Synthesis and characterization of some new thallium(III) macrocyclic complexes and their biological studies

Article abstract of DOI:10.1515/mgmc-2015-0027

New symmetrically para-substituted tetraphenylporphyrin Tl(III) salicylate complexes, having the general formula SA/5-SSATl(III)t(4-Y)PP (Y=-H, -CH₃, -OCH₃); SA=salicylates and 5-SSA=5-sulfosalicylates, were synthesized and character

Full text of DOI:10.1515/mgmc-2015-0027

Main Group Met. Chem. 2016; 39(1-2): 19–29
GSayurni Dt. hBaejjus*,iSsapananKdatocchh, GaitraaDecvit,eSurjaitzaaKutnidoann, Asohfu asnod Mmadehulnlikea wBhagat
thallium(III) macrocyclic complexes and their
biological studies
DOI 10.1515/mgmc-2015-0027
Received August 31, 2015; accepted February 8, 2016; previously
published online April 22, 2016
special place in modern chemistry functioning as reac-
tion catalysts (Karimipour et al., 2007, 2012, 2013), oxygen
transporters, chemical sensors (Cosma et al., 2009; Mus-
turappa et al., 2013), or in molecular electronic devices
(Drain et al., 2002). Porphyrins were reported to exhibit
a variety of biological activities. This is due to the fact
that natural and synthetic porphyrins have relatively low
toxicity in vitro and in vivo, and they possess antitumor
(Antonova et al., 2010; Fadda et al., 2013) and antioxidant
effects (Stojiljkovic et al., 2001; Yuasa et al., 2007) and
have a good potential for ion complexation. The ability for
numerous chemical modifications and the large number
of different mechanisms by which porphyrins affect
microbial and viral pathogens place porphyrins into a
group of compounds with an outstanding potential for
discovery of novel agents, procedures and materials active
against pathogenic microorganisms. Porphyrins with only
one, two, or more substituents present a compact archi-
tecture that suits a wide variety of applications or further
synthetic elaboration. To synthesize porphyrins bearing a
molecular recognition site, porphyrin synthons that have
functional groups at the p-positions of the meso-phenyl
groups are usually employed, since these functional
groups might be further modified by chemical treatments
to enhance selectivity in the porphyrin-mediated reac-
Abstract: New symmetrically para-substituted tetraphe-
nylporphyrin Tl(III) salicylate complexes, having the gen-
eral formula SA/5-SSATl(III)t(4-Y)PP (Yꢀ=ꢀ-H, -CH3, -OCH3);
SAꢀ=ꢀsalicylates and 5-SSAꢀ=ꢀ5-sulfosalicylates, were syn-
thesized and characterized by elemental analysis, optical
absorption/emissionstudies,infraredspectrum,NMRstud-
ies (1H, 205Tl), thermal analysis and mass spectra; the com-
plexes are in good consistency with experimental results.
All the newly synthesized complexes exhibited good opti-
cal property, and thermogravimetric analysis (TGA) results
showed their excellent thermal stability (ꢀ>ꢀ400°C). Mac-
rocyclic complexes of Tl(III) ligate to axial ligand to form
six-coordinate complex, the nature of which influences the
photophysical properties of the former depending upon
the spin-orbital coupling character of the axial ligand. A
square-based pyramidal structure has been proposed on
the basis of these studies. In addition, some of the synthe-
sized complexes of thallium porphyrins were also screened
for anti-bacterial activity. Cytotoxic activity of 5-SSATl(III)t
(4-OCH3)PP evaluated against four human cancer cell lines
exhibited strong (up to 90%) growth inhibition.
Keywords: antibacterial activity; cytotoxic activity; macro- tions. Although the coordination of most of the metallic
cyclic complexes; salicylates; tetraphenylporphyrins.
elements to the porphyrin macrocycle has been demon-
strated for many years, it was transition-metal porphyrin
complexes which were the focus of the most intense atten-
tion. More recently, there has been a resurgence of interest
in main-group chemistry, driven by the search for new con-
Introduction
Tetrapyrrolic macrocycles like porphyrin and phthalo- ducting materials and new chemotherapeutic agents and
cyanines have attracted considerable interest and hold a the recent discovery of previously unsuspected bonding
modes for main-group elements. Porphyrin complexes of
the main-group elements have not been excluded from
this renewed interest, and there has been recent activity in
the study of elements from groups 13 and 14 coordinated
to the porphyrin macrocycle. Gallium(III), indium(III) and
thallium(III) porphyrins have been receiving more atten-
tion due to their good medical application and non-linear
optical (NLO) properties (Rajesh et al., 2010; Fitzgerald
*Corresponding author: Gauri D. Bajju, Department of Chemistry,
University of Jammu, New Campus, Baba Sahib Ambedkar Road,
Jammu 180 006, India, e-mail: gauribajju@gmail.com
Sapna Katoch, Gita Devi, Sujata Kundan and Ashu: Department
of Chemistry, University of Jammu, New Campus, Baba Sahib
Ambedkar Road, Jammu 180 006, India
Madhullika Bhagat: School of Biotechnology, University of Jammu,
New Campus, Baba Sahib Ambedkar Road, Jammu 180 006, India
Unauthenticated
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ꢀꢀꢀꢁ
20ꢀ ꢀG.D. Bajju et al.: Porphyrin-like tetrapyrrolic macrocycles
Table 2:ꢀOptical absorption data of free base porphyrins and their
et al., 2015). Sn(IV) compounds possessed diversified
applications in industries and agriculture and acts as
good photosensitizer (Manke et al., 2014). Thallium(III)
porphyrins show a range of properties, among the most
striking of which is the remarkable structural diver-
sity which differs from typical coordination geometries
observed for most metalloporphyrin complexes. Another
favorable feature of these complexes is their capability of
hosting tri- or tetravalent central atoms that require the
further coordination of one and two axial substituents,
respectively. In fact, axial substituents indirectly stabi-
lize the electronic excited states which are involved in the
multiphoton absorption processes through either prevent-
ing or reducing intermolecular aggregation in solution
with the increase of molecule concentration. Following
the preceding discussion, we have synthesized the series
of axially substituted thallium(III) porphyrins.
Tl(III) derivatives in different solvents.
