Organometallics
Article
+: m/z 253.9367 ([M]+ calcd 253.9362). Anal. Found: C, 47.17; H,
3.23. Calcd for C10H8FeCl2: C, 47.09; H, 3.16.
Computational Chemistry Software (NSCCS) at Imperial
College London in carrying out this work.
1,1′-Difluoroferrocene (fcF2).5b A mixture of ferrocene (1.678 g,
9.02 mmol, 1 equiv), TMEDA (3.4 mL, 22.68 mmol, 2.5 equiv), and n-
hexane (8.5 mL) was stirred in an oven-dried flask and cooled to 0 °C
(ice-bath). nBuLi (2.5 M) in hexanes (7.9 mL, 19.75 mmol, 2.2 equiv)
was added portionwise, and the mixture slowly raised to ambient
temperature with stirring overnight. (NOTE: the remaining steps were
completed within the same day to minimize product decomposition.)
The resulting bright orange suspension (1,1′-dilithioferrocene/
TMEDA) was isolated by cannula filtration, resuspended in diethyl
ether (22 mL), and cooled to −78 °C (acetone/dry ice), whereby N-
fluorobenzenesulfonimide (6.257 g, 19.84 mmol, 2.2 equiv) was added
over ∼2 min against nitrogen. The reaction mixture was stirred below
−70 °C for 3 h, then allowed to warm slowly to ambient temperature
by not adding dry ice. After ∼15 min at room temperature the yellow
suspension darkened with formation of a precipitate. This mixture was
cooled in an ice-bath and quenched with water (4 mL). Extraction
with diethyl ether and n-hexane and filtration through alumina
(Brockman grade II) provided a dark orange solution.
REFERENCES
■
(1) (a) Kealy, T. J.; Pauson, P. L. Nature 1951, 168, 1039.
(b) Nesmeyanov, A. N.; Perevalova, E. G.; Nesmeyanova, O. A. Dokl.
Akad. Nauk SSSR 1955, 100, 1099. (c) Nesmeyanov, A. N.; Sazonova,
V. A.; Drozd, V. N. Dokl. Akad. Nauk SSSR 1959, 126, 1004.
(d) Hedberg, F. L.; Rosenberg, H. J. Organomet. Chem. 1971, 28, C14.
(2) (a) Atkinson, R. C. J.; Gibson, V. C.; Long, N. J. Chem. Soc. Rev.
2004, 33, 313. (b) Butler, I. R. Eur. J. Inorg. Chem. 2012, 2012, 4387.
(3) (a) Morisaki, Y.; Chujo, Y. Macromolecules 2003, 36, 9319.
(b) Xue, W.-M.; Kuhn; Fritz, E.; Herdtweck, E.; Li, Q. Eur. J. Inorg.
̈
Chem. 2001, 2001, 213. (c) Sanechika, K.; Yamamoto, T.; Yamamoto,
A. Polym. J. 1981, 13, 255.
(4) (a) Engtrakul, C.; Sita, L. R. Nano Lett. 2001, 1, 541.
(b) Chawdhury, N.; Long, N. J.; Mahon, M. F.; Ooi, L.-l.; Raithby,
P. R.; Rooke, S.; White, A. J. P.; Williams, D. J.; Younus, M. J.
Organomet. Chem. 2004, 689, 840. (c) Vollmann, M.; Butenschon, H.
C. R. Chim. 2005, 8, 1282. (d) Getty, S. A.; Engtrakul, C.; Wang, L.;
Liu, R.; Ke, S.-H.; Baranger, H. U.; Yang, W.; Fuhrer, M. S.; Sita, L. R.
Phys. Rev. B: Condens. Matter Mater. Phys. 2005, 71, 241401. (e) Klein,
A.; Lavastre, O.; Fiedler, J. Organometallics 2006, 25, 635. (f) Ma, J.;
After reducing the solution in volume to ∼200 mL, it was washed
with 0.5 M aqueous FeCl3 (3 × 50 mL). When FcH and FcF
contaminants had been removed (composition monitored with 1H
NMR between washings), the organic phase was extracted with water
until the washings were colorless and reduced in volume to <5 mL.
The crude product was purified using column chromatography (silica;
n-pentane), collecting the first yellow band. The majority of solvent
was carefully removed under reduced pressure (NOTE: fcF2 is readily
sublimed in vacuo), then a concentrated solution was further dried in
air to yield fcF2 as an orange-yellow crystalline solid (0.041 g, 2%).
Crystals suitable for X-ray diffraction were grown by slow evaporation
Vollmann, M.; Menzel, H.; Pohle, S.; Butenschon, H. J. Inorg.
Organomet. Polym. Mater. 2008, 18, 41. (g) Engtrakul, C.; Sita, L. R.
Organometallics 2008, 27, 927. (h) Fan, Y.; Liu, I. P.-C.; Fanwick, P. E.;
̈
Ren, T. Organometallics 2009, 28, 3959. (i) Baumgardt, I.; Butenschon,
̈
H. Eur. J. Inorg. Chem. 2010, 2010, 1076. (j) Lu, Q.; Wang, X.-H.;
Wang, F.-S. Chin. J. Appl. Chem. 2011, 28, 136. (k) Inkpen, M. S.;
Albrecht, T.; Long, N. J. Organometallics 2013, 32, 6053. (l) Inkpen,
M. S.; White, A. J. P.; Albrecht, T.; Long, N. J. Dalton Trans. 2014, 43,
15287.
