W.-Y. Yeh et al. / Journal of Organometallic Chemistry 689 (2004) 1014–1018
1017
Table 2
Crystal data and refinement details for 4
1,4-dibromobenzene (160 mg, 0.68 mmol) in 5 ml of
toluene at 0 ꢁC. The resulting p-BrC6H4Li reagent was
then added into a solution of 1 (200 mg, 0.336 mmol) in
20 ml of THF. The mixture was stirred at 50 ꢁC for 5 h,
followed by addition of MeOH (2 ml). The solvent was
removed under vacuum and the residue subjected to
column chromatography (silica gel), with n-hexane/di-
chloromethane/ethyl acetate (3:1:1) as eluant. Com-
pound 2 (75 mg, 30%) was obtained from the second
green band. Anal. Calc. for C30H23BrFe4O4: C, 47.99;
H, 3.09. Found: C, 47.62; H, 3.04%. IR (CH2Cl2,mCO):
Formula
T (K)
C54H42Fe8O8
150(1)
Crystal system
Crystal solvent
Space group
Unit cell dimensions
Rhombohedral
4(C6H6) + 0.67(CHCl3)
ꢁ
R3
ꢀ
a (A)
33.696(1)
33.696(1)
15.0885(5)
120
ꢀ
b (A)
ꢀ
c (A)
c (ꢁ)
3
ꢀ
V (A )
14836.6(8)
9
1.670
1636 cmꢀ1
.
1H NMR (CDCl3, 25 ꢁC): 7.62 (d, 2H,
Z
Dcalc (g cmꢀ3
F ð000Þ
)
JH–H ¼ 10 Hz), 7.55 (d, 2H, JH–H ¼ 10 Hz, C6H4), 4.96
(br, 2H), 4.86 (br,2H, C5H4), 4.59 (s, 15H, Cp) ppm.
13C{1H} NMR(CDCl3, 25 ꢁC): 290.8, 290.5 (l3-CO),
131.5, 131.3, 127.9, 122.3 (C6H4), 104.4, 100.6, 95.2
(C5H4), 99.1 (Cp) ppm. MS (FAB) m=z 750 [Mþ, 79Br].
7602
0.71073
1.849
ꢀ
Radiation k (A)
l (mmꢀ1
)
h range (ꢁ)
R1
1.21–27.50
0.0470
0.1133
1.118
wR2
Goodness-of-fit on F 2
3.3. Preparation of 3
Under a nitrogen atmosphere, n-butyl lithium (0.35
mmol) was slowly added into a solution of 2 (126 mg,
0.16 mmol) in 5 ml of toluene at 0 ꢁC. The mixture was
stirred at room temperature for 1 h, followed by addi-
tion of MeOH (1 ml). The reaction was worked up in a
fashion identical with that above. Compound 3 (56 mg,
40%) was obtained from the first green band. Anal.
Calc. for C34H31BrFe4O4: C, 50.61; H, 3.87. Found: C,
3.5. Cyclic voltammetric measurements for 2 and 4
Electrochemical measurements were taken with a CV
50 W system. Cyclic voltammetry was performed with a
Pt button working electrode, a Pt-wire auxiliary elec-
trode, and an Ag/AgCl reference electrode. The experi-
ments were carried out with 1 mM of 2 and 4,
respectively, in dry CH2Cl2 solvent containing 0.1 M (n-
C4H9)4NPF6 as the supporting electrolyte. Potential was
scanned at 100 mV sꢀ1 at 27 ꢁC.
51.03; H, 3.95%. IR (CH2Cl2, mCO): 1634 cmꢀ1 1H
.
NMR (CDCl3, 25 ꢁC): 7.61 (d, 2H), 7.56 (d, 2H,
JH–H ¼ 10 Hz, C6H4), 4.93 (m, 2H,), 4.82 (m, 2H,
C5H4), 4.52 (s, 10H, Cp), 4.46 (m, 2H), 4.30 (m,
2H, C5H4), 2.43 (t, 2H, JH–H ¼ 12 Hz), 1.26 (m, 4H),
0.93 (t, 3H, JH–H ¼ 12 Hz, Bu) ppm. MS (FAB) m=z 806
[Mþ, 79Br].
3.6. Structure determination for 4
A crystal of 4 with approximate dimensions of
0.5 · 0.08 · 0.08 mm3 was mounted in a thin-walled glass
capillary and aligned on the Bruker Smart ApexCCD
diffractometer with graphite-monochromated Mo–Ka
3.4. Preparation of 4
ꢀ
radiation (k ¼ 0:71073 A). The data were collected at
Under a nitrogen atmosphere, n-butyl lithium (1.74
mmol) was slowly added into a solution of 1,4-dib-
romobenzene (200 mg, 0.85 mmol) in 5 ml of toluene at
0 ꢁC. The mixture was heated at 50 ꢁC for 4 h to result in
a pale yellow precipitate of p-C6H4Li2. The supernatant
was removed by a syringe, and the solid washed with
freshly distilled toluene (3 · 5 ml). A solution of 1 (150
mg, 0.251 mmol) in 40 ml of THF was added. The re-
sulting mixture was vigorously stirred at 50 ꢁC for 5 h,
followed by addition of MeOH (2 ml). The reaction was
worked up in a fashion identical with that above.
Compound 4 (38 mg, 24%) was obtained from the
fourth green band. Anal. Calc. C54H42Fe8O8: C, 51.24;
H, 3.34. Found: C, 50.93; H, 3.58%. IR (CH2Cl2, mCO):
150 K. All data were corrected for the effects of ab-
sorption. The structures were solved by the direct
method and refined by full-matrix least-square on F 2.
The program used was the SHELXTL package [18]. All
non-hydrogen atoms were refined with anisotropic dis-
placement parameters. Hydrogen atoms were included
but not refined. A summary of relevant crystallographic
date is provided in Table 2.
4. Supplementary material
Crystallographic data for the structural analysis of 4
has been deposited with the Cambridge Crystallographic
Data Centre, CCDC No. 217582. Copy of this infor-
mation may be obtained free of charge from The Di-
rector, CCDC, 12 Union Road, Cambridge CB2 1EZ,
1632 cmꢀ1
.
C6H4), 5.01 (br, 4H), 4.86 (br, 4H, C5H4), 4.55 (s, 30H,
Cp) ppm. MS (FAB) m=z 1266 [Mþ].
1H NMR (CDCl3, 25 ꢁC): 7.78 (s, 4H,
Yeh, Wen-Yann
