Doping effect on MX-chain compound

The ([Pt(en) 2 ][PtBr 2 (en) 2 ]} 3 (CuBr 4 ) 4 which consists of the double chain structures of the main one-dimensional Pt(II)-Pt(IV) chain and one-dimensional counteranion of trigonal bipyramidal Cu(I) ions, is doped with Br 2 . The intensities of d-d transitions and ESR spectra in Cu(II) species in counteranions increase as increase of exposure time. Accordingly, the induced Pt(III) species attributable to neutral solitons are considered to increase in the main chain by doping.