bis-(l-tyrosinato)copper(ii) was reacted with 3-(chloropropyl)-trimethoxysilane functionalized silica that has infused magnetite to yield a magnetically separable catalyst in which the copper carboxylate is covalently linked to the silica matrix through the silane linkage. the immobilized catalyst has been characterized by spectroscopic studies (such as ft-ir, epr, magnetic measurement, sem) an...

Photosystem II (PS II) is unique among photosynthetic reaction centers in having secondary electron donors that compete with the primary electron donors for reduction of P680(+). We have characterized the photooxidation and dark decay of the redox-active accessory chlorophylls (Chl) and beta-carotenes (Car) in oxygen-evolving PS II core complexes by near-IR absorbance and EPR spectroscopies at ...

The effect of Zn(2+) or Cu(2+) ions on Mn-depleted photosystem II (PS II) has been investigated using EPR spectroscopy. In Zn(2+)-treated and Cu(2+)-treated PS II, chemical reduction with sodium dithionite gives rise to a signal attributed to the plastosemiquinone, Q(A)(*)(-), the usual interaction with the non-heme iron being lost. The signal was identified by Q-band EPR spectroscopy which par...

Eight new complexes of Cu(II), Co(II), Ni(II) and Zn(II) with isonicotinic acid hydrazide (isoniazid, (INH)) and isonicotinic acid (1-naphthylmethylene)hydrazide (INNMH), having the formula of the type [M(INH)(ac)2] or [M(INNMH)(ac)2] (M = Co(II), Ni(II) and Zn(II)) and [Cu(INH)(ac)2]2, [Cu(INNMH)(ac)2]2, were synthesized and characterized. All complexes were characterized based on elemental an...

Heterogeneous textures due to phase separation in molten polypropylene (PP)/ ethylene-propylene-rubber (EPR) blends were investigated in relation to their dynamic viscoelastic properties. As characteristic to heterogeneous liquids, slow relaxation mechanisms due to the existence of such phases were found for dynamic moduli of PP/EPR blends. These moduli were analyzed by using the linear viscoel...

Blue copper proteins (Type I) exhibit unusual spectral and chemical properties such as higher reduction potentials and small hyperfine coupling constants A|| in the EPR spectrum in comparison with other copper(II) complexes. Such unusual properties are justified partly by the tetralhedral geometry around the copper(II) site and partly by the CuN2S2 chromophores in which the soft S atoms coordin...

The understanding of the biotransformations of insulin mimetic vanadium complexes in human blood and its transport to target cells is an essential issue in the development of more effective drugs. We present the study of the interaction of oxovanadium(iv) with human serum albumin (HSA) by electron paramagnetic resonance (EPR), circular dichroism (CD) and visible absorption spectroscopy. Metal c...

The physical meaning of the EPR–chameleon experiment proposed in [1, 2], in which the EPR correlations are reproduced by local, independent, deterministic choices is reexamined. In addition we extend the mathematical model of [1, 2] by showing that the dynamics considered there is effectively the reduced dynamics of a fully reversible evolution. We also propose a new protocol, more directly cor...

This paper presents the findings of electron paramagnetic resonance (EPR) spectroscopy experiments conducted on two different samples: 2,2-diphenyl-1-picrylhydrazyl (DPPH) and Manganese Chloride (MnCl2) dissolved in H2O. The were at Dr. D. Petasis EPR lab located Allegheny College, Meadville, PA, USA. A Varian X-Band spectrometer was utilized for analysis absorption spectra. primary objective t...

Simulations are performed of 34- and 9-GHz EPR spectra, together with 94-GHz EPR spectra, from phospholipid probes spin-labelled at the C4-C14 positions of the sn-2 chain, in liquid-ordered and gel-phase membranes of dimyristoyl phosphatidylcholine with high and low cholesterol contents. The multifrequency simulation strategy involves: (i) obtaining partially averaged spin-Hamiltonian tensors f...