close

Вход

Забыли?

вход по аккаунту

?

A Near-Infrared-Fluorescent Chemodosimeter for Mercuric Ion Based on an Expanded Porphyrin.

код для вставкиСкачать
Communications
Expanded Porphyrins
DOI: 10.1002/anie.200600248
A Near-Infrared-Fluorescent Chemodosimeter
for Mercuric Ion Based on an Expanded
Porphyrin**
Xun-Jin Zhu, Shi-Tao Fu, Wai-Kwok Wong,*
Jian-Ping Guo, and Wai-Yeung Wong
In recent years, there has been an upsurge of interest in the
development of expanded porphyrins with five or more
[*] X. Zhu, S. Fu, Prof. W.-K. Wong, Dr. W.-Y. Wong
Department of Chemistry and
Centre for Advanced Luminescence Materials
Hong Kong Baptist University
Waterloo Road, Kowloon Tong, Hong Kong (P.R. China)
Fax: (+ 852) 3411-7348
E-mail: wkwong@hkbu.edu.hk
S. Fu
Department of Chemistry
Wuhan University
Wuhan, Hubei (P.R. China)
Dr. J.-P. Guo
Department of Chemistry
Shanxi Universtiy
Taiyuan, Shanxi (P.R. China)
[**] This work was supported by a CERG Grant from the Research
Grants Council of the Hong Kong SAR, P.R. China (Project
HKBU2021/03P), and Hong Kong Baptist University.
Supporting information for this article is available on the WWW
under http://www.angewandte.org or from the author.
3150
2006 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Angew. Chem. Int. Ed. 2006, 45, 3150 –3154
Angewandte
Chemie
conjugated pyrrolic rings, because of their spectral and
electronic features, their interesting and often unprecedented
cation-coordination properties, and, in many cases, their
ability to bind anions in certain protonation states.[1–3]
Continuing research efforts have culminated in the synthesis
of a variety of large pyrrole-containing macrocycles such as
corrole (1), N-confused porphyrin (2), sapphyrin (3), rubyrin
(4), rosarin (5), hexaphyrin 6, heptaphyrin 7, octaphyrin 8,
nonaphyrin 9, and higher homologues.[4–10] Recently, the X-
ray crystal structure of an N-confused pentaphyrin was also
reported.[11] Among these macrocycles, a significant subset
shares the structural motif of one or more direct a,a’bipyrrole linkages (e.g. 1, 3, 4, 5) and display interesting and
potentially useful properties.[12]
Recently, an improved “[3+1+1]” procedure to sapphyrin
with a high yield was reported by Sessler and co-workers.[6b]
However, the similar presumed structure of a [26]hexaphyrin(1.1.1.1.1.0) (10) is not yet known and inspired us to
reinvestigate the cyclization reaction under different conditions. Herein, we report the chemistry of the new expanded
porphyrin 10, which contains one a,a’-bipyrrole, four pyrrolic
rings, and five pentafluorophenyl rings. The porphyrinoid
exhibits near-infrared (NIR) luminescence with lem > 900 nm,
a region that is free of optical interference from commonly
used matrix and other organic compounds under assay
conditions. We describe how 10 may serve as a chemodosimetric tool with high sensitivity and selectivity for Hg2+
ions. Many efforts have been devoted to the development of
sensors for Hg2+ ions, and promising results were obtained
with,[13] for example, some water-soluble porphyrins that can
be used for sensing heavy-metal ions by purely optical means
or reversed-phase HPLC.[14] However, to our knowledge,
there are very few reports dealing with the use of NIRAngew. Chem. Int. Ed. 2006, 45, 3150 –3154
fluorescent expanded porphyrins for the accurate and rapid
determination of trace amounts of mercury(ii) ions.[15]
The synthesis of 10 was carried out under modified
Lindsey conditions, at relatively low reactant concentrations
(10 mm) of both pentafluorobenzaldehyde and unsubstituted
pyrrole in CH2Cl2 in the presence of methanesulfonic acid
(7 mm). After oxidation of the product with 2,3-dichloro-5,6dicyano-1,4-benzoquinone (DDQ), repeated chromatography over a silica gel column led to the isolation of normal
tetra(pentafluorophenyl)porphyrin and two expanded porphyrins 6 and 10, besides traces of other porphyrin derivatives. The absorption spectrum of 10 in MeOH shows broad
bands at l = 543 nm (e = 2.64 > 105 cm 1m 1), 704 nm (e = 1.6 >
104 cm 1m 1), and 768 nm (e = 1.21 > 104 cm 1m 1). Upon photoexcitation at l = 514 nm, porphyrinoid 10 shows intense
NIR emission peaks at 959 and 1085 nm.
