A novel family of lipophilic, photo-responsible supramolecular wires that contain 1D Fe(II) triazole complexes is developed. A triazole ligand 2 contains azobenzene group and it formed a 1D iron(II) complex Fe(2)3(BF 4)2, which is soluble in common organic solvents. Atomic force microscopy (AFM) of the sample in dilute chloroform solutions showed flexible molecular wires (length, 10 - 100 nm, width, ca. 7 nm). On the other hand, it formed aggregates and gave organogels when dispersed in chlorocyclohexane. The yellow chlorocyclohexane gel is liquefied by UV-irradiation and an orange-colored solution was obtained. This is ascribed to the trans-to-cis photoisomerization of azobenzene units, which is accompanied by morphological changes to undulated molecular wires. Visible-light illumination of the Fe(cw-2)3(BF4)2 complex reversibly afforded Fe(trans-2)3(BF4)2 complex, which is accompanied by physical gelation. Thus, the molecular wire of Fe(2) 3(BF4)2 show reversible conformational changes with maintaining the linear complex structures. This is the first example of photo-responsive 1D metal complexes which are dispersed in solution.
|Number of pages||2|
|Publication status||Published - Dec 1 2006|
|Event||55th Society of Polymer Science Japan Symposium on Macromolecules - Toyama, Japan|
Duration: Sep 20 2006 → Sep 22 2006
|Other||55th Society of Polymer Science Japan Symposium on Macromolecules|
|Period||9/20/06 → 9/22/06|
All Science Journal Classification (ASJC) codes