Synthesis and characterization of 5,10- and 5,15-disubstituted porphodimethenes

Article abstract of DOI:10.1002/cjoc.201200321

The four porphodimethene isomers, 5,10- and 5,15-disubstituted, have been synthesized in a one-pot reaction by the Lindsey protocol. Three of them have been characterized by X-ray crystallography. Structures show that two of them are 5,15-porphodimethenes: one is syn-equatorial, another is anti-configuration; the third one is 5,10-porphodimethene. In the 5,10-porphodimethene, the tripyrrane subunit remains planar conformation. ¹H NMR and UV-vis spectra have also been characterized. Both spectra reveal remarkable difference between 5,10- and 5,15-disubstituted isomers.

Full text of DOI:10.1002/cjoc.201200321

FULL PAPER
DOI: 10.1002/cjoc.201200321
Synthesis and Characterization of 5,10- and 5,15-Disubstituted
Porphodimethenes
Feng, Zhiqianga(冯志强)
Kai, Xiaoxua(怯小旭)
Hu, Chuanjiang*,a,b(胡传江)
Jiang, Jiaxuna(蒋佳珣)
a Key Laboratory of Organic Synthesis of Jiangsu Province, College of Chemistry, Chemical Engineering and Ma-
terials Science, Soochow University, Suzhou, Jiangsu 215123, China
b State Key Lab & Coordination Chemistry Institute, Nanjing University, Nanjing, Jiangsu 210093, China
The four porphodimethene isomers, 5,10- and 5,15-disubstituted, have been synthesized in a one-pot reaction by
the Lindsey protocol. Three of them have been characterized by X-ray crystallography. Structures show that two of
them are 5,15-porphodimethenes: one is syn-equatorial, another is anti-configuration; the third one is 5,10-por-
1
phodimethene. In the 5,10-porphodimethene, the tripyrrane subunit remains planar conformation. H NMR and
UV-vis spectra have also been characterized. Both spectra reveal remarkable difference between 5,10- and
5,15-disubstituted isomers.
Keywords calixphyrin, porphodimethene, Lindsey protocol, isomers
relation to calix[n]pyrrole chemistry.[24-27] Senge et al.
have independently developed their own approaches to
this class of compounds.[20,28-32] Among those por-
phodimethenes, 5,15-porphodimethenes can be synthe-
sized by MacDonald-like condensation-based ap-
proaches.[33-35] For example, Scott and coworkers have
reported that the reaction between dipyrromethanes and
acenaphthenequinone led to the formation of the corre-
sponding 5,15-porphodimethenes and they were subse-
quently converted into dinaphthylporphyrin dicarboxylic
acids.[34] They also converted tert-butyl substituted ace-
naphthenequinones into 5,15-porphodimethenes and then
made unusual fused ring porphyrins.[13] But the synthesis
of 5,10-porphodimethenes is more difficult, and few
studies have been reported.[24,29,36,37] Considering ace-
naphthenequinone may lead to spirocyclic structure
which could stabilize the corresponding porphodi-
methenes species, we have synthesized the 5,10- and
5,15-porphodimethene isomers in a one-pot reaction
with mixed acenaphthenequinone, benzaldehyde and
pyrrole by the Lindsey protocol.[38-40] The four isomers
have been characterized by X-ray crystallography, mass
spectroscopy, 1H NMR and UV-vis spectroscopy, etc.
Introduction
Calix[4]phyrins are a class of hybrid molecules that
lie at the structural crossroads between porphyrins and
calix[4]pyrroles. A typical feature of porphyrins is full
conjugation throughout the macrocyclic skeleton,[1-3]
while calixphyrins possess a mixture of sp2- and
sp3-hybridized meso carbon bridges and have been
shown to be good receptors for cations and anions.[4-8]
Because of such bonding features, calixphyrins possess
reasonably flexible frameworks as well as rigid π-con-
jugated networks, whose characters vary considerably
depending on the number and position of the sp3
meso-carbon atoms. They are observed in numerous
porphyrinic intermediates known as porphomethenes,
porphodimethenes, isoporphyrins or phlorins.[9,10]
Porphodimethenes belong to an intermediate class of
calix[4]phyrins.[11-19] They possess two sp2- and two
sp3-hybridized meso carbon centers, which have the
potential to possess both the binding properties of
calixpyrroles and the biological affinity of (hydro)-
porphyrins.[20] This disruption in the π-electronic con-
jugation has been shown to cause drastic conformational
changes and significant modifications of their overall
properties.[21-23] But such species are unstable in many
cases. Porphodimethenes have been intensively investi-
gated by several groups. For example, Sessler et al.
have established convenient methods for the synthesis
of a series of calix[n]phyrins and systematically inves-
tigated their structures and conformational mobilities in
Experimental
Materials and general methods
Acenaphthenequinone (Alfa Aesar) and tetrachloro-
1,4-benzoquinone were used as received. Pyrrole and
*
E-mail: cjhu@suda.edu.cn
Received April 1, 2012; accepted May 22, 2012.
