ORIGINAL PAPER Synthesis and Characterization of a Novel Conformation of 2,9,10-Tribromoanthracene-1,4-dione Kıymet Berkil Akar • Osman C ¸ akmak • Ertan S ¸ ahin Received: 28 January 2013 / Accepted: 16 September 2013 / Published online: 8 October 2013 Ó Springer Science+Business Media New York 2013 Abstract Synthesis and X-ray analysis of single crystals of 2,9,10-tribromoanthracene-1,4-dione 4 has been described and its novel conformation is reported. Single crystals were grown by slow evaporation technique from toluene solution at -15 °C. The compounds have been characterized by ele- mental analysis, FT-IR, Mass and NMR spectroscopy. The compound crystallizes in the triclinic space group P-1 with unit cell dimensions a = 7.6842(2), b = 9.4865(2), c = 19.9388(4) A ˚ , a = 78.784(5), b = 76.980(5), c = 67.834(4) A ˚ ; V: 1,301.75(7) A ˚ 3 ;Z = 2, R 1 = 0.0748, and wR 2 = 0.131. Keywords 1,4-Anthraquinone Á Bromoanthraquinone Á Single crystals Á X-ray diffraction Introduction Natural and synthetic anthraquinones have received a great deal of attention due to their wide application such as dyes, biologically active substances, medical agents, analytical reagents, indicators, catalysts for industrially important processes and data storage materials [1]. Although 9,10- anthraquinones have been extensively studied, 1,4-anthra- quinones have been scarcely studied [2]. There are many 1,4- anthraquinones used as tumor-cell-growth inhibitors [3, 4], optoelectronic dyes [5] and organic conductors [6]. Also this type of anthraquinones such as adriamycin and daunomycin are considered to be the basic building for the broad-spec- trum anti-cancer drugs. For these reason, interest in bioactive 1,4-anthraquinones has increased considerably [7]. Most recently [8], we have developed a selective and efficient method for the preparation of 2,9,10-tribromoan- thracene-1,4-dione (3) from 2,9,10-tribromo-1,4-dihydro- anthracene-1,4-diol (2). The reaction of (1R,2S,3R,4S)- 2,3,9,10-tetrabromo-1,2,3,4-tetrahydroanthracene-1,4-diol (1) with sodium methoxide afforded tribromodihydrox- yanthracene-1,4-diol 2 and whose oxidation with PCC gave 2,9,10-tribromoanthracene-1,4-dione (3) (Scheme 1). However, when we reacted compound 1 with PCC we encountered a novel conformer of 3 (Scheme 2). In this study, we report reaction procedure and detailed compar- ative spectral analysis of the both compounds 3 and 4. We also report here its crystal structure analysis obtained from single crystal X-ray diffraction method. Experimental Procedure Physical Techniques and Materials Dihydroxyanthracene 1 was prepared by silver ion assisted hydrolysis of (1R,2S,3R,4S)-1,2,3,4,9,10-hexabromo-1,2, 3,4-tetrahydroanthracene (6)[8]. Other reagents and sol- vents for synthesis, growth and analysis were commercially K. Berkil Akar (&) Department of Bioengineering, Faculty of Engineering and Natural Sciences, Gaziosmanpas ¸a University, Tas ¸lıc ¸iftlik, Tokat 60250, Turkey e-mail: kiymet.berkilakar@gop.edu.tr O. C ¸ akmak Department of Chemistry, Faculty of Art and Sciences, Yıldız Technical University, Davutpas ¸a, 34210 Istanbul, Turkey e-mail: cakmak.osman@gmail.com E. S ¸ ahin Department of Chemistry, Faculty of Science, Atatu ¨rk University, 25400 Erzurum, Turkey e-mail: ertan@atauni.edu.tr 123 J Chem Crystallogr (2013) 43:677–684 DOI 10.1007/s10870-013-0472-4