Cyanide-bridged iron(II,III) cube with multistepped redox behavior.
A building unit of Prussian blue was isolated as a cyanide-bridged iron cube of [Fe(II)4Fe(III)4(CN)12(tp)8] x 12 DMF x 2 Et2O x 4 H2O [tp(-) = hydrotris(pyrazolyl)borate]. A cyclic voltammogram showed quasi-reversible four-stepped redox waves, which correspond to [Fe(III)4Fe(II)4]/[Fe(III)5Fe(II)3](+), [Fe(III)5Fe(II)3](+)/[Fe(III)6Fe(II)2](2+), [Fe(III)6Fe(II)2](2+)/[Fe(III)7Fe(II)1](3+), and [Fe(III)7Fe(II)1](3+)/[Fe(III)8](4+) processes. Controlled potential absorption spectral measurements revealed two intervalence charge-transfer bands at 816 and 1000 nm, which were assigned to charge transfers from Fe(II) ions to adjacent and remote Fe(III) ions, respectively, in the cube.
Graduate School of Pure and Applied Sciences, Department of Chemistry, University of Tsukuba, Tennodai 1-1-1, Tsukuba 305-8571, Japan.
Masayuki
M
Nihei
Mayumi
M
Ui
Norihisa
N
Hoshino
Hiroki
H
Oshio