Green synthesis and characterization of crystalline zinc phthalocyanine and cobalt phthalocyanine prisms by a simple solvothermal route

Article abstract of DOI:10.1039/c8ce00215k

A facile, environmentally-friendly and low-cost method for one-step synthesis of zinc phthalocyanine (ZnPc) and cobalt phthalocyanine (CoPc) prism-shaped crystals was proposed. The well-defined crystalline prisms (ZnPc, up to 8 mm and CoPc, more than 1 mm) can be grown during a solvothermal process at 160 °C for 6 h. It is noted that ethanol (pentanol or benzyl alcohol) was used as the reaction medium and no surfactants or other chemical additives were used in this preparation. To the best of our knowledge, this is the first report on the green and direct synthesis from simple raw materials to large ZnPc and CoPc crystals with high quality. Compared to the traditional preparation of MPc solids and their re-crystallization purification by using H₂SO₄, our method is very convenient, safe and time-efficient. The complete characterization, including scanning electron microscopy (SEM), transmission electron microscopy (TEM), atomic force microscopy (AFM), single crystal X-ray diffraction, powder X-ray diffraction, and Fourier transform infrared (FT-IR) and Raman spectrometry, was performed to measure the molecular structures, crystal structures, and surface morphologies. The highly predominant crystal face of ZnPc crystals was determined to be (100) and the probable crystal growth mechanism was proposed. Moreover, the thermal and photoelectric measurements of ZnPc and CoPc crystals show their excellent thermal stability and photoelectric transformation performance, respectively.

Full text of DOI:10.1039/c8ce00215k

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Towards design strategies for anion–π interactions in crystal engineering
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Green Synthesis and Characterization of Crystalline Zinc
Phthalocyanine and Cobalt Phthalocyanine Prisms by a Simple
Solvothermal Route
a,
b,
a
c
b
b
Dapeng Li *, Suxiang Ge **, Tianci Yuan , Jingjing Gong , Baojun Huang , Weiwei Tie , Weiwei
He b
a School of Chemistry and Chemical Engineering, Key Laboratory of Micro-Nano Materials for
Energy Storage and Conversion of Henan Province, Xuchang University, Henan 461000, P. R. China
b Institute of Surface Micro and Nano Materials, Key Laboratory of Micro-Nano Materials for Energy
Storage and Conversion of Henan Province, Henan Joint International Research Laboratory of
Nanomaterials for Energy and Catalysis, Xuchang University, Henan 461000, P. R. China
c School of Chemistry, The University of Edinburgh, Scotland, eh9 3fj, The United Kingdom of Great
Britain and Northern Ireland
Abstract
A facile, environment-friendly and low-cost method for one step synthesis of zinc phthalocyanine
(ZnPc) and cobalt phthalocyanine (CoPc) prism-shaped crystals was proposed. The well-defined
crystalline prisms (ZnPc, up to 8 mm and CoPc, more than 1 mm) can be grown during a solvothermal
o
process at 160 C for 6 h. It is noted that the ethanol (pentanol or benzyl alcohol) was used as reaction
medium and none of surfactants or other chemical additives was used in this preparation. To the best
of our knowledge, this is the first report on the green and direct synthesis from simple raw materials to
large ZnPc and CoPc crystals with high quality. Compared to the traditional preparation of MPc solids
and their re-crystallization purification by using H
2
SO , our method is very convenient, safe and
4
time-efficient. The complete characterizations, including scanning electron microscopy (SEM),
transmission electron microscope (TEM), atomic force microscopy (AFM), X-ray single crystal
diffractometor, X-ray powder diffractometor, Fourier transform infrared (FT-IR) and Raman
spectrometers were performed to measure the molecule structures, crystal structures, and surface
morphologies. The highly predominant crystal face of (100) for ZnPc crystals was determined and the
probable crystal growth mechanism was proposed. Moreover, the thermal and photoelectric
measurements of ZnPc and CoPc crystals show the excellent thermal stability and photoelectric
transformation performance, respectively.
Corresponding authors:
*e-mail: lidapengabc@126.com (Dapeng Li); **e-mail: 365063148@qq.com (Suxiang Ge)
1

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1
. Introduction
Since metal phthalocyanine (MPc) complexes were found for the first time in the 1930’s, they had
drawn considerable attentions for their bright color, stable physical and chemical properties, and low
cost of production. Besides the traditional dye and pigment applications, versatile functions of MPc
complexes have been explored in recent years, such as microelectronics,1-3 chemical sensors,4,5
6
7,8
9
single-crystal field-effect transistors, electrochromic devices, information storage, liquid-crystal
color display,10,11 and photocatalysis,12-14 and so on. Meanwhile, plenty of structural dates for more
than ten thousands of MPc complexes have been reported. Despite of the remarkable progress, the
synthesis method of some simplest MPcs, i.e., unsubstituted MPcs, especially their single crystals, has
still been followed with interest.
