Metal–organic layers stabilize earth-abundant metal–terpyridine diradical complexes for catalytic C–H activation

Metal–organic layers stabilize Fe II or Co II -terpyridine diradical complexes to catalyze alkylazide C sp3 –H amination and benzylic C–H borylation, respectively

Global, regional, and national incidence, prevalence, and years lived with disability for 354 diseases and injuries for 195 countries and territories, 1990–2017: A systematic analysis for the Global Burden of Disease Study 2017

Background: The Global Burden of Diseases, Injuries, and Risk Factors Study 2017 (GBD 2017) includes a comprehensive assessment of incidence, prevalence, and years lived with disability (YLDs) for 354 causes in 195 countries and territories from 1990 to 2017. Previous GBD studies have shown how the decline of mortality rates from 1990 to 2016 has led to an increase in life expectancy, an ageing global population, and an expansion of the non-fatal burden of disease and injury. These studies have also shown how a substantial portion of the world's population experiences non-fatal health loss with considerable heterogeneity among different causes, locations, ages, and sexes. Ongoing objectives of the GBD study include increasing the level of estimation detail, improving analytical strategies, and increasing the amount of high-quality data. Methods: We estimated incidence and prevalence for 354 diseases and injuries and 3484 sequelae. We used an updated and extensive body of literature studies, survey data, surveillance data, inpatient admission records, outpatient visit records, and health insurance claims, and additionally used results from cause of death models to inform estimates using a total of 68 781 data sources. Newly available clinical data from India, Iran, Japan, Jordan, Nepal, China, Brazil, Norway, and Italy were incorporated, as well as updated claims data from the USA and new claims data from Taiwan (province of China) and Singapore. We used DisMod-MR 2.1, a Bayesian meta-regression tool, as the main method of estimation, ensuring consistency between rates of incidence, prevalence, remission, and cause of death for each condition. YLDs were estimated as the product of a prevalence estimate and a disability weight for health states of each mutually exclusive sequela, adjusted for comorbidity. We updated the Socio-demographic Index (SDI), a summary development indicator of income per capita, years of schooling, and total fertility rate. Additionally, we calculated differences between male and female YLDs to identify divergent trends across sexes. GBD 2017 complies with the Guidelines for Accurate and Transparent Health Estimates Reporting. Findings: Globally, for females, the causes with the greatest age-standardised prevalence were oral disorders, headache disorders, and haemoglobinopathies and haemolytic anaemias in both 1990 and 2017. For males, the causes with the greatest age-standardised prevalence were oral disorders, headache disorders, and tuberculosis including latent tuberculosis infection in both 1990 and 2017. In terms of YLDs, low back pain, headache disorders, and dietary iron deficiency were the leading Level 3 causes of YLD counts in 1990, whereas low back pain, headache disorders, and depressive disorders were the leading causes in 2017 for both sexes combined. All-cause age-standardised YLD rates decreased by 3·9% (95% uncertainty interval [UI] 3·1-4·6) from 1990 to 2017; however, the all-age YLD rate increased by 7·2% (6·0-8·4) while the total sum of global YLDs increased from 562 million (421-723) to 853 million (642-1100). The increases for males and females were similar, with increases in all-age YLD rates of 7·9% (6·6-9·2) for males and 6·5% (5·4-7·7) for females. We found significant differences between males and females in terms of age-standardised prevalence estimates for multiple causes. The causes with the greatest relative differences between sexes in 2017 included substance use disorders (3018 cases [95% UI 2782-3252] per 100 000 in males vs 1400 [1279-1524] per 100 000 in females), transport injuries (3322 [3082-3583] vs 2336 [2154-2535]), and self-harm and interpersonal violence (3265 [2943-3630] vs 5643 [5057-6302]). Interpretation: Global all-cause age-standardised YLD rates have improved only slightly over a period spanning nearly three decades. However, the magnitude of the non-fatal disease burden has expanded globally, with increasing numbers of people who have a wide spectrum of conditions. A subset of conditions has remained globally pervasive since 1990, whereas other conditions have displayed more dynamic trends, with different ages, sexes, and geographies across the globe experiencing varying burdens and trends of health loss. This study emphasises how global improvements in premature mortality for select conditions have led to older populations with complex and potentially expensive diseases, yet also highlights global achievements in certain domains of disease and injury

Global, regional, and national age-sex-specific mortality and life expectancy, 1950-2017: a systematic analysis for the Global Burden of Disease Study 2017

