Crystal structure, vibrational spectra, optical properties and density functional theory approach of a picrate salt based on substituted triphenylphosphinium

Article abstract of DOI:10.1016/j.molstruc.2018.11.103

A new organic crystal, [BzTPP][PIC](1) ([BzTPP]⁺ = benzyl triphenylphosphinium, [PIC]^- = picrate), has been grown by slow evaporation solution growth technique. Single crystal XRD reveals that it belongs to monoclinic system with P2₁/c. The two neighboring [BzTPP]⁺ cations from a dimer through C-H···π interaction while anions stack into a columnar structure through N?O, O?O and π···π interaction. The anions and cations form a column structure alternately in ···AC-AC-AC-AC··· sequence through C-H?O hydrogen bonds. The experimental vibrational bands (IR and Raman) have been discussed and assigned based on DFT calculations. The HOMO-LUMO energy gap explains the charge transfer interactions in the molecule. The thermal stability of the hybrid crystal was analyzed by TG-TDA-MS technique and revealed that the title crystal was stable up to 290 °C. The fluorescence spectra reveal three main emission peaks at 295, 388 and 543 nm upon excitation at 250 nm in solid state at room temperature. The energy of weak interactions in the molecule and nonlinear optical properties were studies using DFT calculations.

Full text of DOI:10.1016/j.molstruc.2018.11.103

Accepted Manuscript
Crystal structure, vibrational spectra, optical properties and density functional theory
approach of a picrate salt based on substituted triphenylphosphinium
Ting Li, Zhi-Hao Gan, Cai-Hong Liu, Jia-Rong Zhou, Xiao-Ping Liu, Le-Min Yang,
Chun-Lin Ni
PII:
S0022-2860(18)31416-9
DOI:
https://doi.org/10.1016/j.molstruc.2018.11.103
MOLSTR 25932
Reference:
To appear in: Journal of Molecular Structure
Received Date: 21 February 2018
Revised Date: 7 September 2018
Accepted Date: 28 November 2018
Please cite this article as: T. Li, Z.-H. Gan, C.-H. Liu, J.-R. Zhou, X.-P. Liu, L.-M. Yang, C.-L. Ni, Crystal
structure, vibrational spectra, optical properties and density functional theory approach of a picrate
salt based on substituted triphenylphosphinium, Journal of Molecular Structure (2018), doi: https://
doi.org/10.1016/j.molstruc.2018.11.103.
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ACCEPTED MANUSCRIPT
Graphical Abstract-Pictogram
LUMO (excited state)
Eg = 2.31 eV
HOMO (ground state)

ACCEPTED MANUSCRIPT
Crystal structure, vibrational spectra, optical properties and density
functional theory approach of a picrate salt based on substituted
triphenylphosphinium
Ting Li, Zhi-Hao Gan, Cai-Hong Liu, Jia-Rong Zhou*, Xiao-Ping Liu, Le-Min Yang, Chun-Lin Ni*
College of Materials and Energy, Institute of Biomaterial, South China Agricultural University, Guangzhou
510642, P. R. China
+
Abstract: A new organic crystal, [BzTPP][PIC](1) ([BzTPP] = benzyl triphenylphosphinium,
-
[
PIC] = picrate), has been grown by slow evaporation solution growth technique. Single crystal
+
XRD reveals that it belongs to monoclinic system with P2 /c. The two neighboring [BzTPP]
1
cations from a dimer through C-H···π interaction while anions stack into a columnar structure
through N···O, O···O and π···π interaction. The anions and cations form a column structure
alternately in ···AC-AC-AC-AC··· sequence through C-H···O hydrogen bonds. The experimental
vibrational bands (IR and Raman) have been discussed and assigned based on DFT calculations.
The HOMO-LUMO energy gap explains the charge transfer interactions in the molecule. The
thermal stability of the hybrid crystal was analyzed by TG-TDA-MS technique and revealed that
the title crystal was stable up to 290 °C. The fluorescence spectra reveal three main emission
peaks at 295, 388 and 543 nm upon excitation at 250 nm in solid state at room temperature. The
energy of weak interactions in the molecule and nonlinear optical properties were studies using
DFT calculations.
Keywords: Substituted benzyl triphenylphosphinium picrate; Crystal structure; vibrational spectra;
Optical properties; DFT calculations.
—
——————
*Corresponding author.
E-mail address: scauchem534@126.com (Jia-Rong Zhou); niclchem@scau.edu.cn (Chun-Lin Ni)
1

