Isolation of a Cu-H Monomer Enabled by Remote Steric Substitution of a -Heterocyclic Carbene Ligand: Stoichiometric Insertion and Catalytic Hydroboration of Internal Alkenes.

Transient Cu-H monomers have long been invoked in the mechanisms of substrate insertion in Cu-H catalysis. Their role from Cu-H aggregates has been mostly inferred since ligands to stabilize these monomeric intermediates for systematic studies remain limited. Within the last decade, new sterically demanding -heterocyclic carbene (NHC) ligands have led to isolable Cu-H dimers and, in some cases, spectroscopic characterization of Cu-H monomers in solution.

Redox-switchable carboranes for uranium capture and release.

The uranyl ion (UO; U(VI) oxidation state) is the most common form of uranium found in terrestrial and aquatic environments and is a central component in nuclear fuel processing and waste remediation efforts. Uranyl capture from either seawater or nuclear waste has been well studied and typically relies on extremely strong chelating/binding affinities to UO using chelating polymers, porous inorganic or carbon-based materials, as well as homogeneous compounds. By contrast, the controlled release of uranyl after capture is less established and can be difficult, expensive or destructive to the initial material.

An untethered C-symmetric triarylphosphine oxide locked by intermolecular hydrogen bonding.

A para-substituted triphenylphosphine oxide with terminal vanadocene centers has been prepared and is, to our knowledge, the first example of an untethered C3v-symmetric triarylphosphine oxide in the solid state. Crystallographic and DFT studies suggest this locked conformation is due to intermolecular H-bonding interactions. Electrochemical measurements suggest these interactions may persist in solution.

Probing Hydrogen Atom Transfer at a Phosphorus(V) Oxide Bond Using a "Bulky Hydrogen Atom" Surrogate: Analogies to PCET.

Recent computational studies suggest that the phosphate support in the commercial vanadium phosphate oxide (VPO) catalyst may play a critical role in initiating butane C-H bond activation through a mechanism termed reduction-coupled oxo activation (ROA) similar to proton-coupled electron transfer (PCET); however, no experimental evidence exists to support this mechanism. Herein, we present molecular model compounds, (PhN)V═N-P(O)Ar (Ar = CF (2a), Ph (2b)), which are reactive to both weak H atom donors and a MeSi (a "bulky hydrogen atom" surrogate) donor, 1,4-bis(trimethylsilyl)pyrazine. While the former reaction led to product decomposition, the latter resulted in the isolation of the reduced, silylated complexes (PhN)V-N═P(OSiMe)Ar (3a/b).

A Mono-, Di-, and Trivanadocene Phosphorus Oxide Series: Synthesis, Magnetism, and Chemical/Electrochemical Properties.

In this Article, we outline the synthesis of B(CF)-coordinated mono-, di-, and trivanadocene phosphorus oxide complexes, CpVOP(OB(CF))Ph (2), (CpVO)P(OB(CF))Ph (3), and (CpVO)P(OB(CF)) (4), respectively (Cp = η-cyclopentadienyl). The complexes were synthesized from the known reagents, CpVF and PhP(O)OSiMe (for 2) or PhP(O)(OSiMe) (for 3) or (MeSiO)PO (for 4), via MeSiF elimination and in the presence of B(CF). The multimetallic complexes (3 and 4) could not be synthesized without the capping B(CF) Lewis acid, whereas the uncapped version of 2, CpVOP(O)Ph (1), has previously been reported by us.

Methemoglobinemia in a Pediatric Oncology Patient Receiving Sulfamethoxazole/Trimethoprim Prophylaxis.

BACKGROUND Methemoglobinemia due to the administration of sulfamethoxazole/trimethoprim has been documented in a series of case reports. However, all of these reports are on adult patients, and all patients received at least daily administration of sulfamethoxazole/trimethoprim for the treatment of active or suspected infection. CASE REPORT Herein we report the development of methemoglobinemia in a pediatric patient receiving sulfamethoxazole/trimethoprim three times weekly for the prophylaxis of opportunistic infections.

Vasopressin rescue for in-pediatric intensive care unit cardiopulmonary arrest refractory to initial epinephrine dosing: a prospective feasibility pilot trial.

Objectives: To assess the feasibility of a large, randomized controlled trial of combination epinephrine-arginine vasopressin for in-pediatric intensive care unit cardiopulmonary arrest refractory to initial epinephrine dosing.

Design: Prospective, pilot, matched controlled clinical trial using exception from informed consent.

Setting: Pediatric intensive care unit in a university-affiliated tertiary care children's hospital.

Effectiveness of the informed consent process for a pediatric resuscitation trial.

Objective: When prospective informed consent is not feasible, clinical research that presents more than minimal risk can proceed only with an exception from informed consent. Our objectives were (1) to describe the in-hospital community consultation and public disclosure process for a clinical trial and (2) to evaluate our in-hospital public disclosure process.

Methods: Community consultation included parents, providers, and administrators in a PICU via focus groups, conferences, and other methods.

Epidural analgesia and severe perineal laceration in a community-based obstetric practice.

Background: This study assessed whether epidural analgesia was an independent risk factor for severe perineal laceration.

Methods: A retrospective cohort study analyzed 2,759 patients at St. Francis Regional Medical Center who had vertex, spontaneous or induced, singleton, live, vaginal deliveries of neonates of at least 36 weeks' gestation.