Single crystals of MPc are significant and practical materials for structure determination and
device construction. Therefore, seeking for appropriate methods, especially the environment-friendly,
low cost, and convenient ones to prepare and purify large MPc crystals is a mater of great concern.
Thus, the re-crystallization method is not appropriate because the concentrated H
2
SO is often used
4
for the dissolution of MPc. According to the recent literatures, vapor phase technologies are common
and preferred for the physical preparation of most MPcs single crystals.15,16 Jiang reported the growth
of millimeter-sized needle-shaped crystals of copper phthalocyanine (CuPc) and zinc phthalocyanine
6
(
ZnPc) by a physical vapor transport method. Laudise introduced the physical vapor growth method
of crystalline CuPc needles with the length up to 5 mm.17 Although the MPc crystals with the
considerable size and well-defined crystal planes could be obtained by above methods, the quartz tube
furnace with the rigid conditions of high temperature and low pressure were necessary for MPc crystal
growth. Furthermore, the raw materials must be the ready-made MPc powders. Recently, Du’s group
found crystalline millimeter-sized CuPc needles could be produced by two routes, one is the
1
8
19
exaltation-evaporation growth method and the other is the solvothermal technology . It is noted that
the crystalline CuPc needles with maximum length exceeding 10 mm could be directly obtained with
1
,3-diiminoisoindoline and copper acetate as the raw materials in a solvothemal process.19
o
Unfortunately, the harmful quinoline solvent and high reaction temperature of 270 C are necessary
for the synthesis mentioned above. Fu’s group synthesized the ZnPc complexes by the solvothermal
reaction for 3 days and the Soxhlet extract and re-crystallization from N,N-dimethylformamide were
2
0
needed to grow crystals. Later in 2010, Shao’s group presented the ZnPc microcrystals prepared by
2

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solvothermal method with ammonium molybdate ((NH
4
)
2
MoO
4
) as the catalyst and ethylene glycol as
2
1
the solvent. However, the size of as-prepared ZnPc crystals has not yet achieved to the millimeter
level. Very recently, our group found that the big single crystals of manganese phthalocyanine (MnPc)
2
2
up to 10 mm and millimeter-sized CuPc single crystals can be prepared via one-step solvothermal
2
3
reaction . Importantly, these two MPc crystals with well-defined shapes could be obtained just within
h in ethanol medium, none of surfactants and chemical additives was needed. Though the
3
solvothermal strategies for preparing MPc single crystals have been proved, very few kinds of MPc
crystals could be synthesized successfully in one step. Moreover, some harmful solvents and much
high reaction temperature were necessary for the preparation and purification of MPc single crystals.
Therefore, the expanding ethanol-mediated solvothermal approach for preparing MPc single crystals
is more attractive to material scientists.
In this paper, a green, low-cost, and facile solvothermal strategy for synthesis of large ZnPc single
crystals (≥8 mm) and cobalt phthalocyanine (CoPc) single crystals (≥1 mm) was presented for the first
time. It is noted that the ZnPc micro-scaled crystals prepared by the solvothermal method have been
reported,21 while the quantity of the large ZnPc crystals prepared by our one-step method is much
excellent. Herein, we successfully prepared ZnPc and CoPc single crystals with considerable size in
ethanol medium via the solvothermal process. Our investigation aims at the synthesis and
characterization of ZnPc and CoPc crystals and presents the fundamental data on their chemical
structures and physical properties. The complete characterizations, including X-ray single crystal and
powder diffraction, optical microscope, SEM, TEM, AFM, Fourier transform infrared (FT-IR)
spectrometer, Raman spectroscopy, thermogravimetry and differential scanning calorimetry (TG-DSC)
and the transient photovoltage curve (TPV) measurement were performed for ZnPc and CoPc prism
crystals, and the possible growth mechanism of ZnPc single crystals was proposed.
2
. Experimental section
2.1 Chemicals
O-phthalodinitrile (>99%) was purchased from Shanghai D&B Chemicals Technology Co., Ltd. Zinc
acetate and cobalt acetate were AR grade and purchased from Sinopharm Chemcial Reagent Co., Ltd.
