Synthesis and spectroscopic properties of a series of metal-free and metallo-phthalocyanines substituted with 8-quinolinoxy moieties

Article abstract of DOI:10.3184/174751911X12970818575209

Peripherally tetraquinolinoxy-substituted, metal-free phthalocyanines and metallo-phthalocyanines 1c-f, 2c-f have been synthesised by reaction of an inorganic salt with phthalonitriles substituted with 5-(phenylamino)methyl-8- quinolinoxy and 5-[(4-chloro

Full text of DOI:10.3184/174751911X12970818575209

JOURNAL OF CHEMICAL RESEARCH 2011
RESEARCH PAPER 135
MARCH, 135–139
Synthesis and spectroscopic properties of a series of metal-free and
metallo-phthalocyanines substituted with 8-quinolinoxy moieties
Wei-Li Li, Ji-Cheng Ma, Wen-Ju Li, Qiang Fu* and Kun Wang
Faculty of Chemistry; N,ortheast Normal University, Changchun 130024, P. R. China
Peripherally tetraquinolinoxy-substituted, metal-free phthalocyanines and metallo-phthalocyanines 1c–f, 2c–f have
been synthesised by reaction of an inorganic salt with phthalonitriles substituted with 5-(phenylamino)methyl-
8-quinolinoxy and 5-[(4-chlorophenylamino)methyl]-8-quinolinoxy groups, respectively. The effects of metal ions
[Zn(II), Cu(II), Co(II); N,i(II)], substituent, solvent and concentration on the UV-Vis spectra of these new complexes
and their fluorescent properties are also described. The diamagnetic Zn(II) and Ni(II) complexes display intense
fluorescence.
Keywords: phthalocyanines, synthesis, 8-quinolinoxy, UV–Vis, fluorescence
Phthalocyanines (Pcs), which are capable of including more
than 70 metallic and non-metallic ions in the ring cavity,1 have
attracted considerable interest for many decades because of
their remarkable electronic and optical properties. These prop-
erties make them suitable for a wide range of applications.
Phthalocyanines are used not only as classical dyes in practical
use but also as modern functional materials in scientific
research.2,3 Current research on phthalocyanines has expanded
into several new applied fields including photovoltaics,
electrochromism, optical data storage, laser dyes and liquid
crystals, as well as chemical sensors and photosensitisers for
photodynamic therapy.4–9 However, due to the intermolecular
interactions between the macrocycles, peripherally unsubsti-
tuted metal Pcs are practically insoluble in common organic
solvents, thereby minimising their applications. The synthesis
of soluble Pcs derivatives is important for solving this prob-
lem. Several synthetic strategies have been designed: one of
the principal strategies for the molecular design and control of
properties of phthalocyanines involves ring substitution on the
peripheral and non-peripheral positions of the phthalocyanine
ring, the other way is to introduce a different kind of transition
metal to the central cavity.10,11 In such a system, the metal in
the central macrocyclic cavity and periphery can be chosen
independently and special physical properties are introduced
that are not observed in the phthalocyanine or metal fragment
alone. So far, many novel substituted metal phthalocyanines
have been synthesised using these strategies.12–17 The family of
reactive phthalocyanine molecules has been an interesting
target for the development of further chemical reactions with
phthalocyanine complexes.18 Designed peripheral moieties on
the phthalocyanines bearing heteroatoms (N, O, S) are used
to confer solubility.19–22 Notably, 8-quinolinol (8-QH) groups
are especially useful to achieve solubility in most common
solvents.23,24 In addition, 8-QH is an electroluminescent mate-
rial, thus the periphery of a phthalocyanine subsituted by 8-QH
should show better optical properties.
containing 5-(phenylamino)methyl-8-quinolinoxy or 5-[(4-
chlorophenylamino)methyl]-8-quinolinoxy groups on the
periphery positions using a liquid state method, and investi-
gated their properties.
Experimental
5-(Phenylamino)methyl-8-quinolinol and 5-[(4-chlorophenylamino)
methyl]-8 -quinolinol were prepared according to the literature.29 All
other reagents and solvents were commercially available and used
without further purification. IR spectra were recorded on a Magna 560
FT-IR spectrophotometer using KBr pellets. The UV spectra were
performed on a Cary 500 UV-Vis–NIR spectrophotometer. MS spec-
tra were recorded on an LDI-1700 MALDI-TOF mass spectrometer.
