Supramolecular ensembles based on the donor-acceptor interactions of porphyrins

Article abstract of DOI:10.1134/S1070363211010221

Dimeric and trimeric supramolecular structures were synthesized on the basis of donor-acceptor interactions of manganese(III) and tin(IV) complexes of 5,15-diphenyl-3,7,13,17-tetramethyl-2,8,12,18-tetrabutylporphyrin with 5-(4a€-oxyphenyl)-15-phenyl-3,7,13,17-tetramethyl-2,8,12, 18-tetrabutylporphyrin. The structure of the compounds was studied by NMR spectroscopy and TLC.

Full text of DOI:10.1134/S1070363211010221

ISSN 1070-3632, Russian Journal of General Chemistry, 2011, Vol. 81, No. 1, pp. 135–141. © Pleiades Publishing, Ltd., 2011.
Original Russian Text © S.G. Pukhovskaya, L.Zh. Guseva, A.S. Semeikin, O.A. Golubchikov, 2011, published in Zhurnal Obshchei Khimii, 2011, Vol. 81,
No. 1, pp. 138–143.
Supramolecular Ensembles Based on the Donor–Acceptor
Interactions of Porphyrins
S. G. Pukhovskaya, L. Zh. Guseva, A. S. Semeikin, and O. A. Golubchikov
Ivanovo State University of Chemical Technology, F. Engelsa pr. 7, Ivanovo, 153460 Russia
e-mail: puhovskaya@isuct.ru
Received June 22, 2010
Abstract―Dimeric and trimeric supramolecular structures were synthesized on the basis of donor–acceptor
interactions of manganese(III) and tin(IV) complexes of 5,15-diphenyl-3,7,13,17-tetramethyl-2,8,12,18-
tetrabutylporphyrin with 5-(4'-oxyphenyl)-15-phenyl-3,7,13,17-tetramethyl-2,8,12,18-tetrabutylporphyrin. The
structure of the compounds was studied by NMR spectroscopy and TLC.
DOI: 10.1134/S1070363211010221
The ability of metalloporphyrins to attach ad-
ditional ligands (extracoordination) is an important
property of the compounds belonging to this class [1].
The additional ligands can be attached to the fifth,
sixth, etc. coordination sites in the inner coordination
sphere of the metal. To the metalloporphyrins extra-
complexes and to the phenomenon of extra-
coordination a great attention is now paid both in
experimental and theoretical studies. Thus, the self-
assembly of supramolecular porphyrin systems is
based on the donor–acceptor interaction of porphyrins
containing electron-donor groups on the periphery of
the macrocycle with the coordination-unsaturated
metalloporphyrins. Determination of conditions for the
formation of the molecular ensembles and synthesis of
these structures can serve as a basis for obtaining new
materials, including those used in the nanotechnology.
The porphyrins used in this work are 5,15-di-
phenyl-3,7,13,17-tetramethyl-2,8,12,18-tetrabutylpor-
phyrin (I) and 5-(4'-hydroxyphenyl)-15-phenyl-
3,7,13,17-tetramethyl-2,8,12,18-tetrabutylporphyrin (II),
synthesized by condensation of 3,3'-dibutyl-4,4'-di-
methyldipyrrolyl-2,2'-methane with a mixture of 4-hyd-
roxybenzaldehyde and benzaldehyde in methylene
chloride under the action of trichloroacetic acid, with
subsequent oxidation of the reaction mixture with p-
chloranil:
Me
Me
R
Me
CHO
Bu
Bu
CHO
Bu
Bu
Bu
Bu
NH
NH
NH
N
(1) CCl3COOH
+
+
(2) p-Chloranil
HN
N
OH
Me
Me
Me
R1
I, R = R1 = Ph; II, R = Ph, R1 = 4-HOC6H4; III, R = R1 = 4-HOC6H4.
This reaction besides the porphyrins I and II
affords symmetrically substituted at the phenyl rings
5,15-bis-(4'-hydroxyphenyl)-3,7,13,17-tetramethyl-
2,8,12,18-tetrabutylpofirin (III).
A high affinity of the Sn(IV) in coordination com-
pounds with porphyrins toward the oxygen-containing
extraligands is known [1]. Using this property of the
Sn(IV) cation in the complex with 5,15-diphenyl-
135

136
PUKHOVSKAYA et al.
