We present a comparison of experimental and simulated frequency- and field-domain electron paramagnetic resonance (EPR) spectra of integer and half-integer high-spin transition-metal ion complexes. For the simulation of EPR spectra a new tool within the EPR simulation software EasySpin is introduced, which allows for field- and frequency-domain EPR simulations with the same theoretical model an...

Since Mg(+) ions are isoelectronic to Na atoms, an easy single electron transfer (SET) can be expected for MgBr. Even at 190 K, the radical MgBr (obtained via its sophisticated condensation) in a metastable solution transfers its electron to a diazadiene entity. A paramagnetic Mg(II) compound [MgBr(L(1))˙]2 (4; L(1) = DippN=C(Me)C(Me)=NDipp) is formed consisting of a singly reduced ligand. As s...

Interactions between metals and activated sludge microorganisms substantially affect the speciation, immobilization, transport, and bioavailability of trace heavy metals in biological wastewater treatment plants. In this study, the interaction of Cu(II), a typical heavy metal, onto activated sludge microorganisms was studied in-depth using a multi-technique approach. The complexing structure of...

The nuclear modulation effect in pulsed EPR spectroscopy was used to probe the metal-protein bonds in Cu(II)=transferrin complexes as a function of pH. In preparations in equilibrium with air at pH 4.8 no modulation features other than those attributable to protons were observed, in keeping with conventional EPR studies indicating that at this pH only nonspecific binding takes place (Zweier, J....

The osmolyte dimethylsulfoniopropionate (DMSP) is a key nutrient in marine environments and its catabolism by bacteria through enzymes known as DMSP lyases generates dimethylsulfide (DMS), a gas of importance in climate regulation, the sulfur cycle, and signaling to higher organisms. Despite the environmental significance of DMSP lyases, little is known about how they function at the mechanisti...

A 16-line pattern has been theoretically predicted, but hitherto not reported, for the Electron Paramagnetic Resonance (EPR) spectrum of antiferromagnetically coupled CuII triangles experiencing isotropic exchange isosceles magnetic symmetry.

A type I absorbance change is observed in suspensions of adrenal cortical mitochondria as the temperature is increased from O-22”. This “heat-generated” type I absorbance change is similar in magnitude to the pregnenolone-induced type II absorbance change of these mitochondria. Studies with inhibitors of cholesterol side chain cleavage indicate that the heat-generated type I absorbance change r...

EPR spectroscopy was applied to investigate the inhibition of electron transport in photosystem II by Cu2+ ions. Our results show that Cu2+ has inhibitory effects on both the donor and the acceptor side of photosystem II. In the presence of Cu2+, neither EPR signal IIvery fast nor signal IIfast, which both reflect oxidation of tyrosinez, could be induced by illumination. This shows that Cu2+ in...

We consider several natural situations where the union or intersection of an uncountable family of measurable (in various senses) sets with a “good” additional structure is again measurable or may fail to be measurable. We primarily deal with Lebesgue measurable sets and sets with the Baire property. In particular, uncountable unions of sets homeomorphic to a closed Euclidean simplex are consid...

We present analytical calculation of the first seven moments of the heavy quark vacuum polarization function in the three-loop order. The obtained results are compared against the asymptotic formulas following from the threshold singulari-ties. We also discuss the µ dependence of the moments within the BLM procedure.