The crystal structure of 10 was confirmed by X-ray
analysis (Figure 1).[16] This macrocycle displays a nonplanar
Figure 1. X-ray crystal structure for meso-pentafluorophenyl[26]hexaphyrin(1.1.1.1.1.0) (10). Thermal ellipsoids are shown at the 30 %
probability level; hydrogen atoms are omitted for clarity; labels for N,
F, and selected C atoms are shown. Selected bond lengths [G]: N–Ca
1.327(6)–1.383(6), Ca–Cmeso 1.385(7)–1.427(7), Cb–Cb 1.316(7)–
1.366(7), Ca–Cb 1.383(7)–1.463(7), C1–C30 1.484(7), C1–C2 1.408(7),
C2–C3 1.401(7), C3–C4 1.364(7).
conformation with four exo pyrrolic rings and two endo rings.
p-Electron delocalization in the macrocyclic core is apparent
from the observed bond lengths: 1.327(6)–1.383(6) D for the
N Ca bond and 1.385(7)–1.427(7) D for the Ca Cmeso bonds.
On the other hand, the bond lengths observed for the C C
bonds in the pyrrole rings suggest double and single bond
character for these bonds: 1.316(7)–1.366(7) D for the Cb Cb
bonds and 1.383(7)–1.463(7) D for the Ca Cb bonds. The five
pentafluorophenyl rings are tilted by 56.3–82.58 relative to the
least-square plane defined by the atoms of the macrocyclic
core. Consequently, the average bond length of 1.4854 D
between the meso carbon atoms and the pentafluorophenyl
rings indicates the absence of interactions between those rings
2006 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.angewandte.org
3151
Communications
and the macrocyclic core. These structural features are
consistent with a 26p-electron aromatic current ring extended
over the nitrogen atoms, the a-pyrrolic carbon atoms, and the
meso carbon atoms of the macrocyclic ring. The nonplanarity
of the macrocycle in 10 is presumably attributed to the large
molecular dimensions of the six pyrrole rings as compared to
four pyrrole rings in regular porphyrin, together with the
steric bulk of the five meso-pentafluorophenyl rings. To
minimize the steric interactions, the macrocycle loses the
planarity of its core, leading to an average deviation of
0.3064 D from the least-square plane defined by the atomic
positions of the macrocycle.
We next investigated the affinity of 10 for a series of
acetate salts of transition-metal ions (Mn2+, Co2+, Cd2+, Zn2+,
Fe3+, Ag+ and Hg2+) and some Group 1 (Li+ and K+) and
Group 2 (Ca2+ and Ba2+) metal ions in methanol. Generally,
only minor changes in the UV/Vis spectra were observed
when 2 equiv of the metal ions were used with the exception
of the Hg2+ ion, for which marked hyperchromic shifts were
observed. The bright red solution of 10 turned purple and
then deep blue upon complexation with Hg2+, and the color
changes were clearly visible to the naked eye (see Supporting
Information). Analogous to the previous observation,[13] the
complexation process caused notable changes in the absorption spectrum of 10 upon the addition of an increasing amount
of Hg2+ ion. A marked bathochromic shift in its lmax value was
apparent (see Supporting Information). The absorption
Figure 2. a) NIR fluorescence response of 10 (2 mm, lex = 514 nm) to
the addition of Hg2+ ion in methanol. [Hg2+]/[10] = R = 0, 0.1, 0.2, 0.4,
0.6, 1.0, 1.2, 1.4, 1.6, 2.0, 2.2, 2.5, 3.0, 3.2, and 3.5. b) NIR fluorescence
intensity values (lex = 514 nm) versus the number of equivalents of
Hg2+ ions added.