Supporting information for this article is available on the WWW under http://dx.doi.org/10.1002/cjoc.201200321 or from the author.
Chin. J. Chem. 2012, 30, 1715—1721 © 2012 SIOC, CAS, Shanghai, & WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
1715

Feng et al.
FULL PAPER
methylene chloride were freshly distilled before use.
Other solvents were used as received. UV-vis spectra
were measured on a Shimadzu UV-3150 spectrometer.
1H NMR spectra were carried out using a Bruker
AVANCE 400 spectrometer with tetramethylsilane
(TMS) as the internal standard. Mass spectra were taken
with Agilent 6220 Accurate-Mass TOF LC/MS.
4.06, N 7.15.
For 2a, yield 0.11 g (4.1%); UV-vis (CH2Cl2) λmax
－
－
1
1
[ε/(L•mol •cm )]: 341 (0.46×105), 371 (0.44×105),
543 (0.26×105), 578 (0.28×105) nm; H NMR (400
1
MHz, CDCl3) δ: 13.26 (s, 1H), 11.90 (s, 1H), 8.13 (d,
J＝7.9 Hz, 2H), 7.92 (d, J＝8.5 Hz, 4H), 7.82—7.76 (m,
2H), 7.76—7.66 (m, J＝7.1 Hz, 4H), 7.51—7.33 (m,
10H), 6.64 (s, 2H), 6.19 (s, 2H), 6.05 (s, 2H), 5.41 (s,
2H); 13C NMR (101 MHz, CDCl3) δ: 197.62, 171.12,
152.75, 142.15, 140.82, 139.87, 139.19, 138.12, 136.93,
131.99, 131.64, 131.22, 131.07, 129.20, 129.11, 128.79,
128.71, 127.71, 125.76, 125.04, 123.64, 123.58, 123.12,
106.30, 62.40; IR (KBr) v: 3446, 1712, 1590, 1500,
1440, 1390, 1250, 1232, 1201, 1175, 1072, 1015, 962,
Preparation of the four porphodimethene isomers
The reaction was carried out under anaerobic condi-
tion. Acenaphthenequinone (2.52 g, 13.8 mmol), ben-
zaldehyde (1.33 mL, 13.8 mmol) and pyrrole (1.9 mL,
27.6 mmol) were dissovled in methylene chloride (500
mL). BF3•OEt2 (1 mL, 7.90 mmol) was added to the
above solution and stirred for 1 h at room temperature,
then tetrachloro-1,4-benzoquinone (6.72 g, 27.6 mmol)
was added. After 2 h under reflux, triethylamine (8.0
mL) was added, and the mixture was stirred for another
0.5 h. When it was cooled down to r.t., it was filtered by
sintered glass funnel. The filtrate was evaporated to
dryness under vacuum, the black solid was further puri-
fied by column chromatography [silica, V(CH2Cl2)∶
V(petroleum ether)＝1∶1]. The first (1a), second yel-
low band (1b) and second (2a), third purple band (2b)
were collected respectively. (The first purple species is
TPP, tetraphenylporphyrin.)
－
1
825, 781, 700 cm ; LC-ESI-MS: 769.26 (calcd for [M＋
＋
H]
769.25, M ＝ C54H32N4O2). Anal. calcd for
C54H32N4O2•0.5CH2Cl2: C 80.68, H 4.10, N 6.91; found
C 80.49, H 4.4, N 6.68.
