Synthesis, Characterization and Properties of Asymmetrical Porphyrin with [p-Flourobenzoyl]-m-Ethyloxy] Phenyl and its Metal Complexes

Article abstract of DOI:10.1080/15533170903066582

A new asymmetrical 5-[p-(4-flourobenzoyloxy)-m-ethyloxy] phenyl-10, 15, 20-triphenyl porphyrin and its transition metal (Zn, Cu, Ni, Co, Mn) complexes were synthesized. Their constitute and structure were characterized by elemental analyses, UV-vis, IR, molar conductances and ¹H NMR. Optical properties were discussed by fluorescence spectrum, and their high thermal stability was explained by thermal analytical results.

Full text of DOI:10.1080/15533170903066582

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Synthesis, Characterization and Properties of
Asymmetrical Porphyrin with [p-Flourobenzoyl]-m-
Ethyloxy] Phenyl and its Metal Complexes
Xiaoling Cui a , Yan Zheng b , Jianhui Shi a , Yujing Zhang a , Miao Yu a & Guofa Liu a
a College of Chemistry , Jilin University , Changchun, 130023, P.R. China
b Anesthesia Department of China-Japan Unitedhospital , Jilin University , Changchun,
130033, P.R. China
Published online: 30 Dec 2009.
To cite this article: Xiaoling Cui , Yan Zheng , Jianhui Shi , Yujing Zhang , Miao Yu & Guofa Liu (2009) Synthesis,
Characterization and Properties of Asymmetrical Porphyrin with [p-Flourobenzoyl]-m-Ethyloxy] Phenyl and its Metal
Complexes, Synthesis and Reactivity in Inorganic, Metal-Organic, and Nano-Metal Chemistry, 39:6, 302-306
To link to this article: http://dx.doi.org/10.1080/15533170903066582
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Synthesis and Reactivity in Inorganic, Metal-Organic, and Nano-Metal Chemistry, 39:302–306, 2009
Copyright © Taylor & Francis Group, LLC
ISSN: 1553-3174 print / 1553-3182 online
DOI: 10.1080/15533170903066582
Synthesis, Characterization and Properties of Asymmetrical
Porphyrin with [p-Flourobenzoyl]-m-Ethyloxy] Phenyl
and its Metal Complexes
Xiaoling Cui,1 Yan Zheng,2 Jianhui Shi,1 Yujing Zhang,1 Miao Yu,1
and Guofa Liu1
1College of Chemistry, Jilin University, Changchun 130023, P.R. China
2Anesthesia Department of China-Japan Unitedhospital in Jilin University, Changchun,
130033, P.R. China
hand, the functions of materials are related to the molecular
alignments as well as the molecular structures.[7]
A new asymmetrical 5-[p-(4-flourobenzoyloxy)-m-ethyloxy]
phenyl-10, 15, 20–triphenyl porphyrin and its transition metal (Zn,
Cu, Ni, Co, Mn) complexes were synthesized. Their constitute and
structure were characterized by elemental analyses, UV-vis, IR,
molar conductances and 1H NMR. Optical properties were dis-
cussed by fluorescence spectrum, and their high thermal stability
was explained by thermal analytical results.
Porphyrin synthesis has always been hampered by numerous
side reactions leading to low product yields. Even with this syn-
thetic shortcoming, a vast array of porphyrins containing practi-
cally every imaginable meso-substituent exist in literature.[8−11]
There also have been a number of reports on transition metal
complexes. In this paper, a new meso-substituted unsymmetrical
porphyrin, 5-[p-(4-flourobenzoyloxy)- m-ethyloxy] phenyl-10,
15, 20–triphenyl porphyrin and its transition metal (Zn, Cu, Ni,
Co, Mn) complexes were synthesized. They have been charac-
terized by elemental analyses, molar conductances, UV-vis, IR
and 1H NMR spectra. We also studied their luminescent prop-
erties by emission spectra and thermal stabilities by differential
thermal analyses.
Keywords asymmetrical porphyrin, characterization, synthesis,
transition metal complexes
INTRODUCTION
The synthesis of functionalized porphyrins is of growing
interest for their use as model compounds.[1] Such substi-
tuted porphyrins have also been employed in various mate-
rials applications.[2] Porphyrins also play important roles in
vital biological processes, in particular photosynthesis (chloro-
phyll), oxygen transport (hemoglobin), and oxygen activation
(cytochrome) processes, and they have been characterized as
“pigments of life.”[3] Notably, metalloporphyrins play an im-
portant role in biological activities as for instance hemoprotens,
EXPERIMENTAL
Apparatus and Measurements
All chemicals were reagent grade and were dried before use.