1H NMR spectra were recorded on a Varian XL-500 NMR spe-
ctrometer in DMSO-d6. Elemental analyses were determined on a
Perkin-Elmer 2400 CHN elemental analyser. Fluorescent spectra were
measured on a Cary Eclipse fluorimeter.
4-(5-(Phenylamino)methyl-8-quinolinoxy)phthalonitrile (1a): Com-
pounds 1a and 2a were prepared in the same way; 1a is taken as
example. 5-Phenylaminomethyl-8-quinolinol (0.01 mol, 2.50 g) and
4-nitrophthalonitrile (0.01 mol, 1.73 g) were dissolved in DMSO
(30 mL). After stirring for 15 min, finely powdered LiOH (0.02 mol,
0.38 g) was added in portions during 2 h with efficient stirring.
The reaction mixture was stirred at room temperature for 3 days, then
the solution was poured into cool water (400 mL). The resulting
precipitate was collected by filtration and washed by water, dried
and recrystallised from ethanol to give a brick red solid 1a. Yield:
90%. m.p. > 250 °C; IR (KBr), υ /cm−1: 3043 (ArH), 2231 (C≡N),
1249 (C–O–C). 1H NMR (500 MHz, DMSO-d6) (δ: ppm): 8.83–8.69
(m, 2H, ArH), 8.00–6.27 (m, 11H, ArH), 4.74–4.76 (d, 2H, J = 5.0,
–CH2), 4.57 (m, 1H; N,–H). Elemental anal. Calcd for C24H16N4O
(M = 376.13): C, 76.58; H, 4.28; N, 14.88. Found: C, 76.43; H, 4.25;
N, 14.96%.
4-(5-[(4-chlorophenylamino)methyl]-8-quinolinoxy)phthalonitrile
(2a):Yield: 86%. m.p. > 250 °C; IR (KBr), υ /cm−1: 3041 (ArH), 2229
1
(C≡N), 1247 (C–O–C). H NMR (500 MHz, DMSO-d6) (δ: ppm):
8.86–8.87 (dd, 2H, J = 1.5, J = 1.5, ArH), 7.71–6.50 (m, 10H, ArH),
5.23 (t, 1H; N,–H), 4.76–4.75 (d, 2H, J = 5.0, –CH2); Elemental anal.
Calcd for C24H15ClN4O (M = 410.09): C, 70.16; H, 3.68; N, 13.64.
Found: C, 70.33; H, 3.58; N, 13.55%.
Phthalocyanines are usually prepared by a high-temperature
cyclotetramerisation processes of either phthalonitrile (liquid
state method), phthalic anhydride (solid state method) and
microwave-assisted methods,25–27 in which the template effect
afforded by a suitable metal cation is required. The reactions
can be carried out in variety of solvents in the liquid state as
well as under solvent-free conditions, but the second processes
require temperature above 200 °C and difficult purification
procedures.28 The microwave-assisted method is a new syn-
thetic method with short time and high yield characteristics,
but is not conducive to mass production and lacks controllabil-
ity, reproducibility and safety aspects. We now describe
the synthesis of a series of new phthalocyanine compounds
Syntheses of 2,9,16,23-tetrakis(5-(phenylamino)methyl-8-quinoli-
noxy)-phthalocyanine (1b): Lithium metal (10 mmol, 0.08 g) was
dissolved in 1-pentanol (30 mL) at 80 °C and then compound 1a
(1.8 mmol, 0.32 g) was added. The reaction mixture was heated to
135 °C and refluxed under N2 for 5 h then the dark blue solution was
allowed to cool to room temperature. A mixture of ethanol (20 mL)
and glacial acetic acid (20 mL) was added. The resulting suspension
was allowed to stand for 12 h, then the dark green product was filtered
off and washed several times with ethanol to dissolve any unreacted
precursor. The green product (1b) was dried under vacuum and puri-
fied by column chromatography (silica gel, CHCl3), Compound 1b:
Yield: 49%. m.p. > 250 °C; IR (KBr), υ /cm−1: 3406 (–NH), 2926
(alkyl CH2), 1324 (C–N), 1250, 1088 (C–O–C). 1H NMR (500 MHz,
DMSO-d6), (δ: ppm): 8.98–8.50 (m, 8H, ArH), 7.81–6.29 (m, 46H,
ArH), 4.79–4.84 (m, 4H, –NH–CH2), 4.73 (d, 8H, –CH2); UV-Vis
λmax (nm) in DMF: 612, 680; Elemental anal. Calcd for C96H66N16O4
* Correspondent. E-mail: fqiang@nenu.edu.cn

136 JOURNAL OF CHEMICAL RESEARCH 2011
(M = 1506.55): C, 76.48; H, 4.41; N, 14.86. Found: C, 76.43; H, 4.46;
N, 14.93%.