For 2b, yield 0.17 g (6.4%); UV-vis (CH2Cl2) λmax
－
－
1
1
[ε/(L•mol •cm )]: 332 (0.41×105), 364 (0.37×105),
540 (0.24×105), 578 (0.27×105) nm; H NMR (400
1
MHz, CDCl3) δ: 12.97 (s, 1H), 11.29 (d, J＝24.9 Hz,
1H), 8.11 (d, J＝8.1 Hz, 2H), 7.98 (d, J＝7.0 Hz, 2H),
7.91 (d, J＝8.3 Hz, 2H), 7.78 (d, J＝6.9 Hz, 2H), 7.70
(dd, J＝15.0, 7.1 Hz, 4H), 7.48—7.35 (m, 10H), 6.58 (d,
J＝4.6 Hz, 2H), 6.14 (s, 2H), 5.87 (d, J＝4.6 Hz, 2H),
5.58 (d, J＝2.4 Hz, 2H); 13C NMR (101 MHz, CDCl3) δ:
198.07, 172.08, 152.19, 142.33, 140.10, 139.91, 138.65,
138.47, 137.29, 132.01, 131.84, 131.17, 131.06, 128.96,
128.72, 128.63, 127.65, 127.58, 125.66, 125.14, 123.91,
123.52, 123.18, 107.37, 80.85, 62.45; IR (KBr) v: 3439,
1724, 1585, 1493, 1433, 1382, 1256, 1224, 1193, 1158,
For 1a, yield 0.18 g (6.8%); UV-vis (CH2Cl2) λmax
－
－
1
1
[ε/(L•mol •cm )]: 323 (0.27×105), 439 (0.74×105),
498 (0.057×105) nm; H NMR (400 MHz, CDCl3) δ:
1
13.96 (s, 2H), 8.82 (d, J＝6.7 Hz, 2H), 8.21 (d, J＝8.1
Hz, 2H), 8.15 (d, J＝7.0 Hz, 2H), 8.08—7.93 (m, 4H),
7.81 (t, J＝7.6 Hz, 2H), 7.45—7.29 (m, 10H), 6.37 (d,
J＝3.4 Hz, 4H), 6.20 (d, J＝3.6 Hz, 4H); 13C NMR (101
MHz, CDCl3) δ: 199.08, 155.34, 141.81, 141.78, 141.64,
139.86, 137.43, 132.62, 132.09, 131.33, 131.06, 129.86,
129.43, 128.86, 128.50, 127.61, 125.12, 124.61, 123.31,
116.87, 61.54; IR(KBr) v: 3447, 1711, 1580, 1505, 1470,
1433, 1383, 1311, 1259, 1228, 1162, 1127, 1045, 1017,
962, 925, 829, 780, 719 cm－1; LC-ESI-MS: 769.26
(calcd for [M＋H]＋ 769.25, M＝C54H32N4O2). Anal.
calcd for C54H32N4O2•0.3CH2Cl2: C 82.10, H 4.14, N
7.05; found C 81.88, H 4.15, N 7.01.
－
1
1066, 1005, 959, 923, 831, 783, 701 cm ; LC-ESI-MS:
769.26 (calcd for [M＋H]＋ 769.25, M＝C54H32N4O2).
Anal. calcd for C54H32N4O2•0.6CH2Cl2: C 79.99, H 4.08,
N 6.83; found C 80.13, H 4.29, N 6.61.
X-ray crystallography
The single crystals of 1a, 1b and 2b were obtained
through the diffusion of their methylene chloride/hexane
solutions. All X-ray data collections were made on a
Rigaku Mercury CCD X-ray diffractometer by using
graphite monochromated Mo Kα (λ＝0.071073 nm) at
223(2) K. Their structures were solved by direct meth-
ods and refined on F2 using full matrix least-squares
methods with SHELXTL version 97.[41] All non-hy-
drogen atoms were refined anisotropically. In the three
structures, all the N—H hydrogen atoms were found in
difference Fourier maps, and their coordinates and iso-
tropic temperature factors were refined, other hydrogen
atoms were theoretically added and riding on their par-
ent atoms. Complete crystallographic details, atomic
coordinates, anisotropic thermal parameters, and fixed
hydrogen atom coordinates are given in the cif file
(CCDC number: 872251, 872252 and 872253). For 1a,
one asymmetric unit contains one independent por-
phodimethene molecule and one disorder methylene
chloride solvate. For 2b, one asymmetric unit contains
For 1b, yield 0.12 g (4.5%); UV-vis (CH2Cl2) λmax
－
－
1
1
[ε/(L•mol •cm )]: 321 (0.28×105), 441 (1.00×105),
505 (0.076×105) nm; H NMR (400 MHz, CDCl3) δ:
1
13.98 (s, 2H), 8.18 (d, J＝8.1 Hz, 2H), 8.12 (d, J＝7.0
Hz, 2H), 8.03 (d, J＝8.3 Hz, 2H), 7.97 (d, J＝6.9 Hz,
2H), 7.87—7.76 (m, 4H), 7.49—7.42 (m, 2H), 7.37 (d,
J＝4.2 Hz, 4H), 7.31 (s, 4H), 6.32 (d, J＝4.2 Hz, 4H),
6.00 (d, J＝4.2 Hz, 4H); 13C NMR (101 MHz, CDCl3) δ:
195.84, 154.25, 142.42, 141.92, 138.83, 137.76, 131.99,
131.20, 131.14, 131.05, 130.75, 129.11, 128.99, 128.59,
127.48, 125.58, 124.32, 124.22, 116.94, 62.13; IR(KBr)
v: 3436, 1729, 1580, 1494, 1473, 1430, 1385, 1324,
1222, 1153, 1125, 1053, 1002, 961, 919, 830, 782, 719
－
＋
1
cm ; LC-ESI-MS: 769.26 (calcd for [M＋H] 769.25,
M ＝ C54H32N4O2). Anal. calcd for C54H32N4O2•
0.2CH2Cl2: C 82.84, H 4.16, N 7.13; found C 83.08, H
1716
www.cjc.wiley-vch.de
© 2012 SIOC, CAS, Shanghai, & WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
Chin. J. Chem. 2012, 30, 1715—1721

Synthesis and Characterization of 5,10- and 5,15-Disubstituted Porphodimethenes
two independent porphodimethene molecules (mole-
cules C and D), one ordered methylene chloride mole-
cule and one disordered methylene chloride solvate.
