Molecular Zr phosphides are extremely rare, with no examples containing a one-coordinated and terminal triple-bonded phosphorus atom. We report here an isolable and relatively stable Zr phosphide complex, [(PN)Zr≡P{μ-Na(OEt)}] (), stemming from a cyclometalated Zr-hydride, [(PN)(PN')Zr(H)] (), and NaPH. Complex is prepared from two- or one-electron reductions of precursors [(PN)ZrCl] () or metastable Zr[(PN)ZrCl], respectively.
View Article and Find Full Text PDFRecent studies have demonstrated that the production of bidirectional enhancer-derived transcripts (eRNAs) is a characteristic of an active Cis-regulatory element (CRE). Higher levels of eRNA synthesis correlate with the activation of histone modifications, a potentially valuable tool for deciphering the complexity of the gene regulatory network. To understand the changes of CREs during gonadal development in mice, we collected gonadal WT1-positive cells from the piggyBac-Wt1-mCherry-2A-EGFP (PBWt1-RG) reporter strain at E13.
View Article and Find Full Text PDFPhotocatalytic C-H activation is an emerging area of research. While cerium chloride photocatalysts have been extensively studied, the role of alcohol additives in these systems remains a subject of ongoing discussion. It was demonstrated that the photocatalyst [NEt][CeCl] () produces •Cl and added alcohols exhibit zero-order kinetics.
View Article and Find Full Text PDFThe reactivity of the V[triple bond, length as m-dash]C Bu multiple bonds in the complex (dBDI)V[triple bond, length as m-dash]C Bu(OEt) (C) (dBDI = ArNC(CH)CHC(CH)NAr, Ar = 2,6- PrCH) with unsaturated substrates such as N[triple bond, length as m-dash]CR (R = Ad or Ph) and P[triple bond, length as m-dash]CAd leads to the formation of rare 3d transition metal compounds featuring α-aza-vanadacyclobutadiene, (dBDI)V(κ- , - BuC(R)N) (R = Ad, 1; R = Ph, 2) and β-phospha-vanadacyclobutadiene moieties, (dBDI)V(κ- , - BuPAd) (3). Complexes 1-3 are characterized using multinuclear and multidimensional NMR spectroscopy, including the preparation of the 50% N-enriched isotopologue (dBDI)V(κ- , - BuCC(Ad)N) (1-N). Solid-state structural analysis is used to determine the dominant resonance structures of these unique pnictogen-based vanadacyclobutadienes.
View Article and Find Full Text PDFReduction of [K{(pyrrpyr)Fe}(μ-N)] (1) with two equiv. of KC in the presence of crown-ether 18-C-6 yields the N adduct [{K(18-C-6)}(pyrrpyr)Fe(N)] (2). Complex 2 heterolytically splits the C-H bond of benzene to form [{K(18-C-6)}(pyrrpyr)Fe(CH)] (3), whereby usage of a diboron Bpin promotes hydride elimination to form the salt [K(18-C-6)HBPin] (4).
View Article and Find Full Text PDFBackground: Appropriate anticoagulation is crucial for the success of left ventricular assist device patients. Currently, there is no consensus on the optimal management of their subtherapeutic INR in ambulatory setting. Our goal is to evaluate both the short-term adverse events and long-term outcomes of enoxaparin bridging at a major transplant center, following the implementation of bridging safety criteria.
View Article and Find Full Text PDFBackground: Previous research has shown that women's perceptions of their childbirth environment are critical in ensuring that they feel supported and in facilitating physiological childbirth.
Aim: To develop and validate the Perception of Childbirth Environment Scale (PCES) for expectant mothers.
Methods: The PCES was developed based on findings from a scoping review and a qualitative study on childbirth environments conducted by the authors.
Background: Appropriate weight gain reduces the risk of fetal macrosomia and large for gestational age (LGA) in women with gestational diabetes mellitus (GDM), especially in the second and third trimester. This study aims to identify the optimal weight g-ain for such women across several pre-pregnancy body mass index (BMI) categories to lower the risk of macrosomia and LGA.
Methods: This retrospective cohort study enrolled women with GDM in north Taiwan who delivered between January 2012 and July 2022.
A new triazole-based -heterocyclic carbene Ir cationic complex with a tetra-fluorido-borate counter-anion and hemi-solvating di-chloro-methane, [Ir(CH)(CHN)(CHP)]BF·0.5CHCl, has been synthesized and structurally characterized. There are two independent ion pairs in the asymmetric unit and one di-chloro-methane solvent mol-ecule per two ion pairs.