(nm) in DMF: 669. Elemental anal. Calcd for C96H60N16Cl4O4Co (M =
1699.31): C, 67.73; H, 3.55; N, 13.16. Found: C, 67.75; H, 3.58;
N, 13.23%.
Synthesis of 2,9,16,23-tetrakis(5-(phenylamino)methyl-8-quinoli-
noxy)-phthalocyaninatonickel(II) (1f) and 2,9,16,23-tetrakis(5-[(4-
chlorophenylamino)methyl]-8-quinolinoxy)-phthalocyaninatonickel
(II)(2f)
The preparation of compound 1f was similar to that of compound
1c, in which compound 1a (1.80 mmol, 0.32 g); NiCl2•6H2O
(0.60 mmol, 0.15 g) and DBU (0.55 mL) were selected as the reac-
tants. The preparation of compound 2f was similar to that of
compound 1f, in which compound 2a (1.81 mmol, 0.33 g) was the
reactant.
Syntheses of 2,9,16,23-tetrakis (5-[(4-chlorophenylamino)methyl]-
8-quinolinoxy)-phthalocyanine (2b): The preparation of compound
2b was similar to that of compound 1b, but in which compound 2a
(1.80 mmol, 0.33 g) was the reactant. Compound 2b: Yield: 52%.
m.p. > 250 °C; IR (KBr), υ /cm−1: 3387 (–NH), 2959–2863 (alkyl-
CH2), 1299 (C–N), 1252, 1093 (C–O–C). 1H NMR (500 MHz, DMSO-
d6) (δ: ppm): 8.82–7.94 (m, 8H, ArH), 7.60–6.46 (m, 42H, ArH), 5.30
(m, 4H, CH2N–H), 4.70 (d, 8H, –CH2); UV-Vis λmax (nm) in DMF:
672, 704; MS (MALDI-TOF): m/z 1647.8 [M+2H]+. Elemental anal.
Calcd for C96H62Cl4N16O4 (M = 1645.44): C, 70.07; H, 3.80; N, 13.62.
Found: C, 70.10; H, 3.72; N, 13.56%.
Syntheses of 2,9,16,23-tetrakis(5-(phenylamino)methyl-8-quinoli-
noxy)-phthalocyaninatozinc(II) (1c) and 2,9,16,23-tetrakis (5-[(4-
chlorophenylamino)methyl]-8-quinolinoxy)-phthalocyaninatozinc(II)
(2c): A mixture of compound 1a (1.80 mmol, 0.32 g), Zn(CH3COO)2•
2H2O (0.30 mmol, 0.066 g) and 1, 8-diazabicyclo[5.4.0]undec-7-ene
(DBU) (0.75 mL) was heated at 135 °C in dry 1-pentanol (20 mL)
with stirring under N2 for 8 h. After cooling to room temperature, the
reaction mixture was treated with ethanol and then filtered off and
washed with water to remove unreacted Zn(CH3COO)2•2H2O. The
obtained product was purified by column chromatography (silica gel,
CHCl3–MeOH, 95:5). The green product (1c) was collected, then
dried under vacuum. The preparation of compound 2c was similar to
that of compound 1c.
1f:Yield: 51%. m.p. > 250 °C; IR (KBr), υ /cm−1: 2927–2856 (alkyl
CH2), 1252 (C–O–C), 1360 (C–N), 741 (M–N). UV-Vis λmax (nm) in
DMF: 676. Elemental anal. Calcd for C96H64N16NiO4 (M = 1562.46):
C, 73.71; H, 4.12; N, 14.33. Found: C, 73.75; H, 4.15; N, 14.30%.
2f:Yield: 49%. m.p. > 250 °C; IR (KBr), υ /cm−1: 2923–2854 (alkyl
CH2), 1254 (C–O–C), 748 (M–N) cm−1. UV-Vis λmax (nm) in DMF:
640, 674. Elemental anal. Calcd for C96H60Cl4N16NiO4 (M = 1698.31):
C, 67.74; H, 3.55; N, 13.17. Found: C, 67.77; H, 3.59; N, 13.20%.