For 1b, one asymmetric unit contains two inde-
pendent porphodimethene molecules (molecule A and B)
and methylene chloride solvate. In one of the por-
phodimethenes, one naphthalene ring and one phenyl
ring were found to be disordered over two positions, a
major and a minor position. Both components were re-
fined as rigid groups, and their thermal displacement
parameters were restrained. In the final refinement, the
occupancy for the major component is 0.54 and 0.62,
respectively. For 1b, methylene chloride molecules
were badly disordered. SQUEEZE[42] was used to model
the disordered methylene chloride solvate. The residue
electron count in the interporphyrins voids amounted to
212 electrons per unit-cell (corresponding roughly to
1.25 molecule of CH2Cl2 per porphodimethene). Brief
crystal data for these structures are listed in Table 1.
Results and Discussion
The synthesis of compounds 1a, 1b and 2a, 2b is
summarized in Scheme 1. Briefly, these four isomers
were prepared in a one-pot reaction by the Lindsey pro-
tocol. These compounds have been characterized by
electrospray-ionization (ESI) mass spectrometry. It re-
vealed the ion peaks at m/z＝691.25 for all four species,
(corresponding to [M＋H]＋), which confirmed they are
isomers. By comparison, we also did reaction between
5-phenyldipyrromethane and acenaphthenequinone with
2∶2 ratio, only 1a and 1b were obtained. So 1a and 1b
are most likely 5,15-porphodimethenes, while 2a and 2b
are not. Theoritically, our reaction could lead to porphy-
rinoid systems with one, three or four acenaphthene-
quinone units. But we did not obtain these species, one
possible reason is that their yields could be too low.
These new compounds have been further investigated
by X-ray crystallography, 1H NMR and UV-vis
spectroscopy etc.
Table 1 Crystallographic data for 1a, 1b and 2ba
1a 1b
C55H34Cl2N4O2 C108H64N8O4
Complex
2b
Empirical formula
Formula weight/(g•mol－
Temperature/K
Wavelength/Å
Crystal system
space group
C110H68Cl4N8O4
1707.52
1
)
853.76
1537.67
223(2)
223(2)
223(2)
0.71073
0.71073
0.71073
Monoclinic
P2(1)/n
Triclinic
Triclinic
P-1
P-1
a＝16.477(3) Å
b＝11.827(2) Å
c＝22.737(5) Å
α＝90°
a＝13.725(3) Å
b＝17.162(3) Å
c＝19.852(4) Å
α＝84.00(3)°
β＝82.56(3)°
γ＝87.05(3)°
4607.9(16)
2
a＝13.244(3) Å
b＝16.274(3) Å
c＝20.582(4) Å
α＝110.16(3)°
β＝92.90(3)°
γ＝91.33(3)°
4155.0(14)
2
Unit cell dimensions
Volume/Å3
β＝110.63(3)°
γ＝90°
4146.6(14)
4
Z
ρ/(g•cm－
)
1.368
1.108
1.365
3
F(000)
1768
1600
1768
Crystal size/mm3
0.20×0.60×0.55
3.15° to 25.00°
－14≤h≤19
－13≤k≤14
－27≤l≤124
20200/7251
7251/56/602
1.158
0.30×0.60×0.40
3.01° to 25.00°
－16≤h≤15
－20≤k≤20
－22≤l≤23
38708/16175
16175/406/1179
1.009
0.20×0.40×0.4
3.02° to 25.00°
－14≤h≤15
－17≤k≤19
－24≤l≤24
34886/14571
14571/65/1175
1.131
Theta range for data collection
Limiting indices
Reflections collected/unique
Data/restraints/parameters
GOF
R1＝0.0827
wR2＝0.1939
R1＝0.0973
wR2＝0.2049
0.220 and －0.527
R1＝0.0890
wR2＝0.2370
R1＝0.1395
wR2＝0.2648
0.314 and －0.269
R1＝0.0912
wR2＝0.1797
R1＝0.1394
wR2＝0.2027
1.044 and －0.416
R1,wR2 [I＞2σ(I)]
R1,wR2 (all data)
Largest diff. peak and hole/(e•Å3)
2
2
a w＝1/[σ2(Fo )＋(aP)2＋bP] where P＝(Fo ＋2Fc2)/3.
Chin. J. Chem. 2012, 30, 1715—1721
© 2012 SIOC, CAS, Shanghai, & WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
www.cjc.wiley-vch.de
1717

Feng et al.
FULL PAPER
Crystal structures
naphthyl groups toward each other, which will cause
large repulsion.[44]
The solid state structures of 1a, 1b (molecule B) and
2b (molecule D) are shown in Figures 1, 2 and 3, re-
spectively. ORTEP diagrams of 1b (molecule A) and 2b
(molecule C) are provided in SI. Structures clearly show
that compounds 1a and 1b are 5,15-disubstituted por-
phodimethenes, while 2b is a 5,10-disubstituted species.
