TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preparation (Claimed): Preparation of (I) comprises carrying out at least one condensation reaction between an aldehyde compound and an aryl compound having at least one amino group. Preferred Definitions:    E = S(=O)2, where the group E is in m or p to the group Y1;    W1 = N;    X = CR1;    Y1 = NR1; and    R1 = 5-20 membered heteroaryl ring containing heteroaryl five or six ring with two or more heteroatoms such as N, O or S or carbazole ring (all optionally substituted with R2).    SPECIFIC COMPOUNDS - 82 Compounds (Q) are disclosed e.g. 1-(4,6-diphenyl-(1,3,5)triazin-2-yl)-2-phenyl-5-(toluene-4-sulfonyl)-1H-benzoimidazole of formula (Qa), 9-(6-benzenesulfonyl-1-phenyl-1H-benzoimidazol-2-yl)-9H-carbazole, 9-(5-benzenesulfonyl-1-phenyl-1H-benzoimidazol-2-yl)-9H-carbazole, 5-benzenesulfonyl-1-(4,6-diphenyl-(1,3,5)triazin-2-yl)-2-phenyl-1H-benzoimidazole and 6-benzenesulfonyl-1-(4,6-diphenyl-(1,3,5)triazin-2-yl)-2-methyl-1H-benzoimidazole.    EXAMPLE - 5((2-Phenyl-1H-benzimidazol-5-yl)thio)-9-phenyl-N-carbazole (22.9 g) was added to glacial acetic acid (0.3 l) under inert gas. Further 30% hydrogen peroxide solution (33 ml) was drop-wise added and stirred overnight. The mixture was treated with sodium sulfite solution and the phases were separated. The solvent was removed in vacuum to obtain 5((2-phenyl-1H-benzimidazol-5-yl)sulfonyl)-9-phenyl-N-carbazole (23.2 g). 5((2-Phenyl-1H-benzimidazol-5-yl)sulfonyl)-9-phenyl-N-carbazole (14.3 g) was dissolved in dimethylformamide under inert gas (225 ml) and reacted with 60% sodium hydride (5 g) in mineral oil (37.5 mmole). After 1 hour at room temperature, a solution of 2-chloro-4,6-diphenyl-(1,3,5) triazine (8.5 g) was added drop-wise added in dimethylformamide (75 ml). The reaction mixture was then stirred at room temperature for 12 hours. Further the reaction mixture was poured on ice and extracted three times with dichloromethane. The combined organic phases were dried over sodium sulfate and concentrated. The residue was extracted with hot toluene, recrystallized in toluene and finally sublimed in high vacuum to obtain 9-(4-(1-(4,6-diphenyl-(1,3,5)triazin-2-yl)-2-phenyl-1H-benzoimidazole-5-sulfonyl)-phenyl)-9H-carbazole with a purity of 99.9% (17.36 g).