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Dicyclohexane-annelated anthracene was synthesized by a new efficient method, which employed the Diels–Alder reaction between in situ-generated 2,3-dehydronaphthalene and dicyclohexane-fused furan. The molecule adopted antiparallel face-to-face slipped π-stacking in its crystal structure, which induced an excimer-like emission in the solid state.

We synthesized 1,4-dipropyltetracene on a 200-mg scale, the key step of which involved a Diels-Alder reaction between alkyl-substituted o-quinodimethane, generated in situ, and 1,4-naphthoquinone. The product was obtained as an orange solid, which was soluble in organic solvents including hexane. The optical properties of the product in solution showed no marked differences from those of other 1,4,7,10-tetraalkyltetracenes. Solid-state absorption and fluorescence spectra

Other polycyclic compounds Q 1150Facile Synthesis, Crystal Structure, and Solid-State Fluorescence of Dicyclohexane-Anellated Anthracene. -Diels-Alder reaction between in situ-generated 2,3-dehydronaphthalene and the dicyclohexane-fused furan (II) gives rise to adduct (IV). The transformation of (IV) into the dicyclohexane-anellated anthracene (V) is achieved by one-step deoxygenation with low-valent titanium. Intermediate (II) is obtained by homocoupling of cyclohexanone (I) with NiO2, followed by the Paal-Knorr furan synthesis. For comparison purposes the synthesis of dipropylanthracene (VIII) is presented. Compound (V) adopts anti-parallel face-to-face slipped π-stacking in its crystal structure, inducing an excimer-like emission, whereas the fluorescence of (VIII) is an exciton-like emission. -(KITAMURA*, C.; MATSUMOTO, C.; KAWATSUKI, N.; YONEDA, A.; ASADA, K.; KOBAYASHI, T.; NAITO, H.; Bull. Chem. Soc. Jpn. 81 (2008) 6, 754-756; Dep. Mater. Sci. Chem., Univ. Hyogo, Himeji, Hyogo 671, Japan; Eng.) -H. Hoennerscheid 39-088