Compound
ꢁ Solvent
ꢁ
B bandꢁ
λmax (nm)
Q bands
λmax (nm)
H2tPP
ꢂ Acetone
ꢂ
422ꢂ 514, 549, 590, 646,
414ꢂ 512, 546, 592, 644
422ꢂ 517, 533, 592, 648
420ꢂ 515, 533, 590, 646
422ꢂ 516, 557, 594, 651
420ꢂ 515, 556, 592, 649
ꢂ Chloroformꢂ
H2t(4-CH3)TPP ꢂ Acetone
ꢂ Chloroformꢂ
H2t(4-OCH3)PP ꢂ Acetone
ꢂ Chloroformꢂ
(OH)(H2O)Tlt(4-H)PP ꢂ Acetone
ꢂ Chloroformꢂ
(OH)(H2O)Tlt(4-CH3)PP ꢂ Acetone
ꢂ
ꢂ
ꢂ
438ꢂ
438ꢂ
449ꢂ
447ꢂ
431ꢂ
430ꢂ
568, 606
566, 605
453, 671
451, 672
518, 568
517, 566
ꢂ
ꢂ Chloroformꢂ
(OH)(H2O)Tlt(4-OCH3)PPꢂ Acetone
ꢂ
ꢂ Chloroformꢂ
In particular, we prepared meso-tetraphenylporphyrin
(H2tPP) and its para-substituted derivative H2t(4-Y)PP
Yꢀ=ꢀp-CH3, p-OCH3) aquo-meso-(5,10,15,20-tetraarylpor-
phyrinato)thallium(III)hydroxide, [(OH)(H2O)Tlt(4-Y)PP],
axially ligated Tl(III) porphyrins; meso-tetraphenylpor-
phyrinato salicylato thallium(III), Tlt(4-Y)PPSA and meso-
tetraphenylporphyrinato 5-sulphosalicylatothallium(III),
Tlt(4-Y)PP 5-SSA. Finally, the biological activity of the
newly synthesized porphyrin ligands and their complexes
was tested against some Gram (+) and Gram (-) bacteria
(Escherichia coli, Pseudomonas florescens, Staphylococcus
aureus and Bacillus subtilis).
Absorption spectroscopy
The B and the Q bands in the spectrum of typical porphy-
rin both arise from π-π* transitions and can be explained
by considering the four frontier orbitals (Milgrom, 1997)
(HOMO and LUMO orbitals) (the Gouterman four-orbital
model). From the UV-Vis absorption values given in the
Experimental section, it can be clearly observed that vari-
ation of the peripheral substituents on the porphyrin ring
causes minor changes in the intensity and wavelengths of
these absorptions, and their spectral data in different sol-
vents (Table 2) shows that many of the absorption bands
of para-substituted derivatives exhibit bathochromic (red
shift) as compared to the unsubstituted porphyrin. The
electronic absorption spectra of aquo-meso-tetraaryl
porphyrinato thallium(III) hydroxide (OH)(H2O)T1(III)
tpp and (OH)(H2O)T1(III)t(4-Y)PP, Yꢀ=ꢀ-CH3, -OCH3 are of
normal two-banded type. It is apparent from the spectra
that there is no major distortion of the macrocycle ring
Results and discussion
Elemental analysis
All the resulting solids are soluble in CHCl3, CH2Cl2, upon metalation and that the large metal atom is situ-
CH3OH and DMSO. The analytical data of the complexes of ated above rather than in the plane of the porphyrin ring.
thallium(III) metal complexes are given in Table 1.
Both B bands (350–450 nm) and Q bands (500–700 nm)
Table 1:ꢀAnalytical data of some of the axially ligated complexes of Tl(III) porphyrins.
Elemental analysis ꢁꢁ Calculated percentageꢁꢁ
Found percentage
Cꢁ
Hꢁ
Nꢁ
S
Cꢁ
Hꢁ
Nꢁ
S
SATltpp
ꢂ
ꢂ
ꢂ
ꢂ
ꢂ
62.87ꢂ
59.04ꢂ
63.18ꢂ
60.52ꢂ
60.13ꢂ
47.6ꢂ
3.60ꢂ
3.08ꢂ
3.90ꢂ
3.75ꢂ
3.73ꢂ
3.55ꢂ
5.73ꢂ
5.40ꢂ
5.36ꢂ
5.13ꢂ
5.10ꢂ
4.85ꢂ
0.00ꢂ
3.08ꢂ
0.00ꢂ
2.93ꢂ
0.00ꢂ
2.77ꢂ
62.36ꢂ
59.02ꢂ
63.38ꢂ
60.23ꢂ
60.25ꢂ
47.59ꢂ
3.68ꢂ
3.06ꢂ
3.73ꢂ
3.62ꢂ
3.69ꢂ
3.43ꢂ
5.72ꢂ
5.48ꢂ
5.30ꢂ
5.23ꢂ
5.33ꢂ
4.78ꢂ
0.00
3.10
0.00
2.74
0.00
2.83
5-SSATltpp
SATlt(4-CH3)PP
5-SSATlt(4-CH3)PP
SATlt(4-OCH3)PP
5-SSATlt(4-OCH3)PPꢂ
Unauthenticated
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ꢁꢀꢀꢀ
G.D. Bajju et al.: Porphyrin-like tetrapyrrolic macrocyclesꢃ
ꢃ21
were found to be red-shifted in all thallium porphyrins is more influenced by this structural change. The f values
(Figure 1). Also, the molar absorbance of both the main (oscillator strength) of some of the metalated porphyrin
Soret and the Q bands of the metalloporphyrins are and their axially ligated derivatives (Table 3) show that
higher than the corresponding values for the free-base change in polarity of the solvent does not significantly
porphyrin (Tables 2 and 3). According to earlier observa- alter the position of transitions but result in an enhanced
tions (Horvath et al., 2004, 2006; Valicsek et al., 2004, full width at half maximum (fwhm) (1/2) value indicating
Valicsek et al., 2011) this type of spectral properties is weak interactions with the solvent.
unambiguously characteristic for OOP (out of plane) or
The optical absorption spectra of axially ligated Tl(III)
Sat (sitting atop) complexes, confirming the expectations porphyrins when recorded in different solvents show
based on the size (95 pm ionic radius) of Tl(III). Not only only marginal change in λmax values. The spectrum of the
metalation but also axial coordination is accompanied complex SATl(III)t(4-CH3)PP is shown in Figure 2.
by red shifts of the characteristic absorption bands. As
the corresponding values for B(0,0) itself indicate, the
larger OOP distance in case of axially ligated porphyrin Infrared spectroscopy
results in the higher dome distortion of the porphyrin
ligand. For the Q(0,0) band the effect of the axial ligand The infrared (IR) spectral data of various synthesized
is much stronger, indicating that the energy of the S1 state complexes of thallium porphyrins are listed in Table 4.
566
3.5
A
B
(OH)(H2O)Tl(4-H)PP 438
4.5
4.0
3.5
3.0
2.5
2.0
1.5
1.0
0.5
0.0
H2tpp
H2tpp, 418
3.0
2.5
2.0
1.5
1.0
0.5
0.0
(OH)(H2O)Tl(4-H)PP
512
605
546
592
644
480 500 520 540 560 580 600 620 640 660
max (nm)
380
400
420
440
460
480
500
λ
max (nm)
λ
Figure 1:ꢀUV visible spectra of free base porphyrin and thallium(III) porphyrin.
(a) UV-visible overlapped B-bands of H2tpp and (OH)(H2O)Tltpp. (b) UV-visible overlapped Q-bands of H2tpp and (OH)(H2O)Tltpp.
Table 3:ꢀOptical absorption data of axially ligated thallium porphyrins in different solvents together with logε and υ1/2
.