3152
www.angewandte.org
maximum at 543 nm gradually decreased in intensity and
was accompanied by the formation of a new absorption band
at 568 nm (Dlmax = 15 nm). A distinct decrease in the
integrated NIR emission was observed upon addition of
Hg2+. It is likely that the fluorescence quenching of 10 results
from the cation interactions between the heavy atom and the
electron-rich aromatic ring.[11] Metal-binding titration experiments indicate that 10 forms a 1:2 porphyrin/metal complex
with Hg2+ in MeOH (Figure 2). The cumulative association
constant for the complexation event of 10 with Hg2+ was
evaluated by the spectroscopic titration method to be 1.62 >
109 m 1 (see Supporting Information).[17]
The fluorescent response of 10 to various cations and its
selectivity for Hg2+ is illustrated in Figure 3. The response of
10 towards Hg2+ was unaffected in a background of environ-
Figure 3. a) Fluorescence response (F) of 10 to various cations in
methanol; F0 is the response for the free expanded porphyrin. The bars
represent the NIR fluorescence of 10 (2 mm) in the presence of
40 equiv of the cation of interest: 1) Li+; 2) Na+; 3) Rb+; 4) Mg2+;
5) Ca2+; 6) Sr2+; 7) Ba2+; 8) Cr3+; 9) Ag+; 10) Co2+; 11) Pd2+; 12) Ni2+;
13) Zn2+; 14) Cd2+; 15) Hg2+; 16) K+; 17) Pb2+. b) The selectivity of 10
for Hg2+ ions in the presence of other cations in methanol. The gray
bars represent the NIR fluorescence of 10 (2 mm) in the presence of
40 equiv of the cation of interest. The black bars represent the change
in integrated NIR fluorescence that occurs upon subsequent addition
of 40 equiv of Hg2+ ion to a solution containing 10 and a cation of
interest (1–17).
2006 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Angew. Chem. Int. Ed. 2006, 45, 3150 –3154
Angewandte
Chemie
mentally relevant alkali and alkaline earth metal ions including Li+, Na+, K+, Rb2+, Mg2+, Ca2+, Sr2+, and Ba2+. The
Group 12 Zn2+ and Cd2+ ions, in addition to Cr3+ and Pb2+, did
not inhibit the fluorescence response of 10 to Hg2+. From
Figure 3, it is seen that 10 reveals a high selectivity and
sensitivity for Hg2+ ion. Furthermore, at the concentrations of
the probe employed in our studies, Hg2+ could be detected
down to a concentration of 10 7 m, that is, at concentrations in
the ppb range.[13c,d,e] We also investigated the possible interference owing to the counteranion(s) used. The results
showed that the selected anions have almost no interaction
with 10 in methanol (see Supporting Information).
In summary, we have prepared and structurally characterized a new expanded porphyrin, which can be exploited as
a highly sensitive near-infrared-fluorescent chemodosimeter
selective for the detection of Hg2+ ions.