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1
. Introduction
New nonlinear optical materials have been attracting much attention in recent researches due to
their potential applications in many optical fields [1-5]. Compared to the inorganic materials,
organic materials not only own delocalized p-electrons with conjugated double bond systems but
also show excellent properties such as high optical quality, superior long-term orientation, high
packing densities and larger photo-chemical stabilities, etc [6-9]. Organic crystals also possess
unsatisfactory poor thermal and mechanical properties for they are usually formed through weak
van der Waals forces [10-12]. In order to overcome the limitations of those materials, the design
and preparation of hybrid materials from organic electron donor-acceptor system have been
implemented to improve their chemical and thermal stability, mechanical strength and optical
non-linearity [13-16]. It is well known that the picric acid (2,4,6-trinitrophenol) acts not only as
an acceptor but also acidic ligand and has strong tendency to form the hydrogen bonds with other
compounds [17-20]. On the one hand, picric acid is famous as an electron acceptor forming
charge transfer molecular complexes with a number of electron donor compounds through
electrostatic or hydrogen bond interactions [19, 20]. On the other hand, picric acid has the ability
to form ionic bonds with basic amino acids and may also form dissociable charge-transfer
complexes with suitable for aromatic group [21-23]. These outstanding properties make them
suitable for industrial chemical application in the processes of the dye, leather and glass industry
[
24, 25]. According to our previous work, several researches on the inorganic-organic hybrid
materials containing triphenylphosphinium cations and onions containing metal atoms have been
done such as [BzTPP] [Co(NCS) ] which exhibits a magnetic coupling interaction from
2
4
ferromagnetic to antiferromagnetic around 30 K as the temperature is lowered [26], and
2

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[
BzTPP][Ni(mnt) ] the adjacent cations of which are connected together via π-π interaction
2
+
between the conjugated phenyl rings of [BzTPP] cation [27]. Despite recent efforts, the
synthesis of define crystalline materials is still far rational and typically relies on spontaneous.
Hence, the synthesis of defined building blocks and studies of their structural properties are
desirable in order to provide a sound base for their subsequent use in the preparation of
+
crystalline materials. Taking the outstanding properties of picric acid and [BzTPP] cations into
consideration, thus in the present work we introduce picric acid instead of the metal anions
mentioned above into the system of [BzTPP][M(mnt) ](M = Cu, Ni), combining with
2
benzyltriphenylphosphinium. Herein, as shown in Fig. 1, a new picric salt, [BzTPP][PIC](1), was
designed and investigated by means of single crystal XRD, IR, Raman, UV-visible and
fluorescence spectroscopy, and thermal and nonlinear optical analysis.
2
. Experimental
2.1 General materials
Picric acid, K CO , benzyl bromide, triphenylphosphine and all solvents were purchased from
2
3
commercial sources and used without further purification. All manipulations were performed in
air. Benzyl triphenylphosphinium bromide was synthesized following the literature procedure
[
28].
2.2 Synthesis of the title crystal
A methanol solution (10 mL) of picric acid (0.23 g, 1.0 mmol) was added to the methanol
solution (10 mL) of K CO (0.07 g, 0.5 mmol) and stirred violently for 2 hours at room
2
3
temperature, and 20 mL methanol solution of [BzTPP]Br (0.43 g, 1.0 mmol) were dropped to the
mixture, and stirred for another 1 h. The yellow precipitate was filtered off, then washed with
3

