TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preparation (claimed): The process for preparation of the compound (I) (where R1, R2, R3 and R4 are H, Cl or Br, with the proviso that at least one of R1, R2, R3 and R4 is Cl, or Br), involves: chlorinating or brominating a tetraazapyren compound of formula (i) using a chlorination or bromination agent. The tetraazapyrene compound (i) is obtained by reacting tetraaminonaphthalene hexachlorostannate with a carboxylic acid anhydride of formula R5-C(=O)-O-C(=O)-R5. Preferred Components: The chlorination agent is N,N'-dichloroisocyanuric acid. The bromination agent is N.N'-dibromoisocyanuric acid. Preferred Definitions:    R1 and R3=Cl, Br, 6-14C aryloxy, or 6-14C arylthio;    R2 and R4=H, Cl, Br, 6-14C aryloxy, or 6-14C arylthio;    R5 and R6=phenyl (substituted by 1-5 F), or 1-6C perfluoroalkyl.    SPECIFIC COMPOUNDS - 10 Compounds are disclosed as the compound (I) e.g. 2,7-bis-(pentafluorophenyl)-4,5,9,10-tetrabromotetraazapyrene of formula (I'); 2,7-bis-(pentafluoroethyl)-tetraazapyrene; 2,7-bis-(heptafluoropropyl)-tetraazapyrene; 2,7-bis-(trifluoromethyl)-4,5,9,10-tetrachloro-1,3,6,8-tetraazapyrene; and 4,9-bis-(4-cyanophenyl)-1,3,6,8-tetraazapyrene.    EXAMPLE - 1,4,5,8-Tetraaminonaphthalene hexachlorostannate (704 mg) was suspended in anhydrous tetrahydrofuran (20 ml). To the suspension, anhydrous triethylamine (1 ml) was added. 2,3,4,5,6-Pentrafluorobenzoic acid anhydride (3.31 g) was added, obtained reaction mixture was stirred for 72 hours at 70 degrees C under argon atmosphere, and then reaction was worked up to give 2,7-pentafluorophenyl-1,3,6,8-tetraazapyrene. To a solution of 2,7-pentafluorophenyl-1,3,6,8-tetraazapyrene (60 mg) in concentrated sulfuric acid (20 ml) was added bromine (1 ml). The solution was stirred at 90 degrees C for 4 hours, and then reaction was worked up to give 2,7-bis-(pentafluorophenyl)-4,5,9,10-tetrabromotetraazapyrene (15 mg, yield = 16%). The charge carrier mobility of compound (I') ( mu ) was found to be 0.0006 cm2/Vs.