2
.2 Typical synthesis procedure of ZnPc and CoPc crystals
In a typical synthesis of ZnPc crystals, 6 mmol of o-phthalodinitrile, 1.5 mmol of zinc acetate, and 30
mL of absolute ethanol were added into a 50 mL Teflon-lined stainless steel autoclave. Then the
3

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o
autoclave was placed into a programmed oven with setting temperature of 160 C for 6 h. After natural
cooling to room temperature, the large purple crystals were taken out from the bottom of autoclave
and placed into a Busher funnel washing with hot ethanol and deionized water. Finally, the ZnPc
o
crystals were dried at 100 C in an oven overnight for characterization. For the synthesis of CoPc
crystals, cobalt acetate was used instead of zinc acetate and the experimental operation is same to that
of ZnPc synthesis.
2
.3 Characterization
The optical images of MPc crystals were recorded on an Olympus SZX7 stereoscopic microscope.
FT-IR spectrum was performed on a Thermo Nicolet Nexus FT-IR spectrometer with the standard
KBr pellet method. Raman spectrum was performed on a Renishaw inVia Raman spectrometer. A
Zeiss EVO LS-15 scanning electron microscopy (SEM), JEM-2100 (HR) transmission electron
microscope (TEM) and AFM (DI Nanoscope IV instrument, Veeco) were used to observe the
morphologies of MPc crystals. X-ray diffraction (XRD) patterns were investigated using a Bruker D8
ADVANCE X-ray powder diffractometer with Cu Kα radiation. The molecule structure and
crystal-packing diagram were investigated by an X-ray single crystal diffractometor of Bruker
SMART APEX CCD. Thermogravimetry and differential scanning calorimetry (TG-DSC) were
carried out by using a Netzsch STA 409PC thermal analyzer in synthetic air at a heating rate of
10 °C/min. Transient photovoltage (TPV) curve measurement was performed as the following steps: a
sample chamber like a parallel-plate sandwich-like capacitor consisted of a film of ITO, Mica spacer,
and layer of ZnPc (or CoPc) crystals on the Cu foil substrate from top to bottom in sequence. An
ultrafast laser pulse (λ=355 nm and a pulse width of 4 ns) through a third-harmonic Nd:YAG laser
(
Quantel Brilliant Eazy: BRILEZ/IR-10) was employed as the light source. The transient surface
photovoltage data was recorded by a 500 MHz digital oscilloscope (TDS 3054C, Tektronix).
3
. Results and discussion
3.1 The shapes and morphologies of ZnPc and CoPc crystals
Fig. 1a and b record the optical micrographs of ZnPc crystals grown in the solvothermal process at
o
1
60 C for 6 h with absolute ethanol as reaction medium. It is obvious that the as-prepared ZnPc
crystals show the long prism-like shapes and different lengths in Fig. 1a, and some of them exceed 2
o
mm (Fig. 1b). For the growth of larger crystals, different reaction temperature of 160-200 C and
reaction time from 1 to 12 h were tested and the as-prepared ZnPc crystals have no appreciable shape
4

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changes. Thus, other alcohol solvent was employed as the reaction medium instead of ethanol. Since
-pentanol is the common solvent for reflux synthesis of various MPc compounds,24,25 the
1
solvothermal treatment with 1-pentanol as medium was tried. Fig. 1c and d show the crystalline ZnPc
needles with higher draw ratio. Their average length is longer than that from ethanol system and most
of them lie in the range of 1-3 mm. Besides, benzyl alcohol was utilized as reaction medium to
observe the crystal growth. From Fig. 1e and f, the large crystalline needles with smooth crystal faces
were produced and their lengths exceed to 8 mm. In addition, we found that the as-synthesized ZnPc
crystals show much brighter purple than those from ethanol and 1-pentanol systems. For CoPc crystals,
the same synthesis strategy was carried out. The optical images for CoPc crystals obtained from
ethanol, 1-pentanol and benzyl alcohol system are depicted in Fig. 2 a, b and c, respectively. We find
that all the CoPc crystals are thin needles and their maximum lengths are more than 1 mm. The CoPc
needles obtained from ethanol system show the brightest purple among them.