Porphodimethenes with unsymmetrically substituted
carbon atoms at the meso sp3 centers can exist in three
configurations: syn-axial, syn-equatorial and anti.[26,43]
In our case, compound 1a has anti configuration, 1b has
syn-equatorial configuration (two carbonyl oxygens face
to each other). As one kind of calixphyrins, the typical
feature of porphodimethenes is a mixture of sp2- and
sp3-hybridized bridging meso carbon centers. In com-
pounds 1a and 1b, the 5,15-carbons are sp3-hybidized,
and 10,20- carbons are sp2-hybidized, which are con-
firmed by the corresponding bond number, bond dis-
tances and angles. Related values are listed in Table 2
and SI.
For 1a, the structure shows the two saturated carbon
atoms force the tetrapyrrolic macrocycle to adopt a
strong rooflike folded structure with an interplanar roof
angle defined by the dipyrromethene units of 117.8°.
The two O…O distance is 3.26 Å. In 1b, there are two
independent molecules (molecules A and B), the corre-
sponding angles are 130.5° and 130.8°. The dipyrrome-
thene moieties in 1a are quite planar with the dihedral
angles of the pyrrole conjugated units 4.59° and 5.99°,
respectively. But the two conjugated pyrrole units
within the each dipyrromethene moieties in 1b are more
distorted, the corresponding dihedral angles are 2.63°
and 13.12° for molecule A, 16.21° and 19.63° for mole-
cule B.
Compounds 2a and 2b can not be obtained by the
MacDonald method. We were able to grow crystals of
2b suitable for X-ray crystallographic analysis. In the
crystal structure shown in Figure 3, it is clear that there
are two sp3 carbons. All the related bond distances, bond
angles and bond numbers in Table S1 suggested the two
sp3 centers are at the 5- and 10-positions and the two sp2
centers are at the 15- and 20-positions. It has syn-equa-
torial configuration, the two acenaphthylen-1(2H)-one
subunits are located at the adjacent sp3-hybirdized meso
carbons, two carbonyl oxygens face to each other with
the corresponding distance 3.640 Å for molecule C and
3.837 Å for molecule D. As expected, the macrocycle is
nonplanar, the tetrapyrrole ring is divided into a conju-
gated tripyrrane unit and an isolated pyrrole unit. In this
case, the tripyrrane subunit is almost planar, with the
dihedral angle among the three conjugated pyrrole units
0.38°, 11.68° and 11.32° for molecule C, 8.32°, 8.54°
and 9.21° for molecule D. It is much different from
those in other structural characterized 5,10-porphodi-
methenes[45] which have nonplanar tripyrrane subunits.
In the structure of 2b, the tripyrrane and isolated pyrrole
subunits display rotation angle of 64.82° for molecule C
and 63.63° for molecule D.
We were not able to obtain the crystal structure of 2a.
But as similar reason to those 5,15-disubstituted porpho-
dimethene, the syn-axial configuration of 5,10-disub-
stituted species could be unfavorable as well due to the
repulsion involving naphthyl groups and the isolate
pyrrole unit. So it is most likely compound 2a has
anti-configuration. But we can not completely rule out
the possibility of syn-axial configuration.
In our experiments, we did not obtained syn-axial
configuration (two carbonyl oxygens are away from
each other). Considering about the structure, one possi-
ble reason is that such configuration causes both
1H NMR analysis
In the fully conjugated porphyrin, TPP, the β-protons
on the periphery of the macrocycle are strongly
Scheme 1 Synthetic route to 5,10- and 5,15-disubstituted porphodimethenes
O
CHO
+
+
N
H
O
.
