Synthesis and electrochemical and photophysical studies of tetrathiafulvalene-annulated phthalocyanines

Article abstract of DOI:10.1021/jo0501801

The synthesis of tetrakis(tetrathiafulvalene)-annulated metal-free and metallophthalocyanines 5-8 via the tetramerization of the phthalonitrile derivative 4 is reported. All of them have been fully characterized by electronic absorption spectroscopy, thin-layer cyclic voltammetry, mass spectrometry, and elemental analysis. Their solution electrochemical data show two reversible four-electron oxidation waves, indicating that these fused systems are strong π-electron donors, which give rise to tetra- or octaradical cation species. For the metal-free phthalocyanine 5, additionally a reversible one-electron wave was found in the negative direction arising from the reduction of the macrocycle. Moreover, the tetrathiafulvalene unit acts as an efficient reductive electron-transfer quencher for the phthalocyanine emission, but upon its oxidation, an intense luminescence is switched on.

Full text of DOI:10.1021/jo0501801

Synthesis and Electrochemical and Photophysical Studies of
Tetrathiafulvalene-Annulated Phthalocyanines
†
†
†
†
‡
‡
Claudia Loosli, Chunyang Jia, Shi-Xia Liu, Marco Haas, Maryl e` ne Dias, Eric Levillain,
§
§
|
,†
Antonia Neels, Gael Labat, Andreas Hauser, and Silvio Decurtins*
Departement f u¨ r Chemie und Biochemie, Universit a¨ t Bern, Freiestrasse 3, 3012 Bern, Switzerland,
Groupe Syst e` mes Conjugu e´ s Lin e´ aires, Laboratoire de Chimie, Ing e´ nierie Mol e´ culaire et Mat e´ riaux
d’Angers, UMR CNRS 6200, 2 Bd Lavoisier, 49045 Angers, France, Institut de Chimie, Universit e´ de
Neuch aˆ tel, Avenue de Bellevaux 51, 2007 Neuch aˆ tel, Switzerland, and D e´ partement de Chimie Physique,
Universit e´ de Gen e` ve, 30 Quai Ernest-Ansermet, 1211 Gen e` ve 4, Switzerland
decurtins@iac.unibe.ch
Received January 28, 2005
The synthesis of tetrakis(tetrathiafulvalene)-annulated metal-free and metallophthalocyanines 5-8
via the tetramerization of the phthalonitrile derivative 4 is reported. All of them have been fully
characterized by electronic absorption spectroscopy, thin-layer cyclic voltammetry, mass spectrom-
etry, and elemental analysis. Their solution electrochemical data show two reversible four-electron
oxidation waves, indicating that these fused systems are strong π-electron donors, which give rise
to tetra- or octaradical cation species. For the metal-free phthalocyanine 5, additionally a reversible
one-electron wave was found in the negative direction arising from the reduction of the macrocycle.
Moreover, the tetrathiafulvalene unit acts as an efficient reductive electron-transfer quencher for
the phthalocyanine emission, but upon its oxidation, an intense luminescence is switched on.
Introduction
importance as model compounds to mimic biological
functions and as materials for constructing electrocata-
lytic, electronic, and optical devices, but also Pcs show
a rich and diverse chemistry as well as specific electronic,
optical, structural, and coordination properties. Obvi-
ously, there is keen interest in exploring new structural
modifications to the porphyrin and Pc systems and in the
present context it means to couple them with the favor-
able redox properties of the TTF units.
Ensembles of covalently linked tetrathiafulvalenes
TTFs) and phthalocyanines (Pcs) or porphyrins are
3
(
mainly investigated for their multielectron redox activi-
ties and photophysical properties. On one hand, the
redox-active TTF unit and its derivatives are π-electron
donors and the oxidation of their ring systems to the
cation radical and dication species occurs sequentially1
and reversibly within a very accessible potential window.
On the other hand, it is well-known that porphyrins and
2
It has been shown that metal-free Pc (H Pc) derivatives
bearing one, two, four, or eight peripheral TTF units,
respectively, all linked by spacer groups exhibited the
2
in particular metalloporphyrins have long been of great
†
Universit a¨ t Bern.
