The regioselectivity of the C-H activation of 1-butanol and 1-methoxybutane by an iridium(iii) phenanthroline complex was studied in the gas phase and revealed activation at gamma and delta carbons. In the ether, nearly exclusive gamma activation was observed. DFT calculations were used to explore the origin of this substrate-driven selectivity. The data show that the iridium(iii) complex is a potent and potentially highly selective remote C-H activation agent.A systematic investigation of the experimental conditions for the chemical exfoliation of MoS2 using n-butyllithium as intercalating agent has been carried out to unravel the effect of reaction time and temperature for maximizing the percentage of monolayer thick-flakes and achieve a control over the content of metallic 1T vs. semiconductive 2H phases, thereby tuning the electrical properties of ultrathin MoS2 few-layer thick films.Asia Pacific (AP) is the largest regional vehicle market and accounted for 48% of global sales in 2019. Air quality is a pressing issue in many AP countries and together with increased vehicle sales has led to intense scrutiny of vehicle emissions. The heterogeneity of socio-economic features and transportation patterns in AP countries has resulted in different emission levels and control policies. We present an assessment of the historical and future emissions of on-road transportation and strategies to tackle emission challenges. First, we collected historical country-level population, economic development, vehicle ownership, and transportation policy data from 1900 to 2020, and forecast future development of on-road transportation activity (both passenger and freight) based on its historical relationship with socio-economic development through 2050. We considered major countries (China, India, Japan, South Korea, Australia) individually and other AP countries as a group. Second, we generated a series of em and new technologies are adopted according to national plans, road transportation GHG emissions in AP peak in approximately 2040.Photoactivatable diazidodihydroxido Pt(iv) complex trans,trans,trans-[Pt(N3)2(OH)2(py)2] (1; py = pyridine) is a promising anticancer agent which can be activated by visible light to induce cancer cell death. DNA has been thought to be involved in the mechanism of action of this kind of Pt(iv) prodrug. However, the detailed photodecomposition pathways of complex 1 and its interaction modes with DNA are complex. https://www.selleckchem.com/products/ferrostatin-1.html Herein we report that upon light irradiation complex 1 can bind to all four nucleosides covalently with the reduced Pt(ii) species. Moreover, apart from the covalent coordination, various oxidation adducts of these four nucleosides induced by the reactive oxidative species (ROS) generated during the photoactivation of the complex 1 have also been identified, especially the induced oxidation of adenosine and cytidine which was firstly reported for this kind of photoactivatable Pt(iv) prodrug. Such dual-action may contribute to the highly potent photo-antiproliferativity of complex 1 towards cancer cells, which may account for the unique mechanism of action of the photoactivatable diazido Pt(iv) anticancer complexes.As a new antiperovskite nitride, ZnFe3N was synthesized and characterized by almost completely substituting iron atoms at corner positions of γ'-Fe4N. The magnetic interactions of the system with the space group Pm3[combining macron]m are fully investigated. The critical behavior was investigated based on the measured magnetic data around the ferromagnetic phase transition temperature. In this work, the values of critical exponents (β, γ and δ) were obtained systematically using the Kouvel-Fisher method in the critical region. The Widom scaling law (δ = 1 + γβ-1) and the scaling equation (m = f±(h)) were used to reveal the reliability of these values. The values of the critical exponents (β = 0.325, γ = 1.228, and δ = 4.778) are different from those predicted by the three-dimensional (3D) Heisenberg model and mean-field model, and are very close to those of the 3D-Ising model. Combined with ESR analysis, the spin clusters induced by changes in chemical bonds are considered to be the cause for the existence of an anisotropic short-range ordered state in this ferromagnetic system.Chiral α-hydroxy-β-lactams are key fragments of many bioactive compounds and antibiotics, and the development of efficient synthetic methods for these compounds is of great value. The highly enantioselective dynamic kinetic resolution (DKR) of α-keto-β-lactams was realized via a novel proton shuttling strategy. A wide range of α-keto-β-lactams were reduced efficiently and enantioselectively by