B. Xi et al. / Journal of Organometallic Chemistry 693 (2008) 1656–1663
1661
(Mꢀ1 cmꢀ1)): 1049 (7310), 658 (11400), 499 (7780); Elec-
trochemistry (THF), E1/2/V, DEp/V, ibackward/iforward: A,
0.915 (Epa); B, ꢀ0.244, 0.070, 1.057; C, ꢀ1.348, 0.068,
0.810.
warmed to room temperature and stirred for another hour.
The suspension was transferred to a flask containing a
THF solution (40 mL) of Ru2(MeOap)4Cl (0.085 g,
0.08 mmol). The solution color changed from dark green
to red immediately, and the reaction mixture was stirred
for 30 min. After the removal of the solvents under vac-
uum, the residue was dissolved in THF and filtered through
a silica gel pad (2 cm). The product was further purified on
silica column eluted with a mixture of THF, hexanes and
Et3N (10/30/1, v/v/v) to give pure compound 6 (0.070 g,
72%). Data for 6: Rf (THF/hexanes/Et3N = 10/30/1, v/v/
v): 0.42. MS-ESI (m/e, based on 101Ru): 1210 [M+]. Anal.
Calc. for C60H53N8O4FeRu2, C, 59.65; H, 4.39; N, 9.28.
Found: C, 59.69; H, 4.44; N, 9.05%. UV–Vis, kmax (nm, e
(Mꢀ1 cmꢀ1)): 753 (5450), 473 (7850); Electrochemistry
(THF), E1/2/V, DEp/V, ibackward/iforward: A, 0.654, 0.072,
1.102; B, 0.416, 0.069, 0.715; C, ꢀ0.886, 0.071, 0.922.
Magnetic (293 K): vg, 5.34 ꢁ 10ꢀ6 esu; vmol(corr) 7.20 ꢁ
10ꢀ3 esu molꢀ1; leff = 4.11 lB.
4.6. Preparation of Ru2(MeOap)4(C4SiMe3) (4)
To a 10 mL THF solution containing 0.16 mmol of
Me3SiC„CC„CSiMe3 was added 0.06 mL of n-BuLi
(2.5 M in hexanes) at liquid nitrogen temperature. The mix-
ture was slowly warmed to room temperature and stirred
for another hour to yield an off-white suspension. A por-
tion of the suspension (6 mL) was transferred to a flask
containing a 30 mL THF solution of Ru2(MeOap)4Cl
(0.083 g, 0.08 mmol). The solution color changed from
green to brown immediately, and the reaction mixture
was stirred for an hour. Removal of the solvents in vacuo
yielded a brown residue, which was purified on a silica col-
umn using a linear gradient of eluents (hexanes/ethyl ace-
tate, 90/10–60/10, v/v) to afford pure 4 (0.055 g, 61%
based on Ru). Data for 4: Rf (THF/hexanes/Et3N = 10/
30/1, v/v/v): 0.44. MS-ESI (m/e, based on 101Ru): 1121
[M+]. UV–Vis, kmax (nm, e (Mꢀ1 cmꢀ1)): 770 (7540),
493 (10200). Electrochemistry (THF), E1/2/V, DEp/V,
ibackward/iforward: B, 0.500, 0.067, 0.939; C, ꢀ0.716, 0.057,
0.922. Magnetic (293 K): leff = 3.91 lB.
4.9. Preparation of Ru2(ap)4(C4Fc) (7)
To a 20 mL THF solution containing 0.37 mmol of
FcC4H was added 0.16 mL of n-BuLi (2.5 M in hexanes)
at liquid nitrogen temperature. The mixture was slowly
warmed to room temperature and stirred for another hour.
The suspension was transferred to a flask containing a
THF solution (40 mL) of Ru2(ap)4Cl (0.229 g, 0.25 mmol).
The solution color changed from dark green to red imme-
diately, and the reaction mixture was stirred for 30 min.
