Discovery of a new type of organic ferroelectric materials in natural biomass dehydroabietylamine Schiff bases

Article abstract of DOI:10.1039/c0jm03461d

Three kinds of Schiff bases, 5-chlorosalicylidene dehydroabietylamine (ClDHA), 5-bromosalicylidene dehydroabietylamine (BrDHA) and 5-nitrosalicylidene dehydroabietylamine (NODHA), have been prepared and characterized by elemental analyses, IR, circular dichroism (CD), and X-ray structural analyses. Ferroelectric, dielectric and NLO properties are reported for the first time in cheap natural biomass resource dehydroabietylamine derivatives and their ferroelectric properties can be easily tuned through the substituents of the aromatic aldehyde. With the increase in electron-withdrawing properties of the substituents from -Br to -Cl and then -NO₂, the P_s values or the ferroelectric properties gradually increased. The Royal Society of Chemistry.

Full text of DOI:10.1039/c0jm03461d

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PAPER
Discovery of a new type of organic ferroelectric materials in natural biomass
dehydroabietylamine Schiff bases†
ab
Dong-Sheng Liu,ab Rong-Hua Hua and Hong-Mei Chena
*
Yan Sui,
Received 13th October 2010, Accepted 4th January 2011
DOI: 10.1039/c0jm03461d
Three kinds of Schiff bases, 5-chlorosalicylidene dehydroabietylamine (ClDHA), 5-bromosalicylidene
dehydroabietylamine (BrDHA) and 5-nitrosalicylidene dehydroabietylamine (NODHA), have been
prepared and characterized by elemental analyses, IR, circular dichroism (CD), and X-ray structural
analyses. Ferroelectric, dielectric and NLO properties are reported for the first time in cheap natural
biomass resource dehydroabietylamine derivatives and their ferroelectric properties can be easily tuned
through the substituents of the aromatic aldehyde. With the increase in electron-withdrawing
properties of the substituents from –Br to –Cl and then –NO2, the Ps values or the ferroelectric
properties gradually increased.
ferroelectric based on Schiff base nickel coordination complexes
Introduction
with polarization values higher than KDP.8 As an extension of
our interest in molecular ferroelectric materials, we turned to the
ferroelectric properties of pure organic compounds.
Ferroelectricity is one of the major subjects in the field of
materials science due to its wide applications in ferroelectric
random-access memories (FeRAM), switchable nonlinear
optical devices, electro-optical devices, and light modulators.1
Since the discovery of ferroelectricity in Rochelle salt in 1920,
many efforts have been ongoing towards the design and synthesis
of noncentrosymmetric ferroelectric compounds.2–4 But much of
the attention in this field has been focused on developing ferro-
electric and high-dielectric inorganic or inorganic–organic
hybrid compounds such as KH2PO4 (KDP), BaTiO3, LiNbO3,
CaCu3Ti4O12 and triglycine sulfate (TGS) etc.5 To the best of our
knowledge, pure organic ferroelectrics, especially low-molecular-
mass organic ferroelectrics, still remain sparse.6 However,
ferroelectric materials based on organic compounds may be
particularly important in organic electronics. One of the merits
of low-molecular-mass organic compounds is applicability with
solution and/or dry processes such as spin-coating, spray-on,
inkjet printing and vapor-phase deposition techniques. This
would be also advantageous in the fabrication of flexible, light-
weight, large-area, low-cost organic devices. Therefore, all-
organic electronic and photonic devices have gained great
interest.7 Recently, we have reported a new type of ionic
Biomass resources have attracted great interest in both
industry and fundamental research, not only because of their
abundance and biodegradation ability, but also due to their
special structures containing several chiral centers.9 Dehy-
droabietylamine is a naturally occurring enantiomeric pure
diterpenic amine with the hydrophanthrene structure.10 The
chirality in the dehydroabietylamine molecule prompts us to
study the ferroelectric property of this compound. In this paper,
we report the crystal structures, ferroelectric, dielectric and NLO
properties of dehydroabietylamine Schiff bases (ClDHA,
BrDHA and NODHA, Scheme 1). To the best of our knowledge,
it is the first time that ferroelectricity was discovered in cheap
natural biomass resource dehydroabietylamine derivatives.
Experimental section
General materials and methods
All reagents and solvents were purchased from commercial
sources and used as received. Elemental analyses for C, H, and N
were performed on a CHN-O-Rapid analyzer and an Elementar
Vario MICRO analyzer. The IR spectra were taken on a Bruker
Vector 22 FT-IR spectrometer with KBr discs in the 4000–400
aSchool of Chemistry and Chemical Engineering, The Key Laboratory of
Coordination Chemistry of Jiangxi Province, Jinggangshan University,
Jiangxi, 343009, P. R. China. E-mail: ysui@163.com
bSchool of Chemistry and Chemical Engineering, Nanjing National
Laboratory of Microstructures, Nanjing University, Nanjing, 210093,
P. R. China
cmꢀ1 range. The H NMR spectra were recorded with a Bruker
1
DRX 500 spectrometer at 500 MHz. The CD spectra were
recorded on a JASCO J-810 Spectropolarimeter. The electric
hysteresis loops were recorded on a Ferroelectric Tester Precision
Premier II made by Radiant Technologies, Inc. The temperature
dependence of the dielectric constant and dielectric loss at
† Electronic supplementary information (ESI) available: E–P hysteresis
of powdered samples, leakage currents. X-Ray crystallographic files
(CIF) for BrDHA and NODHA. CCDC reference numbers 806391 and
806392. For ESI and crystallographic data in CIF or other electronic
format, see DOI: 10.1039/c0jm03461d
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Scheme 1 Synthesis of dehydroabietylamine Schiff bases.