Me
Me
Bu
Bu
Bu
Bu
N HN
Bu
Bu
Me
Me
Me
Me
L
NH N
N
N
N
N
M
Me
Me
Bu
Bu
L
Bu
Bu
Bu
Bu
I, M = 2H; Sn(IV); Mn(III)
Me
Me
Me
Me
O
Sn
O
N
N
N
N
Bu
Bu
Me
Me
Me
Me
N
N
N
N
Me
Me
H
HO
H
Bu
Bu
Bu
Bu
NH N
N HN
Bu
Bu
II
Me
Me
IV
3,7,13,17-tetramethyl-2,8,12,18-tetrabutylporphyrin I we
succeeded to prepare molecular ensemble IV reacting
complex I with 5-(4'-oxyphenyl)-15-phenyl-3,7,13,17-
tetramethyl-2,8,12,18-tetrabutylporphyrin II.
The procedure for the synthesis of trimer IV
includes mixing of benzene solutions of porphyrin H2P
(II) (c = 6.6×10–5 mol l–1) and complex (OH)2SnP
(I) (c = 6.2×10–5 mol l–1) in a ratio of 2:1. The
Table 1. Electron absorption spectra of compounds I – III in benzene and the data of TLC (eluent CHCl3– C6H6, 1:1 + 2% of
C2H5OH)
Compound
(OH)2SnP (I)
H2P (II)
Rf
Electron absorption spectra, λmax, nm (log ε)
0.85
0.20
0.16
–
580 (3.69)
572 (3.85)
580
547 (4.36)
540 (3.72)
545
507 sh
505 (4.22)
505
420 (5.57)
407 (5.46)
417
623 (3.19)
629
IV
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SUPRAMOLECULAR ENSEMBLES BASED ON THE DONOR–ACCEPTOR INTERACTIONS
137
solutions were mixed in an argon atmosphere and kept
for 8 h.
[SnTTP(OH)2] (TTP here was meso-tetratolylpor-
phyrin) with phenol and its substituted analogs,
Langford et al. [2] concluded that the process of coordina-
tion involved a slow stage of water molecule elimina-
tion. The substitution of OH group in (OH)2SnP (I) by
the porphyrin H2P (II) containing a phenolic fragment
takes a fairly long time and proceeds apparently along
the same scheme:
The analysis of the mixture by TLC showed three
zones, which were isolated and characterized by spec-
tral methods (Electron absorption spectra data are listed
in Table 1).
At the study of the formation of axial complexes
R
O
R
H
H
H
H
O
Sn
O
O
−
OH
slowly
O
fast
+
Sn
O
+
Sn
−H2O
R
O
H
H
R
OH
R
O
O
Sn
O
R
Sn
O
H2O
H
R
R = H; 2-NO2; 2-OH; 4-OMe; 4-OH [2].
The structure of the molecular ensemble IV was
elucidated on the basis of the analysis of H NMR
spectra and the published data on the chemical shifts of
o- and m-protons in a phenoxy group coordinated by a
metalloporphyrin: Δδ = δ(complex) – δ(phenol) [2].
(II) increases electron density and enhances the
shielding of the protons. The signals of the protons in
the substituted ring are shifted upfield compared with
the unsubstituted phenyl ring and appear as two
doublets at 6.71 ppm (o-H relative to the oxygen atom)
and at 7.34 ppm (m-H).
1
H
−1.20
At the formation of molecular ensemble IV the
protons in o- and m-positions relative the phenoxy
group of porphyrin H2P (II) get to the region of
shielding by the current of the metalloporphyrin SnP(I)
macrocycle. Their signals are shifted upfield signif-
icantly compared with the uncoordinated porphyrin,
and are obseved at 2.64 ppm (2H, o-position to the
oxygen atom) and 7.07 ppm (2H, m-position to the
oxygen atom). This proves the fact of interaction of the
oxygen atom with the coordination site of Sn complex I
and, consequently, the formation of trimeric structure.
−1.61
H
O
H
−4.95
Sn
O
R
The proton chemical shifts of the coordination
trimer IV in comparison with the original porphyrins
H2P (II) and (OH)2SnP (I) are listed in Table 2. The
introduction of the Sn(IV) cation to the reaction center,
as expected, leads to the disappearance of the signals
of NH protons. The presence of electron-donating OH-
group in one phenyl fragments of the porphyrin H2P
Electron absorption spectra (EAS) of the
manganese with porphyrins coordination compounds
with the central atom in different oxidation states vary
RUSSIAN JOURNAL OF GENERAL CHEMISTRY Vol. 81 No. 1 2011

138
PUKHOVSKAYA et al.
