Magnetic and Optical Bistability Driven by Thermally and Photoinduced Intramolecular Electron Transfer in a Molecular Cobalt−Iron Prussian Blue Analogue

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.

Local Structure in Americium and Californium Hexacyanoferrates – Comparison with Their Lanthanide Analogues

“…From that perspective, donor ligands have always been of interest [ Now an independent fellow in Barcelona, Spain very similar and are arranged in a tricapped trigonal prism polyhedron of coordination number 9 (CN: 9), in which the americium atom is bonded to six nitrogen atoms and to three water molecules. For the californium adduct, a similar comparison and bond length and angle values derived from EXAFS studies suggest that the californium cation sits in a bicapped trigonal prism (CN: 8) 2 O, in which the gadolinium atom is surrounded by 9 atoms. This is one of the rare pieces of information revealed by EXAFS spectroscopy for americium and californium in comparison to lanthanide atoms in molecular solid compounds.…”

“…For instance, several molecular three-dimensional Fe/Co analogues of Prussian blue can exhibit both thermally induced and photoinduced reversible electron transfer. [2] The recent publication of Hocking et al underlines the well-known particularity of the iron-cyano bond in ferri-and ferrocyanide. [3] A considerable number of studies have also been devoted to the structural and electronic characterization of Prussian blue derivatives.…”

Magnetism and Photomagnetism of Prussian Blue Analogue Nanoparticles Embedded in Porous Metal Oxide Ordered Nanostructures

“…[20] Later on, photomagnetic effects were evidenced in several other PBAs, cyanide-based single-chain magnets [27] and singlemolecule magnets. [28][29][30] Beyond the study of molecular compounds in their solid states, the past decade has seen growing interest in the development of approaches enabling control over the size, dispersion and/or organization of a studied species in a solid matrix or on a solid surface. The choice of the processing step leading to the targeted spatial arrangement of the molecular objects and the objectives in terms of new properties or applications strongly depend on the properties of the molecular compounds, on the chemistry involved in their preparation and on the size and shape of the molecular entity.…”

A Multi‐Redox Responsive Cyanometalate‐Based Metallogel

“…The mT value of 1 at 300 K was 7.99 emu mol -1 K, which corresponds to the expected value (8.02 emu mol -1 K) for four uncorrelated spins on the Ni II ions (S = 1, g = 2.3) [8] and four low-spin (LS) Fe III ions (S = 1/2, g = 2.7). [9] The mT values gradually increased as the temperature was lowered, reaching a maximum value of 19.94 emu mol -1 K at 5 K, before an abrupt decrease to 18.56 emu mol -1 K at 1.8 K. This indicates the occurrence of ferromagnetic interactions between the LS Fe III and Ni II ions. The magnetic data of 1 was analyzed by MAGPACK [10] and full details are described in the SI.…”