Results and discussion
The synthetic route in this work is shown in Scheme 1. Compounds 1a
and 2a were prepared by the base-catalysed nucleophilic aromatic
nitro-displacement of 4-nitrophthalonitrile in the presence of 5-
(phenylamino)methyl-8-quinolinol and 5-[(4-chlorophenylamino)
methyl]-8-quinolinol. The reaction was carried out in a single step
synthesis by using the LiOH as the nitro-displacing base at room tem-
perature in DMSO.30,31 the Pcs was prepared by cyclotetramerisation
of the phthalonitrile derivatives 1a and 2a in 1-pentanol at refluxing
temperature under N2 in the presence of DBU or lithium metal
catalyst.32 A similar reaction has been effectively used in the prepara-
tion of a variety of ether-or thioether-substituted phthalonitrile
derivatives.2,33–35 The precursors 1a and 2a were purified by recrystal-
lisation, while phthalocyanines required column chromatography.
The yields of tetra-substituted Pcs were satisfactory. The characterisa-
tions of the products included elemental analysis, mass spectrum, IR,
1H NMR, UV-Vis and fluorescent spectra.
1c: Yield: 52%. m.p. > 250 °C; IR (KBr), υ /cm−1: 3645 (–NH),
2924–2850 (alkyl CH2), 1251, 1088 (C–O–C), 1317 (C–N), 749
1
(M–N). H NMR (500 MHz, DMSO-d6) (δ: ppm): 8.88–8.61 (m,
8H, ArH), 7.84–6.26 (m, 44H, ArH), 4.36 (d, 8H, –CH2), 4.71–4.54
(m, 4H, –NH–CH2); UV-Vis, λmax (nm) in DMF: 352, 613, 683. MS
(MALDI-TOF), m/z: 1569.5 [M+H+]. Elemental anal. Calcd for
C96H64N16O4Zn (M = 1568.46): C, 73.39; H, 4.11; N, 14.26. Found:
C, 73.37; H, 4.15; N, 14.35%.
2c: Yield: 50%. m.p. > 250 °C; IR (KBr), υ /cm−1: 2926 (alkyl CH2),
1249, 1091 (C–O–C), 726 (M–N) cm−1. 1H NMR (500 MHz, DMSO-
d6) (δ:ppm): 8.90–8.63 (m, 8H, ArH), 7.86–6.43 (m, 40H, ArH), 4.69
(d, 8H, –CH2), 4.78 (m, 4H, –NH–CH2); UV-Vis λmax (nm) in DMF:
355, 613, 683. MS (MALDI-TOF), m/z: 1708 (M+4H+). Elemental
anal. Calcd for C96H60N16Cl4O4Zn (M = 1704.3): C, 67.48; H, 3.54;
N, 13.11. Found: C, 67.43; H, 3.58; N, 13.15%.
IR, MS, 1H NMR and elemental analysis
Syntheses of 2,9,16,23-tetrakis(5-(phenylamino)methyl-8-quinoli-
noxy)-phthalocyaninatocopper(II) (1d) and 2,9,16,23-tetrakis (5-
[(4-chlorophenylamino)methyl]-8-quinolinoxy)-phthalocyaninatocop
per(II) (2d): The preparation of compound 1d was similar to that of
compound 1c, in which compound 1a (1.90 mmol, 0.40 g), anhydrous
CuCl2•2H2O (0.60 mmol, 0.10 g) and DBU (0.75 mL) were the
reactants. The preparation of compound 2d was similar to that of
compound 1d, in which compound 2a (1.80 mmol, 0.33 g) was
reactant.