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methanol and ether, and dried in vacuum. Yield 78 %. Anal. Calc. for C H PN O : C, 64.11; H,
3
1
34
3
7
4.27; N, 7.18 %; Found: C, 64.03; H, 4.16; N, 7.23 %.º
2.3 Physical Measurements
Elemental analyses (C, H and N) were recorded on an Elementar Vario EL III instrument.
Infrared spectra were recorded on a Nicolet Nexus 670 FT-IR spectrophotometer in the range
-1
4
000 to 400 cm with the samples in the form of KBr pellets. Raman spectra were recorded in
-1
the region of 3500-400 cm on a Thermo-Fisher Nicolet NXR 9650 FT-Raman spectrometer, and
the excitation wavelength is 1064 nm. Electronic spectra were recorded on a SHIMADZU
UV-3150 spectrophotometer in the range 600 to 200 nm in CH OH. Solid-state UV-Vis
3
absorption and transmission spectra were recorded on a Shimadzu UV-2550 spectrophotometer in
the region of 200-450 nm. Solid-state emission spectra were recorded for the solid samples which
were loaded into a sample cell (1cm diameter) which was then fixed on a bracket at room
temperature with a Shimadzu RF-5301PC fluorescence spectrophotometer. The excitation and
emission slits used for the measurement of the solid state of the crystals were 2.5 and 5.0 nm
-1
wide, the scan speed was 240 nm·min , and the scan voltage was 500V. The X-ray powder
diffraction (XRPD) data were collected by a Rigaku Corporation D/MAX2200VPC using Cu Kα
radiation (λ = 1.5406 Å). Thermogravimetric (TG), differential thermal analyses (DTA) and mass
spectra (MS) of the gaseous products of the decomposition for the title compound were carried
-1
out on a Rigaku Thermo Mass Photo TG-MS analyzer at a heating rate of 10ꢀC min in the
temperature range of 30-800ꢀC in a helium atmosphere.
2.4 Determination of crystal structure
Yellow single crystals suitable for the X-ray structure analysis were obtained by evaporating
4

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the solution of 1 in MeOH for three weeks at room temperature. A photograph of the as-grown
crystals of 1 is shown in Fig. 2. Diffraction data were collected at 291 K with a Bruker Smart
APEX CCD diffractomer using graphite-monochromated Mo Kα radiation (λ = 0.71073 Å) and
operating in ω-ϕ scan mode. Cell parameters of 1 were obtained and refined using the SAINT [29]
program. The structures were solved by direct methods using the SHELXS-97 [30] program, and
2
refined on F by full-matrix least-squares methods using the SHELXTL-97 [31] program for all
non-hydrogen atoms. All hydrogen atoms were introduced in calculated positions and refined
with fixed geometry with respect to their carrier carbon atoms. Crystal data, data collection and
refinement details for 1 are given in Table 1. Selected bond parameters for 1 are listed in Table 2.
2.5 Computational Details
All calculations were carried out using the Gaussian 09 programs [32]. The ground state
geometries of molecules were obtained from optimizations using the B3LYP functional [33, 34]
with the 6-31G (d, p) basis set. Frequency analysis was used to confirm whether the structure is a
minimum (with no imaginary frequency) and to provide IR and Raman spectra. A TD-DFT
calculation was carried out to obtain UV-Vis absorption spectrum. Non-linear optical properties
of the title crystal were studied using DFT calculations. Since the values of the polarizability and
hyperpolarizability given by Gaussian 09 are reported in atomic units (a.u.), the calculated values
-24
have been converted into electrostatic units (esu) (α : 1 a.u. = 0.1482 × 10 esu; β : 1 a.u. =
ij
ijk
-33
8
.3693 × 10 esu).
3
. Results and discussion
3.1 Description of crystal structure and interaction energy
The title salt [BzTPP][PIC](1) crystallizes in the monoclinic system, space group P2 /c. As
1
5

