Electrochromic device

An electrochromic device having an ion conductive layer disposed between two electrically conductive substrates, at least one of which is transparent, wherein said ion conductive layer contains an organic compound having a structure exhibiting a cathodic electrochromic characteristic and a structure exhibiting an anodic electrochromic characteristic, and wherein the organic compound is a metallocene-bipyridine derivative represented by one of formulae (4) to (7):

• wherein A− and B− are each independently a pair-anion selected from the group consisting of a halogen anion, ClO4−, BF4−, PF6−, AsF6−, SbF6−, CHCOO−, and CH3(C6H4)SO3−;
• R1 and R2 are each independently a hydrocarbon group selected from the group consisting of an alkyl, alkenyl and aryl group having 1 to 10 carbon atoms, in the case where R1 or R2 is an aryl group, the aryl group forms a condensed ring together with a cyclopentadienyl ring, m is an integer of 0≦m≦4, n is an integer of 0≦n≦4;
• Me represents Cr, Co, Fe, Mg, Ni, Os, Ru, V, X—HF—Y, X—Mo—Y, X—Nb—Y, X—Ti—Y, X—V—Y or X—Zr—Y wherein X and Y are each independently selected from the group consisting of hydrogen, halogen, and an alkyl group having 1 to 12 carbon atoms;
• R3 and R4 are each independently a hydrocarbon residue having 1 to 20 carbon atoms;
• R5 is a hydrocarbon group selected from the group consisting of an alkyl, cycloalkyl, alkenyl, aryl, or aralkyl group having 1 to 20 carbon atoms, a heterocyclic group having 4 to 20 carbon atoms, and a substituted hydrocarbon or heterocyclic group obtained by substituting part of the hydrocarbon group or heterocyclic group with a substituent group.