(2) (a) The Porphyrin Handbook; Kadish, K. M., Smith, K. M.,
Guilard, R., Eds.; Academic Press: San Diego, CA, 2000, Vols. 1-10,
and 2003, Vols. 11-14. (b) Alexiou, C.; Lever, A. B. P. Coord. Chem.
Rev. 2001, 216-217, 45.
(3) (a) McKeown, N. B. Phthalocyanine Materials: Synthesis, Struc-
ture and Function; Cambridge University Press: Cambridge, UK, 1998.
(b) The Porphyrin Handbook; Kadish, K. M., Smith, K. M., Guilard,
R., Eds.; Academic Press: San Diego,CA, 2003; Vols. 15-20. (c) Inabe,
T.; Tajima, H. Chem. Rev. 2004, 104, 5503.
‡
CNRS Angers.
§
Universit e´ de Neuch aˆ tel.
Universit e´ de Gen e` ve.
|
(1) (a) Bryce, M. R. J. Mater. Chem. 2000, 10, 589. (b) Segura, J. L.;
Mart ´ı n, N. Angew. Chem., Int. Ed. 2001, 40, 1372. (c) Jeppesen, J. O.;
Becher, J. Eur. J. Org. Chem. 2003, 3245. (d) Otsubo, T.; Takimiya,
K. Bull. Chem. Soc. Jpn. 2004, 77, 43. (e) Batail, P. Chem. Rev. 2004,
1
04, 4887.
10.1021/jo0501801 CCC: $30.25 © 2005 American Chemical Society
4988
J. Org. Chem. 2005, 70, 4988-4992
Published on Web 04/12/2005

Synthesis of Tetrathiafulvalene-Annulated Phthalocyanines
expected two-stage oxidation of the TTF units, and for
the latter two cases, oxidation and reduction of the Pc
core were also observed. In addition, it has been dem-
CHART 1. TTF-Annulated Phthalocyanines
4
onstrated that the fluorescence from metal-free Pcs is
efficiently quenched by the addition of TTF as a conse-
2
quence of intermolecular electron transfer between H -
4
c
Pc* and TTF. Furthermore, a range of silicon Pc-TTF
hybrids have been reported and also in these cases, the
quenching of the Pc emission by electron transfer from5
the axially linked TTF groups has been demonstrated.
A zinc Pc represents a case of a metallophthalocyanine
(MPc) bearing four TTF units at the periphery, again
with all of them linked through spacer groups. However,
its electrochemical property could not be measured due
to its insufficient solubility.6a In the following, the
synthesis of the corresponding zinc and magnesium
phthalocyanines with an improved solubility was demon-
6
b
strated. Very recently, tetrakis(tetrathiafulvalene-
crown-ether) substituted metal-free Pc and copper Pc
have been investigated for their self-assembling ability,
indicating the formation of helical tapes which are
nanometers wide and micrometers long. Such self-as-
sembled materials show potentially novel electronic and
structural properties.7 Moreover, specifically for the
SCHEME 1. Synthetic Pathway for the
Tetrakis-TTF-Annulated Phthalocyanine Series
context of molecular donor-acceptor systems that are
expected to show efficient electron transfer, a study of a
TTF-porphyrin dyad and a TTF-porphyrin-fullerene
triad as artificial photosynthetic models has to be men-
8
tioned. Finally, when it comes to the direct annulation
of the TTF unit to a macrocyclic core, up to now there
appeared only two reports about such fused systems in
the literature. In the case of a tetrakis-TTF-porphyrin
9
molecule, the synthesis resulted, however, in a mixture
of the neutral porphyrin and its corresponding radical
cation porphyrin, but in a following report,10 a pure mono-
TTF-annulated porphyrin has been described: it pro-
duces an almost nonfluorescent species that can be
transformed into a fluorescent one by oxidation of the
TTF unit, hence, it behaves as a fluorescence switch.