Elementary analyses were obtained on a Perkin-Elmer 240C
chlorophylls and vitamin B12. They participate in essential bi- auto elementary analyzer. Infrared spectra were recorded on a
ological process such as photosynthesis,[4] dioxygen transport Nicolet 5PC-FT-IR spectrometer using KBr pellets in the re-
and storage.[5] Metalloporphyrin are also used as powerful pho- gion 400–4000 cm−1. Uv-visible spectra were recorded on a
todynamic druges and photosensitizers.[6] It has been found that Shimadzu UV-240 spectrophotometer in the range 350–700 nm
in the above-mentioned properties, the orientation of the por- using chloroform as solvent. Molar conductances of 10−3mol·
phyrin chromophores plays a very important role. On the other dm−3 chloroform solution at 25◦C were measured on a DDX-
1
111A conductometer. H NMR spectra were recorded on a
Varian-Unity-400 NMR spectrometer using CDCl3 as solvent
and tetramethylsilane (TMS) as internal standard. The excita-
Received 10 February 2009; accepted 20 March 2009.
tion and emission spectra were given at room temperature on
The authors are grateful for the financial support of the National
a FS 920 Stead State Fluorescence Spectrometer in the region
Natural Science Foundation of China (No. 20801022).
300–800 nm. TGA and DTA were carried out by DTG-60 si-
Address correspondence to Miao Yu, College of Chemistry,
multaneous DTA-TGA apparatus (sample: 3–4 mg, heating rate:
Jilin University, Changchun 130023, P.R. China. E-mail: yumiao@
jlu.edu.cn
10◦C· min−1, atmosphere: static air).
302

ASYMMETRICAL PORPHYRIN
303
TABLE 1
Characterization data of the compounds∗
Compounds
Empirical formula
C(%)
H(%)
N(%)
FBOEPTPP
C53H37N4O3F
79.43(79.90) 4.61(4.65) 6.93(7.04)
74.60(74.59) 4.08(4.10) 6.54(6.57)
74.19(74.17) 4.11(4.08) 6.56(6.53)
74.03(74.01) 4.05(4.07) 6.54(6.52)
74.59(74.57) 4.12(4.10) 6.55(6.57)
Ni(FBOEPTPP)
Cu(FBOEPTPP)
Zn(FBOEPTPP)
Co(FBOEPTPP)
C53H35N4O3FNi
C53H35N4O3FCu
C53H35N4O3FZn
C53H35N4O3FCo
Mn(FBOEPTPP)Cl C53H35N4O3FMnCl 71.92(71.91) 3.98(3.96) 6.31(6.33)
∗Theoretical values are given in parentheses.
(0.09 g, 0.69 mmol) was added. The mixture was refluxed under
the protection of dry nitrogen atmosphere for about 1 h. The
extent of the reaction was followed by measuring the UV-Vis
spectra of the solution at ten minute intervals. After evaporation
of the solvent, the residue was purified by column chromatogra-
phy (netural aluminum oxide, CHCl3). The title compound was
obtained as a red solid (200 mg, 0.20 mmol, 88%).
Preparation of Ligand and Complexes
Synthesis of FBOEPTPP. [5-(4-hydroxy-3-ethyloxy)
phenyl-10, 15, 20-tri-phenyl]porphyrin, HEPTPP, (HEP=(4-
hydroxy-3-ethyloxy)phenyl; TPP
=
triphenyl porphyrin)
was prepared and purified according to the literature.[12]
4-flourobenoyl chloride was prepared by the reaction of 4-flo-
urobenzoic acid and thioylchloride. 5-[p-(4-flourobenzoyloxy)-
m-ethyloxy] phenyl-10, 15, 20– triphenyl porphyrin,
FBOEPTPP, was prepared by the reaction of HEPTPP with
4-flourobenzoyl chloride. HEPTPP (1.00 g, 1.45 mmol) was
dissolved in 75 mL heating benzene, and added triethylamine
(2.00 mL, 11.37 mmol). Then added dropwise the solution
of 4-flourobenoyl chloride (0.18 mL, 1.52 mmol) and 25 mL
benzene within 2 h to the above solution with quickly stirring at
70◦C. The solution was refluxed for 8 h. Benzene was distilled
out of the mixture. Then mixed the residual with 2 volumes
of distilled water and extracted three times with equal volumes
of water. Concentrated the chloroform solution and added to a
neutral aluminum oxide column (2.5 × 15 cm). The first band
containing HEPTPP was eluted by chloroform. The second band
containing FOEPTPP was eluted by chloroform containing
10% absolute ethanol. This eluant was concentrated and cooled.