Based on the comparison of these needles synthesized by using the three kinds of alcohol solvent,
we found that the same kind of crystals exhibited the distinguishing purple surfaces. Therefore, the
SEM analysis is carried out to determine the microstructures. From Fig. 3a, the ZnPc crystals from
benzyl alcohol system show the smooth surface with some multilayer plates on it, and this feature is
further verified by the high magnified image in Fig. 3b. Besides, the quadrangular shape of ZnPc
crystals was proved by the TEM observation (Fig. 3c). Distinctly different from the growth of ZnPc
crystals in benzyl alcohol, the whole surfaces of quadrangular prisms from 1-pentanol system are
coarse (Fig. 3d and e) and plenty of nanosheets array crisscrossing on the outside surfaces. The
detailed SEM morphologies of these nanosheets show the shape similar to slightly curly discs with the
thickness less than 100 nm (Fig. 3f and g). Additionally, the observed secondary structures on prism
2
1
surfaces are somewhat similar to the reported results. Interestingly, the ZnPc crystals obtained from
ethanol system also exhibit the quadrangular contour (Fig. 3h) with a great quantity of nanorods
distributing perpendicularly on their surfaces (Fig. 3i). Herein, the three kinds of crystalline ZnPc
needles show the similar quadrangular shape but with the distinct secondary structures, which could
inevitably influence the natural light reflection on their surfaces. It is known that the intense reflection
of light results from the large and smooth surface of crystals, therefore, the largest ZnPc crystals
grown in benzyl alcohol show the bright purple among them. The morphologies of CoPc crystals were
also studied by SEM and TEM measurement. Similarly, the CoPc crystals grown from benzyl alcohol
and 1-pentanol system exhibit the hierarchical nanostructure on their surface. Especially, the shape of
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CoPc crystals from benzyl alcohol system is not regular (Fig. 4a and b) and there are densely
populated nanoplates standing on the surface of some big crystals (Fig. 4c). In addition, the CoPc
crystals grown from 1-pentanol solvent show the cylindrical shape (Fig. 4d and e) with the
complicated crossing channel-like structures on their surfaces (Fig. 4f). Differently, the CoPc crystals
obtained from ethanol have the regular quadrangular shape with smooth surfaces, and no binary
structures could be observed (Fig. 4g-i). Therefore, the flat and smooth surfaces of CoPc crystals
would be beneficial to the reflection of natural light, which is coincident with the results of Fig. 2. It is
noted that if the alcohol solvent was replaced by furanidine, pyridine, acetonitrile, or deionized water,
none of MPc products could be obtained. Therefore, the alcohol solvents play the special role in the
formation of MPc complexes and their crystallization processes. Under current synthesis conditions,
three different alcohols were used as the reaction medium. Since their dissolution ability towards the
reagents and dissociation performance (producing alkoxy anion and proton)23 are different, the
distinguishing shapes and surface morphologies of MPc crystals should be closely related to these
properties.
3
.2 The crystal structure of ZnPc and CoPc
The crystal phase structures were studied by powder XRD technology. As can be seen in Fig. 5a, the
diffraction peak with the overwhelming intensity show the dominant growth orientation of (100) and
all the diffractions including the weak ones are well assigned to monoclinic C32
H
16
N
8
Zn (JCPDS No.
o
1
1-714). According to the intensity ratio of two peaks in the low angular range of 5-10 , the as
resulted ZnPc crystals belong to α crystalline form.26 Differently, the CoPc crystals show that the
predominant growth orientates the direction of (102) plane and its diffraction intensity is 2.5 times
higher than that of (100) plane (Fig. 5b). All the diffractions could be matched well with
β-C32H
16
N Co (JCPDS No. 14-948). Moreover, the large ZnPc crystals were further determined by the
8
X-ray single-crystal diffraction. From Fig. 6a, it is clear that the central Zn ion is four-coordinated by
adjacent nitrogen atoms in Pc framework. Compared to the reported Zn–N bond length of 1.979 Å,27
i
our measured Zn–N bond lengths are not absolute same, the bond length of Zn–N1 and Zn–N1 is
i
1
.970 Å, while the bond length of Zn–N3 and Zn–N3 is 1.973 Å. The tiny distance difference
indicates the influence of the interaction from neighboring ZnPc molecules on the inner part of
i
i
o
macrocycle. We found that the bond angle for both N1—Zn—N1 and N3—Zn—N3 is 180 which
show the coplanarity of Zn ion in Pc skeleton. All the structure information on bond lengths and
6

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angles for ZnPc single molecule is listed in Table 1. The detailed crystallographic data and structure
refinement parameters of ZnPc crystals are provided in Table 2. Specially, the molecular formula sum
is C32
H
16
N
8
Zn, belonging to monoclinic system, and the space group is P121/c1 (14). The cell
parameters are a = 14.514(1) Å, b = 4.8442(19) Å, c = 19.190(6) Å, α = 90°, β = 120.54(2)° and γ =
0°. The topological structure of ZnPc unit cell is recorded in Fig. 6b and the corresponding simulated
9
powder X-ray diffraction patterns match very well with the measured results (Fig. S1). To ascertain
the predominant crystal face from the point view of unit cell growth, the (100) face composed of 2×5
unit cells was constructed according to the XRD characterization (Fig. 6c). From the observation of
the topological structures, we found that the ZnPc macrocycles locate in lines and the planes of these
macrocycles keep parallel and all of them are perpendicular to the (100) basal face. It is well-known
that the intermolecular interaction in MPc crystals is mainly the π-π stacking which exits within
neighboring and parallel macrocycles, therefore, it can de deduce that the π-π electronic interaction in
the (100) crystal face is much stronger than that in other crystal faces and decides the crystal habit
with the property of high draw ratio. For the detailed observations of (100) face, the AFM
measurement was performed. Interestingly, the step-like growth (Fig. 6d) was also found which is
similar to the multilayer structures from SEM morphologies images in Fig. 3a and b. In addition, the
depth analysis based on the AFM surface morphologies shows the flatness properties of crystal face
(
Fig. 6e).