View Article and Find Full Text PDFThe use of a nonrigid, pyridyldialdimine-derived macrocyclic ligand (PDAI) enabled the synthesis of well-defined mono-, di-, tri-, and tetra-nuclear Cu(I) complexes in good yields through rational synthetic means. Starting from mono- and diargentous PDAI complexes, transmetalation to Cu(I) proceeded smoothly with formation of AgX (X = Cl, I) salts to generate mono-, di-, and trinuclear copper complexes. Monodentate supporting ligands (MeCN, xylNC, PMe, PPh) were found to either transmetallate with or bind various di- and trinuclear clusters.
View Article and Find Full Text PDFA series of titanate cisoid bis(chalcogenidos) (Ch = Te, Se, and S) complexes supported by the β-diketiminate ligand BDI = [ArNC(CH)]CH (Ar = 2,6-PrCH) are readily assembled via treatment of the Ti precursor (BDI)Ti(CHSiMe) with 2.5 equiv of elemental "Ch" source and 1 equiv of reductant in the presence of crown-ether. In the absence of the electride, Te or S addition to (BDI)Ti(CHSiMe) results instead in the isolation of a mononuclear tellurido-tellurolate [(BDI)Ti(=Te)(TeCHSiMe)] and the bridging sulfido-thiolate complex [(BDI)Ti(SCHSiMe)(μ-S)], respectively.
View Article and Find Full Text PDFA new, cationic -heterocyclic carbene Rh complex with a tetra-fluorido-borate counter-anion, [Rh(CH)(CHN)(CHP)]BF, has been synthesized and structurally characterized. There are two independent ion pairs in the asymmetric unit. Each complex cation exhibits a distorted square-planar conformation around the Rh atom.
View Article and Find Full Text PDFA new neutral triazole-based N-heterocyclic carbene rhodium(I) complex [RhCl(CH)(CHN)], has been synthesized and structurally characterized. The complex crystallizes with two mol-ecules in the asymmetric unit. The central rhodium(I) atom has a distorted square-planar coordination environment, formed by a cyclo-octa-1,5-diene (COD) ligand, an N-heterocyclic carbene (NHC) ligand, and a chlorido ligand.
View Article and Find Full Text PDFWomen who undergo cesarean delivery have reported experiencing mood distress related to the surgery and postoperative pain. Heart rate variability biofeedback (HRVB) training is known to have positive effects on mental health, but its effects on women undergoing cesarean delivery have not yet been determined. This study evaluated the effects of an HRVB training intervention on stress, anxiety, and depression in women undergoing cesarean delivery.
View Article and Find Full Text PDFThe synthesis and characterization of a tris(alkyne) ligand, tris[2-(trimethylsilyl)ethynyl-4--butylbenzyl]amine (), and its silver(I) hexafluorophosphate complex, , are reported. The solid-state structure and luminescence properties of indicate relatively strong silver(I)-alkyne interactions between the metal cation and . No significant changes in the bond angles or lengths were observed upon metalation of with Ag, indicating a relatively unstrained ligand-metal motif.
View Article and Find Full Text PDFTo evaluate bifunctional ligand reactivity involving NH acidic sites in the secondary coordination sphere, complexes where the proton has been substituted with a methyl group (NMe) are often investigated. An alternative strategy involves substitution of the NH group for an O. This contribution considers and compares the merits of these approaches; the synthesis and characterization of cationic square-planar Rh carbonyl complexes bearing diprotic bispyrazole pyridine ligand L1, and the bis-methylated pyrazole pyridine ligand L1Me are described.
View Article and Find Full Text PDFThe title compound, [Ir(CH)(CHN)(CHP)]BF, a new triazole-based N-heterocyclic carbene iridium(I) cationic complex with a tetra-fluorido-borate counter-anion, crystallizes with two cations and two anions in the asymmetric unit of space group . The Ir centers of the cations have distorted square-planar conformations, formed by a bidentate (η + η) cyclo-octa-1,5-diene (COD) ligand, an N-heterocyclic carbene and a tri-phenyl-phosphane ligand with the NHC carbon atom and P atom being . In the extended structure, non-classical C-H⋯F hydrogen bonds, one of which is notably short (H⋯F = 2.