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+
shown in Fig. 3, the asymmetric unit is comprised of one [BzTPP] cation and one picrate
+
monoanion. The [BzTPP] cation adopts a conformation in which four phenyl rings are twisted
relative to C(12)-C(13)-P(1) reference plane, with dihedral angles of 95.8º(2) (θ ) for C(7)-C(12),
1
7
5.6º(2) (θ ) for C(14)-C(19), 150.3º(1) (θ ) for C(20)-C(25) and 95.6º(2) (θ ) for C(26)-C(31)
2 3 4
+
rings respectively. It is observed that the adjacent [BzTPP] cations form a dimer through the
C-H⋅⋅⋅π interactions with a H(29)-Cg (Cg is center of C(24)-C(29) ring) distance of 2.956 Å (Fig.
1
1
4a). For the picrate anion moiety, the loss of a proton from the picric results in the lengthening of
the C(1)-O(1) bond with a distance of 1.233(4) Å [21]. In addition, the C(1)-C(2)(1.450 Å) and
C(1)-C(6) (1.453 Å) distances are both longer than the normal aromatic C-C values 1.4 Å [35]
due to the loss of a hydroxyl proton at O(1) leading to the conversion from the neutral to anionic
state. Meantime the neighboring anions adjoin together forming a columnar (Fig. 4b) through the
interactions of O···O, N···O and π···π with distances of 3.486(2) Å, 3.408(3) Å and 3.618 (3) Å,
respectively [22].
The inter-molecular energy calculations were performed using the Gaussian 03 package at the
DFT/B3LYP/6-31G (d, p) level in order to understand various interactions such as electrostatic
+
-
interaction, hydrogen bonds in [BzTPP] cation and [PIC] anion (Fig. 4c). The total energy for
the intermolecular interaction was calculated to be -45.7 Kcal/mol. The detailed parameters about
of these hydrogen bonds were listed in Table 3. The packing diagram of 1 along the
crystallographic a-axis direction is displayed in Fig. S1. The crystal packing is governed by these
hydrogen bonds which may be effective in the stabilization of the crystal structure.
3.2 Powder X-ray diffraction
The simulated and experimental PXRD patterns of 1 are shown in Fig. 5. The PXRD pattern
6

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fits quite well with simulated one, therefore bulk material purity is confirmed. So the powder
sample of the material was suitable for the measurement of spectral and optical properties.
3.3 Thermal stability
The TG and DTA curves of 1 are presented in Fig. 6. From TG curve, it is clear that there is no
o
obvious weight loss between room temperature to 308 C and hence it shows that the
o
[
BzTPP][PIC] crystal is stable up to 308 C. TG curve indicates two stage mass loss patterns
o
when the material was heated from 30 and 800 C. The first decomposition was started at 308 and
o
o
ended at 355 C with the loss of w98.3% of material. The next weight loss occurs between 355 C
o
and 800 C with the removal of w1.7% of material. It is noted when the decomposition process
o
was carried up to 800 C with the removal of the material into gaseous products [36]. The sharp
o
endothermic peak observed in DTA curve at 308 C shows the melting point of the material, and
the another peak observed in DTA is in consistence with the TG curve. It is fully stable only up to
o
3
08 C so that it can be used for NLO applications up to this temperature.
The gaseous products of the decomposition of [BzTPP][PIC] at ~308 ºC were determined by
mass spectra as shown in Fig. S2. As can be seen from the m/z data, the main gaseous matters
-
were H O (m/z = 18), N (m/z = 28), CO (m/z = 44) from the decomposition of [PIC] anion;
2
2
2
+
3
+
+
5
+
+
C H (m/z = 39), C H (m/z = 51), C H (m/z = 65), and C H (m/z = 77), and PhCH (m/z =
3
4
4
5
6
5
2
+
9
1) from the decomposition of [BzTPP] cation.
3.4 IR and Raman spectra
-1
The FT-IR spectra for 1 in 4000-500 cm region are shown in Fig. 7a, while Fig. 7b shows
-1
spectra Raman spectra in 3500-400 cm region. The theoretical FT-IR and Raman spectra of
+
-
[
BzTPP] cation and [PIC] anion are shown in Figs. S3 and S4, respectively. And the observed
7