3.3 The spectral characterization
The Raman spectral analysis is introduced to determine the specific group vibrations for
predicting the molecular structures. In Fig. 7a, the full scan of Raman spectra from 100 to 2000 cm-1
-
1
was recorded for ZnPc crystals. The strong vibration bands at 590 and 674 cm can be attributed to
the benzene ring deformation and macrocycle breathing vibration, respectively. The range from 1350
-
1
to 1550 cm can be matched with the in-plane stretching and bending vibrations of metal ion-nitrogen
M–N) as well as displacements on C–N–C bridge bond of the phthalocyanine molecule.28,29
Therefore, the key difference of the Raman spectra between the ZnPc and CoPc crystals is the location
(
-
1
-1
of main peak, 1496 cm for ZnPc and 1530 cm for CoPc, which is closely related to the M–N
coordination bond. The FT-IR spectral measurement is carried out to ascertain the functional group
structures for ZnPc and CoPc. From the absorption spectra of ZnPc in Fig. 7c, the peaks at 1334, 1167,
-
1
30
1
116, 1085, 882, 753 cm can be attributed to phthalocyanine skeletal vibration. The peaks locating
-
1
at 1445 and 1282 cm are assigned the stretching vibration of aromatic phenyl ring and C–N=
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-
1
covalent bond. The peaks at 1085 and 775 cm are assigned the C–H in-plane bending vibrations and
C–H out-of-plane bending vibrations, respectively.31,32 For high similarity of molecular structures
between CoPc and ZnPc complexes, the location of FT-IR absorption peaks is somewhat similar to
each other.
3.4 The thermal performance
The thermal stability of crystals is a practical evaluation for their real application. For this
o
purpose, the TG and DSC analysis were performed over the temperature range from 40 to 1350 C
under the synthetic air atmosphere. From the TG curve of ZnPc crystals in Fig. 8a, the excellent
o
thermal stability can be observed for the almost constant weight before 550 C and subsequently an
o
obvious weight loss of 88% occurred in the range of 550–820 C due to the decomposition of Pc
o
skeleton. For CoPc crystals, nearly no perceptible weight changes can be found until 430 C and the
o
gradual weight loss was located in the temperature range from 430 to 790 C (Fig. 8b). Interestingly,
o
we found that there was a slight increase of weight after 790 C due to the further oxidation of CoO to
Co
3
4
O and the final weight loss was kept to 85%.
3.5 photoelectric properties
The photobehavior of ZnPc and CoPc crystals was investigated by the TPV method. The kinetic
process, including generation, separation and recombination of electron-hole pairs photoinduced on
crystalline MPc surfaces can be illuminated. Fig. 9a shows the TPV response curve of ZnPc needles
under the function of ultrafast laser with the wavelength of 355 nm and the pulse width of 4 ns. It is
clear that the ZnPc samples show a fast and strong response under the irradiation of light which
indicated the high efficiency of charge separation. Besides, the TPV response signal is positive which
showed that the photoinduced electrons transfer to the bulk of ZnPc while the holes move towards the
-
6
external surfaces and accumulates nearby. According to the TPV curve, the maximum of 1×10 s can
be confirmed. By contrast, The TPV response curve of CoPc is similar to that of ZnPc (Fig. 9b), while
-
8
the signals decrease quickly and the maximum is 8×10 s.
