Ferrocenes molecular magnets

Novel species developed for molecular switching have magnetic Fe304 particles linked to the control moiety by derivatized silicate linkages. Two of the control units themselves contain iron, in a ferrocene derivative and in a heme derivative. 

Fe2(III,III)2+ states. By considering that organometallic dendrimers based on conjugated ferrocene units are of special importance since mixed-valence states have interesting electrical, redox, and magnetic properties, recently three generations of polypropylene amine) dendrimers, decorated at their periphery with 4, 8, and 16 (compound 6, Fig. 6.6a) BFc units, respectively, have been synthesized and the electrochemical behavior of the dendrimers complexed with (3-cyclodextrins ([3-CD) and adsorbed at self-assembled monolayers (SAMs) of heptathioether-functionalized [3-CD on gold (molecular printboard) has been studied.40... 

Ferrocene and some of its derivatives are well suited for the formation of CT complexes and offer an entry into solid state organometallic chemistry. Because such CT complexes contain radical species, the consideration of their physical properties is of fundamental importance and now constitutes an interdisciplinary research field. The systematic study of the magnetic properties of CT complexes of, notably, decamethylferrocene, by the Miller Epstein group has led to the discovery of bulk ferromagnetic molecular materials and to new insights into the mechanisms of magnetic coupling. Such results have shown that ID materials, as most CT complexes are, can display 3D properties if the molecular components are matched... 

The method of proton or nuclear magnetic resonance has been applied to the compounds (C5H6)2ReH and Fe(C5H6)2 (213, 132). Furthermore, attempts were made by spectrophotometric methods to establish the formation of a thermodynamically stable molecular complex of fer rocene (H). According to these measurements, ferrocene and iodine together in solution show no charge transfer complex, but are merely in thermal equilibrium with ferricinium triiodide. 

Interest in organometallic maaomolecules has grown exponentially ever since Arimoto and Haven first polymerized vinylferrocene in 1955 [1]. Organometallic polymers are known to possess unique optical, magnetic, and thermal properties which allow for potential applications as chemical sensors, electrocatalysts, modified electrodes, and photo-active molecular devices [2-7]. Organoiron polymers are one of the most prevalent classes of organometallic polymers, with many reports on their synthesis and properties published over the past 50 years [8-11]. Of the many varieties of organoiron species, ferrocene and cationic cyclopentadienyliron complexes are most commonly incorporated into polymers. 

The development of processible high-molecular-weight polymers with skeletal transition metal atoms, as present in ferrocenes, represents a synthetic challenge, and a variety of materials with novel electrical, optical and magnetic properties can be expected . In this context, polymers containing repeating ferrocenyl units are of great interest. Some representative examples are listed in Scheme 18. 

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