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experimental and theoretical of IR and Raman bands frequencies and assignments are given in
Table S1.
+
-1
-1
In the moiety of the [BzTPP] cation. The peaks at 3062 cm in the IR spectra and 3063 cm
in the Raman spectra are assigned to the stretching vibration of the C-H bonds in the benzenyl
-
1
-1
ring, the calculated peaks are located at 3262 cm (IR) and 3267 cm (Raman), respectively. The
-1
-1
peaks occur at 2954, 2918 cm in the IR spectra and 2969, 2912 cm in the Raman assigned as
-1
the C-H vibration of –CH group of the benzyl group. The peaks at 1630, 1558, 1485 cm (IR)
2
-1
and 1571, 1480 cm (Raman) are due to the C=C vibration of the phenyl ring showing great
-1
agreement with the theoretic values, these mode are computed at 1650, 1591, 1480 cm (IR) and
-1
-1
1
640, 1596, 1475 cm (Raman). The asymmetric vibration of CH group appears at 1429 cm
2
-1
-1
(
IR), calculated at 1413 cm (IR) and 1408 cm (Raman). The bending (δNO ) mode give rises
2
-1
to the band present at 1330 cm (IR), which have great similarities in the DFT, more explicitly,
-1
1
373 cm (DFT) in both IR and Raman spectra. As the same time, the rocking ρCH mode are
2
-1
-1
observed at 1186, 1155, 1113, 912 cm (IR) and 1191, 1153, 1101, 912 cm (Raman), 1190, 1156,
-1
-1
1
114, 919 cm (IR, DFT), 1256, 1114, 923 cm (Raman, DFT). The C-P characteristic peak is
-1
-1
discovered at 751 cm (IR) and 755 cm (Raman), the DFT of IR and Raman are recorded in 767
-1
-1
cm (IR) and 762 cm .
-
As the portion of [PIC] anion, the main characteristic vibrations show great relationships with
the nitro group. Means, the groups of -NO have characteristic vibration active in both IR and
2
-1
Raman spectra. The most intense lines in the 1315 (IR) and 1310 cm (Raman) are owing to the
symmetric stretching vibration of nitro group (ν NO ) and are characteristic of the picrate anion,
s
2
-1
-1
calculated at 1311 cm (IR) and 1307 cm Raman. The asymmetric stretching vibration of nitro
8

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-1
-1
-1
-1
groups sit at 1558, 1552 cm (IR) 1571 cm (Raman), 1591, 1529 cm (DFT, IR) and 1596 cm
(
DFT, Raman). The bending in plane (δNO ), wagging (ωNO ), scissoring (φNO ), rocking(ρNO )
2 2 2 2
-1
-1
-1
vibration mode of nitro groups are assigned at nearby ~800 cm , ~740 cm , 710 cm and 530
-
1
[4, 19]
-1
-1
cm .
Peaks of 1155 cm in IR and 1101 cm in Raman are ascribed to the phenolic O and
the main characteristic of the picrate anion [24]. Those vibration mode shows good agreement
with the theoretic values calculated in the DFT, showing in the Table 4.
3.5 UV-vis and transmittance spectra analysis
The electronic absorption spectrum of [BzTPP][PIC] shows two strong absorption bands at 245
and 373 nm in Fig. 8a. The strong absorption band at 373 nm, is attributed to π-π* transition of
picrate ion, accompanying a slight blue shift at 375 nm compared with previously reported
compound [37], which indicated that there is a charge activity in compound 1 as a consequence
of C-O group transition and delocation in the benzene of picrate and triphenylphosphine [1, 38].
To support experimental observations, the theoretical absorption wavelengths and electronic
excitation energies were calculated by the TD-DFT method. The calculations predicts two intense
+
-
electronic transition at 247 and 363 nm of the [BzTPP] cation and 375 nm of the [PIC] anion
(Fig. S5), which are similar to the measured experimental data (245 and 373 nm). The highest
occupied molecular orbitals and lowest unoccupied molecular orbitals of [BzTPP][PIC] are
shown in Fig. 8b. The orbital that primarily acts as an electron donor is the HOMO, while is the
orbital that mainly acts as an electron acceptor is the LUMO. The energy gap of 2.31eV explains
the eventual charge transfer interactions taking place in the material [39].
The recorded transmittance spectrum is shown in Fig. 8c and it has good transparency of
about 63% with lower cut-off wavelength 465 nm. The lower cut-off wavelength is due to the
9

