Methyleneanthrone forms solid coloured complexes with chlorides of antimony (V), bisumth (III) and chlorides and bromides a of boron and aluminium (III) in the ratio 1:1 and with tin, titanium and zir-conium chlorides and bromides in the ratio 2:1. It does not from addition complexes with iodides of these metels. The complexes of tin (IV) and antimony (V) halides are nonionic and monomeric in nitrobenzene. Thermogravimetric analysis of titanium (IV) halide adducts suggest there existence as addition dimers. unlike complexes of other metal halides, titanium (IV) halide adducts do not show lowering of cabonly stretching frequency in the infrared spectra. The probable reason has been discussed.