V ¼ 4272.9 (9) A, Z ¼ 6, T ¼ 150 (2) K, 27 848 reflections collected,
4372 independent reflections [R(int) ¼ 0.0749], R(F) ¼ 0.0545, wR2 ¼
0.1319, CCDC 612042 (Found: C, 47.4; H, 6.4; N, 5.8.
C17H26Cl2CuN2O2ꢁCH3OH requires C, 47.3; H, 6.6; N, 6.1%). MS
(FAB, NOBA) m/z 390 ([M ꢀ Cl]1 90%).
[Zn2(L2)2Cl4]. L2 (29.0 mg, 0.1 mmol) in CHCl3 (10 ml) and ZnCl2
(1.36 g, 10 mmol) in water (10 ml) were stirred together for 16 h, the
phases separated and the organic phase slowly evaporated to give
colourless crystals of [Zn2(L2)2Cl4]ꢁ4CHCl3. C34H52N4O4Zn2ꢁ4CHCl3,
ꢀ
Mr ¼ 1330.81, triclinic, space group, P1, a ¼ 14.1922 (16), b ¼ 15.2573
(17), c ¼ 15.8100 (17) A, a ¼ 90.166 (2), b ¼ 107.680 (2), g ¼ 117.492
(2)1, V ¼ 2851.6(5) A, Z ¼ 2, T ¼ 150 (2) K, 25 571 reflections
collected, 13 277 independent reflections [R(int) ¼ 0.0195], R(F) ¼
0.045, wR2 ¼ 0.1165, CSD 660775. The crystals were sensitive to
solvent loss, and after exposure to air gave an off white solid which
analysed as [Zn2(L2)2Cl4]ꢁ2CHCl3 (13.1 mg, 24%) (Found: C, 39.9; H,
5.1; N, 5.3. C34H52Cl4N4O4Zn2ꢁ2CHCl3 requires C, 39.6; H, 5.0; N,
5.1%). MS (FAB, NOBA) m/z 818 ([M ꢀ Cl]1 25%) 781 ([M ꢀ 2Cl]1
74%).
[Cu(L2)2(NO3)2]. Cu(NO3)2ꢁ3H2O (23.3 mg, 0.096 mmol) and L2
(52.0 mg, 0.179 mmol) were mixed in methanol (20 ml) for 16 h and
the solvent removed in vacuo to give a brown solid (71.8 mg, 99%).
Crystals suitable for analysis by X-ray diffraction were grown by
Fig. 4 The solid state structure of [Cu(L2)2(NO3)2], showing the inter-
action of the nitrate anion with the piperidinium N–H group,
N62Aꢁ ꢁ ꢁO4S ¼ 2.842(2) A, and the CuII cation, Cu1ꢁ ꢁ ꢁO3S ¼ 2.722(2) A.
Fig. 1 were obtained. [Cu(L2)2(NO3)2]y is typical, and shows
the characteristic 14-membered pseudomacrocyclic H-bonding
arrangement of bis-salicylaldoximato copper(II) species7
(Fig. 4). Protonation of the piperidine moieties has generated
two equivalent anion loading sites occupied by the nitrate
anions, which are bound by a combination of electrostatic and
H-bond interactions. One oxygen atom of each nitrate anion is
located above and below the CuO2N2 coordination plane.