Spectral investigations of the newly synthesised intermediates and
phthalocyanines are in accordance with the proposed structures. Com-
parison of the IR spectra of each step offer some information as to the
nature of the products. It is found that the sharp peak for the C≡N
vibrations around 2230 cm−1 are associated with nitrile groups, which
disappeared after phthalocyanine formation. The appearance of new
absorption bands at about 1254 cm−1 and 1092 cm−1 (Ar–O–Ar) for
1b–f and 2b–f clearly indicates that substituents have connected to the
phthalocyanine ring. In order to further confirm the proposed struc-
tures of Pcs, the mass spectrum of representatives 1c, 2b and 2c were
measured. Molecular ion peaks of 1c, 2b and 2c at 1569, 1647.8 and
1707 are observed, respectively, consistent with the proposed struc-
tures. In addition, the 1H NMR spectra of 1a–c and 2a–c display the
characteristic resonances for precursors and Pc; the 1H NMR spectra
of 1a and 2a are almost identical except for a small shift. Taking
compound 1a for example, in its 1H NMR spectrum, the peak at 8.83
can be attributed to the quinoline ring CH=N proton absorption peak,
while the multiple absorption peaks of protons on the benzene ring
are between 8.00 ppm and 6.27 ppm. Furthermore, absorption peaks
at 4.76–4.74 ppm and 4.57 ppm are assigned to methylene and –NH
protons, respectively. 1H NMR spectra of H2Pc and MPc derivatives in
DMSO show that all the substituent and Pc ring protons are observed
in their respective regions. A singlet, assigned to quinoline ring pro-
tons, appears in the range of 8.98–8.50 (integrating for 8 protons) in
the 1H NMR spectra of 1b–2b and 1c–2c. A multiplet, assigned to Pc
aromatic ring protons, appears in the range of 7.81–6.29 (integrating
for 42 protons) in the 1H NMR spectra of 1b–2b and 1c–2c. Compar-
1d: Yield: 59%. m.p. > 250 °C; IR (KBr), υ /cm−1: 3033–2856
(alkyl CH2), 1251 (C–O–C), 1367 (C–N), 734 (M–N). UV-Vis λmax
(nm) in DMF: 678. Elemental anal. Calcd for C96H64N16O4Cu (M =
1567.46): C, 73.48; H, 4.11; N, 14.28. Found: C, 73.69; H, 4.13;
N, 14.36%.
2d:Yield: 59%. m.p. > 250 °C; IR (KBr), υ /cm−1: 2924–2853 (alkyl
CH2), 1248, 1084 (C–O–C), 1370 (C–N), 790 (M–N). UV-Vis λmax
(nm) in DMF: 350, 620, 683. Elemental anal. Calcd for
C96H60N16Cl4O4Cu (M = 1703.3): C, 67.55; H, 3.54; N, 13.13. Found:
C, 67.59; H, 3.51; N, 13.24%.
Synthesis of 2,9,16,23-tetrakis(5-(phenylamino)methyl-8-quinoli-
noxy)-phthalocyaninatocobalt(II) (1e) and 2,9,16,23-tetrakis(5-[(4-
chlorophenylamino)methyl]-8-quinolinoxy)-phthalocyaninatocobalt
(II) (2e)
The preparation of compound 1e was similar to that of 1c, in which
compound 1a (1.80 mmol, 0.32 g), CoCl2•6H2O (0.60 mmol, 0.15 g)
and DBU (0.75 mL) were selected as the reactants. The preparation of
compound 2e was similar to that of compound 1e, in which compound
2a (1.80 mmol, 0.33 g) was the reactant.
1
1e:Yield: 53%. m.p. > 250 °C; IR (KBr), υ /cm−1: 2925–2856 (alkyl
CH2), 1373 (C–N), 1252 (C–O–C), 750 (M–N). UV-Vis λmax (nm) in
DMF: 672. Elemental anal. Calcd for C96H64N16O4Co (M = 1563.46):
C, 73.70; H, 4.12; N, 14.32. Found: C, 73.73; H, 4.11; N, 14.35%.
2e:Yield: 56%. m.p. > 250 °C; IR (KBr), υ /cm−1: 2929–2858 (alkyl
CH2), 1252, 1074 (C–O–C), 1369 (C–N), 789 (M–N). UV-Vis λmax
ing the H NMR spectra of 1c with 1a, the hydrogens around the Pc
ring show similar, poorly resolved wide peaks with the same chemical
shift order. These peaks become wide, which is one of the characteris-
tics of Pc compounds with an M(II) ion at the center of the Pc ring,
and the poor peak split may be ascribed to the limited solubility of 1c.
In addition, the elemental analytical results of the starting materials

JOURNAL OF CHEMICAL RESEARCH 2011 137
Scheme 1 Synthesis of 1b–f, 2b–f.
and phthalocyanines also show good agreement with the calculated
values.
ences UV-Vis absorbance intensity, and at Q-band, the relationship of
λmax intensity and concentration is generally consistent with the Beer-
Lambert law. The concentration dependence of the UV-Vis spectra of
these derivatives is further assessed in order to prove the absence of
aggregation. Although the position of the Q-band of 1c at 683 nm and
612 nm is constant with increasing the concentration, the aggregate
absorption peak becomes stronger with increasing the concentration.