Background: Assessments of age-specific mortality and life expectancy have been done by the UN Population Division, Department of Economics and Social Affairs (UNPOP), the United States Census Bureau, WHO, and as part of previous iterations of the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD). Previous iterations of the GBD used population estimates from UNPOP, which were not derived in a way that was internally consistent with the estimates of the numbers of deaths in the GBD. The present iteration of the GBD, GBD 2017, improves on previous assessments and provides timely estimates of the mortality experience of populations globally. Methods: The GBD uses all available data to produce estimates of mortality rates between 1950 and 2017 for 23 age groups, both sexes, and 918 locations, including 195 countries and territories and subnational locations for 16 countries. Data used include vital registration systems, sample registration systems, household surveys (complete birth histories, summary birth histories, sibling histories), censuses (summary birth histories, household deaths), and Demographic Surveillance Sites. In total, this analysis used 8259 data sources. Estimates of the probability of death between birth and the age of 5 years and between ages 15 and 60 years are generated and then input into a model life table system to produce complete life tables for all locations and years. Fatal discontinuities and mortality due to HIV/AIDS are analysed separately and then incorporated into the estimation. We analyse the relationship between age-specific mortality and development status using the Socio-demographic Index, a composite measure based on fertility under the age of 25 years, education, and income. There are four main methodological improvements in GBD 2017 compared with GBD 2016: 622 additional data sources have been incorporated; new estimates of population, generated by the GBD study, are used; statistical methods used in different components of the analysis have been further standardised and improved; and the analysis has been extended backwards in time by two decades to start in 1950. Findings: Globally, 18·7% (95% uncertainty interval 18·4–19·0) of deaths were registered in 1950 and that proportion has been steadily increasing since, with 58·8% (58·2–59·3) of all deaths being registered in 2015. At the global level, between 1950 and 2017, life expectancy increased from 48·1 years (46·5–49·6) to 70·5 years (70·1–70·8) for men and from 52·9 years (51·7–54·0) to 75·6 years (75·3–75·9) for women. Despite this overall progress, there remains substantial variation in life expectancy at birth in 2017, which ranges from 49·1 years (46·5–51·7) for men in the Central African Republic to 87·6 years (86·9–88·1) among women in Singapore. The greatest progress across age groups was for children younger than 5 years; under-5 mortality dropped from 216·0 deaths (196·3–238·1) per 1000 livebirths in 1950 to 38·9 deaths (35·6–42·83) per 1000 livebirths in 2017, with huge reductions across countries. Nevertheless, there were still 5·4 million (5·2–5·6) deaths among children younger than 5 years in the world in 2017. Progress has been less pronounced and more variable for adults, especially for adult males, who had stagnant or increasing mortality rates in several countries. The gap between male and female life expectancy between 1950 and 2017, while relatively stable at the global level, shows distinctive patterns across super-regions and has consistently been the largest in central Europe, eastern Europe, and central Asia, and smallest in south Asia. Performance was also variable across countries and time in observed mortality rates compared with those expected on the basis of development. Interpretation: This analysis of age-sex-specific mortality shows that there are remarkably complex patterns in population mortality across countries. The findings of this study highlight global successes, such as the large decline in under-5 mortality, which reflects significant local, national, and global commitment and investment over several decades. However, they also bring attention to mortality patterns that are a cause for concern, particularly among adult men and, to a lesser extent, women, whose mortality rates have stagnated in many countries over the time period of this study, and in some cases are increasing

Methanol Oxidation to Formate on ALD-Prepared VO_<i>x</i>/θ-Al₂O₃ Catalysts: A Mechanistic Study

Well-defined supported VO_<i>x</i>/θ-Al₂O₃ catalysts were prepared by atomic layer deposition (ALD) with vanadium coverages of 0.48, 1.20, and 3.40 wt %. In-situ Raman and UV–vis diffuse reflectance spectroscopy confirm that the monovanadate, VO₄, is the predominant vanadium species at low loadings (0.48 and 1.20 wt %), while polyvanadate VO₄ is the predominant vanadium species for the 3.40 wt % VO_<i>x</i>/θ-Al₂O₃ catalyst. In-situ FTIR spectroscopy of methanol oxidation to formate, in the absence of gas-phase oxygen, on the 0.48 wt % VO_<i>x</i>/θ-Al₂O₃, identified two different formates. A comparison of the frequencies for the formates adsorbed on just V₂O₅ and on just θ-Al₂O₃ demonstrates that one of these formates is located on aluminum sites of VO_<i>x</i>/θ-Al₂O₃ while the other is located on vanadium sites. The oxidation state of vanadium for the VO_<i>x</i>/θ-Al₂O₃ catalyst was determined by XPS after different reaction times. On the basis of the time dependence of the formate absorptions and the change in the oxidation state of vanadium in VO_<i>x</i>/θ-Al₂O₃, a mechanism is proposed for methanol oxidation and we discuss the role of the alumina support in the mechanism

Tuning Lewis Acidity of Metal–Organic Frameworks via Perfluorination of Bridging Ligands: Spectroscopic, Theoretical, and Catalytic Studies