View Article and Find Full Text PDFExamples of stable 3d transition metal methylidene complexes are extremely rare. Here we report an isolable and stable vanadium methylidene complex, [(PNP)V(=NAr)(=CH)] (PNP = N[2-PPr-4-methylphenyl], Ar = 2,6-PrCH), via H atom transfer (HAT) from [(PNP)V(NHAr)(CH)] or [(PNP)V(=NAr)(CH)] using two or one equivalents of the TEMPO radical (TEMPO = (2,2,6,6-tetramethylpiperidin-1-yl)oxyl), respectively. Alternatively, the vanadium methylidene moiety can also be formed via the treatment of transient [(PNP)V=NAr] with the Wittig reagent, HCPPh.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
August 2024
The nitrido-ate complex [(PN)Ti(N){μ-K(OEt)}] (1) (PN=(N-(2-PPr-4-methylphenyl)-2,4,6-MeCH) reductively couples CO and isocyanides in the presence of DME or cryptand (Kryptofix222), to form rare, five-coordinate Ti complexes having a linear cumulene motif, [K(L)][(PN)Ti(NCE)] (E=O, L=Kryptofix222, (2); E=NAd, L=3 DME, (3); E=NBu, L=3 DME, (4); E=NAd, L=Kryptofix222, (5)). Oxidation of 2-5 with [Fc][OTf] afforded an isostructural Ti center containing a neutral cumulene, [(PN)Ti(NCE)] (E=O, (6); E=NAd (7), NBu (8)) and characterization by CW X-band EPR spectroscopy, revealed unpaired electron to be metal centric. Moreover, 1e reduction of 6 and 7 in the presence of Kryptofix222cleanly reformed corresponding discrete Ti complexes 2 and 5, which were further characterized by solution magnetization measurements and high-frequency and -field EPR (HFEPR) spectroscopy.
View Article and Find Full Text PDFHerein, we report the preparation and characterization of the Group 13 metal complexes of a tripodal tris(nitroxide)-based ligand, designated (TriNOx)M (M = Al (), Ga (), In ()). Complexes and both activate the O-H bond of a range of alcohols spanning a ∼10 p unit range via an element-ligand cooperative pathway to afford the zwitterionic complexes (HTriNOx)M-OR. Structures of these alcohol adduct products are discussed.
View Article and Find Full Text PDFIn the title triazole-based N-heterocyclic carbene rhodium(I) cationic complex with a tetra-fluorido-borate counter-anion, [Rh(CH)(CHN)(CHP)]BF, which crystallizes with two cations and two anions in the asymmetric unit, the Rh center has a distorted square-planar coordination geometry with expected bond distances. Several nonclassical C-H⋯F hydrogen-bonding inter-actions help to consolidate the packing. Two of the F atoms of one of the anions are disordered over adjacent sites in a 0.
View Article and Find Full Text PDFWe introduce the arsenido ligand onto the Ti ion, yielding a remarkably covalent Ti≡As bond and the parent arsinidene Ti═AsH moiety. An anionic arsenido ligand is assembled via reductive decarbonylation involving the discrete Ti salt [K(cryptand)][(PN)TiCl] () (cryptand = 222-Kryptofix) and Na(OCAs)(dioxane) in thf/toluene to produce the mixed alkali ate-complex [(PN)Ti(As)](μ-KNa(thf)) () and the discrete salt [K(cryptand)][(PN)Ti≡As] () featuring a terminal Ti≡As ligand. Protonation of or with various weak acids cleanly forms the parent arsinidene [(PN)Ti═AsH] (), which upon deprotonation with KCHPh in thf generates the more symmetric anionic arsenido [(PN)Ti(As){μ-K(thf)}] ().
View Article and Find Full Text PDFReported is the catalytic cyclic polymer synthesis by a 3d transition metal complex: a V(V) alkylidyne, [(dBDI)V≡CBu(OEt)] (), supported by the deprotonated β-diketiminate dBDI (dBDI = ArNC(CH)CHC(CH)NAr, Ar = 2,6-PrCH). Complex is a precatalyst for the polymerization of phenylacetylene (PhCCH) to give cyclic poly(phenylacetylene) (-PPA), whereas its precursor, complex [(BDI)V≡CBu(OTf)] (; BDI = [ArNC(CH)]CH, Ar = 2,6-PrCH, OTf = OSOCF), and the zwitterion [((CF)B-dBDI)V≡CBu(OEt)] () exhibit low catalytic activity despite having a neopentylidyne ligand. Cyclic polymer topologies were verified by size-exclusion chromatography (SEC) and intrinsic viscosity studies.
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