The solid-state molecular structure of centrohexaindane (), a unique hydrocarbon comprising six benzene rings clamped to each other in three dimensions around a neopentane core, and the molecular packing in crystals of ·CHCl3 are reported. The molecular Td-symmetry and the Cartesian orientation of the six indane wings of in the solid state have been confirmed. The course and limitation of electrophilic aromatic substitution of are demonstrated for the case of nitration. Based on nitration experiments of a lower congener of , tribenzotriquinacene , the six-fold nitrofunctionalisation of has been achieved in excellent yield, giving four constitutional isomers, two nonsymmetrical ( and ) and two C3-symmetrical ones ( and ), all of which contain one single nitro group in each of the six benzene rings. The relative yields of the four isomers (∼3 : 1 : 1 : 3) point to a random electrophilic attack of the electrophiles at the twelve formally equivalent outer positions of the aromatic periphery of , suggesting electronic independence of its six aromatic π-electron systems. In turn, the pronounced conformational rigidity of the centrohexacyclic framework of enables the unequivocal structural identification of the isomeric hexanitrocentrohexaindanes by (1)H NMR spectroscopy.

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Centrohexaindane was converted into its T -symmetrical 2,3,6,7,10,11,14,15,20,21,26,27-dodecabromo and -dodecaiodo derivatives using N-bromo- and N-iodosuccinimide, respectively, in the presence of trifluoromethanesulfonic acid as a catalyst in single, highly efficient steps. Sonication or microwave irradiation was indispensable to enforce exhaustive halogenation of the twelve equivalent peripheral positions of this Cartesian polyaromatic hydrocarbon. Despite their extremely poor solubility in most organic solvents, the new dodecahalo derivatives were fully characterized, including single crystal X-ray structure analysis. Subsequent Pd -catalyzed twelve-fold C-C cross-coupling reactions furnished the corresponding dodecamethyl, dodeca(phenylethynyl) and dodecaphenyl derivatives in good to excellent yields. The latter hydrocarbon was also analyzed by X-ray diffraction.

The synthesis of three multiply substituted fenestrindanes (all‐cis‐tetrabenzo[5.5.5.5]fenestranes) is described in detail. Depending on the stereochemical course of the twofold Michael addition of a 1,3‐indanedione to a dibenzylideneacetone in the very first step, the corresponding all‐cis‐tribenzo[5.5.5.6]fenestranones or the strained cis,cis,cis,trans isomers are obtained. In the latter case, stereochemical adjustment to the all‐cis configuration can be achieved by base‐induced epimerization. Conversion of the all‐cis‐[5.5.5.6]fenestranones in five subsequent steps affords the target fenestrindanes bearing either methyl groups at four of the inner (bay) positions or methoxy groups at four or six of the outer (peripheral) positions of the molecular framework.

The single functionalization of the parent centropolyindane hydrocarbons fenestrindane (2) and centrohexaindane (3) at the molecular arene periphery has been studied. The monoformylation of 2 and 3 using the Rieche method resulted in the corresponding aldehydes, 7 and 10, in 23% and 35% yield, respectively. The Friedel-Crafts acetylation of 2 furnished 2-acetylfenestrindane (8) in 53% yield, and the Baeyer-Villiger oxidation of 7 followed by hydrolysis resulted in the 2-hydroxyfenestrindane (9) in 72% yield. The results show that electrophilic attack at one of the eight or, respectively, even 12 equivalent positions of 2 and 3 is a viable method for the monofunctionalization of these polycyclic aromatic hydrocarbons.