Then the product was dried in vacuo. The yield was 1.0 g.
Synthesis of transition metal complexes. We take
Zn(FBOEPTPP) for example.
There are similar preparation methods and results for other
transition metal complexes.
RESULTS AND DISCUSSION
Elemental Analyses
The elemental analyses of the ligand and complexes are given
in Table 1.
UV-Vis Spectra
Table 2 gives ultra-violet visible spectral data of ligand
FBOEPTPP and complexes.
Characteristic Q and B (Soret) bands of porphyrins and metal
porphyrins in visible and near-ultra violet ranges are assigned
as the transitions from ground state (S0) to the lowest excited
singlet (S1) and second lowest excited singlet state (S2), respec-
tively. Compared with the ligand H2(P-Cl)TPP, the number of
the absorption bands of the complexes decreases, it is due to
symmetry of the complexes increase. In comparison these com-
plexes and TPP and its transition complexes, the data is accord,
FBOEPTPP (0.2 g, 0.23 mmol) was dissolved in the mix-
ture of 20 mL DMF and 20 mL chloroform, and ZnCl2· 2H2O
TABLE 2
UV-vis spectra of the ligand and complexes
λ max (nm) (lgε)
Ligand/complexes
Soret (B) band
Q bands
FBOEPTPP
417(5.46)
415(5.26)
415(5.45)
422(5.44)
410(5.41)
479(4.93)
515(4.35) 549(4.08) 590(3.99) 637(3.94)
Ni(FBOEPTPP)
Cu(FBOEPTPP)
Zn(FBOEPTPP)
Co(FBOEPTPP)
Mn(FBOEPTPP)Cl
528(4.22)
539(4.33)
552(4.27) 594(3.93)
530(4.28)
581(4.08) 617(4.10)

304
X. CUI ET AL.
TABLE 3
Infrared spectra frenquenceies (cm−1) of the ligand and complexes
FBOEPTPP
Ni
Cu
Zn
Co
Mn
Assignment
3320wa
2922w
2852w
1743s
1601s
1469w
1350w
1259s
1120s
ν (N H)(pyrrole)
2920w 2922w 2922w 2922w 2922w ν (C H) (phenyl?pyrrole)
2850w 2852w 2852w 2852w 2852w
1743s
1601s
1743s
1601s
1747s
1601s
1743s
1604s
1743s
1606s
ν (C O)
ν (C C)(phenyl)
1463w 1461w 1441w 1467w 1442w δ (C H)(pyrrole)
1352w 1344w 1338w 1350w 1342w ν (C N)(pyrrole)
1257s
1120s
1259s
1120s
1259s
1117s
1259s
1120s
1259s
1122s
ν (C O C)
ν (C F)(phenyl)
as: strong, w: weak.
1H NMR
which indicate that the valence state of manganese atom in the
compound is +3 and that of the nickel, copper, zinc and cobalt
atom is +2.[13]
We take Mn comples for example.
1
The H NMR chemical shift values (δ, ppm) were mea-
sured in deuterium chloroform. The 1H NMR data of the ligand
FBOEPTPP are given as follows: 9.038–8.931 (8H, pyrrole,
ring), 4.97 (2H, flouro-phenyl-2,6-protons), 7.368 (2H, flouro-
phenyl-3,5-protons), 8.29–8.31 (10H, 10, 20-phenyl), 7.61–7.97
(8H,5,15-phenyl) and −2.71 (2H, pyrrole, N-H). In the com-
plexes, Mn(FBOEPTPP)Cl, the singal peak of ligand at −2.71
(2H, pyrrole, N-H) disapperars because the hydrogen atom of
N-H bond has been replaced by Mn ion to form Mn-N. Other
peaks are analogous to the ligand.
Infrared Spectra
The main band frequencies (cm−1) and assignments of the
ligand and complexes were given in Table 3. The bands at about
1743 cm−1 which assigned to the C=O stretching vibration
appeared. This showed that the 4-flourobenoyl chloride had been
linked to oxygen. The band at 3320 cm−1 in the free porphyrin
is assigned to the N-H stretching of the porphyrin core. While
this band is absent in the complexes, the hydrogen atoms has
been replaced by the transition metal ions to form M-N bands.
From the above results, we can draw the following conclu-
sions: The valence state of nickel, copper, zinc and cobalt atom
in the compound is +2 and manganese is +3. The strcture of
the ligand, FBOEPTPP and complexes, M(FBOEPTPP) and
Mn(FBOEPTPP)Cl are shown in Figure 1.