A obvious difference of λmax is observed when the MPc dissolve in
different solvents. As shown in Fig. 2, the λmax of Q band is located at
701 and 688 nm when 2c is dissolved in DMF and CHCl3, respec-
tively. It is suggested that there is interaction between MPc and sol-
vent. On the one hand, the polar of solvents plays an important role for
ground state and excited states of Pc complexes, this may result in a
smaller π–π* energy gap, corresponding to a red shift of λmax. On the
UV-Vis analysis
The Pcs (1b–f and 2b–f) shows two characteristic absorption regions:
one of them is in the UV region at about 300–400 nm (B band) and the
other is in the visible part of the spectra around 600–800 nm (Q band).
In this study, we mainly discuss the impacts of concentration, solvent,
central metal ion and peripheral group on the Q band.
The UV-Vis spectra of 1c and 2c show similar phenomena in their
solutions in DMF at different concentrations, and the UV-Vis spectra
of 1c should give much information. Thus the UV-Vis spectrum of 1c
is selected to account for the impacts of concentration on UV-Vis
absorbance. As shown in Fig. 1, the concentration significantly influ-
Fig. 1 UV-Vis spectra of 1c in DMF at various concentration: 1
= 5 × 10−5 mol L−1, 2 = 2.5 × 10−5 mol L−1, 3 = 1 × 10−5 mol L−1, 4 =
0.2 × 10−5 mol L−1.
Fig. 2 UV-Vis spectra of 2c in DMF (dash line) and CHCl3 (solid
line) Concentration = 1 ×10−5 mol L−1.

138 JOURNAL OF CHEMICAL RESEARCH 2011
The results show that an obvious difference of Q band is observed
between 1c and 2c when the peripheral groups are replaced by 5-
(phenylamino)methyl-8-quinolinoxy and 5-[(4-chlorophenylamino)
methyl]-8-quinolinoxy, respectively. A possible reason is that the
chlorine atoms attract the electron cloud of the conjugated phthalo-
cyanine ring, when the hydrogen atoms on the benzene ring are
substituted by chlorine atoms. The π–π* of the energy gap becomes
narrow with changing the distribution of electron cloud density to
induce the red-shift of Q band.38
Fluorescent characterisation
The emission spectra of 1b–f and 2b–f in DMF were recorded at room
temperature after correcting for self-absorption. The spectra of 2b–f
in DMF show similar phenomena as 1b–f. As shown in Fig. 5. The
metal-free phthalocyanine 1b exhibits two strong emission peaks
located at 475 and 719 nm. The metallo-phthalocyanines 1c–f show
various fluorescent emissions, which can be attributed to two catego-
ries. The fluorescent emissions of 1d and 1e, containing the para-
magnetic Cu(II) and Co(II) atoms, are relatively weak. In contrast, 1c
and 1f, containing the diamagnetic Zn(II) and Ni(II), display intense
fluorescence emission. In particular, 1c presents strong fluorescent
emissions located at 715 and 754 nm. The reason is that no single
electron occupies the central metal ion with a closed-shell electronic
structure, which greatly reduces the role of spin-orbit coupling.
Then, intersystem crossing probability is reduced. As a result, the
probability of fluorescence emission is improved.39 This phenomenon
is in good agreement with reported results.40, 41
Fig. 3 UV-Vis spectra of 1c–f in DMF concentration = 5 × 10−6
mol L−1.
other hand, the coordinating groups of solvent can stabilise the phtha-
locyanine ground state, thus resulting in λmax blue shift. Usually, these
two factors tend to be mixed for polar solvents containing O-or
N-donor groups.36 DMF is a typical strong polarity solvent, which
obviously can cause a λmax red shift; but the weakly coordinated effect
of the DMF molecule through its oxygen atom can only result in
inappreciable blue shift. Thus the mixed effects result in a λmax red
shift to 701 nm. The polarity of CHCl3 is weaker than that of DMF,
Solubility
The substitution of Pcs decreases intermolecular interactions, which
prohibits them forming dimers. Thus, substituents on the periphery of
a Pc significantly enhances its solubility in organic solvents, such as
in pyridine, chloroform, acetone and DMF. On the other hand, based
on our experimental results, the solubility of MPc is also central metal
ion dependent. It is found that H2Pc and ZnPc have better solubility
than the other systems.
corresponding to slight red shift for λmax
.