Experimental Section
A solution of pentafluorobenzaldehyde (1.23 mL, 0.01 mmol) and
pyrrole (715 mL, 0.01 mmol) in dichloromethane (1.0 L) was placed in
a 2.0-L round-bottomed flask under nitrogen. Methanesulfonic acid
(MSA; 450 mL, 7.0 mmol) was added to this solution, and the mixture
was stirred for 30 min. After adding 2,3-dichloro-5,6-dicyano-1,4benzoquinone (DDQ), the solution was stirred for another 30 min
and then passed through a short column of basic alumina. The crude
reaction mixture was separated by column chromatography over
silica gel with CH2Cl2/petroleum ether (2:1 v/v). Three different
colored fractions were obtained, first violet, second red, and last deep
violet, which afforded the regular porphyrin (9–12 % yield), the
[26]hexaphyrin(1.1.1.1.1.1) (15–20 % yield), and 10 (8–12 % yield),
respectively. The violet band was purified by preparative thin-layer
chromatography eluting with CH2Cl2/petroleum ether (7:3 v/v),
followed by protonation with CF3COOH and recrystallization from
a CHCl3/MeOH mixture to give another batch of pure product 10
with satisfactory NMR spectroscopic data. 10: m.p. > 300 8C
(decomp); 1H NMR (400 MHz, CD3OD): d = 10.10 (d, J = 4.8 Hz,
1 H), 9.75 (d, J = 4.8 Hz, 1 H), 9.59–9.48 (m, 5 H), 9.42 (d, J = 4.8 Hz,
1 H), 3.18 (d, J = 4.8 Hz, 1 H), 3.30 (d, J = 4.8 Hz, 1 H), 3.82 (d,
J = 4.8 Hz, 1 H),
4.26 ppm (d, J = 4.8 Hz, 1 H); 19F NMR
(CF3COOH, 376.33 MHz, CD3OD): d = 139.26, 139.54, 140.12,
149.88,
150.39,
151.73,
151.89,
161.83,
162.38,
162.67 ppm; HR-MS (ESI): m/z calcd for [M+H]+: 1283.1862;
found: 1283.1864.
Received: January 20, 2006
Published online: April 3, 2006
[3]
[4]
[5]
[6]
[7]
[8]
[9]
[10]
[11]
[12]
[13]
.
Keywords: fluorescence · mercury · nitrogen heterocycles ·
porphyrinoids · sensors
[1] a) J. L. Sessler, A. Gebauer, S. J. Weghorn, The Porphyrin
Handbook, Vol. 2 (Eds.: K. M. Kadish, K. M. Smith, R. Guilard),
Academic Press, San Diego, 2000, p. 421; b) T. D. Lash, Angew.
Chem. 2000, 112, 1833 – 1837; Angew. Chem. Int. Ed. 2000, 39,
1763 – 1767; c) B. Franck, A. Nonn, Angew. Chem. 1995, 107,
1941 – 1957; Angew. Chem. Int. Ed. Engl. 1995, 34, 1795 – 1811;
d) A. Srinivasan, T. Ishizuka, A. Osuka, F. Furuta, J. Am. Chem.
Soc. 2003, 125, 878 – 879; e) J. L. Sessler, D. Seidel, A. E. Vivian,
V. Lynch, B. L. Scott, D. W. Keogh, Angew. Chem. 2001, 113,
611 – 614; Angew Chem. Int. Ed. 2001, 40, 591 – 594.
[2] a) J. L. Sessler, M. J. Cyr, V. Lynch, E. MaGhee, J. A. Ibers, J.
Am. Chem. Soc. 1990, 112, 2810 – 2813; b) J. L. Sessler, T.
Angew. Chem. Int. Ed. 2006, 45, 3150 –3154
[14]
Morishima, V. Lynch, Angew. Chem. 1991, 103, 1018 – 1020;
Angew. Chem. Int. Ed. Engl. 1991, 30, 977 – 980; c) J. L. Sessler,
S. J. Weghorn, V. Lynch, M. R. Johnson, Angew. Chem. 1994,
106, 1572 – 1575; Angew. Chem. Int. Ed. Engl. 1994, 33, 1509 –
1512; d) J. Setsune, S. Maeda, J. Am. Chem. Soc. 2000, 122,
12 405 – 12 406; e) V. G. Anand, S. K. Pushpan, S. Venkatraman,
A. Dey, T. K. Chandrashekar, B. S. Joshi, R. Roy, W. Teng, K. R.
Senge, J. Am. Chem. Soc. 2001, 123, 8620 – 8621; f) N. Sprutta, L.