Molar Conductances
The molar conductance values of the ligand and its Ni, Cu,
Zn, Co complexes are at 0.015, 0.01, 0.015, 0.015 and 0.01
ꢀ−1 cm2 mol−1, respectively, in 10−3 mol· L−1 chloroform
Luminescence of the Ligand and Complexes
solution at 25◦C. But Mn complex is at 53 ꢀ−1 cm2 mol−1
,
There are fluorescence of the S2(B, Soret band) and S1(Q
band) in porphyrin complexes. Fluorescence of the B(Soret)
band is attributed to transition from the second excited singlet
state S2 to ground state S0, S2 → S0. The Soret fluorescence
is about two orders of magnitude weaker than the S1 → S0 of
Q band emission. Its quantum yield is so low that sometimes
fluorescence becomes unobservable. This fluorescence emis-
sion was not observed at room temperature in the experimental
excited wavelength, 417 nm. Q(0-1) bands of the complexes
are in the region 649–654 nm and Q(0-2) bands 715–717 nm.
They are mirror symmetric to the absorption spectra. Quantum
yields(ꢁf) of Q band for the complexes are in the range 0.0016–
0.043. The S1 → S0 quantum yield depends on the relative
rates of the radiative process S1 → S0 and two radiationless
and it is very clear that the ligand and Ni, Cu, Zn, Co com-
plexes show nonelectrolytic behavior, but Mn complex shows
1:1 type electrolytes.[14] This suggests that the valence state
of manganese atom in the compound is +3. The structure is
Mn(FBOEPTPP)Cl.
TABLE 4
Emission spectral data of ligand and complexes
Compounds
Q(0-0)
Q(0-1)
Q(0-2)
ꢁf
FBOEPTPP
651
651
654
649
653
651
719
716
717
0.02
Ni(FBOEPTPP)
Cu(FBOEPTPP)
Zn(FBOEPTPP)
Co(FBOEPTPP)
Mn(FBOEPTPP)Cl
600
0.0096
0.002
0.043
0.0016
0.0401
proceses S1 → S0 and S1
Tn. The fluorescence quantum
603
602
600
yield of our complexes is far less than 0.20. Thus, the excited
state S1 is primarily deactivated by radiationless decay. This
715
715
indicates that the spin-forbidden process S1
Tn is the

ASYMMETRICAL PORPHYRIN
305
FIG. 1. The strcture of the complexes: a. M(FBOEPTPP) (M = Ni, Cu, Zn, Co); b. Mn(FBOEPTPP)Cl.
predominant route for radiationless deactivation of S1 in the
complexes.
From the quantum yield of the sampes, the ꢁf of Co and
Cu porphyrins are the lowest. Since Co and Cu are open-shell
metal ions with paramagnetic property, and d orbital in electron
configuration of external layer has single electron, those single
electrons destroy the conjugate system when metal ions coordi-
nate with conjugate porphyrin ring.[15] While close-shell metal
Zn can not destroy the conjugate configuration of porphyrin,
so the ꢁf of Zn-porphyrin is stronger than that of porphyrin
ligand.
Thermal Stability of the Ligand and Complexes
FIG. 3. DTA(—) and TGA(. . . . . . ) pictures of Cu(FBOEPTPP).
Figures 2 and 3 are TGA and DTA pictures of the ligand,
FBOEPTPP and complex Cu(FBOEPTPP), respectively. Figure
2 shows that DTA curve of the ligand has two exothermic peaks
and TGA curve two stages. Ligand FBOEPTPP has begun to be
decomposed at 395◦C and decomposed completely at 613◦C.
TGA and DTA curves of the ligand do not have stages or peaks
up to 395◦C, therefore it is stable under 395◦C. Figure 3 indicates
that DTA of the Cu(FBOEPTPP) has two exothermic peaks and
TGA curve one stage. For the complex, it began to decompose
at about 298◦C, and at about 555◦C, about 8% of it remained
which represented the content of CuO. It is very easy to see that
porphyrin and its complexes have higher thermal stability. And
they are stable in air, can be dried under 298◦C.
CONCLUSIONS
In this article, we have described the synthesis and charac-
terization of a new unsymmetrical porphyrin and its transition
metal (Zn, Cu, Ni, Co, Mn) complexes. Spectroscopy and mo-
lar conductances evidences suggests that the structure of Zn,
Cu, Ni and Co complexes can be considered as 4 coordinated
species with four N of the porphyrinate coordinated to the metal
centre. The valence state of nickel, copper, zinc and cobalt atom
in the compound is +2 and the complexes show nonelectrolytic
behavior. Mn(III) porphyrin is a 1:1 type of electrolyte. The
analysis of photoluminescence(PL) spectrum shows that the PL
of close-shell Zn porphyrin is stronger and the PL of open-shell
Co and Cu porphyrin with paramagnetic property is weaker.