The Lewis acidity of metal–organic frameworks (MOFs) has attracted much research interest in recent years. We report here the development of two quantitative methods for determining the Lewis acidity of MOFsbased on electron paramagnetic resonance (EPR) spectroscopy of MOF-bound superoxide (O₂^•–) and fluorescence spectroscopy of MOF-bound <i>N</i>-methylacridone (NMA)and a simple strategy that significantly enhances MOF Lewis acidity through ligand perfluorination. Two new perfluorinated MOFs, Zr₆-fBDC and Zr₆-fBPDC, where H₂fBDC is 2,3,5,6-tetrafluoro-1,4-benzenedicarboxylic acid and H₂fBPDC is 2,2′,3,3′,5,5′,6,6′-octafluoro-4,4′-biphenyldicarboxylic acid, were shown to be significantly more Lewis acidic than nonsubstituted UiO-66 and UiO-67 as well as the nitrated MOFs Zr₆-BDC-NO₂ and Zr₆-BPDC-(NO₂)₂. Zr₆-fBDC was shown to be a highly active single-site solid Lewis acid catalyst for Diels–Alder and arene C–H iodination reactions. Thus, this work establishes the important role of ligand perfluorination in enhancing MOF Lewis acidity and the potential of designing highly Lewis acidic MOFs for fine chemical synthesis

Tuning Lewis Acidity of Metal–Organic Frameworks via Perfluorination of Bridging Ligands: Spectroscopic, Theoretical, and Catalytic Studies

The Lewis acidity of metal–organic frameworks (MOFs) has attracted much research interest in recent years. We report here the development of two quantitative methods for determining the Lewis acidity of MOFsbased on electron paramagnetic resonance (EPR) spectroscopy of MOF-bound superoxide (O₂^•–) and fluorescence spectroscopy of MOF-bound <i>N</i>-methylacridone (NMA)and a simple strategy that significantly enhances MOF Lewis acidity through ligand perfluorination. Two new perfluorinated MOFs, Zr₆-fBDC and Zr₆-fBPDC, where H₂fBDC is 2,3,5,6-tetrafluoro-1,4-benzenedicarboxylic acid and H₂fBPDC is 2,2′,3,3′,5,5′,6,6′-octafluoro-4,4′-biphenyldicarboxylic acid, were shown to be significantly more Lewis acidic than nonsubstituted UiO-66 and UiO-67 as well as the nitrated MOFs Zr₆-BDC-NO₂ and Zr₆-BPDC-(NO₂)₂. Zr₆-fBDC was shown to be a highly active single-site solid Lewis acid catalyst for Diels–Alder and arene C–H iodination reactions. Thus, this work establishes the important role of ligand perfluorination in enhancing MOF Lewis acidity and the potential of designing highly Lewis acidic MOFs for fine chemical synthesis

Titanium(III)-Oxo Clusters in a Metal–Organic Framework Support Single-Site Co(II)-Hydride Catalysts for Arene Hydrogenation

Titania (TiO₂) is widely used in the chemical industry as an efficacious catalyst support, benefiting from its unique strong metal–support interaction. Many proposals have been made to rationalize this effect at the macroscopic level, yet the underlying molecular mechanism is not understood due to the presence of multiple catalytic species on the TiO₂ surface. This challenge can be addressed with metal–organic frameworks (MOFs) featuring well-defined metal oxo/hydroxo clusters for supporting single-site catalysts. Herein we report that the Ti₈(μ₂-O)₈(μ₂-OH)₄ node of the Ti-BDC MOF (MIL-125) provides a single-site model of the classical TiO₂ support to enable Co^II-hydride-catalyzed arene hydrogenation. The catalytic activity of the supported Co^II-hydride is strongly dependent on the reduction of the Ti-oxo cluster, definitively proving the pivotal role of Ti^III in the performance of the supported catalyst. This work thus provides a molecularly precise model of Ti-oxo clusters for understating the strong metal–support interaction of TiO₂-supported heterogeneous catalysts

Atomic-Scale View of VO_X–WO_X Coreduction on the α‑Al₂O₃ (0001) Surface

The catalytic activity of oxide-supported vanadium oxide is improved by the presence of tungsten oxide for the selective catalytic reduction of nitric oxides. We propose a mechanism for V–W synergy through studies of the reduction–oxidation behavior of near-monolayer VO_X and WO_X species grown by atomic layer deposition on the α-Al₂O₃ (0001) single crystal surface. <i>In situ</i> X-ray standing wave measurements reveal an overlayer of W⁶⁺ species that is correlated with the substrate lattice as well as a redox-reversible shift from uncorrelated V⁵⁺ to correlated V⁴⁺. X-ray photoelectron spectroscopy and electronic structure calculations show a partial reduction of W⁶⁺ in the presence of V⁴⁺, improving the Brønsted acidity in mixed V–W catalyst systems. This mechanism of V–W synergy suggests that control of W d-states might be used as a design parameter for Brønsted acid sites in multicomponent oxide catalysts