The group 1 alumanyls, [{SiN}AlM] (M = K, Rb, Cs; SiN = {CHSiMeNDipp}), display a variable kinetic facility (K < Rb < Cs) toward oxidative addition of the acidic C-H bond of terminal alkynes to provide the corresponding alkali metal hydrido(alkynyl)aluminate derivatives. Theoretical analysis of the formation of these compounds through density functional theory (DFT) calculations implies that the experimentally observed changes in reaction rate are a consequence of the variable stability of the [{SiN}AlM] dimers, the integrity of which reflects the ability of M to maintain the polyhapto group 1-arene interactions necessary for dimer propagation. These observations highlight that such "on-dimer" reactivity takes place sequentially and also that the ability of each constituent Al(I) center to effect the activation of the organic substrate is kinetically differentiated.
View Article and Find Full Text PDFSpatial hearing relies on the encoding of perceptual sound location cues in space. It is critical for communicating in background noise, and understanding where sounds are coming from (sound localization). Although there are some monoaural spatial hearing cues (i.
View Article and Find Full Text PDFReactions of a m-terphenylhydridostannylene with β-diketiminato magnesium and calcium hydrides provide bis-μ-hydrido species, the heterobimetallic constitutions of which are maintained after the addition of THF donor solvent. In both cases, reactions with hex-1-ene result in the formation of tetravalent organostannyl alkaline earth derivatives. Whereas the magnesium reagent undergoes facile twofold addition, the calcium-centered process is arrested after a single alkene reduction event.
View Article and Find Full Text PDFThe dimeric calcium and magnesium hydrides, [(BDI)AeH] [BDI=HC{(Me)CNDipp}, Dipp=2,6-i-PrCH; Ae=Mg or Ca] do not react with PhGeH in non-coordinating solvent. Addition of THF, however, induces deprotonation and access to monomeric Ae-germanide complexes, [(BDI)Ae{GePh}(THF)], both of which have been structurally characterized. Although this process is facile when Ae=Ca, the analogous magnesium-based reaction requires heating to temperatures >100 °C, under which conditions germanide formation is complicated by THF ring opening and the generation of an alkaline earth germyl-C-terminated n-butoxide, [(BDI)Mg{μ-O(CH)GePh}].
View Article and Find Full Text PDFThe reaction of [Ir(IPr)H][BAr] (; IPr = 1,3-bis(2,6-diisopropylphenyl)imidazol-2-ylidene; BAr = B{CH(3,5-CF)}) with ZnMe proceeds with CH elimination to give [Ir(IPr)(IPr')(ZnMe)H][BAr] (, where (IPr') is a cyclometalated IPr ligand). reacts with H to form tetrahydride [Ir(IPr)(ZnMe)H][BAr], , that loses H under forcing conditions to form [Ir(IPr)(ZnMe)H][BAr], . Crystallization of also results in the formation of its noncyclometalated isomer, [Ir(IPr)(ZnMe)][BAr], , in the solid state.
View Article and Find Full Text PDFIntroduction: Despite proven effectiveness in refractory schizophrenia, clozapine remains underutilised, and it is important to understand potential reasons for this. This study's aim was to examine in a National sample of Consultant Psychiatrists their knowledge of, attitudes and perceived barriers to clozapine use.
Methods: A novel questionnaire was designed and distributed by email to 275 Consultant Psychiatrists in Republic of Ireland.
Organometallics
September 2024
The behavior of the potassium alumanyl, [{SiN}AlK] ({SiN} = {CHSiMeN(Dipp)}; Dipp = 2,6--PrCH), toward organic nitriles has been investigated. In common with earlier studies of the reactivity of charge neutral Al(I) species with multiply bonded small molecules, it is suggested that the initial step in all the reactions involves [2 + 1] cycloaddition and the generation of an [η-C=N-Al] alumina azacyclopropane unit. In the cases of - and -tolyl-substituted aryl nitriles, this species is too kinetically labile to allow its isolation and undergoes C-C coupling via immediate Al-C/C≡N insertion to yield the alumina diazabutadiene derivatives.
View Article and Find Full Text PDFRange maps are used to estimate the geographic extent of taxa, providing valuable information for biodiversity and conservation research and management. Freshwater macroinvertebrates are not well-represented in the range map literature relative to freshwater vertebrates. To address this knowledge gap, we provide range maps for 1158 freshwater macroinvertebrate genera based on two decades of publicly available occurrence data from the USEPA National Aquatic Resource Surveys, which included 11,628 sites and 6,906,990 organisms across the contiguous USA.
View Article and Find Full Text PDF[{SiN}BeClM] ({SiN} = {CHSiMeN(Dipp)}; M = Li, Na, K, Rb) are converted to ionic species by treatment with a crown ether. Whereas the lithium derivative reacts with Na or K to provide [{SiN}BeCl][M(12-cr-4)] (M = Na, K), the resultant sodium species is resistant to reduction by potassium. These observations are rationalised by a hybrid experimental/theoretical analysis.
View Article and Find Full Text PDFCycle threshold (CT) refers to the number of cycles in a reverse transcriptase polymerase chain reaction (RT-PCR) assay needed to amplify viral RNA and can be used to indicate viral load. CT is inversely related to viral load, where lower CT values indicate higher viral levels. Data suggest lower CT scores are associated with worse outcomes in COVID; however, quantitative CT scores are not typically reported to patients.