Latos-Grażyński, Chem. Eur. J. 2001, 7, 5099 – 5112.
a) S. Shimizu, V. G. Anand, R. Taniguchi, K. Furukawa, T. Kato,
T. Yokoyama, A. Osuka, J. Am. Chem. Soc. 2004, 126, 12 280 –
12 281; b) S. Mori, A. Osuka, J. Am. Chem. Soc. 2005, 127, 8030 –
8031.
a) J. L. Sessler, D. Seidel, Angew. Chem. 2003, 115, 5292 – 5333;
Angew. Chem. Int. Ed. 2003, 42, 5134 – 5175; b) A. Ghosh,
Angew. Chem. 2004, 116, 1952 – 1965; Angew. Chem. Int. Ed.
2004, 43, 1918 – 1931; c) R. Paolesse, L. Jaquinod, D. J. Nurco, S.
Mini, F. Sagone, T. Boschi, K. M. Smith, Chem. Commun. 1999,
1307 – 1308; d) Z. Gross, N. Galili, I. Saltsman, Angew. Chem.
1999, 111, 1530 – 1533; Angew. Chem. Int. Ed. 1999, 38, 1427 –
1429.
a) H. Furuta, T. Asano, T. Ogawa, J. Am. Chem. Soc. 1994, 116,
767 – 768; b) P. J. Chmielewski, L. Latos-Grażyński, K. Rachlewicz, T. Głowiak, Angew. Chem. 1994, 106, 805 – 808; Angew.
Chem. Int. Ed. Engl. 1994, 33, 779 – 781.
a) P. J. Chmielewski, L. Latos-Grażyński, K. Rachlewicz, Chem.
Eur. J. 1995, 1, 68 – 73; b) S. V. Shevchuk, J. M. Davis, J. L.
Sessler, Tetrahedron Lett. 2001, 42, 2447–2450.
a) J. L. Sessler, T. Morishima, V. Lynch, Angew. Chem. 1991, 103,
1018 – 1020; Angew. Chem. Int. Ed. Engl. 1991, 30, 977 – 980;
b) S. Shimizu, R. Taniguchi, A. Osuka, Angew. Chem. 2005, 117,
2265 – 2269; Angew. Chem. Int. Ed. 2005, 44, 2225 – 2229; c) S. K.
Pushpan, V. R. G. Anand, S. Venkatraman, A. Srinivasan, A. K.
Gupta, T. K. Chandrashekar, Tetrahedron Lett. 2000, 41, 3391 –
3394.
J. L. Sessler, S. J. Weghorn, T. Morishima, M. Rosingana, V.
Lynch, V. Lee, J. Am. Chem. Soc. 1992, 114, 8306 – 8307.
M. G. P. M. S. Neves, R. M. Martins, A. C. Tome, A. J. D. Silvestre, A. M. S. Silva, V. Felix, M. G. B. Drew, J. A. S. Cavaleiro,
Chem. Commun. 1999, 385 – 386.
Y. Shin, H. Furuta, K. Yoza, S. Igarashi, A. Osuka, J. Am. Chem.
Soc. 2001, 123, 7190 – 7191.
Y. Shin, H. Furuta, A. Osuka, Angew. Chem. 2001, 113, 639 – 641;
Angew. Chem. Int. Ed. 2001, 40, 619 – 621.
a) S. K. Pushpan, S. Venkatraman, V. G. Anand, J. Sankar, H.
Rath, T. K. Chandrashekar, Proc. Indian Acad. Sci. Chem. Sci.
