heated with stirring for 30 min. After standing for 2 d at room
temperature colourless crystalline plates (42 mg, 36%) formed which
readily lose solvent. Calc. (%) for C52H69ClDy3N6O28 (corresponds to
{Dy3}ꢀ5H2O): C 35.31; H 3.88; N 4.75. Found (%): C 35.41; H 3.74;
N 4.51. IR (KBr disk, cmꢁ1): 3434, 3941, 1629, 1603, 1559, 1462, 1331,
1274, 1239, 1219, 11094, 1074, 959, 851, 755, 734, 629.
y Crystal data for 1: C55H69ClDy3N6O26.5, M = 1761.11, monoclinic,
P21/n, a = 22.3234(13), b = 12.1453(7), c = 24.1194(14) A, b =
94.405(1)1, U = 6520.0(7) A3, T = 100 K, Z = 4, Dc = 1.794 Mg mꢁ3
,
m(Mo-Ka) = 3.530 mmꢁ1, F(000) = 3472, colourless plate 0.22 ꢃ
0.19
ꢃ
0.08 mm. 34 986 reflections measured, 14 520 unique
(Rint = 0.0267). 848 parameters, wR2 = 0.0929, S = 1.054 (all data);
R1 = 0.0338 (13 671 data with I 4 2s(I)); largest final difference
peak/hole +3.14 (amongst disordered perchlorate)/ꢁ1.45 e Aꢁ3
.
1 D. Gatteschi, R. Sessoli and J. Villain, Molecular Nanomagnets,
Oxford University Press, Oxford, 2006.
2 R. Sessoli and A. K. Powell, Coord. Chem. Rev., 2009, 253,
2328–2341.
3 (a) A. Mishra, W. Wernsdorfer, K. A. Abboud and G. Christou,
J. Am. Chem. Soc., 2004, 126, 15648–15649; (b) A. Mishra,
W. Wernsdorfer, S. Parsons, G. Christou and E. K. Brechin, Chem.
Commun., 2005, 2086–2088; (c) C. Aronica, G. Pilet, G. Chastanet,
W. Wernsdorfer, J.-F. Jacquot and D. Luneau, Angew. Chem., Int.
Ed., 2006, 45, 4659–4662; (d) V. Mereacre, M. A. Ako, R. Clerac,
W. Wernsdorfer, I. J. Hewitt, C. E. Anson and A. K. Powell,
Chem.–Eur. J., 2008, 14, 3577–3584; (e) G. Novitchi,
W. Wernsdorfer, L. F. Chibotaru, J.-P. Costes and C. E. Anson,
Angew. Chem., Int. Ed., 2009, 48, 1614–1619; (f) A. M. Ako,
V. Mereacre, R. Clerac, W. Wernsdorfer, I. J. Hewitt,
C. E. Anson and A. K. Powell, Chem. Commun., 2009, 544–546.
4 (a) N. Ishikawa, M. Sugita, T. Ishikawa, S. Koshihara and Y. Kaizu,
J. Am. Chem. Soc., 2003, 125, 8694–8695; (b) L. G. Westin, M. Kritikos
and A. Caneschi, Chem. Commun., 2003, 1012–1013; (c) J. Tang,
I. Hewitt, N. T. Madhu, G. Chastanet, W. Wernsdorfer, C. E. Anson,
C. Benelli, R. Sessoli and A. K. Powell, Angew. Chem., Int. Ed., 2006, 45,
1729–1733; (d) S. Takamatsu, T. Ishikawa, S. Koshihara and
N. Ishikawa, Inorg. Chem., 2007, 46, 7250–7252; (e) X. Gu and
D. Xue, Inorg. Chem., 2007, 46, 3212–3216; (f) J. Luzon, K. Bernot,
I. J. Hewitt, C. E. Anson, A. K. Powell and R. Sessoli, Phys. Rev. Lett.,
2008, 100, 247205; (g) Y.-Z. Zheng, Y. Lan, C. E. Anson and
A. K. Powell, Inorg. Chem., 2008, 47, 10813–10815;
(h) M. A. Aldamen, J. M. Clemente-Juan, E. Coronado, C. Marti-
Gastaldo and A. Gaita-Arino, J. Am. Chem. Soc., 2008, 130, 8874–8875;
Fig. 3 Temperature dependence of the in-phase signal, w0 (top),
out-of-phase signal, w00 (bottom), and the resulting Arrhenius plot
(inset) from the ac susceptibility measurements of 1 without an applied
static field.