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π-π* transition of the phenyl group of the title compound [40]. The yellow crystal of 1 is active in
the visible region, indicating potential application as optical material. When wavelength is more
than 465 nm, the reflection ability of the material increases exponentially, and tends to be stable
when the wavelength is more than 540 nm.
3.6 Fluorescence properties
The luminescent properties of title compound and the corresponding intermediate [BzTPP]Br
were investigated in solid state at room temperature. As shown in Fig. 9 upon excitation at 250
nm, the intermediate [BzTPP]Br shows main luminescent emissions peaks at 390, 466 and 543
nm with a weaker shoulder emission peak at 309 nm. There also exists three peaks at 543, 388
and 295 nm in the compound 1, more explicitly, the maximum emission peak changes from 390
to 388 nm with an slightly blue-shifted of 2 nm, the peak at 309 changes to 295 nm with
blue-shifted of 15 nm when the intermediate [BzTPP]Br is combined with the self-assembly
priciate anion and formed [BzTPP][PIC] molecular solid. The difference of locations of peaks
and the change of the intensity may be a result of C-H···N weak interactions between the
+
-
[
BzTPP] anion and [PIC] cation and the neighboring anions forming of a column [22, 41].
3.7 NLO properties
The electric dipole moment (ꢀ ), polarizability (α ) and the first hyperpolarizability (β ) of the
i
ij
ijk
[
BzTPP][PIC] calculated by the B3LYP/6-31G(d, p) are listed in Table S2. The calculated dipole
moment is equal to 31.90 D. The highest absolute value of the dipole moment is observed for the
component ꢀ . In this direction, the value is equal to 31.81. The calculated polarizability (α ), is
x
tot
-24
equal to 52.99 × 10 esu. As we can see, the first hyperpolarisability (β ) of the compound has
tot
-31
for value 109.58 × 10 esu, which is about 16 times that of the reference crystal KDP (βKDP
=
1
0

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-31
6
.85 × 10 esu). The above results show that the [BzTPP][PIC] is a good material for NLO
applications. Also, it is remarkable, according to Table 4, that the value of the hyperpolarizabity
+
of the [BzTPP][PIC] cluster is distinctly larger than that of the picrate anion and the [BzTPP]
cation, which shows that the interactions between the anion and the cation play an important role
not only in the generation of the crystal structure and its stability, but also in the enhancement of
its optical properties [42].
4
. Conclusion
A new organic crystal of benzyl triphenylphosphinium picrate was synthesized, and the single
crystals were grown by a slow evaporation method. The crystal structural analysis shows that the
anions stack into a columnar structure through N···O, O···O and π···π interaction, while the two
+
neighboring [BzTPP] cations from a dimer through C-H···π interaction. The anions and cations
form a column structure alternately in ···AC-AC-AC-AC··· sequence through C-H···O hydrogen
bonds. The powder X-ray diffraction study confirms that the crystalline perfection is fairly good.
The thermal stability and the main gaseous products of the decomposition of [BzTPP][PIC] at
308 ºC of the hybrid crystal was analyzed by TG-TDA-MS technique and revealed that the title
crystal was stable up to 220 °C. The experimental vibrational bands (IR and Raman) have been
discussed and assigned based on DFT calculations. The HOMO-LUMO energy gap explains the
charge transfer interactions in the molecule. The fluorescence spectra reveal three main emission
peaks at 295, 388 and 543 nm upon excitation at 250 nm in solid state at room temperature. The
energy of weak interactions in the molecule and nonlinear optical properties were studies using
DFT calculations and reveal the first hyperpolarisability (β ) of the crystal is about 16 times that
tot
of the reference crystal KDP. So, from the present investigation, it is concluded that [BzTPP][PIC]
1
1

