Seven-Minute Synthesis of Pure C s -C 60 Cl 6 from [60]Fullerene and Iodine Monochloride: First IR, Raman, and Mass Spectra of 99 mol% C 60 Cl 6 Igor V. Kuvychko, [a] AlexeyV. Streletskii, [b, c] Alexey A. Popov, [b] Sotirios G. Kotsiris, [c] Thomas Drewello,* [c] Steven H. Strauss,* [a] and Olga V. Boltalina* [a, b] Introduction Among the simple, s-bonded derivatives of fullerenes, halo- genated compounds have attracted a great deal of attention over the years. Dozens of C 60 derivatives containing from 2 to 48 fluorine atoms and, in many cases, other substituents as well have been extensively studied. [1,2] In addition, bromi- nation of C 60 yielded the three single-composition/single- isomer products C s -C 60 Br 6 , C 2v -C 60 Br 8 , and T h -C 60 Br 24 , all of which have been structurally characterized. [3,4] As far as chloro[60]fullerenes are concerned, the situation is paradoxi- cal. Although chlorination was one of the first C 60 derivati- zations reported in the literature, revealing the formation of C 60 Cl 6 [5] and putative C 60 Cl n compounds with up to 24 chlor- ine atoms s-bonded to the C 60 cage, [6,7] structurally-charac- terized compounds such as T h -C 60 Cl 24 , [8] C 1 -C 60 Cl 28 , [9] C 2 - C 60 Cl 30 , [9] and D 3d -C 60 Cl 30 [10] have only been reported in the past few months (the compound C 60 Cl 6 is believed to have the same structure as C s -C 60 Br 6 based on its 13 C NMR spec- trum [5] ). Nevertheless, after nearly 15 years the composition- al purity of C 60 Cl 6 , which has always been assumed to be high, [5,11,12] has never been satisfactorily demonstrated (i.e., none of the three previous reports of its synthesis properly established its purity [5,11,12] ). In fact, recent work by us [13] and others [14] suggests that it may be only about 75% pure. The facile transformation of fullerene C ÀCl bonds into C À R or C À Ar bonds by Olah and co-workers in 1991 sug- gested that chlorofullerenes could be useful synthons. [7] Sub- sequent papers by others reported the use of C 60 Cl 6 to pre- pare organic derivatives of C 60 . [14–16] It is possible that chlor- ofullerenes could also be used to prepare new inorganic full- erene derivatives under mild conditions (a recent, related example involving a bromofullerene is the transformation of T h -C 60 Br 24 to kinetically-stable T h -C 60 F 24 at 25 8C [17] ). Howev- er, significant progress in the use of chlorofullerene synthons Abstract: Three previously reported procedures for the synthesis of pure C s - C 60 Cl 6 from C 60 and ICl dissolved in benzene or 1,2-dichlorobenzene were shown to actually yield complex mix- tures of products that contain, at best, 54–80% C s -C 60 Cl 6 based on HPLC in- tegrated intensities. MALDI mass spec- trometry was used for the first time to identify other components of the reac- tion mixtures. An improved synthetic procedure was developed for the syn- thesis of about 150 mg batches of chlor- ofullerenes containing 90% C s -C 60 Cl 6 based on HPLC intensities. The opti- mum reaction time was decreased from several days to seven minutes. Small amounts of the product were purified by HPLC (toluene eluent) to 99% purity. The pure compound C s -C 60 Cl 6 is stable for at least three months as a solvent-free powder at 25 8C. The Raman, far-IR, and MALDI mass spectra of pure C s -C 60 Cl 6 are reported for the first time. The Raman and far- IR spectra, the first reported for any C 60 Cl n chlorofullerene, were used to carry out a vibrational analysis of C s - C 60 Cl 6 at the DFT level of theory. Keywords: fullerenes · iodine · mass spectrometry · Raman spectroscopy [a] I. V. Kuvychko, Prof. S. H. Strauss, Prof. O. V. Boltalina Department of Chemistry, Colorado State University Fort Collins, CO 80523 (USA) Fax: (+ 1)970-491-1801 E-mail: steven.strauss@colostate.edu ovbolt@lamar.colostate.edu [b] Dr. A. V. Streletskii, Dr. A. A. Popov, Prof. O.V. Boltalina Chemistry Department, Moscow State University Moscow 119992 (Russia) [c] Dr. A. V. Streletskii, Dr. S. G. Kotsiris, Dr. T. Drewello Department of Chemistry, Warwick University Coventry CV4 7AL (UK) Fax: (+ 44)024-765-24112 E-mail: t.drewello@warwick.ac.uk Supporting information for this article is available on the WWW under http://www.chemeurj.org/ or from the author: A complete list of experimental and calculated vibrational frequencies, intensities, and normal-mode descriptions. # 2005 Wiley-VCH Verlag GmbH&Co. KGaA, Weinheim DOI: 10.1002/chem.200500185 Chem.Eur.J. 2005, 11, 5426–5436 5426