(i) P.-H. Lin, T. J. Burchell, R. Cle
Int. Ed., 2008, 47, 8848–8851; (j) M. T. Gamer, Y. Lan, P. W. Roesky,
A. K. Powell and R. Clerac, Inorg. Chem., 2008, 47, 6581–6583;
(k) N. Ishikawa, Y. Mizuno, S. Takamatsu, T. Ishikawa and
S. Koshihara, Inorg. Chem., 2008, 47, 10217–10219; (l) B. Hussain,
D. Savard, T. J. Burchell, W. Wernsdorfer and M. Murugesu, Chem.
Commun., 2009, 1100–1102.
´
rac and M. Murugesu, Angew. Chem.,
´
Fig. 4 Top: polyhedral representation of the metal ion centres in
1 showing orthogonal trapezoidal planes with the coordination bonds
to hard donors highlighted orange superimposed to the calculated easy
axes of magnetic anisotropy tensors and the observed easy-axis
(green). Bottom: schematic view of the effect of the opening of the
triangle.
5 (a) N. T. Madhu, J.-K. Tang, I. J. Hewitt, R. Clerac,
´
W. Wernsdorfer, J. v. Slageren, C. E. Anson and A. K. Powell,
Polyhedron, 2005, 24, 2864–2869; (b) I. J. Hewitt, J.-K. Tang,
´
the factors which determine the orientation of the anisotropy.
Thus it seems for the increasing number of lanthanide-based
SMMs being discovered, it will be important to combine
theoretical investigations and experimental studies to identify
the anisotropy direction and gauge its influence on parameters
such as the sign of the magnetic interaction and the energy
barrier height. These insights should help in ligand design for
further enhancement of SMM properties.
N. T. Madhu, R. Clerac, G. Buth, C. E. Anson and A. K. Powell,
Chem. Commun., 2006, 2650–2652.
6 (a) C. M. Zaleski, E. C. Depperman, J. W. Kampf, M. L. Kirk and
V. L. Pecoraro, Angew. Chem., Int. Ed., 2004, 43, 3912–3914;
(b) C. M. Zaleski, J. W. Kampf, T. Mallah, M. L. Kirk and
V. L. Pecoraro, Inorg. Chem., 2007, 46, 1954–1956;
(c) C. J. Milios, A. Prescimone, A. Mishra, S. Parsons,
W. Wernsdorfer, G. Christou, S. P. Perlepes and E. K. Brechin,
Chem. Commun., 2007, 153–155; (d) C. J. Milios, R. Ingliss,
R. Bagai, W. Wernsdorfer, A. Collins, S. Moggach, S. Parsons,
S. P. Perlepes, G. Christou and E. K. Brechin, Chem. Commun.,
2007, 3476–3478; (e) J. Cano, T. Cauchy, E. Ruiz, C. J. Milos,
C. C. Stoumpos, T. C. Stamataos, S. P. Perlepes, G. Christou and
E. K. Brechin, Dalton Trans., 2008, 234.
We acknowledge the DFG (Center for Functional
Nanostructures), MAGMANet (NMP3-CT-2005-515767)
and EC-FP7 Marie Curie Action for a post-doctoral grant
to J.L. (PIEF-GA-2008-220498).
7 L. F. Chibotaru, L. Ungur and A. Soncini, Angew. Chem., Int. Ed.,
2008, 47, 4126.
8 K. Bernot, J. Luzon, L. Bogani, M. Etienne, C. Sangregorio,
M. Shanmugam, A. Caneschi, R. Sessoli and D. Gatteschi, J. Am.
Chem. Soc., 2009, 131, 5573.
9 E. L. Muetterties and L. J. Guggenberger, J. Am. Chem. Soc., 1974,
96, 1748.
Notes and references
z 1ꢀClO4ꢀ112EtOHꢀH2O. Dy(ClO4)3ꢀ6H2O (114 mg, 0.2 mmol) was
added to a 3 ml ethanolic solution containing H2vanox (64 mg,
0.4 mmol) and triethylamine (60 ml, 0.6 mmol). The solution was
ꢂc
This journal is The Royal Society of Chemistry 2009
Chem. Commun., 2009, 6765–6767 | 6767