(1) BF3 OEt2, CHCl3, r.t., 1 h
(2) Tetrachlorobenzoquinone, reflux, 2 h
(3) Triethylamine
O
O
N
O
O
O
O
H
H
N
N
O
NH
Ph
N
HN
NH
Ph
O
N
HN
N
N
N
N
N
H
H
N
N
Ph
Ph
Ph
Ph
Ph
1a (anti)
Ph
1b (syn-equatorial)
2b (syn-equatorial)
2a (anti)
1718
www.cjc.wiley-vch.de
© 2012 SIOC, CAS, Shanghai, & WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
Chin. J. Chem. 2012, 30, 1715—1721

Synthesis and Characterization of 5,10- and 5,15-Disubstituted Porphodimethenes
Table 2 Selected bond lengths (Å) and angles (°) for 1a
C(m1)—C(a2)
C(m2)—C(a4)
C(m3)—C(a6)
C(m4)—C(a8)
C(1)—O(1)
1.523(5) C(A3)-C(m1)-C(11) 111.3(3)
1.422(4) C(A2)-C(m1)-C(11) 113.6(3)
1.525(4) C(A3)-C(m1)-C(1)
1.424(5) C(A2)-C(m1)-C(1)
1.215(4) C(11)-C(m1)-C(1)
106.8(3)
112.5(3)
102.1(3)
C(m1)—C(a3)
C(m2)—C(a5)
C(m3)—C(a7)
C(m4)—C(a1)
C(2)—O(2)
1.515(4) C(A3)-C(m1)-C(A2) 110.1(3)
1.387(5) C(A5)-C(m2)-C(A4) 124.5(3)
1.507(4) C(A5)-C(m2)-C(21) 119.1(3)
1.389(5) C(A4)-C(m2)-C(21) 116.3(3)
1.209(4) C(A7)-C(m3)-C(A6) 110.1(3)
C(31)-C(m3-C(2)
C(A6)-C(m3)-C(2)
101.9(2) C(A7)-C(m3)-C(2)
108.6(3)
109.6(2) C(A1)-C(m4)-C(A8) 124.5(3)
C(A1)-C(m4)-C(41) 118.1(3) C(A8)-C(m4)-C(41) 117.4(3)
Figure 3 ORTEP view for 2b (molecule D) at 50% probability
thermal ellipsoids. The hydrogen atoms have been omitted for
clarity.
are shielded by the ring current and resonate upfield at δ
－2.72. As shown in Figure 4, in these four porphodi-
methenes, β-protons are still in the deshielding region,
but less downfield, resonated at δ 5—7. The loss of
aromaticity in the porphodimethenes causes a reverse
effect on the chemical shifts of the NH protons, which
results in a downfield shift to the range from δ 11 to 14.
For two 5,15-substituted species, there is only single
resonance for NH protons. But for 5,10-substituted spe-
cies, there are two resonance signals. It is obviously due
to the lower symmetry of 5,10-porphodimethene.
Figure 1 ORTEP view for 1a at 50% probability thermal ellip-
soids. The hydrogen atoms have been omitted for clarity.
Figure 4 1H NMR spectra of TPP and four porphodimethene
isomers in CDCl3.
UV-vis analysis
Because of the presence of sp3-hybridized centers,
the overall macrocycles must adopt nonplanar confor-
mations.[11-12,46] The photophysical properties of non-
planar macrocycles differ significantly from those of
their planar analogues.[47-50] The two 5,15-porphodi-
methenes (1a and 1b) are both bright orange solids and
exhibit a characteristic absorption maxima in the UV-vis
Figure 2 ORTEP view for 1b (molecule B) at 50% probability
thermal ellipsoids. The hydrogen atoms have been omitted for
clarity.
deshielded by the diamagnetic ring current. They resonate
at δ 8.87. The NH protons, in the core of the macrocycle,
Chin. J. Chem. 2012, 30, 1715—1721
© 2012 SIOC, CAS, Shanghai, & WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
www.cjc.wiley-vch.de
1719

Feng et al.
FULL PAPER
spectra around 439 or 441 nm caused by two distinct
linear conjugated π-system, and no Q band is observed
(as shown in Figure 5). A weak broad shoulder around
502 nm is a characteristic feature of the porphodi-
methene.[51] Both 2a and 2b are purple solids. Their
UV-vis spectra show two absorption bands at 350 and
550 nm. In 5,10-porphodimethenes, the tetrapyrrole ring
is divided into a tripyrrane unit and an isolated pyrrole
unit. The tripyrrane moiety is responsible for these two
broad absorbances, with the absorption due to the iso-
lated pyrrole unit being too weak to be measured.[20,52]
This is considerably different from the absorption spec-
trum of a porphyrin, where there is an intense Soret
band at 420 nm accompanied by four less intense Q
bands at longer wavelengths.
tion those conformers are flexible and can convert to
each other, UV-vis absorption is the average contribu-
tions from all conformers.
Conclusions
In conclusion, we have successfully synthesized and
isolated four porphodimethene isomers, especially, two
5,10-porphodimethenes, by a one-pot reaction. They
1
have been characterized by X-ray crystallography, H
NMR and UV-vis spectroscopy etc. Structures suggest
1a and 1b are 5,15-porphodimethenes, and 2a and 2b
are 5,10-porphodimethenes. As a 5,10-porphodimethene,
2b shows the distinguished solid structure. Much dif-
ferent from the known 5,10-porphodimethenes, the
tripyrrane subunit of 2b adopt planar conformation.
Consistent with the structural feature, 5,15-porphodi-
methenes and 5,10-porphodimethenes show remarkable
1
different H NMR and UV-vis spectra. We will further
investigate their binding ability to ions in the future.
Acknowledgement
This work was supported by the Natural Science
Foundation of China (No. 20971093) and the Priority
Academic Program Development of Jiangsu Higher
Education Institutions.
