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Preferred IUPAC name Indenoindene | |
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Chemical formula | C16H10 |
Molar mass | 202.256 g·mol |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C , 100 kPa). Infobox references |
Dibenzopentalene (dibenzopentalene or dibenzopentalene) is an organic compound and a hydrocarbon with formula C16H10. It is of some scientific interest as a stable derivative of the highly reactive antiaromatic pentalene by benzannulation. The first derivative was synthesised in 1912 by Brand. The parent compound was reported in 1952. The NICS value for the 5-membered rings is estimated at 7.4 ppm and that of the six-membered rings -9.8 ppm. Aromatic dicationic salts can be obtained by reaction with antimony pentafluoride in sulfuryl chloride. The dianion forms by reduction with lithium metal or deprotonation of 5,10-dihydroindenoindene with two equivalents of butyllithium. The aromatic nature of the dianion has been confirmed by X-ray analysis. Another isomer of this compound exists called dibenzopentalene with one of the benzene rings positioned on the other available pentalene face.
References
- ^ Saito, Masaichi (2010). "Synthesis and Reactions of Dibenzo\a,e]pentalenes". Symmetry. 2 (2): 950–969. Bibcode:2010Symm....2..950S. doi:10.3390/sym2020950.
- Brand, K. Über Gefärbte Kohlenwasserstoffe der Diphensuccinden-Reihe. Ber. Detsch. Chem. Ges. 1912, 45, 3071-3077
- Blood, C. T.; Linstead, R. P. (1952). "422. Fused carbon rings. Part XXI. Dibenzopentalene". Journal of the Chemical Society (Resumed): 2263. doi:10.1039/JR9520002263.
- Willner, Itamar; Rabinovitz, Mordecai (1978). "1,9-Dimethyldibenzo\b,f]pentalene dication and dianion. New 14.pi. And 18.pi. Aromatic systems". Journal of the American Chemical Society. 100: 337–338. doi:10.1021/ja00469a085.
- Willner, Itamar; Becker, James Y.; Rabinovitz, Mordecai (1979). "Manifestation of dual aromaticity in doubly charged annelated pentalenes". Journal of the American Chemical Society. 101 (2): 395. doi:10.1021/ja00496a020.
- Saito, Masaichi; Nakamura, Michio; Tajima, Tomoyuki; Yoshioka, Michikazu (2007). "Reduction of Phenyl Silyl Acetylenes with Lithium: Unexpected Formation of a Dilithium Dibenzopentalenide". Angewandte Chemie International Edition. 46 (9): 1504–7. doi:10.1002/anie.200604067. PMID 17387657.