Compound
ꢁꢁ
Solvent
ꢁꢁ
λmax, nm (logε, m-1 cm-1)ꢁꢁ
υ1/2 (cm-1)ꢁꢁ
Q(1,0)
Fꢁ=ꢁ4.33ꢁ×ꢁ10-9 εΔν1/2
B(0,0)ꢁ
Q(1,0)ꢁ
Q(0,0)
B(0,0)ꢁ
B bandsꢁ
Q bands
SATltpp
ꢂ
ꢂ
ꢂ
ꢂ
ꢂ
ꢂ
ꢂ
ꢂ
ꢂ
ꢂ
Acetone
ꢂ
444(4.553)ꢂ
442(3.875)ꢂ
445(4.553)ꢂ
445(4.550)ꢂ
449(4.571)ꢂ
447(3.571)ꢂ
451(4.043)ꢂ
451(4.044)ꢂ
435(4.670)ꢂ
432(4.672)ꢂ
449(4.747)ꢂ
447(4.735)ꢂ
588(4.452)ꢂ
588(4.230)ꢂ
651(4.861)ꢂ
651(4.332)ꢂ
572(4.243)ꢂ
570(4.243)ꢂ
596(4.341)ꢂ
594(4.235)ꢂ
567(4.307)ꢂ
566(4.302)ꢂ
568(4.241)ꢂ
568(4.113)ꢂ
603(4.218)ꢂ
605(4.107)ꢂ
649(4.434)ꢂ
647(4.603)ꢂ
606(4.421)ꢂ
605(4.314)ꢂ
673(4.210)ꢂ
671(4.130)ꢂ
611(4.313)ꢂ
609(4.221)ꢂ
671(4.04)ꢂ
1319ꢂ
1224ꢂ
1591ꢂ
1530ꢂ
1310ꢂ
1227ꢂ
1398ꢂ
1322ꢂ
1354ꢂ
1269ꢂ
1373ꢂ
1302ꢂ
432ꢂ
463ꢂ
647ꢂ
238ꢂ
644ꢂ
425ꢂ
565ꢂ
326ꢂ
683ꢂ
602ꢂ
588ꢂ
758ꢂ
0.0561ꢂ
0.0413ꢂ
0.0546ꢂ
0.0623ꢂ
0.0431ꢂ
0.2269ꢂ
0.2269ꢂ
0.1342ꢂ
0.2570ꢂ
0.1725ꢂ
0.3233ꢂ
0.0869ꢂ
0.0568
0.0341
0.0534
0.0221
0.0483
0.0322
0.0404
0.0243
0.0600
0.0523
0.0591
0.0425
Chloroformꢂ
5-SSATltpp
Acetone
Chloroformꢂ
Acetone
Chloroformꢂ
Acetone
Chloroformꢂ
Acetone
Chloroformꢂ
Acetone
Chloroformꢂ
ꢂ
SATlt(4-CH3)PP
5-SSATlt(4-CH3)PP
SATlt(4-OCH3)PP
ꢂ
ꢂ
ꢂ
5-SSATlt(4-OCH3)PPꢂ
ꢂ
ꢂ
669(4.232)ꢂ
Unauthenticated
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ꢀꢀꢀꢁ
22ꢀ ꢀG.D. Bajju et al.: Porphyrin-like tetrapyrrolic macrocycles
1H NMR spectroscopy
5
4
3
2
1
0
Acetone
449
The thallium porphyrin complexes with salicylates-
(SA/5-SSA) as axial ligands all exhibit sharp H NMR
spectra. The characteristic data for the NMR of the free
base porphyrins, corresponding metalated complexes of
thallium(III) and their axially ligated derivatives are sum-
marized in Table 5.
447
1
Chloroform
572
570
1H NMR spectra are fruitful in clarifying the insertion
of metal ion in the porphyrin core as the signal related to
N-H protons was found to be absent, and also there was
a shift in the signals of other protons in the NMR spectra
of metalated porphyrins. In the axially ligated derivatives
of thallium porphyrins, the singlet at 5.0 ppm of medium
intensity was observed assigned to the -OH group which
confirms that axial ligation was taking place through the
oxygen atom of carboxylate group. All the δ values corre-
spond to the proton signals of axial ligands in the axially
ligated complexes that exhibited upfield shift when com-
pared with the signals of porphyrin protons and the proton
signal of free axial ligands. This upfield shift is attributed
to the ring current effect (Lu et al., 1999) of the porphyrin
macrocycle.
606
605
380 400 420 440 460 480 500 520 540 560 580 600 620 640 660 680
λ
max (nm)
Figure 2:ꢀUV-visible overlapped B and Q bands of SATlt(4-CH3)PP.
It is found that the ν(N-H) stretching frequency of free
base porphyrins are located at ~3400–3320 cm-1 (Sun
et al., 2011) and disappeared when thallium metal ion
was inserted into the porphyrin ring. There is an addi-
tional Tl-N stretch vibration at 400–500 cm-1 in metalated
complexes indicating the formation of Tl(III) porphyrins.
The band in the complexes at 1633 cm-1 [νasymmetric(OCO)]
are assigned to the chelating bidentate salicylate ligand.
The bidentate nature of salicylates in the IR spectra of the
complexes was confirmed on the basis of Stoilovo et al. 205Tl NMR spectroscopy
results that unidentate CO2 exhibits three bands (COO
deformation) at 920–720 cm-1 and a strong band at 540 cm-1 The range for 205Tl NMR chemical shift values is very large,
(Suen et al., 1992). All these four bands were absent in i.e. about 7000 ppm. As far as oxidation states are con-
axially ligated thallium porphyrin complexes. Further, cerned, for Tl(I) complexes chemical shift values are in
the band observed near 1724 cm-1 is assigned to ν(Cꢀ=ꢀO) the range -200 to +200 ppm, and for Tl(III) these lie in the
stretching frequency. The frequency corresponding to free range +2000 to +3000 ppm. 205Tl NMR spectra of SATl(III)
O-H group is observed at 3418 cm-1 confirming the coordi- t(4-CH3)PP when recorded in CDCl3 exhibits a sharp reso-
nation of axial ligand through carboxylate oxygen atoms. nance at δ 2588 ppm which confirms the presence of Tl(III)
The decrease in vibrational frequency of OH group is due ion in the complex. On comparing this value with the
to the weakening of O-H bond as -CO2 in its vicinity from chemical shift value of the complexes already reported in
salicylate ring ligates to the metal atom.
literature (Ma et al., 2003), it was found that this value has
Table 4:ꢀMain infrared absorption frequencies corresponding to the simple porphyrin H2tpp and various groups in XTlt(4-Y)PP (Xꢂ=ꢂSA, 5-SSA)
and (Yꢂ=ꢂ-H, -CH3, -OCH3).
