TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preparation (Claimed): Preparation of (I) comprises (a) contacting (2,1';5',2'')ternaphthalene-3,3''-dicarboxylic acid (c3) with polyphosphoric acid to produce tetraceno(2,1,12-qra)tetracene-8,17-dione (c4), contacting (c4) with R-silyl acetylene, tetrahydrofuran and n-butyl lithium (where R is triisopropyl or N-octyldiisopropylsilyl), contacting the result with tin(II) chloride in hydrochloride to give 7,14-diethynyl-dibenzo(b,def)chrysene compounds of formula (p1) (representative of (I)) or (b) contacting dimethyl 2,2'-(naphthalene-1,5-diyl)dibenzoate compounds of formula (3A) with polyphosphoric acid to produce dibenzo(b,def)chrysene compounds of formula (4A), contacting (4A) with R-acetylene, and n-butyl lithium, contacting the result with tin(II) chloride in hydrochloride to give (I). Preferred Method: The method further comprises: contacting (2,1';5',2'')ternaphthalene-3,3''-dicarboxylic acid dimethyl ester (c2) with potassium hydroxide in methanol and tetrahydrofuran to yield (c3) and contacting 3-(4,4,5,5-tetramethyl-(1,3,2)dioxaborolan-2-yl)-naphthalene-2-carboxylic acid methyl ester (c1) with 1,5-dibromonaphthalene, palladium(0), tetrahydrofuran and potassium carbonate to yield (c2); or contacting dimethyl 2,2'-(naphthalene-1,5-diyl)dibenzoate compound of formula (2A) with potassium hydroxide in methanol and tetrahydrofuran to yield (3A) and contacting 2-(4,4,5-trimethyl-(1,3,2)dioxaborolan-2-yl)-benzoic acid methyl ester compounds of formula (1A) with 1,5-dibromonaphthalene, palladium(0), tetrahydrofuran and potassium carbonate to yield (2A). Preferred Components: The palladium(0) is tetrakis(triphenylphosphine)palladium(0). The FET is a single crystal. SPECIFIC COMPOUNDS - 2 Compounds (I) are specifically claimed i.e. 8,17-bis((triisopropylsilyl)ethynyl)tetraceno(2,1,12-qra)tetracene of formula (Ia) and 8,17-bis((diisopropyl(octyl)silyl)ethynyl)tetraceno(2,1,12-qra)tetracene.    EXAMPLE - To a solution of 1.27 g triisopropylsilylacetylene in dry 100 ml tetrahydrofuran, 2.7 ml n-butyl lithium at 0 degrees C was added. The solution was stirred for 1 hour at 0 degrees C before the addition of 0.5 g anthanthrene quinone. The mixture was warmed and stirred overnight. A solution of 1 g tin(II) chloride dihydrate in 2.5 ml hydrochloric acid was added to the solution, and stirred for 3 hours and poured into 500 ml water, extracted with chloroform, and dried. The crude product was purified to give 8,17-bis((triisopropylsilyl)ethynyl)tetraceno(2,1,12-qra)tetracene (65%).