As the favoured formation of 1 : 1 L : MCl2 assemblies
with copper and zinc and their solubility in water-immiscible
solvents appears to be very dependent on the new ligands
addressing the chloride ions in the outer coordination sphere,
it might be expected that L1 and its analogues will be selective
for chloride over other anions. Preliminary results suggest that
this is the case. Cation selectivity is also essential for commer-
cial success,3 and detailed studies of these properties and other
important features such as hydrolytic stability and solubility
are in progress.9
diffusion of diethyl ether into a methanol solution. C34H52CuN6O10
,
Mr ¼ 768.37, monoclinic, space group, P21/n, a ¼ 11.8940 (6), b ¼
11.1620 (6) c ¼ 14.8410 (7) A, b ¼ 112.682 (3)1, V ¼ 1817.92 (16) A3, Z
¼ 2, T ¼ 150 (2) K, 29 119 reflections collected, 5192 independent
reflections [R(int) ¼ 0.049], R(F) ¼ 0.0409, wR2 ¼ 0.1119, CSD 683051
(Found: C, 53.6; H, 6.9; N, 10.3. C34H52CuN6O10ꢁ0.5C4H10O requires
C, 53.7; H, 7.1; N, 10.4%). MS (FAB, NOBA) m/z 707 ([M ꢀ NO31],
18%).
z 16 papers discussing chloride hydrometallurgy were presented at the
recent 6th Copper/Cobre Conference, Toronto, August 2007, proceed-
8 The mass of copper transported by 1 kg of ligand.5 Under the
conditions in Table 2, L1 has an observed mass transport efficiency of
143 g kgꢀ1 per cycle when stripped with 220 g lꢀ1 HCl, cf. a theoretical
maximum of 121 g kgꢀ1 calculated for the commercial reagent P50
(5-nonyl-2-hydroxybenzaldehyde oxime).
1 S. G. Galbraith and P. A. Tasker, Supramol. Chem., 2005, 17,
191–207.
2 P. A. Tasker, P. G. Plieger and L. C. West, Comprehensive
Coordination Chemistry II, Elsevier, Amsterdam, 2004, vol. 9,
pp. 759–808.
The authors thank Mr Ronald M. Swart and Mr John
Campbell at Cytec Industries Ltd. UK for useful discussions
and the EPSRC for funding.
3 P. A. Tasker, C. C. Tong and A. N. Westra, Coord. Chem. Rev.,
2007, 251, 1868, and references within.
4 N. Akkus, J. C. Campbell, J. Davidson, D. K. Henderson, H. A.
Miller, A. Parkin, S. Parsons, P. G. Plieger, R. M. Swart, P. A.
Tasker and L. C. West, Dalton Trans., 2003, 1932–1940.
5 J. Szymanowksi, Hydroxyoximes and Copper Hydrometallurgy,
CRC Press, London, 1993.
Notes and references
6 P. J. Mackey, CIM Magazine, 2007, 2, 35–42.
7 A. G. Smith, P. A. Tasker and D. J. White, Coord. Chem. Rev.,
2003, 241, 61–85.
z L1 and L2 were prepared (ESIw) in high yields and purity by
oximation10 of their precursor aldehydes, which have been synthesised
previously.11
8 R. F. Dalton, A. Burgess, R. Price and E. Hermana, Proc. Metall.,
1992, 7B, 1145, and references within.
9 R. S. Forgan, D. K. Henderson and P. A. Tasker, UK Pat.,
P14523GB, 2006.
10 D. Stepniak-Biniakiewicz, Pol. J. Chem., 1980, 54, 1567–1571.
11 R. A. Coxall, L. F. Lindoy, H. A. Miller, A. Parkin, S. Parsons, P.
A. Tasker and D. J. White, Dalton Trans., 2003, 55–64.
y Synthesis of complexes: [Cu(L2)Cl2]. L2 (29.0 mg, 0.1 mmol) in
CHCl3 (10 ml) and CuCl2 (1.34 g, 10 mmol) in water (10 ml) were
stirred together for 16 h, the phases separated and the organic phase
evaporated to give a purple solid (39.1 mg, 91%). Crystals of
[Cu(L2)Cl2] were grown by slow diffusion of Et2O into a MeOH
solution. C17H26Cl2CuN2O2, Mr ¼ 424.85, orthorhombic, space
group, Pbcn, a ¼ 16.542 (2), b ¼ 24.736 (3), c ¼ 10.4427 (13) A,
ꢂc
This journal is The Royal Society of Chemistry 2008
Chem. Commun., 2008, 4049–4051 | 4051