4
. Conclusion
In this study, the facile, environment-friendly and low-cost method was proposed for direct
growth of ZnPc and CoPc prisms from the simple raw materials. This investigation was followed by
our previous work on the green solvothermal synthesis of MnPc and CuPc crystals. The synthesis of
prism-shaped ZnPc and CoPc crystals with different draw ratios can be adjusted by using the different
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kind alcohol as reaction medium. The TG analyses show the broad temperature usage range of up to
o
o
5
50 C for ZnPc crystals and no more than 430 C for CoPc crystals, respectively. Besides, the
obvious photoelectric transformation properties measured by TPV method indicate their potential
application in organic semiconductor devices. Our proposed one-step synthesis method for MPc
crystals provides a green and cheap route for the request of high-quality MPc crystals.
Acknowledgements
This work was financially supported by the National Natural Science Foundation of China (Grant
No. 21507107 and 51302241), the Third Outstanding Young Talent Project of Xuchang University, the
Fifth Outstanding Young Teacher Project of Xuchang University, and Plan for Scientific Innovation
Talent of Henan Province (174100510014).
References
1
C. Maleysson, M. Passard, J. P. Blanc, V. Battut, J. P. Germain, A. Pauly, V. Demarne, A. Grisel, C.
Tiret and R. Planade, Sensor Actuat B-Chem., 1995, 26, 144–149.
C. G. Claessens, U. Hahn and T. Torres, Chem. Rec., 2008, 8, 75–97.
G. L. Parkhomov, E. S. Leonov and A. Y. Klimov, Microelectron. J., 2007, 38, 682–685.
L. Valli, Adv. Colloid Interface Sci., 2005, 116, 13–44.
2
3
4
5
T. V. Basova, C. Tasaltin, A. G. Gürek, M. A. Ebeoğlu, Z. Z. Öztürk and V. Ahsen, Sensor Actuat
B-Chem., 2003, 96, 70–75.
6
H. Jiang, P. Hu, J. Ye, Y. X. Li, H. N. Li, X. T. Zhang, R. J. Li, H. L. Dong, W. P. Hu and C. Kloc,
Adv. Mater. 2017, 29, 1605053.
7
8
9
R. J. Mortimer, Electrochim. Acta, 1999, 44, 2971–2981.
P. R. Somani and S. Radhakrishnan, Mater. Chem. Phys., 2003, 77, 117–133.
L. Y. Wei, K. Padmaja, W. J. Youngblood, A. B. Lysenko, J. S. Lindsey and D. F. Bocian, J. Org.
Chem., 2004, 69, 1461–1469.
10 H. Tian and S. J. Yang, Chem. Soc. Rev., 2004, 33, 85–97.
1
1
1
1 W. Lee, S. B. Yuk, J. Choi, D. H. Jung, S. H. Choi, J. Park and J. P. Kim, Dyes Pigments, 2012, 92,
942–948.
2 M. Y. Zhang, C. L. Shao, Z. C. Guo, Z. Y. Zhang, J. B. Mu, T. P. Cao and Y. C. Liu, ACS Appl.
Mater. Interfaces, 2011, 3, 369–377.
3 X. H. Zhang, L. J. Yu, C. S. Zhuang, T. Y. Peng, R. J. Li and X. G. Li, ACS Catal., 2014, 4,
9

CrystEngComm
Page 10 of 21
View Article Online
DOI: 10.1039/C8CE00215K
162–170.
1
1
4 M. Poß, H. Grӧger and C. Feldmann, Chem. Commun., 2018, 54, 1245–1248.
5 K. Xiao, R. J. Li, J. Tao, E. A. Payzant, I. N. Ivanov, A. A. Puretzky, W. P. Hu and D. B. Geohegan,
Adv. Funct. Mater., 2009, 19, 3776–3780.
16 R. Zeis, T. Siegrist and Ch. Kloc, Appl. Phys. Lett., 2005, 86, 022103.
17 R. A. Laudise, Ch. Kloc, P. G. Simpkins and T. Siegrist, J. Cryst. Growth, 1998, 187, 449–454.
18 W. H. Jiang, X. Wang, Y. C. Chang, S. K. Yu, C. Y. Ma, K. Q. Ye, C. H. Cheng and G. T. Du, J.
Cryst. Growth, 2006, 290, 544–547.
19 D. C. Xia, S. K. Yu, R. S. Shen, C. Y. Ma, C. H. Cheng, D. M. Ji, Z. Q. Fan, X. Wang and G. T. Du,
Dyes Pigments, 2008, 78, 84–88.
