Magnetic and optical bistability driven by thermally and photoinduced intramolecular electron transfer in a molecular cobalt-iron prussian blue analogue

Dongfeng Li; Rodolphe Clérac; Olivier Roubeau; Etienne Harté; Corine Mathonière; Rémy Le Bris; Stephen M Holmes

doi:10.1021/ja0757632

Magnetic and optical bistability driven by thermally and photoinduced intramolecular electron transfer in a molecular cobalt-iron prussian blue analogue

J Am Chem Soc. 2008 Jan 9;130(1):252-8. doi: 10.1021/ja0757632. Epub 2007 Dec 13.

Authors

Dongfeng Li¹, Rodolphe Clérac, Olivier Roubeau, Etienne Harté, Corine Mathonière, Rémy Le Bris, Stephen M Holmes

Affiliation

¹ Department of Chemistry, University of Kentucky, Lexington, Kentucky 40506-0055, USA.

PMID: 18076169
DOI: 10.1021/ja0757632

Abstract

A soluble molecular analogue of photoresponsive Co/Fe Prussian blues is described within this report. As judged via a variety of spectroscopic, magnetic, and crystallographic methods, electron transfer within the octanuclear complex (below 250 K) converts paramagnetic red crystals into green diamagnetic ones. The color and magnetic changes are associated with the transformation of FeIIILS-CN-CoIIHS units into FeIILS-CN-CoIIILS fragments in manner that is identical to that found for the An[Co(OH2)(6-6m)][Fe(CN)6]m.xH2O (An = alkali metal cation) family of three-dimensional Prussian blues. Moreover, this intramolecular electron transfer can be quantitatively circumvented via rapid thermal quenching and reversed via simple white light irradiation at low temperatures. Remarkably the data suggests that thermally or photoinduced paramagnetic metastable phases are identical and exhibit long relaxation times that approach 10 years at 120 K.