Electronic structure of spin-mixed iron(III) porphyrins: a proton magnetic resonance study

Dugad, L. B. ; Marathe, V. R. ; Mitra, Samaresh (1985) Electronic structure of spin-mixed iron(III) porphyrins: a proton magnetic resonance study Proceedings of the Indian Academy of Sciences - Chemical Sciences, 95 (1-2). pp. 189-205. ISSN 0253-4134

[img]
Preview
PDF - Publisher Version
1MB

Official URL: http://www.ias.ac.in/j_archive/chemsci/95/1/189-20...

Related URL: http://dx.doi.org/10.1007/BF02839727

Abstract

The proton magnetic resonance studies on the perchlorato iron(III) porphyrins in solution have been described. The isotropic proton shifts in these complexes show anomalous temperature dependence, consistent with its unusual properties in solid state. The NMR data have been analysed on the basis of a crystal field theory which includes lower asymmetric field and spin-orbit interaction. The analysis brings out that the ground state of the ferric ion in these porphyrin complexes exhibits the novel spin-mixed behaviour with spin-mixing between S = 3/2 and S = 5/2. The ground state is predominantly a spin quartet with the spin sextet being a very close lying excited state. Such a spin situation and spin-mixing have been speculated for the ferric ion in some ferricytochromec'. The present paper also highlights that the isotropic proton shift is very sensitive to the electronic structure of the metal ion and hence can be used to determine the electronic structure of the metal ion in heme systems in solution.

Item Type:Article
Source:Copyright of this article belongs to Indian Academy of Sciences.
Keywords:Proton Magnetic Resonance; Perchlorato Iron(III) Porphyrins; Spin State Mixing; Crystal Field Calculations Of IPS; Electronic Structure in Solution
ID Code:20141
Deposited On:20 Nov 2010 14:57
Last Modified:17 May 2016 04:32

Repository Staff Only: item control page