Bond dissociation energies (BDEs) and spectroscopic parameters for the ground states of YbO and NoO were calculated at the Brueckner doubles (BD(T)) level and for NoO at the coupled cluster CCSD(T) level based on the closed-shell configurations Yb(4f)O(2p) and No(5f)O(2p). For YbO, the BD(T) BDE (3.93 eV) and vibrational frequency (686.
View Article and Find Full Text PDFThe nature of the Ni-S bond is investigated due to its role in the absorption of atmospheric Lewis acid gases such as SO and SO onto Ni surfaces. The vibrational frequency and electronic structure of NiS were predicted using CCSD(T), CASSCF, and internally contracted multireference configuration interaction (icMRCI) + Q. 43 density functional theory (DFT) functionals were benchmarked.
View Article and Find Full Text PDFA variety of different ground-state structures of carbene and phosphine groups 1 and 2 cationic, group 11 cationic, and group 10 neutral complexes were studied using density functional theory (DFT) and correlated molecular orbital theory (CCSD(T)) methods. Geometries of complexes with phosphines were studied and compared to available experimental data. Among the three analyzed phosphine ligands, PH, PMe, and PPh, PH was found to have noticeably smaller ligand binding energies (LBEs, Δ).
View Article and Find Full Text PDFThe redox properties of the actinides in aqueous solution are important for fuel production/reprocessing and understanding the environmental impact of nuclear waste. The redox potentials for U, Np, Pu, and Am in oxidation states from 0 up to VII (as appropriate) in aqueous solutions have been predicted at the density functional theory level with the B3LYP functional, Stuttgart small core pseudopotential basis sets for the actinides, and explicit (30HO molecules)/implicit treatment of the aqueous solvent using the self-consistent reaction field COSMO and SMD approaches for the implicit solvation. The predictions of the structural parameters of clusters incorporating first and second solvation shells are consistent with the available experimental data.
View Article and Find Full Text PDFThe nature of the Ni-O bond is relevant to catalytic and environmental applications. The vibrational frequency and electronic structure of NiO were calculated using CASSCF, icMRCI+Q, CCSD(T), and DFT. CASSCF predicted a quintet state (Σ) ground state for the equilibrium bond distance with a state crossing at 1.
View Article and Find Full Text PDFHigh-level electronic structure calculations were conducted to examine the bonding and spectroscopic properties of the UO and UF diatomic molecules. The low-lying Ω states were described by using multireference SO-CASPT2 calculations. The adiabatic electronic affinity (AEA), adiabatic ionization energy (IE), and bond dissociation energy (BDE) were calculated at the Feller-Peterson-Dixon (FPD) level.
View Article and Find Full Text PDFInborn errors of T cell development present a pediatric emergency in which timely curative therapy is informed by molecular diagnosis. In 11 affected patients across four consanguineous kindreds, we detected homozygosity for a single deleterious missense variant in the gene NudC domain-containing 3 () Two infants had severe combined immunodeficiency with the complete absence of T and B cells (TB SCID), whereas nine showed classical features of Omenn syndrome (OS). Restricted antigen receptor gene usage by residual T lymphocytes suggested impaired V(D)J recombination.
View Article and Find Full Text PDFProgress toward the closure of the nuclear fuel cycle can be achieved if satisfactory separation strategies for the chemoselective speciation of the trivalent actinides from the lanthanides are realized in a nonproliferative manner. Since Kolarik's initial report on the utility of bis-1,2,4-triazinyl-2,6-pyridines (BTPs) in 1999, a perfect complexant-based, liquid-liquid separation system has yet to be realized. In this report, a comprehensive performance assessment for the separation of Am from Eu as a model system for spent nuclear fuel using hydrocarbon-actuated alkoxy-BTP complexants is described.
View Article and Find Full Text PDFActivity descriptors are a powerful tool for the design of catalysts that can efficiently utilize H with minimal energy losses. In this study, we develop the use of hydricity and H self-exchange rates as thermodynamic and kinetic descriptors for the hydrogenation of ketones by molecular catalysts. Two complexes with known hydricity, HRh(dmpe) and HCo(dmpe), were investigated for the catalytic hydrogenation of ketones under mild conditions (1.
View Article and Find Full Text PDFA longstanding challenge in catalysis by noble metals has been to understand the origin of enhancements of rates of hydrogen transfer that result from the bonding of oxygen near metal sites. We investigated structurally well-defined catalysts consisting of supported tetrairidium carbonyl clusters with single-atom (apical iridium) catalytic sites for ethylene hydrogenation. Reaction of the clusters with ethylene and H followed by O led to the onset of catalytic activity as a terminal CO ligand at each apical Ir atom was removed and bridging dioxygen ligands replaced CO ligands at neighboring (basal-plane) sites.
View Article and Find Full Text PDFThe aqueous electron affinity and aqueous reduction potentials for F, Cl, Br, I, OH, SH, SeH, TeH, ClO, BrO, and IO were calculated using electronic structure methods for explicit cluster models coupled with a self-consistent reaction field (SMD) to treat the aqueous solvent. Calculations were conducted using MP2 and correlated molecular orbital theory up to the CCSD(T)-F12b level for water tetramer clusters and MP2 for octamer cluster. Inclusion of explicit waters was found to be important for accurately predicting the redox potentials in a number of cases.
View Article and Find Full Text PDFObjective: Musculoskeletal (MSK) causes of chest pain are considered common in emergency care, yet management is limited, reported outcomes are poor and prevalence data in New Zealand are lacking. The present study aims to estimate the prevalence of MSK chest pain in New Zealand EDs and describe the characteristics of MSK chest pain cases.
Methods: A retrospective chart review was conducted based on de-identified clinical notes extracted from four hospitals within the South Island of New Zealand from 3 months spanning 1 March to 31 May 2021.
The interactions between group 1 and 11 monocations and group 2 dications with triphenylphosphine were studied by using a combination of correlated molecular orbital theory and density functional theory. Two binding modes were found: the front side (phosphorus lone pair) and back side (phenyl rings). Group 1 and 2 cations prefer binding to the π system rather than to the lone pair of the phosphorus atom, and their ligand binding energies (LBEs) correlate with the atomic ionic radii as well as the hardness of the atomic ion.
View Article and Find Full Text PDFTransition metal oxide (TMO) clusters are being studied for their ability to absorb acid gases generated by energy production processes. The interaction of SO, a byproduct of common industrial processes, with group 4 metal (Ti, Zr, and Hf) oxide nanoclusters, has been predicted using electronic structure methods. The calculations were done at the density functional theory (DFT) and correlated molecular orbital coupled cluster singles and doubles CCSD(T) theory levels.
View Article and Find Full Text PDFThe extraembryonic yolk sac (YS) ensures delivery of nutritional support and oxygen to the developing embryo but remains ill-defined in humans. We therefore assembled a comprehensive multiomic reference of the human YS from 3 to 8 postconception weeks by integrating single-cell protein and gene expression data. Beyond its recognized role as a site of hematopoiesis, we highlight roles in metabolism, coagulation, vascular development, and hematopoietic regulation.
View Article and Find Full Text PDFThe purely chemical synthesis of fluorine is a spectacular reaction which for more than a century had been believed to be impossible. In 1986, it was finally experimentally achieved, but since then this important reaction has not been further studied and its detailed mechanism had been a mystery. The known thermal stability of MnF casts serious doubts on the originally proposed hypothesis that MnF is thermodynamically unstable and decomposes spontaneously to a lower manganese fluoride and F .
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