The UV-Vis spectra of 1c–f are selected to monitor the impact of
the central metal ion on the Q band as shown in Fig. 3. The strong
absorption regions ranging from 672 to 684 nm (Q band) are associ-
ated with the excitation between the HOMO-A1g ground state [(a21u)(π)]
and the degenerate LUMO-[eg(π*)]. The first excited singlet state
has Eu symmetry from the (a11ue1g) configuration. Clearly, when the
Pcs possess the same substituted group [5-(phenylamino)methyl-8-
quinolinoxy], the Q band of the corresponding Pcs varies with the
central metal ion. The peak shift may be attributed to the different
polarisation of central metal ions.37 In general, as the atomic number
of the metal ion increases, a red shift of the absorption peak is
observed, and the order of red shift is Co(II)<Ni(II)<Cu(II)<Zn(II).
The UV-Vis spectra of 2c–f in DMF also show similar phenomena.
Generally, the substituting groups of Pcs can affect the location
of the Q band to some extent, compared with the unsubstituted ones.
In order to investigate the influence of different substituent groups on
the Q band, the UV-Vis spectra of 1c and 2c are summarised in Fig. 4.
Conclusion
In conclusion, a series of novel soluble Pcs, modified by four
8-HQ derivative moieties, has been successfully prepared and
characterised. The UV-Vis spectra of 1–4 reveal some special
properties in terms of the impact of concentration, organic sol-
vent, metal ion and substituent on the Q-bands. It is found that
concentration has a significant influence on the UV-Vis absor-
bance intensity without position changes; oxygen-containing
groups of solvent and phthalocyanine favour coordination,
resulting in λmax red shifts. The red shift of the absorption peak
Fig. 5 Fluorescent emission spectra of 1b–f in DMF with
concentration = 1 × 10−5 mol L−1 and λex = 380 nm.
Fig. 4 UV-Vis spectra of 1c and 2c in DMF Concentration = 1 ×
10−5 mol L−1.

JOURNAL OF CHEMICAL RESEARCH 2011 139
16 M.A. Diaz-Garcia, I. Ledoux, J.A. Duro. T. Torres, F. Agullo-Lopez and
J. Zyss, J. Phys. Chem., 1994, 98, 8761.
17 A. M.Salih, Dyes Pigm., 2008, 79, 247.
18 S.J. Lange, J.W. Sibert and A.G.M. Barrett, Tetrahedron, 2000, 56, 7371.
19 M.N. Yarasir, M. Kandaz, A. Koca and B. Salih, Polyhedron, 2007, 26,
1139.
20 M. Zhao, C. Zhong, C. Stern, A.G.M. Barrett and B.M. Hoffman, Inorg.
Chem., 2004, 43, 3377.
21 S.L.J. Michel, A.G.M. Barrett and B.M. Hoffman, Inorg. Chem., 2003, 42,
814.
22 B. Akkurt and E. Hamuryudan, Dyes Pigm., 2008, 79, 153.
23 SH Wei, JH Zhou, DY Huang, XS Wang, BW Zhang and J Shen,
Dyes Pigm., 2006, 71, 61.
is central metal dependent, the order of red shift is Co(II)<
Ni(II)<Cu(II)<Zn(II). Moreover, the substituent groups of
Pcs can affect the location of the Q band to some extent. The
central metal ions of Pcs significantly influence fluorescent
intensity.
This work was supported by the application foundation of the
Science and Technology office of Jilin Province (China)
(20080901) and the Ministry of Education of China.
Received 13 September 2010; accepted 7 January 2011
Paper 1000351 doi: 10.3184/174751911X12970818575209
Published online: 23 March 2011
24 JP Xue; H,M Hong, SL Cai; H, Liu; N,S Chen and JL Huang, Chin.
J. Inorg. Chem., 2005, 21, 810.
25 M. Özil, E. Ağar, S. Şaşmaz, B. Kahveci; N,. Akdemir and I.E.
Gümrükçüoğlu, Dyes Pigm., 2007, 75, 732.
26 E. Çelenk and H. Kantekin, Dyes Pigm., 2009, 80, 93.
27 S. Kerim, D. İsmail, Ü.Yasemin, E. Mustafa, K. Cihan and S. Kemal,
J. Organomet. Chem., 2007, 692, 5646.
28 N.B. McKeown, Phthalocyanine materials: synthesis, struture, and
function, Cambridge University Press, Cambridge, 1998.