Table 2. 1H NMR spectra of porphyrins I, (OH)2Sn (II), and molecular ensemble IV in CDCl3
Porphyrin
NH
β-CH3
ms-H
β-Аlk
Phenyl Н
(OH)2SnP (I)
2.52 s (12H)
10.55 s (2H)
4.02 t (8Н)
8.12 m (4Н, о-Н)
2.25 q (8Н)
7.80 m (6Н, m, p-Н)
1.80 m (8Н)
1.15 t (12Н)
3.97 t (8Н)
H2P (II)
–2.42 s (2H)
–2.40 s (2H)
2.53 s (6H)
2.45 s (6H)
10.21 s (2H)
8.06 d (2Н, о-Н)
2.14 m (8Н)
1.73 m (8Н)
1.10 t (12Н)
3.93–4.02 m (16Н)
2.23 m (16Н)
1.78 m (16Н)
1.11 m (24Н)
7.93 m (3Н, m, p-Н)
6.71 d (2H, o-H to OH)
7.34 d (2H, m-ОН)
2.64 s (2H, o-H to OH)
7.07 m (2Н, m-Н to OH)
7.82 m (3Н, m, p-Н)
8.07 m (2Н, о-Н)
2.46 s (6H)
2.53 s (6H)
2.55 s (12H)
10.22 s (2H)
10.60 s (2H)
III
greatly, which is used for their identification [3]. In the
complexes with a porphyrin, the manganese cation in
most cases is in a stable oxidation state +3. Mn(III)
porphyrins have a characteristic electron absorption
spectrum of the so-called hyper-type with a strong
band corresponding to the π→d charge transfer in the
short-wavelength range and a large number of well-
resolved bands in the near infrared region [the Mn(III)
P (I) spectrum is shown in the figure, spectrum (a)].
porphyrin H2P (II) (c = 1.3×10–4 mol l–1) in the ratio
1:1, in the EAS appeared a new absorption band at
437 nm (b).
Addition of pyridine leads to a decrease in the
intensity of the band at 437 nm up to its complete
disappearance, and the EAS looks as a sum of the
spectra of the reagents. This suggested that between
the two porphyrin macrocycles occurs an interaction of
the donor–acceptor (oxygen–manganese) type, giving
rise to the structure V.
At mixing solutions of the complex (Cl)MnP (I)
(c = 0.9×10–4 mol l–1, solvent chloroform) and the
Me
Bu
Me
Bu
N HN
NH N
Bu
Bu
Bu
Me
Me
Bu
Me
Me
Me
Me
O
N
N
N
N
Mn
Bu
Bu
V
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SUPRAMOLECULAR ENSEMBLES BASED ON THE DONOR–ACCEPTOR INTERACTIONS
139
Table 3. Electron absorption spectra of the compounds H2P (II), (Cl)MnP (I), V in chloroform and the data of TLC (eluent
CHCl3–C6H6, 1:1 + 2% C2H5OH)
Compound
(Cl)MnP (I)
H2P (II)
V
Rf
–
Electron absorption spectra, λmax, nm (log ε)
567 (4.00)
540 (3.71)
477 (4.78)
365 (4.84)
407 (5.46)
366
0.25
0.12
623 (3.19)
572 (3.85)
570
505 (4.22)
437
Analysis of the reaction mixture by TLC on the
Alufol plates (developer chloroform–benzene 1:1 +
0.5% ethanol) revealed two zones. The spectrum of the
first zone corresponds to the porphyrin H2P (II), the
spectrum of the second zone, to the molecular complex
V [Table 3 shows the data in comparison with
(Cl)MnP(I)].
porphyrin macrocycle containing phenoxy group on
the periphery of the molecule.
Thus, the propensity of metalloporphyrins to extra-
coordination of the ligands of different nature gives
rise to rather complex systems based on them, which
can be considered as the supramolecular complexes.
Adding phenol solution in chloroform (c =
1.35×10–2 mol l–1) to a solution of (Cl)MnP (I) resulted
in little change in the absorption spectrum (red shift of
the charge transfer band 475→478 and of the band I
555→566), new bands did not arise. However, at
adding sodium phenoxide in an alkaline medium, the
band at 477 nm in the absorption spectrum disappears
and bands appear with the maxima at 426 nm and
437 nm indicating the occurrence of a redox process.
Similar spectra with maximum absorption at 437 nm is
typical for the Mn(II)-porphyrin complexes [3–5]. We
can assume that in our case the formation of molecular
dimer leads to a change in the oxidation state of the
cation Mn(III) in the molecular ensemble V to Mn(II),
and the latter is stabilized under the influence of the
EXPERIMENTAL
3,3'-Dibutyl-4,4'-dimethyldipyrrolyl-2,2'-methane
used for the synthesis of porphyrins H2P (I) and H2P
(II) was prepared according to the previously published
method [6].