In this paper, we report the first examples of tetrakis-
TTF-annulated Pc molecules (Chart 1), specifically their
preparation as well as their electrochemical and photo-
physical characterization.
lined in Scheme 1. The precursor 1,2-bis(S-benzylthio)-
4,5-dicyanobenzene 1 was treated with AlCl in toluene
3
at room temperature under a nitrogen atmosphere before
1,1′-carbonyldiimidazole was added to the mixture. Pu-
rification by means of column chromatography afforded
the pure compound 5,6-dicyanobenzene-1,3-dithiole-2-one
Results and Discussion
2
. The cross-coupling reaction of 2 with 3 in a mixture of
Preparation of the Tetrakis-TTF-Annulated
Phthalocyanines 5-8. The synthetic pathway is out-
triethyl phosphite and toluene at 120 °C under nitrogen
gave the red 5,6-dicyano-2-(4,5-bis(propylthio)-1,3-dithio-
2
-ylidene)benzo[d]-1,3-dithioles 4 in a good yield. Com-
pound 4 is soluble in CHCl , CH Cl , and THF, slightly
soluble in CH CN, acetone, and DMSO, and insoluble in
alcohols. The IR spectrum of 4 shows the typical CtN
(
4) (a) Blower, M. A.; Bryce, M. R.; Devonport, W. Adv. Mater. 1996,
8
, 63. (b) Cook, M. J.; Cooke, G.; Jafari-Fini, A. Chem. Commun. 1996,
3
2
2
1
925. (c) Wang, C.; Bryce, M. R.; Batsanov, A. S.; Stanley, C. F.; Beeby,
3
A.; Howard, J. A. K. J. Chem. Soc., Perkin Trans. 2 1997, 1671. (d)
Wang, C.; Bryce, M. R.; Batsanov, A. S.; Howard, J. A. K. Chem. Eur.
J. 1997, 3, 1679.
-1
stretching vibration at 2234 cm , which disappears upon
tetramerization to the phthalocyanines 5-8.
Red crystals suitable for an X-ray diffraction study of
the key precursor 4 have been obtained by cooling a
saturated DMSO solution of 4. The ORTEP plot (Figure
(5) Farren, C.; Christensen, C. A.; FitzGerald, S.; Bryce M. R.; Beeby,
A. J. Org. Chem. 2002, 67, 9130.
6) (a) Hu, Y.; Shen, Y. J. Heterocycl. Chem. 2002, 39, 1071. (b) Hu,
Y.; Lai, G.; Shen, Y.; Li, Y. Monatsh. Chem. 2004, 135, 1167.
(
(
7) Sly, J.; Kasak, P.; Gomar-Nadal, E.; Rovira, C.; Gorriz, L.;
Thordarson, P.; Amabilino, D. A.; Rowan, A. E.; Nolte, R. J. M. Chem.
Commun. 2005, 10, 1255.
1
) emphasizes not only the planar geometry of the
(
8) (a) Sadaike, S.; Takimiya, K.; Aso, Y.; Otsubo, T. Tetrahedron
functionalized TTF unit, which finally tetramerizes to the
flat Pc core, but also the solubilizing effect of the flexible
end groups.
Lett. 2003, 44, 161. (b) Liddell, P. A.; Kodis, G.; de la Garza, L.; Bahr,
J. L.; Moore, A. L.; Moore, T. A.; Gust, D. Helv. Chim. Acta 2001, 84,
2
765.
(
9) Becher, J.; Brimert, T.; Jeppesen, J. O.; Pederson, J. Z.; Zubarev,
Finally, cyclization of 4 in 1-pentanol in the presence
of lithium pentoxide at 125 °C under argon resulted in
the formation of the metal-free phthalocyanine H
R.; Bjrnholm, T.; Reitzel, N.; Jensen, T. R.; Kjaer, K.; Levillain, E.
Angew. Chem., Int. Ed. 2001, 40, 2497.
2
Pc-
(
10) Li, H.; Jeppesen, J. O.; Levillain, E.; Becher, J. Chem. Commun.
2
003, 846.
(TTF) 5. The compound is soluble in CHCl , CH Cl , and
4
3
2
2
J. Org. Chem, Vol. 70, No. 13, 2005 4989

Loosli et al.
fulvalene derivative 4 with two oxidation waves. Each
oxidation wave was assigned to a one-electron process.