1
of an n-hexane solution. H NMR (400 MHz, CDCl3): δ (ppm) 3.90
(d pseudo-t, 4H, Cp−H, JHF = 1.20 Hz), 4.39 (d pseudo-t, 4H, Cp−H,
JHF = 2.20 Hz, JHH = ∼2.18 and ∼2.27 Hz). 13C{1H} NMR (126 MHz,
CDCl3): δ (ppm) 57.47 (d, 4C, Cp−F, CHα, JCF = 14.9 Hz), 62.53 (br
s, 4C, Cp, CHβ), 135.9 (d, 2C, Cp−F, CF, JCF = 269.2 Hz). 19F{1H}
NMR (377 MHz, CDCl3): δ (ppm) −188.0 (s, 2F, Cp−F). HR-MS
ES+: m/z 221.9949 ([M]+ calcd 221.9943). Anal. Found: C, 54.15; H,
3.60. Calcd for C10H8FeF2: C, 54.08; H, 3.63.
(5) (a) Kovar, R. F.; Rausch, M. D.; Rosenberg, H. Organomet. Chem.
Synth. 1971, 1, 173. (b) Gren, C. K. Vanderbilt University, 2009.
(6) Sunkel, K.; Weigand, S.; Hoffmann, A.; Blomeyer, S.; Reuter, C.
̈
G.; Vishnevskiy, Y. V.; Mitzel, N. W. J. Am. Chem. Soc. 2015, 137, 126.
(7) (a) Peet, J. H. J.; Rockett, B. W. J. Organomet. Chem. 1974, 82,
C57. (b) Adcock, W.; Khor, T. C. J. Organomet. Chem. 1975, 91, C20.
(8) Popov, V. I.; Lib, M.; Haas, A. Ukr. Khim. Zh. (Russ. Ed.) 1990,
56, 1115.
ASSOCIATED CONTENT
* Supporting Information
■
(9) Sunkel, K.; Weigand, S. Inorg. Chim. Acta 2011, 370, 224.
̈
S
(10) (a) Curnow, O. J.; Hughes, R. P. J. Am. Chem. Soc. 1992, 114,
5895. (b) Hughes, R. P.; Zheng, X.; Ostrander, R. L.; Rheingold, A. L.
Organometallics 1994, 13, 1567. (c) Hughes, R. P.; Zheng, X.; Morse,
C. A.; Curnow, O. J.; Lomprey, J. R.; Rheingold, A. L.; Yap, G. P. A.
Organometallics 1998, 17, 457.
The Supporting Information is available free of charge on the
Experimental details, NMR, UV−vis, and IR spectra,
additional electrochemical and crystallographic informa-
(11) (a) Winter, C. H. Synthesis and Properties of Perfluoroferro-
cene and Perfluororuthenocene. A Potential Class of High Temper-
ature Materials; Dept. Chem., Wayne State Univ., Detroit, MI, USA,
1995. (b) Hedberg, F. L.; Rosenberg, H. J. Am. Chem. Soc. 1973, 95,
870.
Crystallographic data (CIF)
(12) Koplitz, L. V.; McClure, D. S.; Crerar, D. A. Inorg. Chem. 1987,
26, 308.
AUTHOR INFORMATION
Corresponding Authors
■
(13) (a) Hedberg, F. L.; Rosenberg, H. Oxidation-resistant metal-
locenes. The synthesis and properties of perchloroferrocene and related
polychlorinated and fluorinated ferrocenes; Air Force Materials
Laboratory, Wright-Patterson Air Force Base, OH, 1970. (b) Hedberg,
F. L.; Rosenberg, H. J. Am. Chem. Soc. 1970, 92, 3239.
(14) (a) Cunningham, K. L.; McMillin, D. R. Polyhedron 1996, 15,
1673. (b) Goeltz, J. C.; Kubiak, C. P. Organometallics 2011, 30, 3908.
(c) Inkpen, M. S.; Du, S.; Driver, M.; Albrecht, T.; Long, N. J. Dalton
Trans. 2013, 42, 2813.
Author Contributions
§M. S. Inkpen and S. Du contributed equally to this work.
Notes
The authors declare no competing financial interest.
(15) Bulfield, D.; Maschke, M.; Lieb, M.; Metzler-Nolte, N. J.
Organomet. Chem. 2015, 797, 125.
ACKNOWLEDGMENTS
■
The authors thank Dr. Ian Butler (Bangor University, UK) for
useful discussions. S.D. thanks the China Scholarship Council,
and M.S.I., T.A., and N.J.L thank the Leverhulme Trust (RPG
2012-754) for funding. M.H. and N.M.H. would like to
acknowledge the use of the EPSRC UK National Service for
(16) Sanders, R.; Mueller-Westerhoff, U. T. J. Organomet. Chem.
1996, 512, 219.
(17) (a) Rausch, M. D.; Ciappenelli, D. J. J. Organomet. Chem. 1967,
10, 127. (b) Bishop, J. J.; Davison, A.; Katcher, M. L.; Lichtenberg, D.
W.; Merrill, R. E.; Smart, J. C. J. Organomet. Chem. 1971, 27, 241.
H
Organometallics XXXX, XXX, XXX−XXX