3,3'-Dibutyl-4,4'-dimethyldipyrrolyl-2,2'-methane.
A solution of 2.0 g (4.66 mmol) of 5,5'-dietoxy-
carbonyl-3,3'-dibutyl-4,4'-dimethyldipyrrolyl-2,2'-
methane, 2.0 g (35.6 mmol) of potassium hydroxide,
and a small amount of hydrazine sulfate in 50 ml of
ethylene glycol was heated to boiling and refluxed for
1 h without air access using a Bunsen valve. Then the
solution was cooled, poured into 200 ml of water, the
(a)
A
1.00
(b)
A
477
407
2.00
365
366
0.50
437
567
477
1.00
622
0.00
320
400
500
λ, nm
300
400
500
600
700
λ, nm
Electron absorption spectra: (a) MnIIIP (I) and (b) a mixture of porphyrins (Cl)MnP (I) and H2P (II) in chloroform.
RUSSIAN JOURNAL OF GENERAL CHEMISTRY Vol. 81 No. 1 2011

140
PUKHOVSKAYA et al.
precipitate formed was filtered off, washed with water,
and dried at room temperature in air. Yield 1.3 g
(97%). The dipyrrolylmethane derivative obtained was
used in reaction (1) without further purification.
0.37 g (21.5%); Rf (Silufol) = 0.29 (chloroform). EAS,
λmax (log ε): 623 (3.19), 572 (3.85), 540 (3.71), 505
(4.22), 408 (5.46) (chloroform). H NMR spectrum, δ
(ppm) (int. TMS): 10.21 s (2H, meso-H); 8.06 d (2H,
2,6-H-Ph); 6.71 d (2H, 2,6-H, HOPh); 7.93 m (3H,
3,4,5-H, Ph); 7.34 d (2H, 3,5-H, HOPh); 3.97 t (8H,
CH2Bu); 2.53 s (6H, 13,17-CH3), 2.45 s (6H, 3,7-
CH3); 2.14 q (8H, CH2-Bu); 1.73 m (8H, CH2Bu); 1.10
t (12H, CH3-Bu); –2.42 br.s (2H, NH) (CDCl3).
1
5,15-Diphenyl-3,7,13,17-tetramethyl-2,8,12,18-
tetrabutylporphyrin (I), 5-(4'-hydroxyphenyl)-15-
phenyl-3,7,13,17-tetramethyl-2,8,12,18-tetrabutyl-
porphyrin (II) and 5,15-bis (4'-hydroxyphenyl)-
3,7,13,17-tetramethyl-2,8,12,18-tetrabutylporphyrin
(III). To a solution of 1.3 g (4.55 mmol) of 4,4'-
dimethyl-3,3'-dibutyldipyrrolyl-2,2'-methane, 0.23 ml
(2.28 mmol) of benzaldehyde and 0.28 g (2.28 mmol)
of 4-hydroxybenzaldehyde in 450 ml of methylene
chloride while stirring under argon was added 0.8 g
(4.9 mmol) of trichloroacetic acid in 30 ml of
methylene chloride. The mixture was stirred for 4 h,
then 1.7 g (6.9 mmol) of p-chloranil was added, and
the stirring was continued for 12 h at room tem-
perature. The solvent was distilled of on a rotary
evaporator, the residue was washed with a solution of
potassium hydroxide, the precipitate was filtered off,
washed with water, and dried at 70ºC in air. A mixture
of porphyrins was dissolved in chloroform and
subjected to chromatography on aluminum oxide of III
degree of activity by Brockmann, eluting with chloro-
form the first zone of porphyrin I. The eluate was
evaporated, and porphyrin was precipitated with
methanol, filtered off, washed with methanol, and
dried in air at 70ºC. Yield 0.2 g (12.1%).
5,15-Bis(4'-hydroxyphenyl)-3,7,13,17-tetramethyl-
2,8,12,18-tetrabutylporphyrin. Yield 0.39 g (22.3%);
Rf (Silufol) = 0.05 ( chloroform). EAS, λmax (log ε):
626 (3.04), 574 (3.56), 543 (3.46), 509 (3.90), 410
1
(5.00), (chloroform). H NMR spectrum, δ, ppm (int.
TMS): 10.19 s (2H, meso-H); 8.06 d (2H, 2,6-H,
HOPh); 7.47d (2H, 3,5-H, HOPh); 3.67 t (8H, CH2Bu);
2.27 s (12H, CH3); 1.71 q (8H, CH2-Bu) 1.43 m (8H,
CH2Bu ) 0.91 t (12H, CH3Bu); –2.70 br.s (4H, NH)
(CDCl3–CF3 COOH).