The data of thermal analysis indicate that porphyrin and metal-
lic porphyrin have a better thermal stability, and they are a kind
of important compound as bio-labels.[16]
REFERENCES
1. (a) Collman, J.P., Boulatov, R., Sunderland, C.J., and Fu, L. Functional
analogues of cytochrome c oxidase, myoglobin, and hemoglobin, Chem.
FIG. 2. DTA(—) and TGA(. . . . . . ) pictures of ligand, FBOEPTPP.

306
X. CUI ET AL.
Rev. 2004, 104, 561–588, and references cited therein; (b) Momenteau, M.,
and Reed, C.A. Synthetic heme-dioxygen complexes, Chem. Rev. 1994, 94,
659–698.
9. Shanmugathasan, S., Edwards, C., and Boyle, R.W. Advances in mod-
ern synthetic porphyrin chemistry, Tetrahedron, 2000, 56(8), 1025–
1046.
2. Chou, J.H., Kosal, M.E., Nalwa, H.S., Rakow, N.A., and Suslick, K.S. In 10. Lindsey, J.S., Prathapan, S., Johnson, T.E., and Wagner, R.W. Porphyrin
The Porphyrin Handbook; Kadish, K.M., Smith, K.M., Guilard, R. (Eds.),
Academic Press, New York, 2000, Vol. 6, Chapter 41, pp 43–132.
3. Zhang, Y.X., Yao, P., Cai, X., Xu, H., Zhang, X.X., and Jiang, J.Z. Density
functional theory study of the inner hydrogen atom transfer in metal-free
porphyrins: Meso-substitutional effects, Journal of Molecular Graphics
and Modelling, 2007, 26, 319–326.
building blocks for modular construction of bioorganic model systems,
Tetrahedron, 1994, 50(30), 8941–8968.
11. Lee, C.-H., and Lindsey, J.S. One-flask synthesis of meso-substituted
dipyrromethanes and their application in the synthesis of trans-
substituted porphyrin building blocks, Tetrahedron, 1994, 50(39), 11427–
11440.
4. Imahori, H. Porphyrin-fullerene linked systems as artificial photosynthetic
mimics. Org. Biomol. Chem., 2004, 2(10), 1425–1433.
12. Liu, G.F., and Shi, T.S. Lanthanide complexes with 4-hydroxyphenyl- triph-
enylprophyrin Polyhedron, 1994, 13, 2255–2258.
5. Ricard, D., L’Her, M., and Richard, P. Boitrel B Iron porphyrins as models
of cytochrome c oxidase. Chem-Eur. J., 2001, 7(15), 3291–3297.
6. Lazzeri, D., Rovera, M., Pascual, L., and Durantini, E.N. Photodynamic
studies and photoinactivation of Escherichia coli using meso-substituted
13. Hou, X.F., Huang, Z.E., and Cai, R.F. Synthesis and characterization of
α, β, γ , δ-tetrakis-(3-methoxy-4-hydroxy-phenyl)porphyrinatometal com-
plexes. Journal of Fudan University (Natural Science), 1997, 36, 53–
57.
cationic porphyrin derivatives with asymmetric charge distribution. Pho- 14. Geary, W.J. The use of conductivity measurements in organic solvents for
tochem. Photobiol., 2004, 80, 286–293.
the characterization of coordination compounds. Cood. Chem. Rew. 1971,
7, 81–122.
15. Hope, F.R., and Whitten, D.G. Porphyrins and Metallporphyrins. Amster-
dam, Elsevier Sci. Pub. Comp. 1975, 671.
7. Liu, W., Shi, T.S., and Liu, G.F. 5, 10, 15, 20-Tetrakisp(p-4-
fluorobenzoyloxy) phenyl porphyrin and its transition metal complexes,
Chem. Res. Chinese U. 2006, 22(4), 419–422.
8. Chandrashekar, T.K., and Venkatraman, S. Core-modified expanded por-
phyrins: new generation organic materials, Acc. Chem. Res., 2003, 36(9),
676–691.
16. Xu, H., Yu, D.Y., Wang, Z.X., and Kan, G.H. Thermal stability and decom-
position kinetics of some metalloporphyrins. Chinese Journal of Applied
Chemistry, 2001, 18, 447–449.