After the removal of the solvents under vacuum, the resi-
due was dissolved in THF and filtered through a silica
gel pad (2 cm). The product was further purified on silica
column with a mixture of THF, hexanes and Et3N (25/
100/1, v/v/v) to yield pure compound 7 (0.098 g, 35%).
Data for 7: Rf (THF/hexanes/Et3N = 10/30/1, v/v/v):
0.66. MS-ESI (m/e, based on 101Ru): 1112 [M+]. Anal.
Calc. for C58H45N8FeRu2 ꢂ 2H2O: C, 60.63; H, 4.27; N,
9.65. Found: C, 60.37; H, 4.70; N, 9.72%. UV–Vis, kmax
(nm, e (Mꢀ1 cmꢀ1)): 755 (7640), 473 (8260). Electrochemis-
try (THF), E1/2/V, DEp/V, ibackward/iforward: A, 0.707, 0.040,
0.280; B, 0.479, 0.060, 0.556; C, ꢀ0.762, 0.068, 0.923.
Magnetic (294 K): vg, 3.77 ꢁ 10ꢀ6 esu; vmol(corr) 4.95 ꢁ
10ꢀ3 esu molꢀ1; leff = 3.41 lB.
4.7. Preparation of Ru2(MeOap)4(C4SiMe3)2 (5)
To a 10 mL THF solution containing 0.30 mmol of
Me3SiC„CC„CSiMe3 was added 0.15 mL of n-BuLi
(2.5 M in hexanes) at liquid nitrogen temperature. The mix-
ture was slowly warmed to room temperature and stirred
for another hour to yield an off-white suspension. The sus-
pension was transferred to a flask containing a 40 mL THF
solution of Ru2(MeOap)4Cl (0.061 g, 0.058 mmol). After
30 min, the reaction mixture was opened in the air with
stirring for another hour to yield a blue-purple solution,
which was filtered through a silica gel pad (2 cm). After
the solvent removal, the residue was purified on a silica col-
umn with hexanes/ethyl acetate (90/10, v/v) to afford 5
(0.050 g, 69% based on Ru). Data for 5: Rf (THF/hex-
anes/Et3N = 10/30/1, v/v/v): 0.60. Anal. Calc. for
C62H62N8O4Si2Ru2 ꢂ H2O: C, 59.07; H, 5.08; N, 8.89.
1
Found: C, 59.05; H, 5.47; N, 8.41%. H NMR: 9.04 (s,
4H, aromatic), 7.25–6.02 (m, 24H, aromatic), 3.42 (s,
12H, OCH3), 0.29 (s, 9H, Si(CH3)3), 0.08 (s, 9H, Si(CH3)3).
4.10. Structure determination
Electrochemistry (THF), E1/2/V, DEp/V, ibackward/iforward
:
Single crystals were obtained by slow evaporation of
either a hexanes/THF solution (1, 6 and 7) or a hexanes/
ethyl acetate solution (2). X-ray intensity data of crystals
1, 2 and 6 were measured on a Bruker SMART1000
CCD X-ray diffractometer and those of 7 on a Nonius-
Kappa CCD X-ray diffractometer using Mo Ka
A, 0.988 (Epa); B, ꢀ0.254, 0.066, 1.019; C, ꢀ1.362, 0.087,
1.109. UV–Vis, kmax (nm, e (Mꢀ1 cmꢀ1)): 657 (11400),
486 (7270).
4.8. Preparation of Ru2(MeOap)4(C2Fc) (6)
˚
(k = 0.71073 A). Structures were solved and refined using
To a 40 mL THF solution containing 0.10 mmol of
FcC2H was added 0.05 mL of n-BuLi (2.5 M in hexanes)
at liquid nitrogen temperature. The mixture was slowly
the Bruker SHELXTLÓ (Version 5.1) software package. Posi-
tions of all non-hydrogen atoms were revealed by direct
method. The asymmetric unit of crystal 1 contains one-