High-field/high-frequency electron spin resonance ~ESR! offers improved sensitivity and resolution compared to ESR at conventional fields and frequencies. However, most high-field/high-frequency ESR spectrometers suffer from limited mm-wave power, thereby requiring long mm-wave pulses. This precludes their use when relaxation times are short, e.g., in fluid samples. Low mm-wave power is also a ...

The effect of pH and inositol hexaphosphate (IHP) on the symmetry of the heme environments in opossum (Didelphius marsupialis) and new Zealand White rabbit hemoglobins has been studied using electron spin resonance (ESR). Each methemoglobin is found to contain two different heme environments as detected by the rhombicity observed in the ESR spectrum. In both cases the rhombic nature of the ESR ...

the spectroscopic properties of the 2,2,6,6-tetramethyl-piperidine-1-oxyl (tempo) radicalderivatives of the fullerene (c60) were theoretically investigated. the ground state optimizedstructures of the radical adducts of the fullerene were calculated by using dft (b3lyp) with 6-31g(d) level. it was concluded that a 6-6 ring junction of c60 moiety generally covalently links to thepiperidine ring ...

The substituted 1,8-naphthyridines, 2-hydroxy-1,8-naphthyridine-3-carboxylic acid hydrazide (HNch) and 2-hydroxy-1,8-naphthyridine-3-carboxylic acid 0-hydroxybenzylidene hydrazide (HNCHBh) react with acetates of Mn(II), Co(II) metal ions to yield complexes of definite composition. The complexes have been characterized by elemental analysis, thermal, conductance, magnetic studies and IR, electro...

A series of complexes of the general formula [Ru Hbbip X Cit, [Ru Hbbip (Xh]+ and [(Ru Hbbip Xh pyz]+; H2bbip = 2,6-bis-(2'-benzimidazyl) pyridine; pyz = pyrazine and X = 2,2'-bipyridine/1, I 0-phenanthroline have been synthesized and characterized by their elemental analysis, spectral (IR, 1 H NMR, UV -visible and ESR) and redox data. Comparative luminescent behaviour of the complexes in the p...

Electron spin resonance (ESR) describes a suite of techniques for characterizing electronic systems with applications in physics, chemistry, and biology. However, the requirement for large electron spin ensembles in conventional ESR techniques limits their spatial resolution. Here we present a method for measuring ESR spectra of nanoscale electronic environments by measuring the longitudinal re...

EPR newsletter 2007 vol.16 no.4 | 11 pelling reasons to invest in the development of modern ESR methods for applications in biophysical and biomedical research. The potential of ESR may best be evaluated by considering (1) its absolute sensitivity, (2) its spectral resolution, (3) its sensitivity to different types of molecular motion, including translation, rotation, and intermolecular relativ...

Highly water-soluble ubiquinone-0 (CoQ0) reacts with ascorbate monoanion (Asc) to mediate the production of ascorbyl free radicals (AFR). Using aqueous reaction mixture of CoQ0 and Asc, we obtained positively enhanced dynamic nuclear polarization (DNP)-magnetic resonance (MR) images of the AFR at low frequency (ranging from 515 to 530 MHz) of electron spin resonance (ESR) irradiation. The shape...

We performed STM-ENDOR experiments where the intensity of one of the hyperfine components detected in ESR-STM is recorded while an rf power is irradiated into the tunneling junction and its frequency is swept. When the latter frequency is near a nuclear transition a dip in ESR-STM signal is observed. This experiment was performed in three different systems: near surface SiC vacancies where the ...

The safety analysis of nuclear systems such as reactors requires transient calculation. Monte Carlo (MC) method has grown rapidly in recent years because its high-fidelity modelling and simulation capability. predictor-corrector quasi-static (PCQS) MC been investigated for kinetic However, the approach to shorten computational time required solve fixed source equation (TFSE) is still under deve...