EPR properties of mixed-valent mu-oxo and mu-hydroxo dinuclear iron complexes produced by radiolytic reduction at 77 K. Export

@article{citeulike:1296876, abstract = {Radiolytic reduction at 77 K of oxo/hydroxo-bridged dinuclear iron(III) complexes in frozen solutions forms kinetically stabilized, mixed-valent species in high yields that model the mixed-valent sites of non-heme, diiron proteins. The mixed-valent species trapped at 77 K retain ligation geometry similar to the initial diferric clusters. The shapes of the mixed-valent EPR signals depend strongly on the bridging ligands. Spectra of the Fe(II)OFe(III) species reveal an S = 1/2 ground state with small g-anisotropy as characterized by the uniaxial component (gz-gav/2 < 0.03) observable at temperatures as high as approximately 100 K. In contrast, hydroxo-bridged mixed-valent species are characterized by large g-anisotropy (gz-gav/2 > 0.03) and are observable only below 30 K. Annealing at higher temperatures causes structural relaxation and changes in the EPR characteristics. EPR spectral properties allow the oxo- and hydroxo-bridged, mixed-valent diiron centers to be distinguished from each other and can help characterize the structure of mixed-valent centers in proteins.}, address = {WR Wiley Environmental Molecular Science Laboratory, Pacific Northwest National Laboratory, Richland, WA 99352-0999, USA.}, author = {Davydov, R. M. and Smieja, J. and Dikanov, S. A. and Zang, Y. and Que, L. and Bowman, M. K.}, citeulike-article-id = {1296876}, citeulike-linkout-0 = {http://view.ncbi.nlm.nih.gov/pubmed/10439074}, citeulike-linkout-1 = {http://www.hubmed.org/display.cgi?uids=10439074}, issn = {0949-8257}, journal = {J Biol Inorg Chem}, keywords = {caged\_compounds, photoreduction, radiation\_damage}, month = {June}, number = {3}, pages = {292--301}, posted-at = {2007-05-15 11:17:54}, priority = {2}, title = {EPR properties of mixed-valent mu-oxo and mu-hydroxo dinuclear iron complexes produced by radiolytic reduction at 77 K.}, url = {http://view.ncbi.nlm.nih.gov/pubmed/10439074}, volume = {4}, year = {1999} }

TY - JOUR ID - citeulike:1296876 L3 - citeulike-article-id:1296876 N2 - Radiolytic reduction at 77 K of oxo/hydroxo-bridged dinuclear iron(III) complexes in frozen solutions forms kinetically stabilized, mixed-valent species in high yields that model the mixed-valent sites of non-heme, diiron proteins. The mixed-valent species trapped at 77 K retain ligation geometry similar to the initial diferric clusters. The shapes of the mixed-valent EPR signals depend strongly on the bridging ligands. Spectra of the Fe(II)OFe(III) species reveal an S = 1/2 ground state with small g-anisotropy as characterized by the uniaxial component (gz-gav/2 < 0.03) observable at temperatures as high as approximately 100 K. In contrast, hydroxo-bridged mixed-valent species are characterized by large g-anisotropy (gz-gav/2 > 0.03) and are observable only below 30 K. Annealing at higher temperatures causes structural relaxation and changes in the EPR characteristics. EPR spectral properties allow the oxo- and hydroxo-bridged, mixed-valent diiron centers to be distinguished from each other and can help characterize the structure of mixed-valent centers in proteins. IS - 3 JF - J Biol Inorg Chem SN - 0949-8257 AD - WR Wiley Environmental Molecular Science Laboratory, Pacific Northwest National Laboratory, Richland, WA 99352-0999, USA. EP - 301 TI - EPR properties of mixed-valent mu-oxo and mu-hydroxo dinuclear iron complexes produced by radiolytic reduction at 77 K. VL - 4 SP - 292 KW - caged_compounds KW - photoreduction KW - radiation_damage AU - Davydov, RM AU - Smieja, J AU - Dikanov, SA AU - Zang, Y AU - Que, L AU - Bowman, MK PY - 1999/06// UR - http://view.ncbi.nlm.nih.gov/pubmed/10439074 ER -