TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preparation (Claimed): Preparation of (I) comprises: subjecting an optionally substituted dibenzothiophene to a Friedel-Crafts reaction with phthalic anhydride to give an optionally substituted 2-(2'-carboxybenzoyl)dibenzothiophene; treating the acid group of the optionally substituted 2-(2'-carboxybenzoyl)dibenzothiophene with a dehydrating agent, to give an optionally substituted anthra(2,3-b)benzo(d)thiophene-7,12-dione; and reacting the optionally substituted anthra(2,3-b)benzo(d)thiophene-7,12-dione with the lithium salt of a trisubstituted silylacetylene reagent, followed by aromatization, preferably utilizing tin (II) chloride, under acidic conditions to give 7,12-bis(trisubstituted silylethynyl)anthra(2,3-b)benzo(d)thiophene (representative of (I)). EXAMPLE - To a mixture of aluminum chloride (40 g) in anhydrous dichloromethane (1000 cm3) was added to a suspension of phthalic anhydride (14.8 g) in anhydrous dichloromethane (200 cm3). The suspension was stirred for 30 minutes, cooled to 5 degrees C and then a solution of dibenzothiophene (20 g) in anhydrous dichloromethane (200 cm3) was added drop wise under cooling with ice. After addition, the mixture was allowed to stir at 23 degrees C for 4 hours. The reaction mixture poured into a solution of water (1000 cm3) and concentrated hydrochloric acid (400 cm3). The obtained product was worked up to afford 2-(ortho-carboxybenzoyl)dibenzothiophene. To a mixture of the 2-(ortho-carboxybenzoyl)dibenzothiophene (35.6 g) and phosphorus pentachloride (33.5 g) in anhydrous 1,2-dichlorobenzene (430 cm3) was added aluminum chloride (21.4 g). The mixture was then heated at 140 degrees C for 17 hours. The reaction mixture was cooled to 23 degrees C and the solvent was removed under vacuum to give a black solid. Acetone (500 cm3) was added and the mixture was filtered to give a green/yellow solid which was dried under vacuum. To the solid, dichloromethane (1000 cm3) was added and the mixture was heated. The hot mixture was passed through a very short plug of silica (dichloromethane) to give anthra(2,3-b)benzo(d)thiophene-7,12-dione as a yellow solid (5.43 g). To a solution of triethylsilyl acetylene (3.68 g) in anhydrous 1,4-dioxane (120 cm3) at room temperature was added n-butyl lithium (2.5 M in hexanes, 9.7 cm3, 24 mmol) drop wise. The reaction mixture was then stirred for 1 hour at 23 degrees C before the anthra(2,3-b)benzo(d)thiophene-7,12-dione (2 g) was added. The reaction mixture was then heated at reflux for 6 hours, the heating turned off and the mixture was allowed to cool in the dark. Solid tin(II) chloride (8.93 g) was added piecewise over 5 minutes and then the reaction mixture was allowed to stir for a further 5 minutes. Concentrated hydrochloric acid (20 cm3) was added slowly, and the mixture was stirred for 1 hour in the dark. The mixture was poured into water (200 cm3) and worked to afford 7,12-bis(triethylsilylethynyl)anthra(2,3-b)benzo(d)thiophene (740 mg).