‚+
The TTF unit is oxidized to the radical cation TTF at a
+
potential of 0.31 V vs Fc /Fc. The second oxidation
potential corresponding to the formation of the dication
TTF2 is located at 0.65 V. In comparison to the tetra-
thiafulvalene molecule, both oxidation steps are shifted
by 0.34 and 0.38 V, respectively, to higher oxidation
potentials due to the electron-withdrawing effect of the
cyano groups. The thin layer cyclic voltammograms of
the phthalocyanines 5-8 reveal that the TTF moieties
are oxidized in two reversible steps involving two four-
electron processes (Figure 2b for 5 as an example).
Noteworthy, the oxidation potentials to the radical
cations show a negative shift of some 0.2 V compared to
that of the precursor compound 4. The splitting of the
first oxidation potential is characteristic for a molecular
system in which the donor moieties interact through
conjugation and/or through space.11 In the present system
it is caused by the annulation of the four TTF units to
the phthalocyanine core, which results in a high degree
of aggregation and also a stabilization of the monoradical
cation. After oxidation of one TTF unit has taken place,
the degree of aggregation decreases, which leads to a
stabilization of the HOMO level. Therefore, further
oxidation of the remaining three TTF units is now shifted
to a more positive potential. As a result of the Coulombic
repulsion among the positively charged species, the four
TTF units now behave like isolated molecules and an
additional four electrons are removed at the same
potential. In the case of the metal-free phthalocyanine
+
FIGURE 1. Crystal structure of compound 4.
TABLE 1. Cyclic Voltammetry Data for 4-8a
1
2
3
compd
E 1/2/V
E 1/2/V
E 1/2/V
4
5
6
7
8
0.31
0.11
0.14
0.14
0.14
0.65
0.62
0.60
0.60
0.59
-0.98
a
+
vs Fc /Fc.
pyridine and slightly soluble in THF and DMSO. The
good solubility is due to substitution at the tetrathiaful-
valene unit with thiopropyl groups. In the MALDI mass
spectrum of 5, a peak was observed at m/z 1809.89, which
corresponds to the monoisotopic mass. An additional peak
was found at m/z 1723.79, which was assigned to a
fragment of 5 with two missing propyl groups. The
metallophthalocyanines CoPc-(TTF)
4
6, NiPc-(TTF)
4
7,
and ZnPc-(TTF)
4
8 have been prepared by refluxing 4 in
the presence of an appropriate anhydrous metal salt in
5
, a reversible one-electron wave was also found at -0.98
DMAE under argon. Compounds 6-8 are soluble in
CHCl , CH Cl , THF, and pyridine, but not in alcohols.
3 2 2
The MALDI mass spectra of 6-8 display the mono-
isotopic molecular peaks at m/z 1866.77, 1865.79, and
+
V vs Fc /Fc, which can be assigned to a reduction of the
phthalocyanine ring system.
Photophysical Studies. The electronic absorption
1
7
871.73. In the case of CoPc-(TTF)
, a peak is found at a higher m/z value corresponding
4
6 and NiPc-(TTF)
4
spectrum for ZnPc-(TTF)
10 M) in its neutral and tetraradical cationic states is
shown in Figure 3a. In its neutral form, ZnPc-(TTF)
4
8 dissolved in THF (c ) 2 ×
-
6
to the phthalocyanines containing one water molecule.
The mass spectra of all metallophthalocyanines show
additional fragment peaks which indicate the loss of
propyl groups.
Electrochemical Studies. The electrochemical char-
acterization of compounds 4-8 was carried out by using
cyclic and thin layer cyclic voltammetry (Table 1). Figure
4
8
shows very similar absorption bands in THF and pyridine
with the main difference being that in THF the broader
component of the Q-band at higher energy is more
intense than the sharper band centered at 700 nm,
whereas in pyridine it is the opposite. The sharper band
being due to a monomeric species,12 this indicates a
higher degree of aggregation in THF than in pyridine.
2a shows the deconvoluted voltammogram of the tetrathia-
2 4
FIGURE 2. Thin layer cyclic voltammogram of 4 (a) and of H Pc-(TTF) 5 (b), in 0.1 M tetrabutylammonium hexafluorophosphate
-
1
in CH
2 2 3
Cl /CH CN (9.5/0.5, v/v) at 0.1 V s , Pt electrode.
