociation of the coordinated N atom of the pendant group from the Rh center. After the formation of a neutral η4-fulvene ligand via combined proton/single electron transfer, a cycloaddition occurs between the exo-ene bond of fulvene and the 9′ and 10′ positions on the pendant anthracenyl group. The resulting experimental UV–visible spectrum recorded in methanol of the polydentate triazolyl-based Rh species revealed the loss of the vibronic coupling typically associated with an anthracenyl functional group. Moreover, TD-DFT modeling indicates the presence of an equilibrium process whereby the N-coordination of the pendant triazolyl group to the RhIII center appears to be highly labile. Charge decomposition analysis (CDA) of the DFT-modeled species with the dissociated triazolyl group revealed a pseudo-η3-allylic interaction between the π-type MOs of the transformed anthracenyl group and the RhIII center; thus, the singly attached chelating ligand is classified as having rare nonadenticity.
{"title":"Triazolyl- vs Pyridyl-Functionalized N-Heterocyclic Carbene Complexes: Impact of the Pendant N-Donor Ligand on Intramolecular C–C Bond Formation","authors":"Betty Y.T. Lee, Andrew D. Phillips*, Muhammad Hanif, Tilo Söhnel and Christian G. Hartinger*, ","doi":"10.1021/acsorginorgau.2c00035","DOIUrl":"https://doi.org/10.1021/acsorginorgau.2c00035","url":null,"abstract":"<p >Organometallic Rh(Cp*) (Cp* = η<sup>5</sup>-pentamethylcyclopentadienyl) complexes with monodentate <i>N</i>-heterocyclic carbene (NHC) ligands bearing a pendant anthracenyl substituent have been shown to undergo intramolecular C–C coupling reactions. Herein, two bidentate NHC ligands substituted with pyridyl or triazolyl donor groups were prepared along with the corresponding M<sup>II/III</sup> (M = Ru<sup>II</sup>, Os<sup>II</sup>, Rh<sup>III</sup>, Ir<sup>III</sup>) complexes. While the Rh(Cp*) complex featuring an NHC-triazole bidentate ligand underwent the equivalent reaction as the monodentate Rh(NHC) complex, <i>i.e.</i>, it formed a polydentate ligand, the pyridyl-pendant derivative was unequivocally shown to be unreactive. This contrasting behavior was further investigated by density functional theory (DFT) calculations that highlighted significant differences between the two types of Rh(III) complexes with pendant pyridyl or triazolyl <i>N</i>-coordinating groups. Modeling of the reaction pathways suggests that the initial formation of a dicationic Rh(III) species is unfavorable and that the internal ligand transformation proceeds first by dissociation of the coordinated N atom of the pendant group from the Rh center. After the formation of a neutral η<sup>4</sup>-fulvene ligand <i>via</i> combined proton/single electron transfer, a cycloaddition occurs between the exo-ene bond of fulvene and the 9′ and 10′ positions on the pendant anthracenyl group. The resulting experimental UV–visible spectrum recorded in methanol of the polydentate triazolyl-based Rh species revealed the loss of the vibronic coupling typically associated with an anthracenyl functional group. Moreover, TD-DFT modeling indicates the presence of an equilibrium process whereby the <i>N</i>-coordination of the pendant triazolyl group to the Rh<sup>III</sup> center appears to be highly labile. Charge decomposition analysis (CDA) of the DFT-modeled species with the dissociated triazolyl group revealed a pseudo-η<sup>3</sup>-allylic interaction between the π-type MOs of the transformed anthracenyl group and the Rh<sup>III</sup> center; thus, the singly attached chelating ligand is classified as having rare nonadenticity.</p>","PeriodicalId":29797,"journal":{"name":"ACS Organic & Inorganic Au","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.acs.org/doi/epdf/10.1021/acsorginorgau.2c00035","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71701272","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}
Pub Date : 2022-09-12DOI: 10.1021/acsorginorgau.2c00049
Géraldine Masson*, Marisa C. Kozlowski* and Scott J. Miller*,
{"title":"Data Availability Statements in The Journal of Organic Chemistry, Organic Letters, and ACS Organic & Inorganic Au","authors":"Géraldine Masson*, Marisa C. Kozlowski* and Scott J. Miller*, ","doi":"10.1021/acsorginorgau.2c00049","DOIUrl":"https://doi.org/10.1021/acsorginorgau.2c00049","url":null,"abstract":"","PeriodicalId":29797,"journal":{"name":"ACS Organic & Inorganic Au","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.acs.org/doi/epdf/10.1021/acsorginorgau.2c00049","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71701833","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}