2
0 L. Y. Cui, J. Yang, Q. Fu, B. Z. Zhao, L. Tian and H. L. Yu, J. Mol. Struct., 2007, 827, 149–154.
1 Z. C. Guo, B. Chen, M. Y. Zhang, J. B. Mu, C. L. Shao and Y. C. Liu, J. Colloid Interface Sci.,
2
2010, 348, 37–42.
2
2
2 D. P. Li, S. X. Ge, G. F. Sun, Q. He, B. J. Huang, G. Z. Tian, W. Y. Lu, G. B. Li, Y. L. Chen, S. N.
An and Z. Zheng, Dyes Pigments, 2015, 113, 200–204.
3 S. X. Ge, Y. G. Zhang, B. J. Huang, S. P. Huang, W. W. Tie, Y. Lei, Q. He, G. L. Tu, Q. Q. Qin, S. S.
Niu, M. T. Li, D. P. Li and Z. Zheng, Mater. Lett. 2016, 163, 61–64.
2
2
2
2
2
4 C. A. Kernag and D. V. McGrath, Chem. Commun., 2003, 0, 1048–1049.
5 P. C. Lo, X. B. Leng, D. K. P. Ng, Coord. Chem. Rev., 2007, 251, 2334–2353.
6 F. Iwatsu, T. Kobayashi, and N. Uyeda. J. Phys. Chem., 1980, 84, 3223–3230.
7 J. O. Morley, M. H. Charlton, J. Phys. Chem., 1995, 99, 1928–1934.
8 M. Szybowicz, W. Bala, K. Fabisiak, K. Paprochi and M. Drozdowski, J. Mater. Sci., 2011, 46,
6589–6595.
29 D. R. Tackley, G. Dent and W. E. Smith, Phys. Chem. Chem. Phys., 2000, 2, 3949–3955.
30 J. Mack and M. J. Stillman, Coordin. Chem. Rev., 2001, 219, 993–1032.
31 B. N. Achar and K. S. Lokesh, J. Solid State Chem., 2004, 177, 1987–1993.
32 H. M. Ding, S. Y. Wang and S. Q. Xi, J. Mol. Struct., 1999, 475, 175–180.
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Fig. 1. The optical images of ZnPc single crystals synthesized from different reaction mediums. (a, b)
ethanol; (c, d) pentanol; (e, f) benzyl alcohol.
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Fig. 2. The optical images of CoPc single crystals synthesized from different reaction mediums. (a)
ethanol; (b) pentanol; (c) benzyl alcohol.
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Fig. 3. The SEM morphologies of ZnPc single crystals obtained from benzyl alcohol system (a, b);
TEM morphologies of ZnPc single crystals from benzyl alcohol system (c); The SEM morphologies
of ZnPc single crystals from pentanol system (d-g); The SEM morphologies of ZnPc single crystals
from ethanol system (h, i).
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Fig. 4. The SEM morphologies of CoPc single crystals obtained from benzyl alcohol system (a-c);
The SEM morphologies of CoPc single crystals from pentanol system (d-f); The SEM morphologies
of CoPc single crystals from ethanol system (g, h). TEM morphologies of CoPc single crystals from
benzyl alcohol system (i).
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Fig. 5. XRD patterns of ZnPc (a) and CoPc (b) crystals.
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Fig. 6. (a) The crystallographically determined structure of ZnPc molecule. (b) Molecular packing
structures in single crystal of ZnPc according to the single crystal X-ray diffraction. (c) Topological
view of predominant (100) face of ZnPc crystals. (d) AFM morphology recording on a large and
smooth surface of ZnPc single crystal selected from benzyl alcohol system. (e) Depth histogram based
on the AFM morphology analysis of (d). Results of depth analysis: peak to peak distance, 71.9578 nm;
minimum peak depth, 124.182 nm; maximum peak depth 196 nm; depth at histogram maximum,
196.139 nm; number peaks found, 138.
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Fig. 7. The Raman spectra of ZnPc crystals (a), CoPc crystals (b), FT-IR spectra of ZnPc crystals (c),
and CoPc crystals (d).
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Fig. 8. TG-DSC curves of ZnPc (a) and CoPc (b) crystals. The TG-DSC was performed by using a
o
Netzsch STA 409 PC thermal analyzer in synthetic air at 10 C/min of heating rate.
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Fig. 9. TPV curves of ZnPc (a) and CoPc (b) crystals.