29 H. Takeo; H,. Kazuhisa and O. Kosaburo, Macromol. Chem. Phys., 1994,
195, 2739.
References
1
M. Kandaz, M.N.U. Yaraşir, A. Koca and Ö.B. Bekaroğlu, Polyhedron,
2002, 21, 255.
2
C.C. Leznoff and A.B.P. Lever, Phthalocyanines properties and
applications, VCH Publishers, Cambridge, 1989, 1993 and 1996. vols 1–
4.
3
4
D. Dini, M. Hanack and M. Meneghetti, J. Phys. Chem. B., 2005, 109,
12691.
30 M. Isaacs, M.J. Aguirre, L.A. Toro, M. Costamagna, M. Páez and
J.H. Zagal, Electrochim. Acta, 1998, 43, 1821.
D.M. Guldi, A. Gouloumis, P. Vázquez, t. Torres, V. Georgakilas and
M. Prato, J. Am. Chem. Soc., 2005, 127, 5811.
M. Durmus, S. Yesilot and V. Ahsen; N,ew. J. Chem., 2006, 30, 675.
C. Yu, M.E. El-Khouly, M. Sasaki, Y. Araki and O. Ito, Org. Lett., 2005, 7,
1613.
31 R.D. Gould, Coord. Chem. Rev., 1996, 156, 237.
32 Mei-Jin Lin and Jun-Dong Wang, J. Mol. Struct., 2007, 837, 284.
33 J. Obirai and T. Nyokong, Electrochim. Acta, 2005, 50, 3296.
34 H.Y.Yenilmez, İ. Özçeşmeci, A. İ. Okur and A. Gul, Polyhedron, 2004, 23,
787.
35 B.O. Taofeek, O. Abimbola and N. Tebello, Dyes Pigm., 2009, 82, 422.
36 M. Rodriguez-Morgade, G.D.L. Torre and T. Torres, Design and synthesis
of low-symmetry phthalocyanine and related systems, the porphrin
handbook, 2003. vol. 15, chap. 99.
37 J. Rusanova, M. Pilkington and S. Decurtins, Chem. Commun., 2002, 19,
2236.
38 Yongmao Jin, Xue Mao and Yanbing Yin, Chem. Ind. Times, 2008, 22, 15.
39 Ziyang H, Jiandong H; N,aisheng C and Jinling H, Spectrosc. Spectr. Anal.,
2009, 29, 1354.
5
6
7
S. Makhseed; N,.B. McKeown and K. Msayib, J. Mater. Chem., 2005, 15,
1865.
8
9
E. Hamuryudan, S. Merey and Z.A. Bayir, Dyes Pigm., 2003, 59, 263.
K. Makbule, C. Ali, I. O. Ali, G. Ahmet and B. Ozer, Dyes Pigm., 2000, 45,
9.
10 M. Saad, A. S. Moyyad, S. Jacob and M. Hacene, Tetrahedron Lett., 2009,
50, 165.
11 S. Mukaddes and H. Esin, Dyes Pigm., 2007, 74, 17.
12 Y. Bian, L. Li, J. Dou, D. Cheng, R. Li, C. Ma, D. K. P. Ng; N,. Kobayashi
and J. Jiang, Inorg. Chem., 2004, 43, 7539.
40 D.M. Oliveira, P.P. Macaroff, K.F. Ribeiro, Z.G.M. Lacava, R.B. Azevedo,
E.C.D. Lima, P.C. Morais and A.C. Tedesco, J. Magn. Magn. Mater., 2005,
289, 476.
13 M. Kandaz and Ö. Bekaroglu, J. Porphyrins Phthalocyanines, 1999, 3,
339.
14 S. Merey and Ö. Bekaroglu, J. Chem. Soc. Dalton Trans., 1999, 24, 4503.
15 A.B.P. Lever, S.R. Pickens, P.C. Minor, S. Licoccia, B.S. Ramaswamy and
K. Magnell, J. Am. Chem. Soc., 1981, 103, 6800.
41 A. Majumder, G.M. Rosair, A. Mallick and N. Chattopadhyay, Polyhedron,
2006, 25, 1753.

Copyright of Journal of Chemical Research is the property of Science Reviews 2000 Ltd. and its content may
not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written
permission. However, users may print, download, or email articles for individual use.