l = 0.71073 A, Z = 3, rcalcd = 1.49 g cmꢁ3, F(000) = 5670, m(MoKa) =
0.95 mmꢁ1, ymax = 32.01. 55 153 reflections collected, 8975 unique [Rint
=
0.052], 355 parameters refined; empirical absorption correction.12
Final R indices: R1 = 0.048, wR2 = 0.143, the final difference Fourier:
0.89/–0.55 e Aꢁ3. CCDC 732800 (1), 732802 (2) and 732801 (3).
1 (a) J.-M. Lehn, Supramolecular Chemistry, VCH, Weinheim, 1995;
(b) L. F. Lindoy and I. M. Atkinson, Self-assembly in Supra-
molecular Chemistry, RSC, Cambridge, 2000; (c) R. W. Saalfrank,
E. Uller, B. Demleitner and I. Bernt, Struct. Bonding, 2000, 96, 149;
(d) M. Ruben, J. Rojo, F. J. Romero-Salguero, L. H. Uppadine
and J.-M. Lehn, Angew. Chem., 2004, 116, 3728 (Angew. Chem.,
Int. Ed., 2004, 43, 3644); (e) L. Han and M. Hong, Inorg. Chem.
Commun., 2005, 8, 406.
2 (a) C. Piguet, G. Bernardinelli and G. Hopfgartner, Chem. Rev., 1997,
97, 2005; (b) C. Piguet, J. Inclusion Phenom. Macrocyclic Chem., 1999,
34, 361; (c) M. Albrecht, J. Inclusion Phenom. Macrocyclic Chem.,
2000, 36, 127; (d) M. Albrecht, Chem.–Eur. J., 2000, 6, 3485;
(e) M. Albrecht, Chem. Rev., 2001, 101, 3457; (f) J.-M. Lehn, Science,
2002, 295, 2400; (g) M. Albrecht, Top. Curr. Chem., 2004, 248, 105;
(h) C. Piguet, M. Borkovec, J. Hamacek and K. Zeckert, Coord.
Chem. Rev., 2005, 249, 705; (i) M. Albrecht and R. Frohlich, Bull.
Chem. Soc. Jpn., 2007, 80, 797.
3 J.-M. Lehn, A. Rigault, J. Siegel, J. Harrowfield, B. Chevrier and
D. Moras, Proc. Natl. Acad. Sci. U. S. A., 1987, 84, 2565.
¨
Fig. 4 Representation of a part of the self-assembly of [CuL2(SO4)]6
showing the p–p stacking interactions. H atoms are omitted for clarity.
12 relatively strong p–p stacking interactions (Cg1ꢀꢀꢀCg2:
3.61–3.64 A) between pyridyl rings of neighbouring molecules
stabilize the arrangement (Fig. 4).
4 (a) M. J. Hannon and L. J. Childs, Supramol. Chem., 2004, 16, 7;
(b) C. R. K. Glasson, L. F. Lindoy and G. V. Meehan, Coord. Chem.
Rev., 2008, 252, 940; (c) A. R. Stefankiewicz, M. Wasa, P. Jankowski,
A. Ciesielski, V. Patroniak, M. Kubicki, Z. Hnatejko,
J. M. Harrowfield and J.-M. Lehn, Eur. J. Inorg. Chem., 2008, 2910.
5 (a) B. Hasenknopf, J.-M. Lehn, B. O. Kneisel, G. Baum and
D. Fenske, Angew. Chem., 1996, 108, 1987 (Angew. Chem., Int.
Ed. Engl., 1996, 35, 1838); (b) B. Hasenknopf, J.-M. Lehn,
N. Boumediene, A. Dupont-Gervais, A. Van Dorsselaer,
B. O. Kneisel and D. Fenske, J. Am. Chem. Soc., 1997, 119,
10956; (c) D. F. Funeriu, J.-M. Lehn, G. Baum and D. Fenske,
Chem.–Eur. J., 1997, 3, 99; (d) B. Hasenknopf, J.-M. Lehn,
N. Boumediene, E. Leize and A. Van Dorsselaer, Angew. Chem.,
1998, 110, 3458 (Angew. Chem., Int. Ed., 1998, 37, 3265).
6 (a) P. L. Jones, K. J. Byrom, J. C. Jeffery, J. A. McCleverty and
M. D. Ward, Chem. Commun., 1997, 1361; (b) O. Mamula, A. von
Zelewsky and G. Berardinelli, Angew. Chem., 1998, 110, 302 (Angew.
Chem., Int. Ed., 1998, 37, 289); (c) E. C. Constable, C. E. Housecroft,
T. Kulke, G. Baum and D. Fenske, Chem. Commun., 1999, 195;
(d) L. J. Childs, N. W. Alcock and M. J. Hannon, Angew. Chem.,
2002, 114, 4418 (Angew. Chem., Int. Ed., 2002, 41, 4244);
