Iron cyanide compounds are among the oldest known synthetic coordination compounds, dating back to the early 18 century. By contrast, iron complexes of the cyaphide ion (C≡P)─a heavy valence isoelectronic analog of the cyanide ion─are unknown. Herein we report the synthesis of highly stable mono- and bis-cyaphide complexes of iron(II), namely Fe(depe)(Cl)(CP) and Fe(depe)(CP) (depe = 1,2-bis(diethylphosphino)ethane).
View Article and Find Full Text PDFHydrogenations are fundamentally and industrially important reactions that are atom economical paths to synthesize value-added products from feedstock chemicals. The cooperative effects of two or more metal centers in multimetallic active sites is a successful strategy to activate small molecules and facilitate catalytic reactions, and this strategy has been recently applied to catalytic hydrogenation reactions. Furthermore, heterobimetallic complexes have been well-documented to provide novel reaction pathways and improved selectivity, compared to their homo-bimetallic and monometallic analogues.
View Article and Find Full Text PDFHeterobimetallic complexes are studied for their ability to mimic biological systems as well as active sites in heterogeneous catalysts. While specific interest in early/late heterobimetallic systems has fluctuated, they serve as important models to fundamentally understand metal-metal bonding. Specifically, the polarized metal-metal multiple bonds formed in highly reduced early/late heterobimetallic complexes exemplify how each metal modulates the electronic environment and reactivity of the complex as a whole.
View Article and Find Full Text PDFRedox-active ligands improve the reactivity of transition metal complexes by facilitating redox processes independent of the transition metal center. A tetradentate square planar (PNCHCHNP)Co (1) complex was synthesized and the ethylene backbone was dehydrogenated through hydrogen atom abstraction to afford (PNCHCHNP)Co (2), which now contains a redox-active ligand. The ligand backbone of 2 can be readily hydrogenated with H to regenerate 1.
View Article and Find Full Text PDFHere we report the synthesis and characterization of diiron complexes containing triaryl N and NS ligands derived from -phenylenediamine. The complexes display significant differences in Fe-Fe distances and magnetic properties that depend on the identity of the flanking NMe and SMe donor groups.
View Article and Find Full Text PDFAims: In October 2023, the Tennessee Department of Health identified an outbreak of Shiga toxin-producing Escherichia coli (STEC) O157:H7 infections among elementary school students who attended school field trips to the same farm animal exhibit. Our aim was to determine STEC source and prevent additional illnesses by initiating epidemiologic, laboratory and environmental investigations.
Methods And Results: We identified cases using laboratory-based surveillance and by surveying caregivers of children who attended the exhibit.
Background: Respiratory syncytial virus (RSV) can cause hospitalization in young children and older adults. With vaccines and monoclonal antibody prophylaxis increasingly available, identifying social factors associated with severe illnesses can guide mitigation efforts.
Methods: Using data collected by the RSV Hospitalization Surveillance Network from 2016 to 2023, we identified RSV hospitalizations in Tennessee.
A tetradentate bis(amido)bis(phosphine) Fe complex, (PNNP)Fe, is shown to activate the terminal C-H bond of aryl alkynes across its Fe-N bonds. (PNNP)Fe is also shown to catalytically dimerize terminal aryl alkynes to produce 1,3-enynes with : ratios as high as 96 : 4 with yields up to 95% and loadings as low as 1 mol% at 30 °C in 2 h. A plausible metal-ligand cooperative mechanism invoking a vinylidene intermediate is proposed.
View Article and Find Full Text PDFSyndromic polymerase chain reaction (PCR) panels are used to test for pathogens that can cause rash illnesses, including measles. Rash illnesses have infectious and noninfectious causes, and approximately 5% of persons experience a rash 7-10 days after receipt of a measles, mumps, and rubella (MMR) vaccine. MMR vaccine includes live attenuated measles virus, which is detectable by PCR tests.
View Article and Find Full Text PDFObjectives: Mpox surveillance was integral during the 2022 outbreak response. We evaluated implementation of mpox surveillance in Tennessee during an outbreak response and made recommendations for surveillance during emerging infectious disease outbreaks.
Methods: To understand surveillance implementation, system processes, and areas for improvement, we conducted 8 semistructured focus groups and 7 interviews with 36 health care, laboratory, and health department representatives during September 9-20, 2022.
The COVID-19 pandemic has disproportionately impacted migrant farmworkers (MFWs). MFWs have experienced higher rates of infection and death than any other occupational group in the United States due to workplace exposure risks, overcrowded housing, and limited access to personal protective equipment. Barriers to accessing COVID-19 vaccines have also contributed to these disparities, especially in rural areas where the pandemic's impact has been devastating.
