A novel photochromic compound NH3CH2CH2NH3Mo3O10 ·4.4H2Ohas been synthesized using ethylendiammonium cations as template under mild chemical conditions. Elemental analysis, TGA curve and IR spectra show that its inorganic framework is constructed from infinite chains of (Mo3O10)∞^2-. Ethylenediammonium cations are bounded to the inorganic chain structure through a supramolecular interaction. It is found that this compound has good photochromic property. Differing from vacuum deposited MoO3 film, this compound turns from white to reddish brown after UV irradiation. EXAFS spectra confirm proton transfer from ethylenediammonium cations to Mo-O^- after UV irradiation.

Key words: SKELETON STRUCTURE, MOLYBDATE P, ETHANEDIAMINE P, SYNTHESIS METHODS, PHOTOCHROMISM, DISCOLORATION MATERIAL