View Article and Find Full Text PDFWe asked whether grammatical number marking has specific influence on the formation of early number concepts. In particular, does comprehension of dual case marking support young children's understanding of cardinality? We assessed number knowledge in 77 3-year-old Arabic-English bilingual children using the Give-a-Number task in both languages. Given recent concerns around the administration and scoring of the Give-a-Number task, we used two complementary approaches: one based on conceptual levels and the other based on overall test scores.
View Article and Find Full Text PDFSmall-cell lung cancer (SCLC) is the most fatal form of lung cancer. Intratumoral heterogeneity, marked by neuroendocrine (NE) and non-neuroendocrine (non-NE) cell states, defines SCLC, but the cell-extrinsic drivers of SCLC plasticity are poorly understood. To map the landscape of SCLC tumor microenvironment (TME), we apply spatially resolved transcriptomics and quantitative mass spectrometry-based proteomics to metastatic SCLC tumors obtained via rapid autopsy.
View Article and Find Full Text PDFProstate cancer lung metastasis represents a clinical conundrum due to its implications for advanced disease progression and the complexities it introduces in treatment planning. As the disease progresses to distant sites such as the lung, the clinical management becomes increasingly intricate, requiring tailored therapeutic strategies to address the unique characteristics of metastatic lesions. This review seeks to synthesize the current state of knowledge surrounding prostate cancer metastasis to the lung, shedding light on the diverse array of clinical presentations encountered, ranging from subtle radiological findings to overt symptomatic manifestations.
View Article and Find Full Text PDFReactions of β-diketiminato alkaline earth alkyldiboranate derivatives [(BDI)Ae{pinBB(R)pin}] (BDI = HC{(Me)CNDipp}; Dipp = 2,6-i-PrCH; Ae = Mg, R = -Bu or Ae = Ca, R = -hexyl) with -BuNC provide access to the respective group 2 derivatives of unprecedented diborata-allyl, {(pinB)CNBpin(-Bu)}, anions. Although the necessary mode of B-C bond cleavage implicated in these transformations could not be elucidated, further studies of the reactivity of magnesium triboranates toward isonitriles delivered a more general and rational synthetic access to analogous anionic moieties. Extending this latter reactivity to a less symmetric triboranate variant also provided an isomeric Mg-C-bonded dibora-alkyl species and sufficient experimental insight to prompt theoretical evaluation of this reactivity.
View Article and Find Full Text PDFAnthropogenic change is contributing to the rise in emerging infectious diseases, which are significantly correlated with socioeconomic, environmental and ecological factors. Studies have shown that infectious disease risk is modified by changes to biodiversity, climate change, chemical pollution, landscape transformations and species introductions. However, it remains unclear which global change drivers most increase disease and under what contexts.
View Article and Find Full Text PDFThe bimetallic species, [{SiN}MgNa] [{SiN} = {CHSiMeN(Dipp)}; (Dipp = 2,6--PrCH)], is shown to be a potent reducing agent, able to effect one- or two-electron reduction of either dioxygen, TEMPO, anthracene, benzophenone, or diphenylacetylene. In most cases, the bimetallic reaction products imply that the dissimilar alkaline metal centers react with a level of cooperativity. EPR analysis of the benzophenone-derived reaction and the concurrent isolation of [{SiN}Mg(OCPh)], however, illustrate that treatment with such reducible, but -basic, species can also result in reactivity in which the metals provide independent reaction products.
View Article and Find Full Text PDFJ Pediatr Gastroenterol Nutr
May 2024
Unsedated transnasal endoscopy (TNE) is an alternative method of examining the esophageal mucosa in pediatric patients with eosinophilic esophagitis (EoE), reducing cost, time, and risk associated with frequent surveillance esophagogastroduodenoscopies (EGD). Adequacy of transnasal esophageal biopsies for the evaluation of eosinophilic esophagitis histologic scoring system (EoEHSS) has not yet been evaluated. We compared procedure times, endoscopic findings, and EoEHSS scoring for EoE patients undergoing TNE versus standard EGD.
View Article and Find Full Text PDFLiquid assisted ball milling of [NHC]HBr (NHC = N-heterocyclic carbene) salts with copper(I) chloride, and a range of alkali metal complexes was shown to efficiently produce (NHC)CuX (NHC = normal or RE-NHC, X = halide, alkoxide, amide, alkyl, aryl; RE-NHC = ring-expanded NHC).
View Article and Find Full Text PDFRoom temperature reaction of elemental cesium with the dimeric lithium chloroberyllate [{SiN}BeClLi] [{SiN} = {CHSiMeN(Dipp)}, where Dipp = 2,6-di-isopropylphenyl, in CD results in activation of the arene solvent. Although, in contrast to earlier observations of lithium and sodium metal reduction, the generation of a mooted cesium phenylberyllate could not be confirmed, this process corroborates a previous hypothesis that such beryllium-centered solvent activation also necessitates the formation of hydridoberyllium species. These observations are further borne out by the study of an analogous reaction performed in toluene, in which case the proposed generation of formally low oxidation state beryllium radical anion intermediates induces activation of a toluene C-H bond and the isolation of the polymeric cesium benzylberyllate, [Cs({SiN}BeCHCH)].
View Article and Find Full Text PDFDeprotonation of triphenyl germane with NHC-supported copper alkoxides afforded four novel (NHC)CuGePh complexes. Of these, (IPr)CuGePh (IPr = :C{N(2,6-iPrCH)CH}) was selected for further investigation. Analysis by EDA-NOCV indicates it to be a germyl nucleophile and its σ-bond metathesis reaction with a range of p-block halides confirmed it to be a convenient source of [PhGe].
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