Communications
on Metalloproteins (Eds.: A. Bertini, A. Sigel, H. Sigel), Marcel
Dekker, New York, 2001, p. 813; d) M. D. Harrison, C. Denni-
son, ChemBioChem 2004, 5, 1579.
methane solution of 2 layered with n-hexane. Crystal data:
C42H54CuN2O2S2 (746.53); monoclinic P21/n; a = 16.3439(2), b =
14.5226(2), c = 16.9358(3) ꢀ; b = 90.140(1)8; V= 4019.8(1) ꢀ3;
[3] a) J. Rall, W. Kaim, J. Chem. Soc. Faraday Trans. 1994, 90, 2905;
b) C. G. Pierpont, C. W. Lange, Prog. Inorg. Chem. 1994, 41, 331;
c) C. G. Pierpont, Coord. Chem. Rev. 2001, 99, 216; d) D. A.
Shultz, Comments Inorg. Chem. 2002, 23, 1.
Z = 4; 1calcd = 1.234 gcmꢀ3
;
m = 0.683 mmꢀ1
;
T= 100(2) K;
number of unique reflections 9142, number of parameters 498;
R1 = 0.0475, wR2 = 0.1143 (I > 2s(I)); R1 = 0.0570, wR2 =
0.1203 (all data); GOOF = 1.044. The structure was solved by
direct methods and refined using the SHELXS-97/SHELXL-97
program package (G. M. Sheldrick, SHELXS-97, Program for
the Solution of Crystal Structures, University of Gꢂttingen,
Germany, 1997, G. M. Sheldrick, SHELXL-97, Program for the
Refinement of Crystal Structures, University of Gꢂttingen,
Germany, 1997). The scattering factors for the neutral atoms
were those incorporated in the programs. CCDC-251450 con-
tains the supplementary crystallographic data for this paper.
These data can be obtained free of charge from the Cambridge
request/cif.
[4] a) J. Rall, M. Wanner, M. Albrecht, F. M. Hornung, W. Kaim,
Chem. Eur. J. 1999, 5, 2802; b) W. Kaim, M. Wanner, A. Knꢂdler,
S. Zalis, Inorg. Chim. Acta 2002, 337, 163; c) G. A. Abakumov,
V. K. Cherkasov, V. I. Nevodchikov, V. A. Kuropatov, G. T. Yee,
C. G. Pierpont, Inorg. Chem. 2001, 40, 2434; d) G. Speier, Z.
Tyeklꢃr, P. Tꢄth, E. Speier, S. Tisza, A. Rockenbauer, A. M.
Whalen, N. Alkire, C. G. Pierpont, Inorg. Chem. 2001, 40, 5653.
[5] a) G. A. Abakumov, V. K. Cherkasov, M. P. Bubnov, O. G.
Ellert, Yu. V. Rakitin, L. N. Zakharov, Yu. T. Struchkov, Yu. N.
Safꢅyanov, Izv. Akad. Nauk Ser. Khim. 1992, 10, 2315; b) A. Dei,
D. Gatteschi, C. Sangregorio, L. Sorace, Acc. Chem. Res. 2004,
37, 827.
[10] a) S. Bhattacharya, P. Gupta, F. Basuli, C. G. Pierpont, Inorg.
Chem. 2002, 41, 5810; b) K. S. Min, T. Weyhermꢆller, E. Bothe,
K. Wieghardt, Inorg. Chem. 2004, 43, 2922.
[6] P. Chaudhuri, C. N. Verani, E. Bill, E. Bothe, T. Weyhermꢆller,
K. Wieghardt, J. Am. Chem. Soc. 2001, 123, 2213.
[7] a) D. M. Dooley, M. A. McGuirl, D. E. Brown, P. N. Turowski,
W. S. McIntire, P. F. Knowles, Nature 1991, 349, 262; b) M. A.
McGuirl, D. E. Brown, D. M. Dooley, J. Biol. Inorg. Chem. 1997,
2, 336.
[11] a) The magnetic susceptibility measurements were performed
on a powder sample of 2 using a Quantum Design MPMSXL7
SQUID magnetometer. The data were corrected for the
diamagnetic contributions to the molar magnetic susceptibility
using Pascalꢅs constants and for temperature-independent para-
magnetism (TIP = 120 ꢁ 10ꢀ6 cm3 molꢀ1); b) The following con-
straints were used: The g values of the radicals and the CuII
center were taken to be 2.00 (see EPR discussion). Furthermore,
the difference between the two exchange interaction parameters
was not allowed to decrease below 300 cmꢀ1 in order to keep the
excited S = 1/2 state at high energies. From the fit (T> 50 K), the
following parameters are obtained: J = ꢀ414 cmꢀ1, and J’ =
ꢀ114 cmꢀ1 (ꢄ 6 cmꢀ1). If not constrained, the radical–radical
exchange interaction tends to increase, leading to similar values
[8] Preparation of Qy: A solution of 2-(methylthio)aniline (1.44 mL,
11.5 mmol) in n-heptane (4 mL) was added dropwise to a
suspension of 3,5-di-tert-butylcatechol (2.56 g, 11.5 mmol) and
triethylamine (0.15 mL) in n-heptane (10 mL). The solution was
heated to reflux for 3 h, the solvent then evaporated to dryness,
and the residue washed with cold n-heptane to yield a colorless
1
solid. Yield 2.37 g (60%). H NMR (250 MHz, 300 K, CDCl3):
d = 6.35–7.48 (m, 6H, arom), 2.45 (s, 3H, SCH3), 1.44 (s, 9H,
C(CH3)3), 1.26 ppm (s, 9H, C(CH3)3). Elemental analysis (%)
calcd for C21H29NOS: C 73.42, H 8.51, N 4.08; found: C 73.49, H
8.42, N 4.07.
for both exchange parameters, J = ꢀ367 cmꢀ1
ꢀ357 cmꢀ1, without significantly improving the fit.
[12] W. Kaim, Coord. Chem. Rev. 1987, 76, 187.
, and J’ =
[9] Synthesis of 2: A solution of Qy (736 mg 2.14 mmol), NEt3
(0.5 mL), and CuCl (106 mg, 1.07 mmol) was heated to reflux
in acetonitrile (25 mL) for 4 h in the presence of air. The dark
precipitate was collected by filtration, then washed with cold
[13] a) D. Herebian, E. Bothe, F. Neese, T. Weyhermꢆller, K.
Wieghardt, J. Am. Chem. Soc. 2003, 125, 9116; b) A. Dogan, B.
Sarkar, A. Klein, F. Lissner, T. Schleid, J. Fiedler, S. Zalis, V. K.
Jain, W. Kaim, Inorg. Chem. 2004, 43, 5973.
[14] W. Kaim, Dalton Trans. 2003, 761.
[15] P. Chaudhuri, K. Wieghardt, Prog. Inorg. Chem. 2001, 50, 151.
acetonitrile.
A dark green microcrystalline material was
obtained. Yield 520 mg (65%). Elemental analysis (%) calcd
for C42H54CuN2O2S2: C 67.57, H 7.29 N 3.75; found: C 67.30, H
7.31, N 3.73. Single crystals were obtained from a dichloro-
2106
ꢀ 2005 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Angew. Chem. Int. Ed. 2005, 44, 2103 –2106