Ni-catalyzed asymmetric hydrogenation, providing the corresponding α-hydroxy-β-lactam derivatives with high yields and enantioselectivities (up to 92% yield, up to 94% ee). Deuterium-labelling experiments indicate that phenylphosphinic acid plays a pivotal role in the DKR of α-keto-β-lactams by promoting the enolization process. The synthetic potential of this protocol was demonstrated by its application in the synthesis of a key intermediate of Taxol and (+)-epi-Cytoxazone.Herein, we report the synthesis and total structure of a Cu-rich alloy nanocluster protected by twelve adamantanethiolate ligands, i.e., [Ag13Cu10(SAdm)12]X3 (-SAdm = SC10H15, X = counterion), which was confirmed by single-crystal X-ray structure determination and electrospray ionization mass spectrometry (ESI-MS). X-ray crystallographic analysis indicated that [Ag13Cu10(SAdm)12]X3 consisted of an icosahedral Ag13 core, covered by a cage-like shell of Cu10(SAdm)12. Furthermore, density functional theory (DFT) and time-dependent DFT (TD-DFT) calculations on the geometric and electronic structures and KS orbitals and UV-vis spectroscopy were performed on the model [Ag13Cu10(SMe)12]3+ and its monometallic analog [Ag23(SMe)12]3+. This work will deepen the understanding of core-shell Ag-Cu alloy nanoclusters.We have developed an efficient protocol using our two-layer Molecules-in-Molecules (MIM2) fragmentation-based quantum chemical method for the prediction of NMR chemical shifts of large biomolecules. To investigate the performance of our fragmentation approach and demonstrate its applicability, MIM-NMR calculations are first calibrated on a test set of six proteins. The MIM2-NMR method yields a mean absolute deviation (MAD) from unfragmented full molecule calculations of 0.01 ppm for 1H and 0.06 ppm for 13C chemical shifts. Thus, the errors from fragmentation are only about 3% of our target accuracy of ∼0.3 ppm for 1H and 2-3 ppm for 13C chemical shifts. To compare with experimental chemical shifts, a standard protocol is first derived using two smaller proteins 2LHY (176 atoms) and 2LI1 (146 atoms) for obtaining an appropriate protein structure for NMR chemical shift calculations. The effect of the solvent environment on the calculated NMR chemical shifts is incorporated through implicit, explicit, or explicit-implicit solvation models.
The regioselectivity of the C-H activation of 1-butanol and 1-methoxybutane by an iridium(iii) phenanthroline complex was studied in the gas phase and revealed activation at gamma and delta carbons. In the ether, nearly exclusive gamma activation was observed. DFT calculations were used to explore the origin of this substrate-driven selectivity. The data show that the iridium(iii) complex is a potent and potentially highly selective remote C-H activation agent.A systematic investigation of the experimental conditions for the chemical exfoliation of MoS2 using n-butyllithium as intercalating agent has been carried out to unravel the effect of reaction time and temperature for maximizing the percentage of monolayer thick-flakes and achieve a control over the content of metallic 1T vs. semiconductive 2H phases, thereby tuning the electrical properties of ultrathin MoS2 few-layer thick films.Asia Pacific (AP) is the largest regional vehicle market and accounted for 48% of global sales in 2019. Air quality is a pressing issue in many AP countries and together with increased vehicle sales has led to intense scrutiny of vehicle emissions. The heterogeneity of socio-economic features and transportation patterns in AP countries has resulted in different emission levels and control policies. We present an assessment of the historical and future emissions of on-road transportation and strategies to tackle emission challenges. First, we collected historical country-level population, economic development, vehicle ownership, and transportation policy data from 1900 to 2020, and forecast future development of on-road transportation activity (both passenger and freight) based on its historical relationship with socio-economic development through 2050. We considered major countries (China, India, Japan, South Korea, Australia) individually and other AP countries as a group. Second, we generated a series of em and new technologies are adopted according to national plans, road transportation GHG emissions in AP peak in approximately 2040.Photoactivatable diazidodihydroxido Pt(iv) complex trans,trans,trans-[Pt(N3)2(OH)2(py)2] (1; py = pyridine) is a promising anticancer agent which can be activated by visible light to induce cancer cell death. DNA has been thought to be involved in the mechanism of action of this kind of Pt(iv) prodrug. However, the detailed photodecomposition