4990 J. Org. Chem., Vol. 70, No. 13, 2005

Synthesis of Tetrathiafulvalene-Annulated Phthalocyanines
the Q-band could also be taken as an indication that even
with the quite substantial excess of the oxidizing agent
FeCl , oxidation of the four TTF units is still not quite
3
complete, and that in order for the fluorescence to be
switched on, all four TTF units have to be oxidized
simultaneously.
Concluding Remarks. During this study we de-
veloped an efficient synthetic route to the important
precursor 5,6-dicyanobenzene-1,3-dithiole-2-one 2, which
can readily react with corresponding thiones in the
presence of a phosphorus(III) compound to afford phtha-
lonitrile derivatives in good yields. Furthermore, we
demonstrated that redox-active TTF units can be annu-
lated to a Pc core and it could be shown that these fused
systems are good π-electron donors. Interestingly, the
closed shell derivatives exhibit an intense redox-state
dependent emission. With the key building block 2 at
hand, this new set of large π-systems might be extended
in a straightforward manner, specifically at the periphery
of the TTF units. More TTF-annulated Pcs with further
functionalities are under investigation.
Experimental Section
4
FIGURE 3. (a) Absorption spectra of ZnPc-(TTF) 8 in THF
-
6
(
c ) 2 × 10 M): (s) neutral form, (- - -) oxidized form. (b)
Synthesis. All reagents were of commercial quality and
used as supplied unless otherwise stated; solvents were dried
where necessary using standard procedures. All reactions were
carried out under an inert atmosphere. 1,2-Bis(S-benzylthio)-
Emission spectrum (s) and excitation spectrum (- - -) of the
oxidized form of 8 in THF.
Importantly, in its neutral form a freshly prepared
solution of 8 dissolved in THF does not show any
luminescence above the detection threshold of the ex-
perimental setup. This is due to the presence of the
electron-donating TTF units fused to the phthalocyanine
chromophore. As has also been observed for monoannu-
lated porphyrin, the TTF is an efficient reductive electron-
transfer quencher.10
13
4
,5-dicyanobenzene 1 and 4,5-bis(propylthio)-1,3-dithiole-2-
14
thione 3 were prepared according to literature procedures
(see the Supporting Information).
5,6-Dicyanobenzene-1,3-dithiole-2-one (2). A solution of
compound 1 (1 g, 2.7 mmol) and AlCl (2.9 g, 21.5 mmol) in
3
toluene (60 mL) was stirred under nitrogen at room tem-
perature for 2 h, then 1,1′-carbonyldiimidazole (0.87 g, 5.4
mmol) was added to the yellow mixture and it was stirred for
an additional 0.5 h. The solvent was removed under reduced
pressure. Chromatography of the residue on a silica gel column
with CH Cl /hexane (3/1) as eluent afforded 0.5 g (85%) of
3
Upon addition of a 5-fold excess of FeCl as mild
oxidizing agent, the absorption spectrum changes quite
dramatically. The sharper peak of the Q-band at 700 nm
gains substantially in intensity at the expense of the
broader component. This indicates that upon oxidation
the now positively charged species have less tendency to
aggregate. In contrast to the neutral compound, the
oxidized species exhibits a very strong luminescence. The
corresponding luminescence spectrum (λex ) 380 nm),
included in Figure 3b, consists of two well-resolved bands
2
2
1
compound 2 as a white powder: mp 239 °C; H NMR (DMSO-
1
3
d
6
) δ 8.68 (s, 2H); C NMR (DMSO-d
6
) δ 188.5, 138.6, 128.7,
1
15.4, 112.4; IR (KBr) νmax 2234 (CtN), 1731 (CdO), 1660
-
1
+
cm ; EI-MS m/z (rel intensity, %) 218 (M , 43). Anal. Calcd
for C O: C, 49.53; H, 0.92; N, 12.84. Found: C, 49.39;
H, 0.99; N, 12.56.