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Table 1 Selected bond length and bond angles for ZnPc crystals (i: -x, 1-y, -z.)
Atoms 1,2 bond length (Å)
Atoms 1,2,3
N1—Zn1—N1i 180.00(12)
bond angle (°)
Atoms 1,2,3
N2—C9—N3
N2—C9—C10
N3—C9—C10
bond angle (°)
127.2(3)
Zn1—N1
Zn1—N1i
Zn1—N3
Zn1—N3i
N1—C1
N1—C4
N2—C9
N2—C4
1.970(3)
1.970(3)
1.973(2)
1.973(2)
1.356(4)
1.367(4)
1.328(4)
1.329(4)
N1—Zn1—N3
89.24(10)
123.8(3)
i
N1 —Zn1—N3 90.76(10)
N1—Zn1—N3i 90.76(10)
N1 —Zn1—N3i 89.24(10)
N3—Zn1—N3i 180.00(14)
109.0(3)
C11—C10—C15 120.4(3)
i
C11—C10—C9
C15—C10—C9
133.3(3)
106.3(3)
C1—N1—C4
C1—N1—Zn1
C4—N1—Zn1
108.9(3)
124.7(2)
126.4(2)
123.5(3)
C12—C11—C10 117.9(3)
C12—C11—H11 121.100
C10—C11—H11 121.100
C11—C12—C13 121.5(3)
C11—C12—H12 119.200
C13—C12—H12 119.200
C14—C13—C12 121.1(3)
C14—C13—H13 119.500
C12—C13—H13 119.500
C13—C14—C15 117.6(3)
C13—C14—H14 121.200
C15—C14—H14 121.200
C14—C15—C10 121.5(3)
C14—C15—C16i 131.7(3)
C10—C15—C16i 106.8(3)
N3—C16i 1.361(4)
N3—C9
N4—C1
N4—C16
C1—C2
C2—C8
C2—C3
C3—C5
C3—C4
C5—C6
C5—H5
C6—C7
C6—H6
C7—C8
C7—H7
C8—H8
C9—C10
1.370(4)
1.327(4)
1.329(4)
1.455(4)
1.380(4)
1.391(4)
1.384(4)
1.450(4)
1.380(5)
0.9300
C9—N2—C4
i
C16 —N3—C9 108.8(3)
i
C16 —N3—Zn1 124.9(2)
C9—N3—Zn1
C1—N4—C16
N4—C1—N1
N4—C1—C2
N1—C1—C2
C8—C2—C3
C8—C2—C1
C3—C2—C1
C5—C3—C2
C5—C3—C4
C2—C3—C4
N2—C4—N1
N2—C4—C3
N1—C4—C3
C6—C5—C3
C6—C5—H5
C3—C5—H5
C5—C6—C7
C5—C6—H6
C7—C6—H6
C8—C7—C6
C8—C7—H7
C6—C7—H7
C7—C8—C2
C7—C8—H8
C2—C8—H8
126.3(2)
123.9(3)
128.1(3)
122.7(3)
109.1(3)
121.7(3)
131.8(3)
106.5(3)
120.3(3)
133.2(3)
106.5(3)
127.3(3)
123.6(3)
109.0(3)
117.7(3)
121.200
121.200
121.5(3)
119.300
119.300
121.0(3)
119.500
119.500
117.8(3)
121.100
121.100
1.390(5)
0.9300
1.369(4)
0.9300
N4—C16—N3i
127.6(3)
N4—C16—C15i 123.4(3)
N3 —C16—C15i 109.0(3)
i
0.9300
1.452(4)
C10—C11 1.378(4)
C10—C15 1.393(4)
C11—C12 1.378(5)
C11—H11 0.9300
C12—C13 1.385(5)
C12—H12 0.9300
C13—C14 1.371(4)
C13—H13 0.9300
C14—C15 1.384(4)
C14—H14 0.9300
C15—C16i 1.449(4)
C16—N3i 1.361(4)
C16—C15i 1.449(4)
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Table 2 Crystallographic data of ZnPc crystals
refinement parameters
ZnPc
Formula sum
Formula weight
Crystal system
Space-group
32 16 8
C H N Zn
577.92 g/mol
monoclinic
P 1 21/c 1 (14)
a=14.514(1); Å b=4.8442(19) Å; c=19.190(6) Å
α=γ=90°; β=120.54(2)°
a/b=2.9962; b/c=0.2524; c/a=1.3222
1162.05(1372) Å3
Cell parameters
Cell ratio
Cell volume
Z
2
Calc. density
1.65156 g/cm3
2
1