(e) L. J. Childs, M. Pascu, A. J. Clarke, N. W. Alcock and
M. J. Hannon, Chem.–Eur. J., 2004, 10, 4291; (f) C. S. Campos-
Fernandez, B. L. Schottel, H. T. Chifotides, J. K. Bera, J. Bacsa,
J. M. Koomen, D. H. Russell and K. R. Dunbar, J. Am. Chem. Soc.,
2005, 127, 12909; (g) S. P. Argent, H. Adams, T. Riis-Johannessen,
J. C. Jeffery, L. P. Harding, O. Mamula and M. D. Ward, Inorg.
Chem., 2006, 45, 3905; (h) J. Hamblin, F. Tuna, S. Bunce, L. J. Childs,
A. Jackson, W. Errington, N. W. Alcock, H. Nierengarten, A. Van
Dorsselaer, E. Leize- Wagner and M. J. Hannon, Chem.–Eur. J., 2007,
13, 9286; (i) N. K. Al-Rasbi, H. Adams, L. P. Harding and
M. D. Ward, Eur. J. Inorg. Chem., 2007, 4770.
7 (a) N. Yoshida and K. Ichikawa, Chem. Commun., 1997, 1091;
(b) M. J. Hannon, C. L. Painting, A. Jackson, J. Hamblin and
W. Errington, Chem. Commun., 1997, 1807; (c) M. J. Hannon,
C. L. Painting and N. W. Alcock, Chem. Commun., 1999, 2023;
(d) N. Yoshida, K. Ichikawa and M. Shiro, J. Chem. Soc., Perkin
Trans. 2, 2000, 17; (e) H. Cheng, D. Chun-ying, F. Chen-jie and
M. Qing-jin, J. Chem. Soc., Dalton Trans., 2000, 2419; (f) L. Xu,
X.-T. Chen, Y. Xu, D.-R. Zhu, X.-Z. You and L.-H. Weng, J. Mol.
Struct., 2001, 559, 361; (g) Y. Parajo, J. Malina, I. Meistermann,
G. J. Clarkson, M. Pascu, A. Rodger, M. J. Hannon and P. Lincoln,
Dalton Trans., 2009, 4868; (h) J. Keegan, P. E. Kruger,
M. Nieuwenhuyzen and N. Martin, Cryst. Growth Des., 2002, 2, 329.
8 APEXII, Bruker-AXS Inc., Madison, WI, USA, 2008.
The unusual hexanuclear meso-helicates are, to the best of our
knowledge, the first examples of nanometre-scale neutral circular
helicates fully self-assembled around Cu(II) under the influence of
hydrogen bonding and p–p stacking interactions. Topological
control of the assembly process is clearly associated with the
bidentate coordination of the sulfate anions which direct the
formation of a double rather than a triple-stranded structure
around the octahedrally coordinated Cu(II) centres. Surprisingly,
the variation in the linker function on the ligands L1–L3, which
significantly changes the linking angle of the pyridylimine strands,
has little influence on the resulting structures. Finally, it is noted
that in work currently in progress, the successful synthesis of a
mixed-ligand (L1 and L3) Cu(II) meso-helicate with a structure
related to the above structures has been achieved.
The authors thank Jens Mizera for assistance with the cover
and abstract artwork.
Notes and references
z The X-ray-data were collected on a Bruker-AXS Kappa Apex II CCD
diffractometer with an Oxford Cryosystems coldhead attached. Programs
used: APEXII,8 SAINT,9 SHELX-97,10 DIAMOND3.111 and
SADABS.12 The crystals of 1, 2 and 3 showed several residual electron
density peaks after refinement. Calculations13 of the voids available for
solvents in the structures indicated that each crystal may contain about
four water molecules per asymmetric unit, which is in reasonable agree-
ment with the analytical data. Thus the electron density peaks
were modeled as disordered water molecules. Crystal data for (1);
ꢀ
C144H156Cu6N24O48S12, Mr = 3756.89, trigonal space group R3, a =
23.7647(6) A, c = 25.3824(8) A, V = 12414.5(6) A3, T = 173(2) K, l =
0.71073, Z = 3, rcalcd = 1.51 g cmꢁ3, F(000) = 5814, m(MoKa) =
1.00 mmꢁ1, ymax = 27.501. 45 135 reflections collected, 6315 unique
(Rint = 0.045), 353 parameters refined; empirical absorption correction.12
Final R indices: R1 = 0.054, wR2 = 0.158, the final difference Fourier:
1.09/ꢁ0.62 e Aꢁ3. Crystal data for (2); C150H168Cu6N24O48S6, Mr
=
3648.68, trigonal space group R3, a = 23.6595(2) A, c = 25.3773(4) A,
ꢀ
V = 12302.3(2) A3, T = 150(2) K, l = 0.71073, Z = 3, rcalcd
=
1.43 g cmꢁ3, F(000) = 5670, m(MoKa) = 0.93 mmꢁ1, ymax = 31.001.
71 838 reflections collected, 8702 unique [Rint = 0.070], 352 parameters
refined; empirical absorption correction.12 Final R indices: R1 = 0.050,
wR2 = 0.138, final difference Fourier: 0.91/ꢁ0.52 e Aꢁ3. Crystal data for
9 SAINT, Bruker-AXS Inc., Madison, WI, USA, 2008.
10 G. M. Sheldrick, SHELX-97, University of Gottingen, Germany, 1997.
¨
11 K. Brandenburg and H. Putz, DIAMOND3.1, Crystal Impact
GbR, Bonn, Germany, 2008.
12 G. M. Sheldrick, SADABS, Bruker AXS, Karlsruhe, Germany, 2002.
13 A. L. Spek, PLATON, Utrecht University, The Netherlands, 2003.
ꢀ
(3); C144H156Cu6N24O54S6, Mr = 3660.53, trigonal space group R3, a =
23.4688(3) A, c = 25.3619(5) A, V = 12097.5(3) A3, T = 150(2) K,
ꢂc
This journal is The Royal Society of Chemistry 2010
Chem. Commun., 2010, 46, 2373–2375 | 2375