H: 4.26, N: 10.99%, Analysis calculated for C84H78O6N18Zn2P4-
F24ؒ2EtOH: C: 47.14, H: 4.01, N: 11.25%. 1H NMR (300 MHz,
DMSO-d6, RT) δ 1.20 (2H, m, HC4), 1.40(2H, m, HC2), 1.80
(2H, m, HC3), 2.25 (2H, m, HC1), 3.80 (2H, br, CH–N), 7.80
(2H, m, bipyH5Ј), 8.20 (2H, m, bipyH4Ј), 8.30 (2H, d, J =
8.0 Hz, bipyH4), 8.55 (2H, d, J = 8.0 Hz, bipyH3Ј), 8.75 (2H, d,
J = 8.0 Hz, bipyH3), 9.00 (4H, m, NH and bipyH6Ј), 9.15 (2H,
s, bipyH6). ESMS: m/z 2002 (30%, [M Ϫ PF6]ϩ), 1856 (40%,
[HM Ϫ 2PF6]ϩ), 1710 (100%, [2HM Ϫ 3PF6]ϩ). IR (KBr disc)
meters provided by Chem3D.22 The two Fe(bipy)3 were con-
strained by optimising the bond lengths to Fe–N: 1.965, C–N:
1.354, C–C: 1.379 (ar) and 1.456.23 The target configuration
was arranged roughly by eye, and the energy minimized at an
RMS gradient of 0.010. The procedure was repeated on five
independant arrangements to ensure that in each case the
desired target configuration was obtained for each of the four
structural configurations considered. Results: (a) axial-∆,∆-
[Fe2(LRR)3]4ϩ minimised to 40.21
Λ,Λ-[Fe2(LRR)3]4ϩ minimised to 60.82
equatorial-∆,∆-[Fe2(LRR)3]4ϩ minimised to 40.4 1.1 kJ molϪ1
(d) equatorial-Λ,Λ-[Fe2(LRR)3]4ϩ minimised to 46.31 0.10 kJ
molϪ1
0.06 kJ molϪ1, (b) axial-
λmax (cmϪ1): 3414 (br, N–H), 1607 (C᎐O stretch).
0.05 kJ molϪ1, (c)
᎐
,
[Cd2(LRR)3][PF6]4 and [Cd2(LSS)3][PF6]4. Yield: 74% and 78%
for the R,R and S,S enantiomers respectively. Found: C: 43.92,
H: 4.23, N: 10.13%, Analysis calculated for C84H78O6N18Cd2-
.
1
P4F24ؒ4H2OؒEtOH. C: 43.17, H: 3.90, N: 10.67%. H NMR
(300 MHz, DMSO-d6, RT) δ 1.40 (2H, m, HC4), 1.60 (2H, m,
HC2), 1.85 (2H, m, HC3), 2.0 (2H, m, HC1), 4.10 (2H, br, CH–N),
7.90 (2H, m, bipyH5Ј), 8.30 (2H, dd, J = 8.0 Hz bipyH4Ј), 8.40
(2H, d, J = 8.0 Hz, bipyH4), 8.70 (2H, d, J = 7.4 Hz, bipyH3Ј),
8.90 (2H, d, J = 8.0 Hz, bipyH3), 8.95 (2H, d, J = 10.0 Hz, NH ),
9.00 (2H, d, J = 4.0 Hz bipyH6Ј), 9.30 (2H, s, bipyH6), 13C NMR
(300 MHz, DMSO-d6) δ 15.0, 25.0, 32.50, 60.0, 122.0, 123.5,
124.30 125.0, 127.5, 128.0, 137.50, 140.0, 149.0 150.0. ESMS:
m/z = 2096 (100%, [M Ϫ PF6]ϩ), 1807 (55%, [H2M Ϫ 3PF6]ϩ).
Acknowledgements
We thank the School of Chemistry, QUB and the EPSRC for
financial support, the EPSRC mass spectroscopy service in
Swansea and Richard Murphy for carrying out the CD and
NMR spectroscopy.
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gonal, space group P43, a = 8.671(5), b = 8.671(5), c = 54.06(4),
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3802 independent reflections were used in the refinement. The
final parameters were wR2 = 0.3011 and R1 = 0.1044 [I > 2σI],
Flack x = 0.2(2).
CCDC reference number 168683.
lographic data in CIF or other electronic format.
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26 SAINT-NT, Bruker, Madison, WI, 1998.
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608
J. Chem. Soc., Dalton Trans., 2002, 602–608