References
[1] Smith, K. M. Porphyrins and Metalloporphyrins, Elsevier Scientific
Publishing Co., Amsterdam, Oxford, 1975, pp. 3—28.
[2] Gouterman, M. In The porphyrins, Ed.: Dolphin, D., Academic Press,
New York, 1978, Vol. 3, pp. 1—165.
Figure 5 UV-vis spectra of the four isomers (1×10－5 mol•L－
in methylene chloride.
)
1
[3] The Porphyrin Handbook, Vol. 2, Eds.: Kadish, K. M.; Smith, K. M.;
Guilard, R. Academic Press, San Diego, 1999, pp. 2—40.
[4] Gupta, I.; Froehlich, R.; Ravikanth, M. Eur. J. Org. Chem. 2008,
1884.
[5] Cafeo, G.; Kohnke, F. H.; White, A. L. P.; Garozzo, D.; Messina, A.
Chem.-Eur. J. 2007, 13, 649.
[6] Bates, G. W.; Gale, P. A.; Light, M. E. Supramol. Chem. 2008, 20,
23.
[7] Gale, P. A.; Anzenbacher, P.; Sessler, J. L. Coord. Chem. Rev. 2001,
222, 57.
[8] Gale, P. A.; Sessler, J. L.; Kral, V. Chem. Commun. 1998, 1.
[9] Bernátková, M.; Andrioletti, B.; Král, V.; Rose, E.; Vaissermann, J.
J. Org. Chem. 2004, 69, 8140.
[10] Matano, Y.; Imahori, H. Acc. Chem. Res. 2009, 42, 1193.
[11] Benech, J. M.; Bonomo, L.; Solari, E.; Scopelliti, R.; Floriani, C.
Angew. Chem., Int. Ed. 1999, 38, 1957.
[12] Dolphin, D. J. Heterocycl. Chem. 1970, 7, 275.
[13] Gill, H. S.; Harmjanz, M.; Santamaría, J.; Finger, I.; Scott, M. J.
Angew. Chem., Int. Ed. 2004, 43, 495.
[14] Harmjanz, M.; Gill, H. S.; Scott, M. J. J. Am. Chem. Soc. 2000, 122,
10476.
The absorption coefficients for all four porphodi-
methenes are much less intense than that of the free-base
porphyrin. This is attributed to the interrupted conjuga-
tion in the macrocycles.[51] However, there is a remark-
able difference between the UV-vis spectra of the
5,15-porphodimethenes and 5,10-porphodimethenes.
The different conjugated pathway in these species could
contribute to such difference. In the 5,15-porphodi-
methenes, the macrocycles were divided into two iden-
tical units containing two conjugated pyrrolic rings by
sp3-hybridized meso carbon centers, which shows a su-
perimposed band which is more intense than the single
two conjugated pyrrolic rings in UV-vis spectra; while
in contrast, the macrocycles of the 5,10-porphodi-
methenes were divided into a tripyrrane unit and an iso-
lated pyrrole unit. The tripyrrane containing three con-
jugated pyrrolic rings mainly contributed to the absorp-
tion bands, and two weak broad bands among 300—600
nm is a characteristic feature of three conjugated pyr-
rolic rings.[52] The spectra of 2a and 2b are very similar
to that of 5,10-porphodimethene in Senge’s study,[20] but
their solid state structures are much different. It was
reported the conformational changes of 5,15-porphodi-
methene can even lead to interconversion between C2
and Ci symmetry forms.[26] So it is possible that in solu-
[15] Kalisch, W. W.; Senge, M. O. Angew. Chem., Int. Ed. 1998, 37,
1107.
[16] Kojima, T.; Hanabusa, K.; Ohkubo, K.; Shiro, M.; Fukuzumi, S.
Chem. Commun. 2008, 6513.
[17] Feng, X.; Senge, M. O. J. Chem. Soc., Perkin Trans. 1 2001, 1030.
[18] Senge, M. O.; Runge, S.; Speck, M.; Ruhlandt-Senge, K.
Tetrahedron 2000, 56, 8927.
1720
www.cjc.wiley-vch.de
© 2012 SIOC, CAS, Shanghai, & WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
Chin. J. Chem. 2012, 30, 1715—1721

Synthesis and Characterization of 5,10- and 5,15-Disubstituted Porphodimethenes
[19] Senge, M.; Smith, K. Z. Naturforsch., B: J. Chem. Sci. 1993, 48,
991.
[20] Finnigan, E. M.; Giordani, S.; Senge, M. O.; McCabe, T. J. Phys.
Chem. A 2010, 114, 2464.
[21] Furuta, H.; Ishizuka, T.; Osuka, A.; Uwatoko, Y.; Ishikawa, Y.
Angew. Chem. 2001, 113, 2385.
[22] Barkigia, K. M.; Renner, M. W.; Xie, H.; Smith, K. M.; Fajer, J. J.
Am. Chem. Soc. 1993, 115, 7894.