,6-Dicyano-2-(4,5-bis(propylthio)-1,3-dithio-2-ylidene)-
9 2 2 2
H N S
5
benzo[d]-1,3-dithiole (4). A solution of compound 2 (50 mg,
0.23 mmol) and compound 3 (156 mg, 0.34 mmol) in a mixture
of triethyl phosphite (10 mL) and toluene (5 mL) was heated
to 120 °C under nitrogen for 3 h. After removal of the solvent
under reduced pressure, chromatography on silica of the
-
1
-1
at 710 (14 080 cm ) and 786 nm (12 720 cm ) with a
-
1
separation of 1360 cm between them. Except for a red
shift of some 25 nm, the luminescence spectrum is
identical with that of phthalocyanine monomers without
TTF functionalities,12 and it can therefore be attributed
to the fluorescence from the Q-band with a characteristi-
cally small Stokes’ shift of only ∼200 cm . At first sight,
the luminescence spectrum does not show the typical
mirror image of the absorption, hence, the broader
component of the Q-band exhibits fluorescence quench-
ing. However, the excitation spectrum (λdet ) 780 nm),
also included in Figure 3b, is indeed the mirror image of
the fluorescence. The fact that it differs from the absorp-
tion spectrum in the range of the broader component of
residue with CH
68%) of compound 4 as a red powder. Single crystals suitable
for X-ray diffraction determination were obtained by cooling
2 2
Cl /hexane (2/1) as eluent afforded 66 mg
(
1
a saturated DMSO solution: mp 233 °C; H NMR (DMSO-d
δ 8.30 (s, 2H), 2.88 (t, 4H, J ) 7.14 Hz), 1.64 (m, 4H, J ) 7.14
6
)
-1
1
3
Hz, J ) 7.35 Hz), 0.98 (t, 6H, J ) 7.35 Hz); C NMR (DMSO-
) δ 143.1, 126.8, 126.2, 114.9, 113.1, 111.8, 107.1, 37.3, 22.3,
2.3; IR (KBr) νmax 3437, 3078, 2960, 2933, 2873, 2234 (Ct
d
6
1
-
1
N), 1566, 1458, 1236, 1216, 1126 cm ; EI-MS m/z (rel
+
intensity, %) 452 (M , 100). Anal. Calcd for C18
16 2 6
H N S : C,
47.75; H, 3.56; N, 6.19. Found: C, 47.77; H, 3.54; N, 5.91.
(
13) Sim a˜ o, D.; Alves, H.; Belo, D.; Raba c¸ a, S.; Lopes, E. B.; Santos,
I. C.; Gama, V.; Duarte, M. T.; Henriques, R. T.; Novais, H.; Almeida,
M. Eur. J. Inorg. Chem. 2001, 3119.
(
11) Khodorkovsky, V.; Becker, J. Y. In Organic Conductors: Fun-
damentals and Applications; Farges, J.-P., Ed.; Marcel Dekker: New
(14) (a) Hansen, J. A.; Becher, J.; Jeppesen, J. O.; Levillain, E.;
Nielsen, M. B.; Petersen, B. M.; Petersen, J. C.; Sahin, Y. J. Mater.
Chem. 2004, 14, 179. (b) Svenstrup, N.; Rasmussen, K. M.; Kruse
Hansen, T.; Becher, J. Synthesis 1994, 809.
York, 1994.
(
12) Farren, C.; FitzGerald, S.; Beeby, A.; Bryce, M. R. Chem.
Commun. 2002, 572.
J. Org. Chem, Vol. 70, No. 13, 2005 4991

Loosli et al.
+
+
2
,3,9,10,16,17,23,24-Tetrakis[4′,5′-bis(propylthio)tetrathi-
afulvalene]phthalocyanine (5). Lithium metal (0.3060 g,
6.9 mmol) was dissolved in 1-pentanol (25 mL) at 80 °C under
argon. To this lithium pentoxide solution was added 0.2033 g
0.45 mmol) of compound 4 and the mixture was heated to 125
C under argon and stirred at this temperature for 5 h. The
DI) 1866.77 (M ), 1884.76 (M + H
2
O). Anal. Calcd for
72 64 8
C H N S24Co: C, 46.25; H, 3.45; N, 5.99. Found: C, 46.11;
4
H, 3.52; N, 5.95.