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is a new candidate for NLO device application.
Supplementary material
Crystallographic data for the structural analysis of 1 have been deposited with the Cambridge
Crystallographic Data Centre, CCDC No. 1468873. Copies of this information may be obtained free of charge
from the Director, CCDC, 12 Union Road, Cambridge, CB2 1EZ, UK (fax: +44-1223-336033;
deposit@ccdc.cam.ac.uk or www: http://www.ccdc.cam.ac.uk).
Acknowledgements
This work has been partially supported by the Science and Technology Project (2016A010103025) from
Guangdong Science and Technology Department, and the Undergraduates' Innovative Experimental Program
(No.1056411137) in University from South China Agricultural University.
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Table 1 Crystallographic data for 1
Compound
1
Empirical formula
Formula weight
Description
C H PN O
31 24 3 7
581.50
Pale Yellow, block
0.13 × 0.17 × 0.21
291(2)
3
Crystal size (mm )
Temperature (K)
Wavelength (Å)
Crystal system
Unit cell dimensions
a (Å)
0.71073
Monoclinic
P2(1)/c
b (Å)
9.950(1)
14.832(1)
19.576(2)
103.93(1)
2804.0(5)
4
c (Å)
β (˚)
3
Volume (Å )
Z
-3
Density (calculated, g cm )
-
1
Absorption coefficient (mm )
1.378
F(000)
0.152
θ range (˚)
1208
Reflection collected
Independent reflection (Rint)
Data, restraints, parameters
2.53 < θ < 26.5
26266
5195 (0.038)
5195, 0, 379
1.04
2
Goodness-of-fit on F
R , wR (I > 2σ(I))
1
2
R , wR (all data)
0.0594, 0.1233
0.0941, 0.1576
1
2
–
3
Largest diff. peak and hole (e Å )
0
.76 and - 0.56
2
2 2
2 2 1/2
R = Σ(||F | - |F ||) / Σ|F |, wR = [Σ w(|F | - |F | ) / Σ w(|F | ) ] .
1
o
c
o
2
o
c
o
1
8

