On the possible magnetic field dependence of the nickel carbonylation rate

The interaction of Ni with CO gas to produce Ni(CO)₄ at 1 atm pressure, has been studied as a function of time, temperature (25 < T < 95°C) and externally applied magnetic field (H ? 500 Oe). We find no significant magnetic field dependence of the nickel carbonylation rate, in sharp contrast with results previously reported by Krinchik et al. The activation energy for this reaction is found to be 0.21 ± 0.05 eV independent of magnetic field.     

The nature of the initial transient in the rate of formation of nickel carbonyl

The transient in the rate of Ni(CO)₄ formation has been studied as a function of the gas used in the initial heat treatment of the nickel samples. Quantitatively similar transient effects were seen whether the samples were heated in reducing (H₂, D₂) or neutral (He) atmospheres. A mechanism is proposed in which the heat treatment activates the surface; in particular a finite number of low coordination nickel sites are activated. These sites are energetically favored for Ni(CO)₄ formation and are responsible for the transient behavior.     

A novel low-E field coil to minimize heating of biological samples in solid-state multinuclear NMR experiments

A novel coil, called Z coil, is presented. Its function is to reduce the strong thermal effects produced by rf heating at high frequencies. The results obtained at 500MHz in a 50 microl sample prove that the Z coil can cope with salt concentrations that are one order of magnitude higher than in traditional solenoidal coils. The evaluation of the rf field is performed by numerical analysis based on first principles and by carrying out rf field measurements. Reduction of rf heating is probed with a DMPC/DHPC membrane prepared in buffers of increasing salt concentrations. The intricate correlation that exists between the magnetic and electric field is presented. It is demonstrated that, in a multiply tuned traditional MAS coil, the rf electric field E(1) cannot be reduced without altering the rf magnetic field. Since the detailed distribution differs when changing the coil geometry, a comparison involving the following three distinct designs is discussed: (1) a regular coil of 5.5 turns, (2) a variable pitch coil with the same number of turns, (3) the new Z coil structure. For each of these coils loaded with samples of different salt concentrations, the nutation fields obtained at a certain power level provide a basis to discuss the impact of the dielectric and conductive losses on the rf efficiency.     

Vancomycin covalently bonded to titanium beads kills Staphylococcus aureus

Periprosthetic infections are life-threatening complications that occur in about 6% of medical device insertions. Stringent sterile techniques have reduced the incidence of infections, but many implant patients are at high risk for infection, especially the elderly, diabetic, and immune compromised. Moreover, because of low vascularity at the site of the new implant, antibiotic prophylaxis is often not effective. To address this problem, we designed a covalent modification to titanium implant surfaces to render them bactericidal. Specifically, we aminopropylated titanium, a widely used implant material and extended a tether by solid phase coupling of ethylene glycol linkers, followed by solid phase coupling of vancomycin. Vancomycin covalently attached to titanium still bound soluble bacterial peptidoglycan, reduced Staphylococcus aureus colony-forming units by 88% +/- 16% over 2 hr, and retained antibacterial activity upon a repeated challenge.     

Interplay of thermochemistry and Structural Chemistry,the journal (volume 27, 2016, issues 1-2) and the discipline

Structural Chemistry - The contents of issues 1 and 2 of Structural Chemistry from the calendar year 2016 are summarized in the present review. A brief thermochemical commentary and possible...     

Engineering of an all‐heteronuclear 5‐qubit NMR quantum computer

The realization of an all‐heteronuclear 5‐qubit nuclear magnetic resonance quantum computer is reported, from the design and synthesis of a suitable molecule through the engineering of a prototype 6‐channel probe head. Full control over the quantum computer is shown by a benchmark experiment. Copyright © 2015 John Wiley & Sons, Ltd.     

Interplay of thermochemistry and structural chemistry,the journal (volume 24, 2013, issues 3–4) and the discipline

The contents of issues 3 and 4 for the calendar year 2013 are summarized in the current review of the journal Structural Chemistry. A brief thermochemical commentary is added to the summary of each paper.     

Interplay of thermochemistry and structural chemistry,the journal (volume 24, 2013, issues 5–6) and the discipline

The contents of issues 5 and 6 for the calendar year 2013 are summarized in the current review of the journal Structural Chemistry. A brief thermochemical commentary is added to the summary of each paper.