The reduction of nitroso-spin traps in chemical and biological sysetms. A cautionary note

The NaBH₄ or enzymatic reduction of 2-methyl-2-nitrosopropane results in a four-line ESR spectrum due to $\text{t}$-butyl hydroniroxide. This spectrum is identical to a previously reported ESR spectrum (C.S. Lai and L.H. Piette, Tet. Letters, $\text{9}$, 775 (1979)) obtained during a Fenton reactions using 2-methyl-2-nitrosopropane, which had been assigned to the hydroxyl radical adduct. This note presents evidence that this four line spectrum can arise from the chemical reduction of the spin trap.     

Oxidation of alcohols by transition metal complexes part V. Selective catalytic monoalkylation of arylacetonitriles by alcohols

Selective catalytic monoalkylation of arylacetonitriles by primary alcohols can be achieved at ≤ 100° using a catalyst prepared in situ from rhodium trichloride, triphenylphosphine and sodium carbonate. RuH₂(PPh₃)₄ is a more effective catalyst for this process.     

Pulse widths and time dilatation

The temporal widths of a light pulse as measured in different inertial frames are shown to have a relation more complicated than that of a simple time dilatation. The result is compared with the dilatation in the twin paradoxGedanken experiment. The light pulse measurement requires two observers in two different frames. The measurements of the observers are compared. For the twin experiment a comparison is made between two clocks which have undergone different histories between the two points at which their world lines intersect.     

Periodic forcing of solutions of a boundary value problem for a second-order differential equation in Hilbert space

We show that if u is a bounded solution on $\text{R}$⁺ of u″(t) ?Au(t) + f(t), where A is a maximal monotone operator on a real Hilbert space H and f∈L_loc²($\text{R}$⁺;H) is periodic, then there exists a periodic solution ω of the differential equation such that u(t) ? ω(t)   0 and u′(t) ? ω′(t) → 0 as t → ∞. We also show that the two-point boundary value problem for this equation has a unique solution for boundary values in $\text{D(A)}$ and that a smoothing effect takes place.     

The non-existence of gaseous cyclopentadienyl cations: An overdue correction to the literature using collision-induced decompositions and charge stripping of negative ions

The C₅H₅⁺ fragment ion bound in many EI spectra is determined not to be cyclopentadienyl cation by CID-MIKE spectrometry.