100–106 Hz frequencies were measured using a dielectric imped-
ance analyzer, Concept 80 system (Novocontrol, Germany).
SHELXS-97 and SHELXTL-97 programs, respectively.12
Anisotropic thermal parameters were applied to all non-
hydrogen atoms. The H atoms were positioned geometrically and
treated as riding on their parent atoms, with C–H distances of
Synthesis of dehydroabietylamine Schiff bases
ꢀ
ꢀ
0.97 A (methylene) and 0.96 A (methyl). Crystal data as well as
details of data collection and refinement for the compounds are
summarized in Table 1. The structure of ClDHA has been
reported by others previously.13
ClDHA. A mixture of dehydroabietylamine (10 mmol, 2.85 g),
5-chlorosalicylaldehyde (10 mmol, 1.56 g) and methanol (200 ml)
was refluxed for 2 h, and then cooled to room temperature. The
precipitate was collected and dried under vacuum. The product
was then dissolved in methanol and the solution was left to stand
undisturbed. Upon slow evaporation at room temperature for
several days, yellow single crystals of the title compound were
collected. m.p.¼ 451 K. FT-IR (KBr, cmꢀ1): 2929(s), 1634(s),
1606(m), 1574(m), 1482(s). Anal. Calcd. for C27H34ClNO: C,
Results and discussion
Crystal structural descriptions
Due to the structural similarity of ClDHA, BrDHA and
NODHA, only BrDHA will be discussed in detail as an example.
As shown in Fig. 1a and 1b, BrDHA contains four crystallo-
graphically distinct six-membered rings (A, B, C and D). The two
rings A and D are planar and the dihedral angle between them is
104.2(3)ꢁ. Whereas rings B or C are not planar, and the internal
torsion angles indicated that a half-chair and a chair confor-
mation were adopted by them, respectively. BrDHA contains
three chiral centers in the C9, C13 and C14 atoms, with R, S and
R absolute configurations, respectively. There is an intra-
molecular O–H/N hydrogen bond; the O1–H1, H1/N1, O1/
1
76.48, H, 8.08, N, 3.30. Found: C, 76.43, H, 8.23, N, 3.47%. H
NMR (500 MHz, CDCl3): d 8.267 (s, 1H, CH]N), 6.903–7.284
(m, 6H, Ph), 3.464–3.540 (m, 2H, N–CH2), 1.071–2.855 (m, 24H,
aliphatic cyclo).
BrDHA. BrDHA was synthesized by a similar method
to ClDHA except 5-bromosalicylaldehyde was used instead of
5-chlorosalicylaldehyde. m.p.¼ 457 K. FT-IR (KBr, cmꢀ1): 2928
(s), 1632(s), 1602(m), 1570(m), 1478(s). Anal. Calcd. for
C27H34BrNO: C, 69.22, H, 7.32, N, 2.99. Found: C, 69.01, H,
ꢀ
ꢀ
1
N1 distances and O1–H1/N1 angle are 1.05 A, 1.54 A, 2.570(6)
7.20, N, 2.87%. H NMR (500 MHz, CDCl3): d 8.257 (s, 1H,
ꢁ
ꢀ
A and 162.6 , respectively.
CH]N), 6.902–7.403 (m, 6H, Ph), 3.459–3.539 (m, 2H, N–CH2),
1.070–2.843 (m, 24H, aliphatic cyclo).
NODHA has a similar crystal structure to BrDHA (Fig. 2), but
there is a non-classical intermolecular C–H/O hydrogen bond
besides an intramolecular O–H/N hydrogen bond. The O3–H3,
NODHA. NODHA was prepared by a similar method
to ClDHA except 5-nitrosalicylaldehyde was used instead of
5-chlorosalicylaldehyde. m.p.¼ 469–470 K. FT-IR (KBr, cmꢀ1):
2927(s), 1639(s), 1615(m), 1543(m), 1478(w). Anal. Calcd. for
C27H34N2O3: C, 74.62, H, 7.89, N, 6.45. Found: C, 74.48, H,
ꢀ
H3/N1, O3/N1 distancesꢁand O3–H3/N1 angle are 0.82 A,
ꢀ
ꢀ
1.81 A, 2.544(4) A and 148.8 , respectively. The C8–H8B, H8B/
ꢀ
O1, C8/O1 distances andꢁ C8–H8B/O1 angle are 0.97 A,
ꢀ
2.41 A, 3.146(5) A and 132.4 , respectively. Its symmetry code is:
ꢀ
1
ꢀx, yꢀ1/2, ꢀz.