Porphyrin
ꢁ
ν(O-H)ꢁ
ν(N-H)ꢁ
ν(C-H)asymꢁ
ν(sp3-CH)ꢁ
ν(ꢁ=ꢁC-H)ꢁ
ν(C-N)ꢁ
ν(Cꢁ=ꢁC)ꢁ
ν(Cꢁ=ꢁO)ꢁ
ν(Tl-N)
(cm-1)
(cm-1)
(cm-1)
sym
(cm-1)
(cm-1)
(cm-1)
H2tpp
(OH)(H2O)Tltpp
SATlt(4-H)PP
ꢂ
ꢂ
ꢂ
ꢂ
ꢂ
ꢂ
ꢂ
ꢂ
3523ꢂ
3419ꢂ
3401ꢂ
3418ꢂ
3401ꢂ
3419ꢂ
3401ꢂ
3425ꢂ
–ꢂ
–ꢂ
–ꢂ
–ꢂ
–ꢂ
2923ꢂ
2920ꢂ
2925ꢂ
2929ꢂ
2919ꢂ
2929ꢂ
2925ꢂ
2929ꢂ
1353ꢂ
1351ꢂ
1328ꢂ
1336ꢂ
1329ꢂ
1335ꢂ
1329ꢂ
1336ꢂ
1582ꢂ
1552ꢂ
1533ꢂ
1535ꢂ
1534ꢂ
1533ꢂ
1532ꢂ
1534ꢂ
–ꢂ
–ꢂ
–
488
472
470
473
470
472
472
–ꢂ
2960ꢂ
2962ꢂ
2960ꢂ
2962ꢂ
2960ꢂ
2961ꢂ
2854ꢂ
2859ꢂ
2855ꢂ
2859ꢂ
2854ꢂ
2859ꢂ
1725ꢂ
1728ꢂ
1724ꢂ
1728ꢂ
1725ꢂ
1728ꢂ
5-SSATlt(4-H)PP
SATlt(4-CH3)PP
5-SSATlt(4-CH3)PP
SATlt(4-OCH3)PP
–ꢂ
–ꢂ
–ꢂ
–ꢂ
5-SSATlt(4-OCH3)PPꢂ
–ꢂ
Unauthenticated
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ꢁꢀꢀꢀ
G.D. Bajju et al.: Porphyrin-like tetrapyrrolic macrocyclesꢃ
ꢃ23
Table 5:ꢀ1H NMR data showing chemical shift (in ppm) values of axially ligated thallium porphyrins in CDCl3 at 300 K.
Porphyrins
ꢁ
Pyrrole protons ꢁ
Meso-aryl protons
ꢁ
Other protons
SATlt(4-H)PP
ꢂ
ꢂ
ꢂ
ꢂ
ꢂ
ꢂ
ꢂ
ꢂ
ꢂ
ꢂ
ꢂ
ꢂ
ꢂ
ꢂ
ꢂ
ꢂ
ꢂ
ꢂ
9.06 (s)
5.6 (d)
ꢂ
ꢂ
ꢂ
ꢂ
ꢂ
8.89s and 8.75s (H2,6
7.72s and 7.71s (H3,5
7.68m (H4)
)
ꢂ
ꢂ
ꢂ
ꢂ
ꢂ
ꢂ
ꢂ
ꢂ
ꢂ
ꢂ
ꢂ
ꢂ
ꢂ
ꢂ
ꢂ
ꢂ
ꢂ
ꢂ
ꢂ
6.78t, H4″
)
6.08d, H3″
6.31d, H6″
6.16 t, H5″, 5.0(s, 1H, O-H)
5.1–6.0m H6″, H4″, H3″
5.0(s, 1H, O-H)
2.0(bs, 1H, SO3H)
6.78t, H4″
5-SSATlt(4-H)PP
8.78(s)
7.19(s), 5.6(dd) ꢂ
8.15 and 8.06 (d, H2,6
7.99 and 7.78(d, H2′,6′
7.7 (bs, H3.5
8.76s and 8.63s(H2,6
7.63s and 7.61(H3,5
)
)
ꢂ
)
SATlt(4-CH3)PP
9.01(s)
5.5(d)
ꢂ
ꢂ
ꢂ
ꢂ
ꢂ
ꢂ
ꢂ
ꢂ
ꢂ
ꢂ
ꢂ
)
)
6.07d, H3″
6.29d, H6″
6.13t, H5″, 5.0(s, 1H, O-H) 2.83(s, 12H, CH3)
4.5–5.6m H6″, H4″, H3″
5.0(s, 1H, O-H), 2.0(bs, 1H, SO3H), 2.83(s, 12, CH3)
5-SSATlt(4-CH3)PP
8.72(s)
7.14(s)
5.5(m)
8.83(s)
5.5(m)
8.02 and 7.98(d, H2,6
)
7.63 and 7.34(d, H2′,6′
)
SATlt(4-OCH3)PP
8.77 and 8.73(s, H2,6
)
)
6.78t, H4″
7.62 and 7.59(s, H3,5
6.06d, H3″
6.30d, H6″
6.11t, H5″, 5.0(s, 1H, O-H) 4.15(s, 12H, OCH3)
4.6–6.0m, H6″, H4″, H3″
5.0(s, 1H, O-H), 2.0(1s, 1H, SO3H)
5-SSATlt(4-OCH3)PPꢂ
8.69 and 7.14(s)ꢂ
5.5(m)
7.83 and 7.13(d, H2,6)
7.64–7.33(d, H2′,6′) 7.3(bs, H3,5) ꢂ
ꢂ
ꢂ
δ in ppm, the nature of splitting patterns(s) (s, singlet; d, doublet; m, multiplet; bs, broad singlet; dd, doublet of doublet; o, ortho; p, para;
m, meta).
shifted towards lower frequency which can be attributed curve shows an initial weight loss of a sulphosalicylate
to the presence of four electron-releasing -CH3 groups on group and one phenyl ring at 158.2°C (obs. wt. lossꢀ=ꢀ27.7%,
the meso-phenyl ring. This parameter causes shielding of calc. wt. lossꢀ=ꢀ27.2%). This is followed by a loss of three
the thallium nucleus and hence shifts towards lower fre- phenyl rings and thallium metal ion at 408.5°C (obs.
quency (Figure 3).
wt. lossꢀ=ꢀ40.2%, calc. wt. lossꢀ=ꢀ40.2%). There are some
exothermal peaks observed in the range of 300–600°C
showing major weight loss in this region. It is a continu-
ous decomposition process; the small exothermic peaks
correspond to the loss of chains of the porphyrin ring
Thermal analysis
The thermogravimetric (TG) curve of one of the synthe- (Zhuang et al., 2009), and the large exothermic peaks at
sized complex 5-SSATl(III)t(4-H)pp (Figure 4) shows a nearly 580°C corresponds to the collapse of the porphy-
continuous weight loss starting from 150°C to 750°C. The rins skeleton. The residual mass was 0 at 751.2°C.