2,3,9,10,16,17,23,24-Tetrakis[4′,5′-bis(propylthio)tet-
{
(
°
rathiafulvalene]phthalocyaninato}nickel(II) (7). Yield
0
3
1
.061 g (88%): mp >250 °C dec; UV-vis (pyridine) λmax (ꢀ)
color changed to an intense green within 15 min. The green
mixture was cooled to room temperature, ethanol (80 mL) and
glacial acetic acid (80 mL) were added, and the suspension
was allowed to stand overnight. A dark green solid was
obtained by decantation, centrifugation, and washing with
large amounts of ethanol, a mixture of ethanol and water, and
ether. The solid was dried at 45 °C and in vacuo yielding 0.140
g (68%): mp >250 °C dec; UV-vis (pyridine) λmax (ꢀ) 355
28 (99 000), 620 (26 000) nm; IR (KBr) νmax 2959, 2925, 2867,
-1
423, 1388, 1069 cm ; MS calcd for C72
64 8
H N S24Ni 1865.79
+
+
+
(
M ), found (MALDI):1865.79 (M ), 1883.76 (M + H
Calcd for C72 24Ni: C, 46.25; H, 3.45; N, 5.99. Found:
C, 46.05; H, 3.54; N, 5.90.
2
O). Anal.
64 8
H N S
{
2,3,9,10,16,17,23,24-Tetrakis[4′,5′-bis(propylthio)tet-
rathiafulvalene]phthalocyaninato}zinc(II) (8). Yield 0.036
g (52%): mp >250 °C dec; UV-vis (pyridine) λmax (ꢀ) 367
(
45 000), 617 (27 000), 691 (22 000) nm; IR (KBr) νmax 3430,
(
125 000), 655 (70 000), 706 (75 000) nm; IR (KBr) νmax 3432,
-
1
2
959, 2923, 2869, 1407, 1071, 1021 cm ; MS calcd for
-1
2
959, 2927, 2870, 1413, 1377, 1063 cm ; MS calcd for
+
+
C
1
3
72
H
66
N
8
S
24 1809.87 (M ), found (MALDI) 1809.89 (M ),
+
+
C
72 64 8
H N S24Zn:1871.78 (M ), found (MALDI) 1871.73 (M ),
+
823.79 (M - 86). Anal. Calcd for C72
H
66
N
8
S
24: C, 47.70; H,
+
1
64 8
786.69 (M - 86). Anal. Calcd for C72H N S24Zn: C, 46.09;
.67; N, 6.18. Found: C, 48.00; H, 3.79; N, 5.81.
H, 3.44; N, 5.97. Found: C, 46.11; H, 3.51; N, 5.93.
General Procedure for the Synthesis of Tetrakis-TTF-
Annulated Metallophthalocyanines. A mixture of 0.050 g
Acknowledgment. Support for this research by the
Swiss National Science Foundation (Grant No. 200021-
100432) is gratefully acknowledged.
(
0.110 mmol) of 4 and 0.037 mmol of the appropriate anhy-
drous metal chloride was heated in 1 mL of DMAE to 135 °C
under argon overnight. The mixture was cooled to room
temperature, and MeOH was added to precipitate the product.
The dark green solid was obtained by decantation, centrifuga-
tion, and washing with large amounts of MeOH, a mixture of
MeOH and water, and ether. The solid was dried at 45 °C and
in vacuo.
Supporting Information Available: General experimen-
tal methods, detailed experimental procedures and character-
1
13
ization data for compounds 1 and 3, H and C NMR spectra
for compounds 2 and 4, UV-vis spectra of compounds 5-8,
and thin layer cyclic voltammogram of compounds 6-8, as well
as an X-ray crystallographic file for 4 in CIF format. This
material is available free of charge via the Internet at
http://pubs.acs.org.
{
2,3,9,10,16,17,23,24-Tetrakis[4′,5′-bis(propylthio)tet-
rathiafulvalene]phthalocyaninato}cobalt(II) (6). Yield
0
3
.042 g (61%): mp >250 °C dec; UV-vis (pyridine) λmax (ꢀ)
33 (114 000), 473 (shoulder, 23 000), 641 (40 000), 687
(
42 000) nm; IR (KBr) νmax 2959, 2927, 2869, 1420, 1386, 1068
-
1
+
cm ; MS calcd for C72
H
64
N
8
S
24Co 1866.79 (M ), found (MAL-
JO0501801
4992 J. Org. Chem., Vol. 70, No. 13, 2005