[36] Krattinger, B.; Callot, H. J. Tetrahedron Lett. 1998, 39, 1165.
[37] Bucher, C.; Devillers, C. H.; Moutet, J. C.; Pécaut, J.; Royal, G.;
Saint-Aman, E.; Thomas, F. Dalton Trans. 2005, 3620.
[38] Lindsey, J. S.; Hsu, H. C.; Schreiman, I. C. Tetrahedron Lett. 1986,
27, 4969.
[39] Lindsey, J. S.; Schreiman, I. C.; Hsu, H. C.; Kearney, P. C.;
Marguerettaz, A. M. J. Org. Chem. 1987, 52, 827.
[40] Lindsey, J. S.; Wagner, R. W. J. Org. Chem. 1989, 54, 828.
[41] Sheldrick, G. M. SHELXL-97, Program for the Refinement of
Crystal Structure, University of Göttingen, Germany, 1997.
[42] Spek, A. L. J. Appl. Crystallogr. 2003, 36, 7.
[23] Floriani, C.; Floriani-Moro, R. In The Porphyrin Handbook, Vol. 3,
Eds.: Kadish, K. M.; Smith, M.; Guilard, R., Academic Press, San
Diego, 2000, Chapter 24, pp. 385—420.
[24] Bucher, C.; Seidel, D.; Lynch, V.; Kral, V.; Sessler, J. L. Org. Lett.
2000, 2, 3103.
[43] Botulinski, A.; Buchler, J. W.; Abbes, N. E.; Scheidt, W. R. Liebigs
Ann. Chem. 1987, 1987, 305.
[25] Bucher, C.; Zimmerman, R. S.; Lynch, V.; Kral, V.; Sessler, J. L. J.
Am. Chem. Soc. 2001, 123, 2099.
[26] Sessler, J. L.; Zimmerman, R. S.; Bucher, C.; Kral, V.; Andrioletti, B.
Pure Appl. Chem. 2001, 73, 1041.
[27] Dolensky, B.; Kroulik, J.; Kral, V.; Sessler, J. L.; Dvorakova, H.;
Bour, P.; Bernatkova, M.; Bucher, C.; Lynch, V. J. Am. Chem. Soc.
2004, 126, 13714.
[44] We have made dum atoms based on the existing coordinates of 2b
by using Shelxl program, and roughly estimated the closed H…H
distance, which is less than 2.0 Å.
[45] Finnigan, E. M.; Giordani, S.; Senge, M. O.; McCabe, T. J. Phys.
Chem. A 2010, 114, 2464.
[46] Runge, S.; Senge, M. Z. Naturforsch., B: J. Chem. Sci. 1998, 53,
1021.
[28] Bischoff, I.; Feng, X. D.; Senge, M. O. Tetrahedron 2001, 57, 5573.
[29] Sergeeva, N. N.; Senge, M. O. Tetrahedron Lett. 2006, 47, 6169.
[30] Sergeeva, N. N.; Shaker, Y. M.; Finnigan, E. M.; McCabe, T.; Senge,
M. O. Tetrahedron 2007, 63, 12454.
[47] Shelnutt, J. A.; Song, X. Z.; Ma, J. G.; Jia, S. L.; Jentzen, W.;
Medforth, C. J. Chem. Soc. Rev. 1998, 27, 31.
[48] Vladimir, S. C.; van Hoek, A.; Victor, A. G.; Igor, V. S.; Schaafsma,
T. J.; Holten, D. J. Phys. Chem. B 2000, 104, 9909.
[31] Senge, M. O.; Kalisch, W. W.; Bischoff, I. Chem.-Eur. J. 2000, 6,
2721.
[49] Rhee, S. W.; Na, Y. H. Inorg. Chim. Acta 2000, 309, 49.
[50] Matano, Y.; Miyajima, T.; Ochi, N.; Nakao, Y.; Sakaki, S.; Imahori,
H. J. Org. Chem. 2008, 73, 5139.
[51] Scheer, H.; Inhoffen, H. H. In The Porphyrins, Vol. 2, Ed.: Dolphin,
D., Academic Press, New York, 1978, pp. 45—90.
[32] Senge, M. O. Acc. Chem. Res. 2005, 38, 733.
[33] Harmjanz, M.; Gill, H. S.; Scott, M. J. J. Org. Chem. 2001, 66, 5374.
[34] Harmjanz, M.; Scott, M. J. Chem. Commun. 2000, 397.
[35] Arsenault, G. P.; Bullock, E.; Macdonald, S. F. J. Am. Chem. Soc.
1960, 82, 4384.
[52] Falk, H. The Chemistry of Linear Oligopyrroles and Bile Pigments,
Springer-Verlag, New York, 1989, pp. 401—415.
(Cheng, F.)
Chin. J. Chem. 2012, 30, 1715—1721
© 2012 SIOC, CAS, Shanghai, & WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
www.cjc.wiley-vch.de
1721