205T1
Fluorescence spectroscopy
The variation of emission properties in free base porphy-
rin H2t(4-Y)PP (Y: -CH3, -OCH3) and their axially ligated
Tl(III) porphyrins have been investigated by means of
fluorescence spectroscopy; data are given in Table 6. Por-
phyrins show two emission bands, a strong Q(0,0) band
at higher energy accompanied by a weak Q(0,1) band at
a lower energy. The free-base porphyrins H2t(4-CH3)PP,
with excitation at 450nm, exhibits two emission bands
at 620 and 672 nm corresponding to Q(0,0) and Q(0,1)
2900 2800 2700 2600 2500 2400 2300 2200 2100 ppm
transitions, respectively, the intensity of the Q(0,0) being
Figure 3:ꢀ205Tl NMR spectrum of the complex SATlt(4-CH3)PP.
higher than the Q(0,1) transition. Meso-subsitution of the
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ꢀꢀꢀꢁ
24ꢀ
ꢀG.D. Bajju et al.: Porphyrin-like tetrapyrrolic macrocycles
27.6°C -0.6%
0
500
158.2°C -27.7%
-20
408.5°C -40.2%
400
300
Heat flow (smoothed) (TLSSA)
-40
-60
-80
200
100
583.5°C -95.7%
751.2°C -100.0%
-100
-120
dM-rel (TLSSA)
500
100
100
200
200
300
400
600
600
700
700
800
800
Temperature (smoothed) (°C)
300
400
500
Temperature (°C)
Figure 4:ꢀThermogravimetric analysis (TGA)-differential thermal analysis (DTA) curve of 5-SSATltpp.
Table 6:ꢀSummary of the characteristic emission data of free base
by the presence of the molecular ion peak followed by
different specific fragmentation pattern. The molecular
ion peak of the investigated complexes was found to be
44 units less than the corresponding molecular weight of
the complex, which is attributed to the loss of stable CO2
molecule from the complex. The major losses are 304, 615,
616 and 81. Besides the molecular ion, an identical peak
m/zꢀ=ꢀ304 fragment, corresponding to the tetrapyrrole
moiety, appears in each spectrum (Cosma et al., 2006).
Two groups of peaks were observed (main signals accom-
panied by isotopic patterns confirming the chemical com-
porphyrin and axially ligated Tl(III) porphyrin at 28K in DMSO.
Complexes
ꢁꢁ
λmax (nm)
Q(0,1)
Q(0,0)ꢁ
H2t(4-CH3)PP
Tlt(4-CH3)PP
SATlt(4-CH3)PP
H2t(4-OCH3)PP
5-SSATlt(4-OCH3)PPꢂ
ꢂ
ꢂ
ꢂ
ꢂ
620ꢂ
606ꢂ
580ꢂ
620ꢂ
582ꢂ
672
653
630
671
630
porphyrin ring leads to red shift of all the emission bands position of the ions) at m/z 615 and 616 that correspond
relative to that of unsubstituted tetraphenylporphyrins. to the fragments of H2tpp+1 and H2tpp+2 (H2tppꢀ=ꢀmeso-
However, the emission bands of axially ligated Tl(III) por- tetraphenyl porphyrin), and the peak at 81 corresponds to
phyrins are blue shifted (Horvath et al., 2006) compared the SO3H group.
to free base porphyrins. This behavior is attributed to an
In addition, the intensities of the registered peaks are
enhanced spin-orbit coupling induced by the presence of significantly higher. The base peak of thallium porphyrin
the heavy central metal atom in thallium porphyrin com- complexes was observed 100% intensity giving evidence
plexes, which leads to a more efficient S1→T1 intersystem about the stability of complexes of thallium porphyrins.
crossing and thus reduces the probability of fluorescent
emission (Knöra and Strasser, 2002). Thus, the excitation
spectrum of fluorescence is in agreement with the absorp- Antibacterial studies
tion spectrum (Figure 5).
Antibacterial activity of the synthesized Tl(III) porphy-
rin complexes was tested by agar well diffusion method.
Mass spectrometry
The free base prophyrins, their corresponding metalated
and axially ligated thallium(III) porphyrin complexes viz.,
The mass spectra of some of the investigated axially H2t(4-OCH3)PP, H2t(4-CH3)PP, (OH)(H2O)Tlt(4-CH3)PP, (OH)
ligated thallium porphyrin complexes are characterized (H2O)Tlt(4-OCH3)PP, SATlt(4-CH3)PP, 5-SSATlt(4-CH3)PP
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ꢁꢀꢀꢀ
G.D. Bajju et al.: Porphyrin-like tetrapyrrolic macrocyclesꢃ
ꢃ25
100
80
60
40
20
0
100
80
60
40
20
0
MB-5
Mitomycin c
100 µM
10 µM
50 µM
100 µM
1 µM
10 µM
50 µM
1 µM
100
100
80
60
40
20
0
80
60
40
20
0
MB-5
50 µM
5
MB-5
Paclitaxel
Fluorouracil
100 µM 1 µM
10 µM
10 µM
50 µM
100 µM
1 µM
Figure 5:ꢀIn vitro cytotoxicity of 5-SSATlt(4-OCH3)PP complex against human cancer cell lines.
and 5-SSATlt(4-OCH3)PP were tested at three concentra-
Conclusion
tions (10-3, 10-4 and 10-5 m) against five bacterial strains
viz., B. subtilis, Micrococcus luteus, S. aureus, Pseu-
The present paper was concerned about the synthesis of
symmetrically substituted meso-tetraphenylporphyrin,
their complexation with thallium metal ion and then axial
ligation with salicylates, SA/5-SSA. The complexes were
characterized by elemental analysis, UV-Vis, IR, fluores-
cence and NMR studies. In the UV-Vis spectra, both the
Soret and Q bands were significantly red shifted on metala-
tion, and further large shift of these bands on axial ligation
was related to the distortion of the porphyrin core. The IR
spectrum of these compounds showed that salicylic acids
(SA/5-SSA) ligate in a bidentate mode through the carboxy-
late group. 1H NMR spectroscopic study of these compounds
showed that due to ring current effect of the porphyrin mac-
rocycle, the proton signals of the axial ligands (SA/5-SSA)
are shifted to higher field in comparison to the signals of por-
phyrin protons and proton signals of free axial ligands. The
production of the monomeric form of thallium porphyrin
domonas florescens and E. coli. The thallium(III) complex
5-SSATlt(4-OCH3)PP was found sensitive only to B. subtilis
(Gram positive) and P. florescens (Gram negative) bacteria
at the concentrations of 10-3 and 10-4 m. Other complex
SATlt(4-CH3)PP) showed sensitivity against B. subtilis
and M. luteus. The remaining complexes, viz., H2t(4-CH3)
PP, (OH)(H2O)Tlt(4-CH3)PP and 5-SSATlt(4-CH3)PP showed
activity only against Gram negative bacteria E. coli with
zone of inhibition ranging from 6 to 14 mm. The rest of
the complexes did not show any activity against bacte-
rial strains. The results were observed in dose-dependent
manner as demonstrated in Table 7.
