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C. Paul-Roth et al. / Tetrahedron 60 (2004) 12169–12175
Electrochemical experiments were performed using either a
Pt disk electrode (diameter 1 mm), or platinum foils (area:
2 cm2). The counter electrode was a vitreous carbon rod and
the reference electrode was a silver wire in a 0.1 M AgNO3
solution in CH3CN. Ferrocene was added to the electrolyte
solution at the end of a series of experiments. The
ferrocene/ferrocenium (Fc/FcC) couple served as internal
standard and all reported potentials were referenced to its
reversible formal potential. Activated Al2O3 was added in
the electrolytic solution to remove excess moisture. The
three electrode cell was connected to a PAR Model 173
potentiostat monitored with a PAR Model 175 signal
generator and a PAR Model 179 signal coulometer. The
cyclic voltammetry traces (CVs) were recorded on an XY
SEFRAM-type TGM 164.
131.12 (Cpyrrole), 129.1 (CJ), 127.0 (CC), 127.1 (CB), 125.3
0
(CD), 120.6 (CI), 120. (CA), 117.9 (CA ), 37.1 (CE). UV–vis
(CH2Cl2): lmax/nm (log 3): 426 nm (5.89), 522 (4.49), 557
(4.4), 598 (4.1) and 650 (4.15). MS (ESI): (m/zC): calcd for
C72H47N4 (MHC) 967.3801. Found: 967.3799.
Dichloromethane with less than 100 ppm of water (ref. SDS
02910E21) and tetrabutylammonium hexafluorophosphate
from FLUKA were used without any purification. Alu-
¨
minium oxide was obtained from Woelm, activated by
heating at 300 8C under vacuum for 12 h and used at once
under argon pressure.
Liquid UV–visible spectra were recorded on a UVIKON XL
from Biotech. Solid UV–visible spectra were recorded
using, either a Guided Wave model 150 spectrophotometer
with optical fibres, a concave platinum surface acted as a
reflector for the optical beam, or a JASCO-V570 Spectro-
photometer, the deposit being on ITO electrode. Scanning
Electron Microscopy was performed on JEOL JSM 301F.
Electronic Microanalysis was performed on JEOL JSM
6400 using an Energy Dispersive spectrometry (EDS)
detector Oxford-Link Isis. Infra Red spectra were performed
in KBr disk in a IFS 28 Bruker. All catalytic reactions were
controlled on a Varian CP-3380 Gas Chromatograph
equipped with a CP-Chirasil-Dex Column. TFPZtetra-
fluorenylporphyrin dianion, TPP tetraphenylporphyrin
dianion.
4.2.2. meso-Tetrakis-5,10,15,20-tetrakis(fluoren-2-
yl)porphyrinato ruthenium carbone monoxide 2. Free
base porphyrin 1 (0.21 mmol, 0.2 g) was dissolved in
distilled 1,2-dichlorobenzene (40 mL) and degassed for
15 min. The reaction mixture was heated at 180 8C and
dodecacarbonyl triruthenium was added (0.31 mmol, 0.2 g)
over a period of 2 h under an argon atmosphere. The mixture
was stirred for an additional hour. The ruthenium insertion
was followed by TLC and UV–vis spectroscopy. The
solvent was removed under vacuum, the black-red residue
was dissolved in dichloromethane and purified by chroma-
tography on silica gel. The dodecacarbonyl triruthenium
was eluted first with pentane and the desired ruthenium
complex was eluted with a mixture hexane/dichloromethane
(6:4). Yield: 50%.
1
0
H NMR: 8.97 (s, 8H, pyrrole), 8.42 (s, 4H, HD ), 8.28 (d,
4.2. Porphyrin synthesis
3
3
0
0
JHHZ8.2 Hz, 4H, HB ), 8.20 (d, JHHZ7.6 Hz 4H, HA ),
8.10 (d, 3JHHZ6.6 Hz, 4H, HA), 7.72 (d, 3JHHZ6.8 Hz, 4H,
HD), 7.56 (t, 3JHHZ5.7 Hz, 4H, HB), 7.46 (t, 3JHHZ6.8 Hz,
4H, HC), 4.23 (s, 8H, HE), UV–visible: 426 nm (Soret band).
MS (ESI): (m/zC): calcd for C74H48N402 (MCCH3OH)C
1126.2842. Found: 1126.2830. IR (KBr, cmK1) 1948 (nCO).
4.2.1. meso-Tetrakis-5,10,15,20-tetrakis(fluoren-2-yl)-
porphyrin 1. Pyrrole (5 mmol), and fluorene-2-carbalde-
hyde (5 mmol) were allowed to react at room temperature in
dry and degassed dichloromethane (1 L) under an argon
atmosphere and protected from light with acid catalysis
(BF3(OEt2)2): 0.5 mmol). The reaction was stirred for 3 h.
3.8 mmol of 2,3-dichloro-5,6-dicyano-1,4-benzoquinone
was added to irreversibly oxidize the tetra-fluorenylpor-
phyrinogene and the solution was stirred for 60 min. After
addition of 1.5 mL of triethylamine, the solvent was
removed under vacuum. The free base porphyrin 1 was
purified twice by chromatography on silica gel using
dichloromethane as eluant. Yield: 45%.
4.2.3. meso-Tetrakis-5,10,15,20-tetrakis(fluoren-2-yl)-
porphyrinatoruthenium bis(tertiobutyl) isocyanide 3.
To a solution of ruthenium carbonyl complex (0.01 mmol)
in CDCl3 in an NMR tube was added terbutylisocyanide
(2 equiv) under an argon atmosphere. The solution was
stirred at room temperature until the reaction was completed
(5 min). The bis-ligation was checked by monitoring the
UV–vis spectrum and then the NMR spectra were
immediately recorded. 1H NMR (CDCl3): 8.51 (s, 8H,
1
0
H NMR (CDCl3): 8.98 (s, 8H, pyrrole), 8.46 (s, 4H, HD ),
0
8.32 (d, 3JHHZ8.2 Hz, 4H, HB ), 8.21 (d, JHHZ7.6 Hz, 4H,
HA ), 8.11 (d, JHHZ6.6 Hz, 4H, HA), 7.76 (d, JHH
pyrrole), 8.35 and 8.33 (2s, 4H, HD ), 8.20 and 8.17 (d,
3
0
3
3
3
3
0
0
0
Z
JHHZ8.2 Hz, 4H, HB ), 8.09 (d, JHHZ7.6 Hz 4H, HA ),
3
6.8 Hz, 4H, HD), 7.59 (t, JHHZ5.7 Hz, 4H, HB), 7.49
8.03 (d, 3JHHZ6.6 Hz, 4H, HA), 7.67 (d, 3JHHZ6.8 Hz, 4H,
HD), 7.59 (t, 3JHHZ5.7 Hz, 4H, HB), 7.49 (t, 3JHHZ6.8 Hz,
4H, HC), 4.18 (broad s, 8H, HE), K0.35 (broad s, 18H,
3
(t, JHHZ6.8 Hz, 4H, HC), 4.26 (s, 8H, HE),
6CH3). 13C NMR (CDCl3): 143.8 (CF), 141.59 (CF ), 141.55
13
0
C NMR (CDCl3): 143.8 (CF), 141.59 (CF ), 141.55
0
0
(CG),141.26 (CG ), 140.66 (CC ), 133.5 (CB ), 131.4 (CD ),
0
0
0
0 0 0
(CG), 141.26 (CG ), 140.66 (CC ), 132.93 (CB ), 130.85