View Article and Find Full Text PDFThe bonding interactions of a synthesized pincer-ligated manganese dicarbonyl complex featuring an N-heterocyclic phosphenium (NHP) central moiety are explored. The pincer ligand [PPP]Cl was coordinated to a manganese center using Mn(CO)Br and 254 nm light to afford the chlorophosphine complex (PPP)Mn(CO)Br () as a mixture of halide exchange products and stereoisomers. The target dicarbonyl species (PPP)Mn(CO) () was prepared by treatment of with 2 equiv of the reductant KC.
View Article and Find Full Text PDFEffective provision of COVID-19 vaccines could mitigate the disproportionate impact of the COVID-19 pandemic experienced by many immigrant communities. To describe organizational experiences in using COVID-19 vaccination programs, qualitative interviews were conducted from September 2020 to April 2021 with representatives from public health, health system, and community organizations responding to the COVID-19 pandemic among immigrant communities across the United States. Interviews followed a semistructured interview guide and were audio recorded, transcribed, and coded.
View Article and Find Full Text PDFMMWR Morb Mortal Wkly Rep
January 2023
Influenza seasons typically begin in October and peak between December and February (1); however, the 2022-23 influenza season in Tennessee began in late September and was characterized by high pediatric hospitalization rates during November. This report describes a field investigation conducted in Tennessee during November 2022, following reports of increasing influenza hospitalizations. Data from surveillance networks, patient surveys, and whole genome sequencing of influenza virus specimens were analyzed to assess influenza activity and secondary illness risk.
View Article and Find Full Text PDFA single bridging phosphinoamide ligand was shown to support a metal-metal triple bond in a Zr/Co heterobimetallic complex. The similarity of the bonding in this compound to previously synthesized Zr/Co species, and therefore the assignment of the Zr/Co triple bond, is supported by the structural parameters of the complex, the electronic structure predicted by density functional theory, and complete-active-space self-consistent-field (CASSCF) calculations. This demonstrates that metal-metal multiple bonds can be realized in heterobimetallic complexes without multiple bridging ligands to enforce the proximity of the two metals.
View Article and Find Full Text PDFDespite the utility of Si-Si bonds, there are relatively few examples of Si-Si bond formation by base metals. In this work, a four-coordinate iron complex, (PNNP)Fe, is shown to strongly activate the Si-H bonds in primary silanes across the Fe-amide bonds in a metal-ligand cooperative fashion. Upon treatment with excess silane, Si-Si dehydrogenative homocoupling is shown to occur across the Fe-N bond without concomitant oxidation and spin state changes at the Fe center.
View Article and Find Full Text PDFThe bonding interactions and electronic structure of a diphosphine pincer ligand featuring an N-heterocyclic phosphenium/phosphido (NHP) central moiety with nickel are explored. Treating Ni(COD) with the pincer ligand [PPP]Cl in the presence of a two-electron phosphine donor ligand PMe generates chlorophosphine complex (PPP)Ni(PMe) (). The cationic Ni complex [(PPP)Ni(PMe)][BPh] () can be prepared by subsequent halide abstraction from with NaBPh.
View Article and Find Full Text PDFPretransplant recommendations advise risk-based screening for strongyloidiasis, schistosomiasis, and Chagas disease. We evaluated the implementation of a chronic parasite screening protocol at a health system in a nonendemic region serving a large foreign-born population. Candidates listed for kidney transplant at Hennepin Healthcare (Minneapolis, MN) between 2010 and 2020 were included.
View Article and Find Full Text PDFFormal and informal bilingual/bicultural organizations and networks form the backbone of support for refugee, immigrant, and migrant (RIM) communities in the United States. They are pivotal in mitigating barriers and inequities in social and structural determinants of health. These organizations and networks are situated within the communities they serve, and often are established and run by members of a community, to serve the community.
View Article and Find Full Text PDFBackground: The delivery of prompt and appropriate antimicrobial therapy for life-threatening infections is an important antimicrobial stewardship measure and a priority for hospitals.
Objectives: To better understand U.S.
Intravenous artesunate has been the global standard of care for severe malaria for over 2 decades. Yet, until recently, artesunate has only been available to patients through an expanded-access protocol from the Centers for Disease Control and Prevention. In May 2020, the Food and Drug Administration approved artesunate, allowing US hospitals to stock the drug and ensuring prompt treatment for this life-threatening infection.
View Article and Find Full Text PDFBackground: Antifungal drugs treat a variety of conditions, ranging from localised dermatologic disease to life-threatening systemic infections. Some common antifungal drugs experienced large price increases in recent years, however, factors contributing to these price increases are poorly understood. We sought to examine trends in antifungal drug prices and determine underlying drivers of price changes.
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