Anticancer activity
In the present work, the cytotoxicities of 5-SSATl(III)t complexes was well confirmed by means of electronspray
(4-OCH3)PP, SATl(III)t(4-OCH3)PP and SATl(III)t(4-CH3)PP ionization mass spectrometry (ESI-MS). The coordination
were evaluated against four human cancer cell lines, viz., of salicylates through COO to these complexes in metha-
breast (MCF-7), leukemia (THP-1), prostate (PC-3) and lung nol solution was clarified using ESI-MS. The ensuing com-
(A549) at different concentrations. One of the complexes, plexes show admirable thermal stability (ꢀ>ꢀ400°C), and the
namely, 5-Sulphosalicylato (meso-tetra-p-methoxypor- decomposition of the complexes comes to an end at 750°C.
phyrinato)thallium(III) (MB-5) shows significant activity 205Tl NMR studies confirm the presence of Tl(III) ion in the
(Figure 5) against lung and leukemia, classifying these complexes. The biological activities were also investigated,
complexes as chemotherapeutically significant. We also and the synthesized compounds showed varying degrees
tested other synthesized compounds against the above of inhibitory effects: low (up to 6 mm) and moderate (up
mentioned panel of cancer cell lines; however, none of the to 11 mm). The parent compounds possessed a low activity
compounds exhibited cytotoxicity even at 100 μm concen- against the bacterial strains at low concentration but indi-
-1
tration (results not shown).
cated a slight rise in the activity at 100 μg mL . Similarly,
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ꢀꢀꢀꢁ
26ꢀ ꢀG.D. Bajju et al.: Porphyrin-like tetrapyrrolic macrocycles
Table 7:ꢀIn vitro antibacterial evaluation of free base porphyrin and the corresponding thallium porphyrin complexes.
Bacterial strains
ꢁ
Conc.ꢁ
B. subtilisꢁ
M. luteusꢁ
S. aureusꢁ
P. flourescensꢁ
E. coli
Zones of inhibition (mm)
ꢃH2t(4-OCH3)PP
ꢃSATlt(4-OCH3)PP
ꢃ5-SSATlt(4-OCH3)PP
ꢃH2t(4-CH3)PP
ꢂ
ꢂ
ꢂ
ꢂ
ꢂ
ꢂ
ꢂ
ꢂ
ꢂ
ꢂ
ꢂ
ꢂ
10-3ꢂ
10-4ꢂ
10-5ꢂ
10-3ꢂ
10-4ꢂ
10-5ꢂ
10-3ꢂ
10-4ꢂ
10-5ꢂ
10-3ꢂ
10-4ꢂ
10-5ꢂ
10-3ꢂ
10-4ꢂ
10-5ꢂ
10-3ꢂ
10-4ꢂ
10-5ꢂ
10-3ꢂ
10-4ꢂ
10-5ꢂ
ꢂ
ꢂ
ꢂ
ꢂ
ꢂ
8
6
–
ꢂ
ꢂ
ꢂ
ꢂ
ꢂ
ꢂ
ꢂ
ꢂ
ꢂ
9ꢂ
ꢂ
6ꢂ
ꢂ
7ꢂ
ꢂ
–ꢂ
ꢂ
–ꢂ
ꢂ
–ꢂ
10ꢂ
ꢂ
ꢂ
8ꢂ
6ꢂ
ꢂ
ꢂ
6ꢂ
–ꢂ
ꢂ
ꢂ
–ꢂ
ꢂ
ꢂ
ꢂ
ꢂ
6
4
–
9
6
–
9
ꢂ
ꢂ
ꢂ
ꢂ
ꢂ
ꢂ
ꢂ
ꢂ
ꢃ(OH)(H2O)Tlt(4-CH3)PPꢂ
ꢂ
ꢂ
ꢂ
ꢂ
ꢂ
ꢂ
ꢂ
ꢂ
ꢂ
ꢂ
ꢂ
ꢂ
ꢂ
ꢂ
ꢃSATlt(4-CH3)PP
ꢂ
ꢂ
ꢂ
ꢂ
ꢂ
ꢂ
ꢂ
ꢂ
ꢂ
7ꢂ
–ꢂ
–ꢂ
9ꢂ
–ꢂ
–ꢂ
19ꢂ
ꢂ
9ꢂ
6ꢂ
–ꢂ
9ꢂ
–ꢂ
–ꢂ
20ꢂ
ꢂ
ꢂ
10ꢂ
ꢂ
ꢂ
ꢂ
ꢂ
ꢃ5-SSATlt(4-CH3)PP
ꢂ
10ꢂ
–ꢂ
–ꢂ
18ꢂ
ꢂ
ꢂ
10
–
–
24
ꢂ
ꢂ
ꢃPositive control
ꢃControl
21ꢂ
ꢂ
ꢂ
ꢂ
+
ꢃCmp 10 μg
ꢂ
ꢂ
ꢂ
Y
thallium porphyrins and their axially ligated derivatives
show rise in the activity when compared with their parent
compounds. Such increase in the activity of the complexes
compared to that of ligands could be explained on the basis
of Overton’s concept (Overton, 1901) and Tweedy’s chela-
tion theory (Tweedy, 1964). One of the complexes screened
for anticancer activity showed up to 90% growth inhibition.
On the basis of the elemental analysis and spectral studies,
confirmed by mass spectra showing characteristic molecu-
lar ion peak at their m/z value for their monomeric form,
a square-pyramidal structure (Figure 6) for SATl(III)t(4-Y)
PP and 5-SSATlt(4-Y)PP complexes has been proposed. All
complexes are soluble in DMSO, CHCl3 and CH3OH.
X
Y
N
Tl
N
N
N
Y
Y
HO
3″
O
O
2″
4″
4″
C
C
1″
6″ 5″
3″
X =
HO
2″
O
O
1″
6″
5″
SO3H
Experimental
Figure 6:ꢀSuggested structure of XTlt(4-Y)PP(Xꢂ=ꢂSA, 5-SSA).
Materials and instrumentation
UV-Vis spectra were recorded on a Systonic 119 UV Visible spectro-
photometer (University of Jammu, Jammu) in the range 350–700 nm.
The oscillator strength (f) of the transitions in absorption spectra were
calculated from the expression
All the chemicals were of analytical grade and were used as received
unless otherwise noted. All the reagents were purchased from Himedia
(Mumbai, India). Pyrrole was distilled over potassium hydroxide pel-
lets under vacuum prior to use. All the organic solvents that were used
for the synthesis and for chromatographic separations were dried
before use. Elemental analysis (C, H, N and S) was performed on a
Vario EL III and CHNS-932 LECO Elemental Analyzer (IIIM, Jammu).
f =4.33×10-9 ε∆ ν
½
where ε is the molar absorption coefficient in dm3 mol-1 cm-1 and
Δν is the fwhm in cm-1. IR spectra were recorded on a Perkin
½
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ꢁꢀꢀꢀ
G.D. Bajju et al.: Porphyrin-like tetrapyrrolic macrocyclesꢃ
ꢃ27
Elmer-spectrum 400 FTIR spectrophotometer using KBr pellets in
from the synthesis reported by Adler et al. (1967). The
appropriate benzaldehyde is refluxed for 30 min with
0.08 mL of pyrrole in 12 mL of propionic acid in a 50-mL
round bottom flask fitted with a water condenser. The
pyrrole must be from a freshly opened bottle or have
recently been purified by vacuum distillation. After reflux-
ing, the reaction mixture is cooled to room temperature,
and 10 mL of cold methanol is added. The deep-purple
solid is filtered by vacuum filtration with a Buchner
funnel. The flask and crude solid is washed with three
portions of cold methanol followed by boiling distilled
water. The crystals are air-dried on the Buchner funnel
for 15 min, dried in a vacuum desiccator and purified by
column chromatography (Scheme 1). The syntheses of the
substituted porphyrins, i.e. H2t(4-CH3)TPP and H2t(4-OCH3)
TPP, are performed in a similar manner. Average yields are
about 40 mg (23%). All the benzaldehydes are commer-
cially available. The resulting porphyrins can be charac-
terized by visible absorption or 1H NMR spectroscopy.