Coordination compounds of manganese and tin
were synthesized by the reaction of porphyrins with an
excess of manganese and tin chlorides of chemically
pure grade in boiling dimethylformamide. The
metalloporphyrins were purified by chromatography
on Al2O3 of III degree of activity, eluent chloroform.
Solution of (Cl)2SnP(I) in CHCl3 was washed with
ammonia solution and then with water. The resulting
(OH)2SnP (I) was subjected to chromatography on
silica gel, eluent chloroform. Individuality of the com-
pounds was monitored by TLC on aluminum plates
with fixed layer of silica gel F254 of 0.5 mm thickness
(Merck) in the system CHCl3–C6H6–C2H5OH (CHCl3–
C6H6, 1:1 + 2% of C2H5OH) and by spectrophotomety.
5,15-Diphenyl-3,7,13,17-tetramethyl-2,8,12,18-
tetrabutylporphyrin (I). Rf (Silufol) = 0.87 (chloro-
form). EAS, λmax, (log ε): 625 (3.29), 574 (3.84), 541
1
(3.73), 507 (4.20), 409 (5.31) (chloroform). H NMR
spectrum, δ, ppm (int. ref. TMS): 10.50 s (2H, meso-
H); 7.98 m (4H, 2,6-H, Ph); 7.68 m (6H, 3,4,5-H, Ph);
4.01 m (8H, CH2Bu); 2.51 s (12H, CH3), 2.25 q (8H,
CH2Bu); 1.80 m (8H, CH2Bu), 1.15 t (12H, CH3Bu);
–2.42 br.s (4H, NH) (CDCl3).
Electron absorption spectra were measured on a
Specord M-400 and a Hitachi U-2000 spectro-
photometers in quartz cells at a temperature of 298 K.
The EAS data of the obtained porphyrins are given in
Tables 1 and 3.
Porphyrins II and III were further eluted from the
column with a chloroform–methanol mixture (10:1)
1
The H NMR spectra were recorded on a Bruker-
200 spectrometer at the operating frequency 200 MHz,
in CDCl3 (internal reference TMS).
and
after
evaporation
were
subjected
to
chromatography again on silica gel, eluting with
chloroform and further with a chloroform – methanol
mixture (100:1), sequentially collecting the fractions of
II and III. The solutions were evaporated, the
porphyrins were precipitated with methanol, filtered
off, washed with methanol, and dried in air at 70°C.
The used solvents (benzene, chloroform, pyridine)
were preliminary purified by the methods described in
the literature [7, 8].
ACKNOWLEDGMENTS
This work was supported by Federal Program
“Research and scientific-pedagogical personnel of
5-(4'-Hydroxyphenyl)-15-phenyl-3,7,13,17-tetra-
methyl-2,8,12,18-tetrabutylporphyrin (II). Yield
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SUPRAMOLECULAR ENSEMBLES BASED ON THE DONOR–ACCEPTOR INTERACTIONS
141
4. Gonzalez, B., Kouba, J., Yee, S., Kirner, J.F., and
Scheidt, W.R., J. Am. Shem. Soc., 1975, vol. 97, no. 11,
p. 3247.
innovation Russia in 2009–2013.” State contract nos.
P1105 and 02.740.11.0106.
5. Valentine, J.S. and Quinn, A.E., Inorg. Chem., 1976,
REFERENECES
vol. 15, no. 8, p. 1997.
6. Berezin, M.B., Semeikin, A.S., and V’yugin, A.I., Zh.
Fiz. Khim., 1996, vol. 70, no. 8, p. 1364.
7. Weisberger, A., Proskauer, E., Riddik, J., and Tups, E.,
Organicheskie rastvoriteli (Organic Solvents), Moscow:
Inostrannaya Literatura, 1958.
8. Gordon, A.J. and Ford, R.A., The Chemist’s Com-
panion. A Handbook of Practical Data, Techniques and
References, New York: Wiley, 1972.
1. Berezin, B.D., Koordinatsionnye soedineniya porphy-
rinov i ftalotsianina (Porphyrins and Phtalocyanine
Coordination Compounds), Moscow: Nauka, 1978.
2. Langford, S.J., Lee, M.A.-P., MacFarlane, K.J., and
Weigold, J., J. Inclusion Phenom. Macrocycl. Chem.,
2001, vol. 41, p. 135.
3. Klyueva, M.E., Doctorate (Chem.) Dissertation,
Ivanovo, 2006.
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