pathways of complex 1 and its interaction modes with DNA are complex. https://www.selleckchem.com/products/ferrostatin-1.html Herein we report that upon light irradiation complex 1 can bind to all four nucleosides covalently with the reduced Pt(ii) species. Moreover, apart from the covalent coordination, various oxidation adducts of these four nucleosides induced by the reactive oxidative species (ROS) generated during the photoactivation of the complex 1 have also been identified, especially the induced oxidation of adenosine and cytidine which was firstly reported for this kind of photoactivatable Pt(iv) prodrug. Such dual-action may contribute to the highly potent photo-antiproliferativity of complex 1 towards cancer cells, which may account for the unique mechanism of action of the photoactivatable diazido Pt(iv) anticancer complexes.As a new antiperovskite nitride, ZnFe3N was synthesized and characterized by almost completely substituting iron atoms at corner positions of γ'-Fe4N. The magnetic interactions of the system with the space group Pm3[combining macron]m are fully investigated. The critical behavior was investigated based on the measured magnetic data around the ferromagnetic phase transition temperature. In this work, the values of critical exponents (β, γ and δ) were obtained systematically using the Kouvel-Fisher method in the critical region. The Widom scaling law (δ = 1 + γβ-1) and the scaling equation (m = f±(h)) were used to reveal the reliability of these values. The values of the critical exponents (β = 0.325, γ = 1.228, and δ = 4.778) are different from those predicted by the three-dimensional (3D) Heisenberg model and mean-field model, and are very close to those of the 3D-Ising model. Combined with ESR analysis, the spin clusters induced by changes in chemical bonds are considered to be the cause for the existence of an anisotropic short-range ordered state in this ferromagnetic system.Chiral α-hydroxy-β-lactams are key fragments of many bioactive compounds and antibiotics, and the development of efficient synthetic methods for these compounds is of great value. The highly enantioselective dynamic kinetic resolution (DKR) of α-keto-β-lactams was realized via a novel proton shuttling strategy. A wide range of α-keto-β-lactams were reduced efficiently and enantioselectively by Ni-catalyzed asymmetric hydrogenation, providing the corresponding α-hydroxy-β-lactam derivatives with high yields and enantioselectivities (up to 92% yield, up to 94% ee). Deuterium-labelling experiments indicate that phenylphosphinic acid plays a pivotal role in the DKR of α-keto-β-lactams by promoting the enolization process. The synthetic potential of this protocol was demonstrated by its application in the synthesis of a key intermediate of Taxol and (+)-epi-Cytoxazone.Herein, we report the synthesis and total structure of a Cu-rich alloy nanocluster protected by twelve adamantanethiolate ligands, i.e., [Ag13Cu10(SAdm)12]X3 (-SAdm = SC10H15, X = counterion), which was confirmed by single-crystal X-ray structure determination and electrospray ionization mass spectrometry (ESI-MS). X-ray crystallographic analysis indicated that [Ag13Cu10(SAdm)12]X3 consisted of an icosahedral Ag13 core, covered by a cage-like shell of Cu10(SAdm)12. Furthermore, density functional theory (DFT) and time-dependent DFT (TD-DFT) calculations on the geometric and electronic structures and KS orbitals and UV-vis spectroscopy were performed on the model [Ag13Cu10(SMe)12]3+ and its monometallic analog [Ag23(SMe)12]3+. This work will deepen the understanding of core-shell Ag-Cu alloy nanoclusters.We have developed an efficient protocol using our two-layer Molecules-in-Molecules (MIM2) fragmentation-based quantum chemical method for the prediction of NMR chemical shifts of large biomolecules. To investigate the performance of our fragmentation approach and demonstrate its applicability, MIM-NMR calculations are first calibrated on a test set of six proteins. The MIM2-NMR method yields a mean absolute deviation (MAD) from unfragmented full molecule calculations of 0.01 ppm for 1H and 0.06 ppm for 13C chemical shifts. Thus, the errors from fragmentation are only about 3% of our target accuracy of ∼0.3 ppm for 1H and 2-3 ppm for 13C chemical shifts. To compare with experimental chemical shifts, a standard protocol is first derived using two smaller proteins 2LHY (176 atoms) and 2LI1 (146 atoms) for obtaining an appropriate protein structure for NMR chemical shift calculations. The effect of the solvent environment on the calculated NMR chemical shifts is incorporated through implicit, explicit, or explicit-implicit solvation models.
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