Luminescence spectrum of a strong electron-phonon coupling system trans-[PtCl2(en)(2)](ClO4)(2)

Electron-phonon interaction is studied on the trans-[PtCl2(en)(2)](ClO4)(2) , where en denotes ethylenediamine. The electronic states of platinum in th is system are directly modulated by the breathing mode of halogen ions and strong electron-phonon interaction occurs. Luminescence spectrum has a Gaus sian-like lineshape which is superimposed by phonon side bands of more than 20 series. The shape of the spectrum is well interpreted by taking account of halogen breathing mode. The estimated coupling strength (Haung-Rhys fac tor) is 9.52.