2002, 114, 311 – 338; b) J. L. Sessler, P. J. Melfi, D. Seidel,
A. E. V. Gorden, D. K. Ford, P. D. Palmer, C. D. Tait, Tetrahedron 2004, 60, 11 089 – 11 097.
a) L. Wang, X. Zhu, W.-Y. Wong, J. Guo, W.-K. Wong, Z. Li,
Dalton Trans. 2005, 3235 – 3240; b) J. V. Ros-Lis, M. D. Marcos,
R. R. MartRnez-MSTez, K. Rurack, J. Soto, Angew. Chem. 2005,
117, 4479 – 4482; Angew. Chem. Int. Ed. 2005, 44, 4405 – 4407;
c) R. Metivier, I. Leray, B. Valeur, Chem. Eur. J. 2004, 10, 4480 –
4490; d) E. M. Nolan, S. J. Lippard, J. Am. Chem. Soc. 2003, 125,
14 270 – 14 271; e) A. B. Descalzo, R. MartRnez-MSTez, R. Radeglia, K. Rurack, J. Soto, J. Am. Chem. Soc. 2003, 125, 3418 – 3419;
f) A. Caballero, R. Martinez, V. Lloveras, I. Ratera, J. VidalGancedo, K. Wurst, A. Tarraga, P. Molina, J. Veciana, J. Am.
Chem. Soc. 2005, 127, 15 666 – 15 667; g) M. Matsushita, M. M.
Meijler, P. Wirsching, R. A. Lerner, K. D. Janda, Org. Lett. 2005,
7, 4943 – 4946; h) E. M. Nolan, S. J. Lippard, J. Mater. Chem.
2005, 15, 2778 – 2783.
a) B. Tatineni, S. Manickam, M. Hideyuki, Analyst 2005, 130,
1162 – 1167; b) H. Otto, V. Zsolt, V. Arnd, Inorg. Chem.
Commun. 2004, 7, 854 – 857; c) K. Krzysztof, P. Krystyna, Talanta
2003, 60, 669 – 678; d) X. Zhang, C. Guo, Z. Li, G. Shen, R. Yu,
2006 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.angewandte.org
3153
Communications
Anal. Chem. 2002, 74, 821 – 825; e) D. Delmarre, R. Meallet, C.
Bied-Charreton, R. B. Pansu, J. Photochem. Photobio. A 1999,
124, 23 – 28.
[15] C. Zhu, L. Li, F. Fang, J. Chen, Y. Wu, Chem. Lett. 2005, 34, 898 –
899.
[16] Crystal data for 10 (C60.5H21Cl3F25N6O1.5): Mw = 1437.18, crystal
dimensions: 0.40 > 0.20 > 0.20 mm3, monoclinic, space group: P1̄,
a = 14.505(2), b = 14.639(2), c = 16.434(2) D, a = 78.480(2)8, b =
74.718(2)8, g = 62.232(2)8, V = 2966.4(8) D3, Z = 2, 1calcd =
1.609 g cm 3, m(MoKa) = 0.283 mm 1, F(000) = 1428, T = 203 K,
2qmax = 50.028. 12 230 reflections measured, of which 10 195 were
unique (Rint = 0.0329). Final R1 = 0.0773 and wR2 = 0.1797 for
4369 observed reflections with I > 2s(I). CCDC-295258 contains
the supplementary crystallographic data for this paper. These
data can be obtained free of charge from The Cambridge
Crystallographic Data Centre via www.ccdc.cam.ac.uk/data_
request/cif.
[17] a) H. Tsukube, H, Furuta, A. Odani, Y. Kudo, Y. Takeda, Y.
Inoue, H. Sakamoto, K. Kimura, Y. Liu in Comprehensive
Supramolecular Chemistry, Vol. 8 (Eds.: J.-M. Lehn, J. E. D.
Davies, J. A. Ripmeester), Pergamon, New York, 1996, p. 426;
b) Y. Pocker, J. C. Ciula, J. Am. Chem. Soc. 1989, 111, 4728 –
4735; c) J. Bourson, J. Pouget, B. Valeur, J. Phys. Chem. 1993, 97,
4552 – 4557; d) J. Raker, T. E. Glass, J. Org. Chem. 2001, 66,
6505 – 6512.
3154
www.angewandte.org
2006 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Angew. Chem. Int. Ed. 2006, 45, 3150 –3154
Документ
Категория
Без категории
Просмотров
2
Размер файла
181 Кб
Теги
base, near, ion, expanded, fluorescence, porphyrio, chemodosimeter, infrared, mercuric
1/--страниц
Пожаловаться на содержимое документа