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Table 2 Selected bond parameters for 1
Bond lengths (Å)
O(2)–N(1)
O(3)–N(1)
O(4)–N(2)
O(5)–N(2)
O(6)–N(3)
O(7)–N(3)
O(1)–C(1)
N(1)–C(2)
N(2)–C(4)
N(3)–C(6)
P(1)–C(13)
P(1)–C(19)
P(1)–C(25)
P(1)–C(31)
Bond Angles (º)
1.173(6)
1.195(5)
1.219(6)
1.214(6)
1.207(5)
1.210(6)
1.233(4)
1.451(4)
1.445(6)
1.457(5)
1.814(3)
1.788(4)
1.798(3)
1.794(3)
O(2)–N(1)–O(3)
O(4)–N(2)–O(5)
O(6)–N(3)–O(7)
O(2)–N(1)–C(2)
O(3)–N(1)–C2)
O(4)–N(2)–C(4)
O(5)–N(2)–C(4)
O(6)–N(3)–C(6)
O(7)–N(3)–C(6)
C(13)–P(1)–C(19)
C(13)–P(1)–C(25)
C(13)–P(1)–C(31)
C(19)–P(1)–C(25)
C(19)–P(1)–C(31)
119.5(3)
123.4(4)
122.3(4)
121.1(3)
119.4(4)
118.9(4)
117.7(4)
119.5(4)
118.3(3)
107.7(1)
110.2(2)
110.5(2)
109.1(2)
110.0(2)
Table 3 Weak hydrogen bonds for 1 (Å and º)
D−H···A
d(D−H)
0.930
0.970
0.930
0.930
0.930
d(H···A)
2.540
d (D···A)
3.421(6)
3.128(4)
3.286(6)
3.187(6)
3.163(4)
<(DHA)
C(7)−H(7)···O(6)
158.0
140.0
144.0
125.0
143.0
C(13)−H(13A)···O(1)#1
C(17)−H(17)···O(3)#2
C(27)−H(27)···O(5)#3
C(30)−H(30···O(1)#1
2.320
2.490
2.560
2.370
Symmetry transformations used to generate equivalent atoms: #1 = -x + 2, y - 1/2, -z + 1/2; #2 = -x + 2,
y + 1, -z; #3 = -x + 1, -y, -z; #4 = x, - y + 2, z - 1/2.
-
1
9

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Table 4 Comparison of the first hyperpolarizability, polarizability, and diple moment of 1
and its constituents calculated using DFT//B3LYP/6-31G(d, p)
-24
-31
Compounds
ꢀtot (D)
2.61
αtot (×10 esu)
17.3
βtot (×10 esu)
-
[
[
[
PIC] anion
75.10
33.77
109.58
+
BzTPP] cation
3.47
45.13
BzTPP][PIC]
31.90
52.99
2
0

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NO2
NO2
NO2
Ph
Ph
Ph
CH OH
K CO
-
+
3
2
3
Br
O N
OH
O N
2
O K +
CH2
P
2
NO2
Ph
NO2
NO2
+
P
Ph -O
Ph
CH2
NO2
Fig. 1. Synthesis route of the title compound

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Fig. 2 Photograph of the title crystal grown by slow evaporation.

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Fig. 3 ORTEP plot (30% probability ellipsoids) showing the molecule structure of 1.
1

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(a)
(b)
(c)
–
Fig. 4 (a) The dimer formed through C–H⋅⋅⋅π interaction between two neighboring [PIC] anions of 1. (b)
The columnar structure formed through N–O, O–O and π⋅⋅⋅π interactions between the cations of 1. (c) The
anion and cation formed an alternating network structure in a ···ACACAC··· sequence through C–H···O
hydrogen bonds of 1.
1

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(b)
(a)
10
20
30
40
50
2θ
(Deg)
Fig. 5 Simulated and experimental powder XRD patterns of 1: (a) experimental (red line) and (b) calculated
from single crystal structural analysis (blue line).
1

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2
1
1
5
0
00
50
00
0
1
00
8
6
4
2
0
0
0
0
0
-50
-100
100 200 300 400 500 600 700 800
o
Temperature ( C)
Fig. 6 TG-DTA thermal curve for 1.
1

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100
(a)
90
80
70
4
000 3500 3000 2500 2000 1500 1000 500
-
1
Wavenumber(cm )
100
80
60
40
20
0
(b)
3
500 3000 2500 2000 1500 1000
500
-1
Raman Shifts (cm )
Fig. 7 The FT-IR (a) and Raman (b) spectra of 1.
1

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5
4
3
2
1
0
2
26
[
BzTPP]Br
(a)
234
PIC
268
336 373
[BzTPP][PIC]
200
300
400
500
600
700
800
Wavenumbers (nm)
LUMO (excited state)
(b)
Eg = 2.31 eV
HOMO (ground state)