Numéro
J. Phys. IV France
Volume 7, Numéro C2, Avril 1997
Proceedings of the 9th International Conference on X-Ray Absorption Fine Structure
Page(s) C2-661 - C2-662
DOI https://doi.org/10.1051/jp4/1997138
Proceedings of the 9th International Conference on X-Ray Absorption Fine Structure

J. Phys. IV France 7 (1997) C2-661-C2-662

DOI: 10.1051/jp4/1997138

XAFS and Crystallographic Studies of Ni(II) Porphyrins in Single Crystals and Solution

M. W. Renner, L. R. Furenlid, K. M. Barkigia and J. Fajer

Department of Applied Science, Brookhaven Nat. Laboratory, Upton, NY 11973, U.S.A.


Abstract
Nickel porphyrins serve as models for the active sites of several biological processes. Crystallographic and EXAFS results for a Ni meso-tetrapropyl porphyrin (NiTPrP) yield different Ni-N distances in solution and in the solid state. The Ni-N distances determined by single crystal polarized XAS and X-ray diffraction agree well. Polarized XANES experiments further establish that the pre-edge feature observed in square planar Ni(H) complexes is a ls-4pz transition. The single crystal and solution EXAFS results demonstrate that conformational variations of the porphyrin macrocycle can readily be imposed by environmental and/or packing forces and can thereby modulate the chemical and physical properties of porphyrinic chromophores and prosthetic groups.



© EDP Sciences 1997