1
the range of 4000–400 cm-1. The H NMR spectra were recorded on
a Bruker Avance II 500 (500 MHz) using tetramethylsilane as inter-
nal standard and CDCl3 as solvent. 205Tl NMR spectra were recorded
on a Bruker Avance 400 MHz spectrometer in CDCl3. TGA and DTA
were recorded on Linseis STA PT-100 thermometer using dry samples
at the heating rate of 10°C min-1 in an air atmosphere. Fluorescence
measurements were performed on Synergy MX BIOTEK Multimode
Reader. The porphyrin solution prepared in CH2Cl2 was 10-6 m.
Biological studies
Antibacterial studies:ꢁQualitative analysis for screening of antimi-
crobial activity of the complexes was carried out by agar well diffu-
sion method with modifications. The complexes were tested against
two Gram positive bacteria (B. subtilis MTCC2389 and S. aureus
MTCC7443) and three Gram negative bacteria (M. luteus MTCC4821, E.
coli MTCC2127 and P. florescens MTCC4828). Twenty milliliters of ster-
ilized nutrient agar were inoculated with 100 mL of bacterial suspen-
sion (108 CFU mL-1) and then poured on to sterilized petri plate. The
agar plate was left to solidify at room temperature. A well of 6 mm was
aseptically bored into the agar plate. Then 20 mL of the complexes
(diluted with DMSO, 1:1) was added in each well. Chloremphenicol
(10 μg) was used as a positive reference to determine the sensitivity
of bacteria. The plates were kept at 4°C for 2 h to allow the dispersal
and then incubated at 37°C for 24 h.
Synthesis of aquo-meso-(5,10,15,
20-tetraarylporphyrinato)thallium(III)
hydroxide, [(OH)(H O)Tltpp and (OH)(H2O)
Tlt(4-Y)PP] (Y: -CH32, -OCH3)
In vitro cytotoxicity against human cancer cell lines
Cell lines and cell cultures:ꢁThe human prostrate (PC-3), lung
(A-549) and acute lymphoblastic leukemia (THP-1) cell lines were
grown and maintained in RPMI-1640 medium, pH 7.4, whereas DMEM
was used for breast (MCF-7). The media were supplemented with FCS
(10%), penicillin (100 units mL-1), streptomycin (100 μg mL-1) and
glutamine (2 mm), and cells were grown in CO2 incubator (Heraeus,
GmbH, Germany) at 37°C with 90% humidity and 5% CO2. Cells were
treated with samples dissolved in DMSO, while the untreated control
cultures received only the vehicle (DMSO, ꢀ<ꢀ0.2%).
A mixture of meso-tetraphenylporphyrins 0.0068 mmol in
CH2Cl2 (10 mL) and Tl(OAC)3 0.12 mmol in MeOH (2.5 mL)
was refluxed for 1 h. After concentration, the residue
was dissolved in CHCl3, dried with anhydrous Na2SO4
and filtered. The filtrate was concentrated and recrystal-
lized from CH2Cl2-MeOH (1:5 v/v) yielding purple solid of
complex, (0.037 mmol, 55%), which was again dissolved
in CH2Cl2-ether [1:1 (v/v)] and layered with MeOH to get
purple crystals of thallium(III) porphyrins (Scheme 1).
Cytotoxicity assay
In vitro cytotoxicity against human cancer cell lines was determined
using sulphorhodamine B dye assay (Thiantanawat et al., 2003;
Tong et al., 2004). Both test sample stock solutions were prepared
in DMSO and serially diluted with growth medium to obtain desired
concentrations.
Synthesis of axially ligated Tl(III) Porphyrins:
Tlt(4-Y)PP, SA and Tlt(4-Y)PP, 5-SSA
(OH)(H2O)Tl(III)t(4-Y)PP 0.15 mmol in 30 mL CHCl3 was
treated with respective salicylates 0.56 mmol in 25 mL
CH3OH and stirred under reflux for 12 h. After concen-
tration, the mixture was dissolved in minimum quantity
of CH2Cl2 and extracted four times with distilled water
to remove excess unreacted salicylates (SA, 5-SSA). The
resulting solution was then filtered through anhydrous
Na2SO4 in order to remove water molecule. The CH2Cl2
Synthesis of axially ligated
thallium(III) porphyrin complexes
Synthesis of macrocycles
H2tPP and H2t(4-Y)TPP (Yꢀ=ꢀ-CH3 and -OCH3) were synthe- layer was then concentrated to dryness, producing
sized. The synthesis of the porphyrins has been adapted purple prism. The same procedure was applied for the
Unauthenticated
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ꢀꢀꢀꢁ
28ꢀ ꢀG.D. Bajju et al.: Porphyrin-like tetrapyrrolic macrocycles
Scheme 1:ꢀSynthesis of meso-tetraphenylporphyrins and their corresponding metalated and axially ligated derivatives.
Fadda, A. A.; El-Mekawy, R. E.; El-Shafei, A.; Freeman, H. S.;
Hinks, D.; El-Fedawy, M. Design, synthesis, and pharmacological
screening of novel porphyrin derivatives. J. Chem. 2013,
2013, 11.
Fitzgerald, J. P.; Huffman, P. D.; Brenner, I. A.; Wathen, J. J.;
Beadie, G.; Pong, R. G. S.; Shirk, J. S.; Flom, S. R. Synthesis,
chemical characterization and nonlinear optical properties
of thallium(III) phthalocyanine halide complexes. Opt. Mater.
Express. 2015, 5, 19.
synthesis of all axially ligated complexes of thallium
porphyrins. The overall route for the synthesis of axially
ligated thallium (III) porphyrin complexes is given in
Scheme 1.
Acknowledgments: We thank Department of Chemistry
and Department of Biotechnology, University of Jammu,
IIIM Jammu, IISC Banglore, India for providing support.
Horvath, O.; Valicsek, Z.; Vogler, A. Unique photoreactivity of
mercury (II) 5,10,15,20-tetrakis (4-sulfonatophenyl)porphyrins.
Inorg. Chem. Commun. 2004, 7, 854–857.
Horvath, O.; Huszank, R.; Valicsek, Z.; Lendvay, G. Photophysics and
photochemistry of kinetically labile, water-soluble porphyrin
complexes. Coord. Chem. Rev. 2006, 250, 1792–1803.
Karimipour, G.; Karami B.; Montazerozohori M.; Zakavi S.
Oxidative decarboxylation of carboxylic acids with
tetrabutylammonium periodate catalyzed by manganese
(III) meso-tetraarylporphyrins: effect of metals, meso-
substituents, and anionic axial ligands. Chinese J. Catal.
