From the earliest days of nuclear magnetic resonance investigation, the ability of paramagnetic ions in aqueous solutions to cause the rapid relaxation of water protons has been recognized.'-' When biologists began to study the NMR relaxation of water protons in living tissues, they raised the question if the shortened spin-lattice relaxation time, or TI, and the spin-spin relaxation time, or T...

The chemistry of high-performance magnetic resonance imaging contrast agents remains an active area of research. In this work, we demonstrate that the potassium permanganate-based oxidative chemical procedures used to synthesize graphite oxide or graphene nanoparticles leads to the confinement (intercalation) of trace amounts of Mn(2+) ions between the graphene sheets, and that these manganese ...

In numerous biominerals exposed to ionizing radiation some stable paramagnetic species are induced. Their nature can differ depending on chemical composition of biominerals. The method of choice to study paramagnetic centers in biominerals is electron paramagnetic resonance (EPR) spectroscopy. When the relationship between EPR signal intensity of stable paramagnetic center and the dose has a li...

An elementary procedure is proposed and applied to study the exchange rate of a solvent or solute molecule bound to a complexed paramagnetic Ln(III) ion, other than Gd(III), from the measured longitudinal and transverse relaxation rates and paramagnetic resonance frequency shift at a given temperature.

A series of ionic liquids containing different paramagnetic anions have been prepared and all show paramagnetic behavior with potential applications for magnetic and electrochromic switching as well as novel magnetic transport; also, the tetraalkylphosphonium-based ionic liquids reveal anomalous magnetic behavior.

A polymer containing viologen radical cation monomer units is shown to reversibly switch between paramagnetic and diamagnetic states via non-covalent host-guest interactions or temperature control in water. Cycling between diamagnetic and paramagnetic forms is accompanied by changes in optical and magnetic properties.

Paramagnetic relaxation enhancement (PRE) measurements on (1)H nuclei have the potential to play an important role in NMR structure determination of macromolecules by providing unique long-range (10-35 A) distance information. Recent methodological advances for covalently attaching paramagnetic groups at specific sites on both proteins and nucleic acids have permitted the application of the PRE...

Creatine kinase from rabbit muscle has been specifically labeled with a derivative of a nitroxide free radical on the two essential sulfhydryl groups, one per active site. The conformation in the environment of the enzyme-bound free radical and the change in conformation induced upon binding of the substrate, metal adenosine diphosphate, has been monitored by two parameters of the bound spin la...

This paper reports the experimental results on paramagnetic properties of carbon-doped titanium dioxide. The electron paramagnetic resonance study of the samples has been carried out both in dark and under illumination. The nature of defects and their dynamics under illumination of carbon-doped TiO_2 samples are discussed.

The secondary coordination ability of a paramagnetic nickel dithiolene complex, bearing an ether coordinating function within a nine-membered flexible ring, has been demonstrated in its [NiCl(DMF)(2)](+) complex, through coordination by both ether and thioether functions, allowing for a ferromagnetic interaction between both paramagnetic entities.