2007, 28, 940–946.
Karimipour, G.; Ghaedi, M.; Behfar, M.; Andikaey, Z.; Kowkabi, S.;
Orojloo, A. H. Synthesis and application of new porphyrin
derivatives for preparation of copper selective electrodes:
influence of carbon nanotube on their responses. IEEE Sens. J.
2012, 12, 2638–2647.
Karimipour, G.; Rezaei M.; Ashouri D. Zeolite encapsulated
Fe-porphyrin for catalytic oxidation with iodobenzene diacetate
(PhI(OAc)2). J. Mex. Chem. Soc. 2013, 57, 276–282.
Knöra, G.; Strasser, A. Coexisting intraligand fluorescence and
phosphorescence of hafnium(IV) and thorium(IV) porphyrin com-
plexes in solution. Inorg. Chem. Commun. 2002, 5, 993–995.
References
Adler, A. D.; Longo, F. R.; Finarelli, J. D.; Goldmacher, J.; Assour, J.;
Korsakoff, L. A simplified synthesis for meso-tetraphenylpor-
phine. J. Org. Chem. 1967, 32, 476–476.
Antonova, N. A.; Osipova, V. P.; Kolyada, M. N.; Movchan, N. O.;
Milaeva, E. R.; Pimenov, Y. T. Study of the antioxidant properties
of porphyrins and their complexes with metals. Macroheterocy-
cles 2010, 3, 139–144.
Cosma, F. G.; Badea, V.; Vlascici, D.; Cosma, F.-E.; Simon, M. The
13th Symposium on Analytical and Environmental Problems,
Szeged. 2006, 84–87.
Cosma, E. F.; Mirica, M. C.; Balcu, I.; Bucovicean, C.; Cretu, C.;
Armeanu, I.; Cosma, G. F. Syntheses, spectroscopic and AFM
characterization of some manganese porphyrins and their
hybrid silica nanomaterials. Molecules 2009, 14, 1370–1388.
Drain, C. M.; Hupp, J. T.; Suslick, K. S.; Wasielewski, M. R.; Chen, X.
A perspective on four new porphyrin-based functional materials
and devices. J. Porphy. Phthal. 2002, 6, 243–258.
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G.D. Bajju et al.: Porphyrin-like tetrapyrrolic macrocyclesꢃ
ꢃ29
Lu, Y. Y.; Tung, J. Y.; Chen, J. H.; Liao, F. L.; Wang, S. L.; Wang, S. S.;
Hwang, L. P. Salicylate exchange in meso-tetraphenylporphyri-
nato salicylato thallium (III), Tl (tpp) (2-OH-C6H4CO2) and 13C NMR
investigation of its homolog thiocyanato (meso-tetra-p-tolyl-
porphyrinato)thallium(III), Tl (tptp)(SCN). Polyhedron. 1999, 1,
145–150.
Ma, G.; Fischer, A.; Ilyukhin, A.; Glaser, J. Formation and structure of
novel ternary complexes of thallium(III)-cyanide–amine (ethyl-
enediamine and triethylenetetramine) in solution and in solid.
Inorg. Chim. Acta. 2003, 344, 117–122.
Suen, S. C.; Lee, W. B.; Hong, F. E.; Jong, T. T.; Chen, J. H. Molecular
structure of thallium (III) meso-tetraphenylporphyrin acetate
Tltpp(OAc). Polyhedron. 1992, 11, 3025–3030.
Sun, Z.-C.; She, Y.-B.; Zhou, Y.; Song, X.-F.; Li, K. Synthesis,
characterization and spectral properties of substituted
tetraphenylporphyrin iron chloride complexes. Molecules.
2011, 16, 2960–2970.
Thiantanawat, A.; Long, B. J.; Bordie, A. M. Signaling pathways of
apoptosis activated by aromatase inhibitors and antiestrogens.
Cancer Res. 2003, 63, 8037–8050.
Manke, A. M.; Geisel, K.; Fetzer, A.; Kurz, P. A water-soluble
tin(IV) porphyrin as a bioinspired photosensitiser for light-
driven proton-reduction. Phys. Chem. Chem. Phys. 2014, 16,
12029–12042.
Milgrom, L. R. The Colors of Life, an Introduction to the Chemistry
of Porphyrins and Related Compounds. Oxford University Press:
Oxford, 1997.
Musturappa, P. K.; Reddy, V. K. R.; Kotresh, H. M. N.; Basappa, C.;
Jayanna, M. B.; Devendrachari, M. C.; Fasiulla. New metalloph-
thalocyanines posture pyridine pendants via 1,3,4-oxadiazole
bridge: synthesis, optical and electrical studies. Chem. Sci. J.
2013, 2013, 11.
Overton CE. Studien uber die Narkose zugleich ein Beitrag zur
allgemeinen Pharmakology. Gustav Fisher, Jena: Switzerland,
1901.
Rajesh, K.; Rahiman, A. K.; Bharathi, K. S.; Sreedaran, S.; Gan-
gadevi, V.; Narayanan, V. Spectroscopic, redox and biological
studies of push-pull porphyrins and their metal complexes. B.
Kor. Chem. Soc. 2010, 31, 2656–2664.
Stojiljkovic, I.; Evavold, B. D.; Kumar, V. Antimicrobial properties of
porphyrins. Expert Opin. Invest. Drugs. 2001, 10, 309–320.
Tong, X.; Lin, S.; Fujii, M.; Hou, D. X. Erratum to Echinocystic
acid induces apoptosis in HL-60 cells through mitochondria-
mediated death pathway. Cancer Lett. 2004, 212, 21–32.
Tweedy, B. G. Plant extracts with metal ions as potential antimicro-
bial agents. Phytopathology. 1964, 55, 910–917.
Valicsek, Z.; Horvath O.; Stevenson, K. L. Photophysics and
photochemistry of water-soluble, sitting-atop bis-thallium(I)
5,10,15,20-tetrakis(4-sulfonatophenyl)porphyrin. Photochem.
Photobiol. Sci. 2004, 3, 669–673.
Valicsek, Z.; Horvath, O.; Lendvay, G.; Kikas, I.; Skoric, I. Formation,
photophysics, and photochemistry of cadmium(II) complexes
with 5,10,15,20-tetrakis(4-sulfonatophenyl) porphyrin and its
octabromo derivative: The effects of bromination and the axial
hydroxo ligand. J. Photoch. Photobio. A. 2011, 218, 143–155.
Yuasa, M.; Oyaizu, K.; Murata, H.; Sahara, Y.; Hatsugai, T.; Ogata, A.
Antioxidant and anticancer properties of metalloporphyrins
embedded in liposomes. J. Oleo Sci. 2007, 56, 87–93.
Zhuang, C.; Tang, X.; Wang, D.; Xia, A.; Lian, W.; Shi, Y.; Shi, T. An
unsymmetrical porphyrin and its metal complexes: synthesis,
spectroscopy, thermal analysis and liquid crystal properties.
J. Serb. Chem. Soc. 2009, 74, 10.
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