7.76, N, 6.37%. H NMR (500 MHz, CDCl3): d 8.267 (s, 1H,
CH]N), 6.903–7.284 (m, 6H, Ph), 3.464–3.540 (m, 2H, N–CH2),
1.071–2.855 (m, 24H, aliphatic cyclo).
Circular dichroism (CD) spectra
To confirm the optical activity of ClDHA, BrDHA and NODHA,
the circular dichroism (CD) spectra were measured in methanol
solutions (Fig. 3). ClDHA exhibits negative Cotton effects at ca.
X-Ray crystallography
Diffraction intensities for ClDHA, BrDHA and NODHA were
collected at 293(2) K on a Bruker Apex II CCD diffractometer
lmax ¼ 220, 253 and 331 nm and a positive signal at ca. lmax
210 nm; BrDHA exhibits negative Cotton effects at ca. lmax
¼
¼
with graphite-monochromated Mo-Ka radiation (l
¼
ꢀ
0.71073 A). Absorption corrections were applied using
SADABS.11 The structures were solved by direct methods and
refined with the full-matrix least-squares technique using
213, 254 and 325 nm and a positive signal at ca. lmax ¼ 221 nm.
Similarly, NODHA exhibits negative Cotton effects at ca. lmax
260 and 387 nm and a positive signal at ca. lmax ¼ 222 nm.
¼
14600 | J. Mater. Chem., 2011, 21, 14599–14603
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Table 1 Crystal data and structure refinements for ClDHA, BrDHA and NODHA
Compound
ClDHA
BrDHA
NODHA
Empirical formula
Formula weight
Crystal system
Space group
C27H34ClNO
424.00
Monoclinic
P21
11.249 (2)
6.1790 (12)
17.276 (4)
103.04 (3)
1169.8 (4)
2
1.204
10–13
2657
2526
275
293 (2)
0.061, 0.16
1.06
C27H34BrNO
468.46
Monoclinic
P21
11.264 (4)
6.189 (2)
17.301 (6)
102.785 (7)
1176.2 (8)
2
C27H34N2O3
434.56
Monoclinic
P21
11.1580 (17)
6.2046 (10)
17.347 (3)
101.490 (3)
1176.9 (3)
2
ꢀ
a/A
ꢀ
b/A
ꢀ
c/A
b (ꢁ)
3
ꢀ
V/A
Z
Dc/Mg mꢀ3
1.323
1.226
q range [ꢁ]
2.69–20.72
6409
4196
275
293 (2)
0.053, 0.119
1.02
ꢀ0.010 (13)
2.40–19.22
7421
4172
295
293 (2)
0.047, 0.099
0.99
0.1(1)
Collected reflections
Unique reflections
Parameters
T/K
R1 [I > 2s(I)], wR2 (all data)a
GOF
Flack parameter
0.07 (18)
a
R1 ¼ S||Fo| ꢀ |Fc||/S|Fo|, wR2 ¼ [Sw(|Fo2| ꢀ |Fc2|)2/Sw(|Fo2|)2]1/2
.
Fig. 3 Circular dichroism (CD) spectra of ClDHA, BrDHA and
NODHA in methanol solutions.
Fig. 1 (a, top) Crystal structure of BrDHA (30% probability thermal
ellipsoids). (b, bottom) The ring conformations of BrDHA (30% proba-
bility thermal ellipsoids, H atoms omitted for clarity).
nonlinear optical and ferroelectric properties were examined.
The second-order nonlinear optical effects were determined on
a LAB130 Pulsed Nd:YAG laser according to the principle
proposed by Kurtz and Perry,14 and preliminary studies of
powder samples of ClDHA, BrDHA and NODHA showed
second harmonic generation (SHG) efficiency with approxi-
mately 0.5, 0.4 and 1.2 times that of urea, respectively. This
implied that the three compounds were all dipolar active
compounds.
The ferroelectric behaviors of ClDHA, BrDHA and NODHA
were also examined given that point group C2 was one of the ten
polar point groups required for ferroelectric materials.15 Under
the symmetry operation of 2-fold screw axes, the components of
the dipole vector are cumulative along the b axis and cancellative
along other axes. Therefore, the three compounds may have
a significant ferroelectric effect along the b axis for the single
crystal samples. The ferroelectric properties were investigated at
room temperature with single crystal samples and recorded on
Fig. 2 Crystal structure of NODHA (30% probability thermal ellip-
soids).
Ferroelectric and nonlinear optical properties
As ClDHA, BrDHA and NODHA crystallize in a chiral polar
space group (P21), belonging to the polar point (C2), their second
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Table 2 Ferroelectric measurement results for single crystal samples
along the b axis
a Ferroelectric Tester Precision Premier II made by Radiant
Technologies, Inc. The ferroelectric measurements along the
polar b axis revealed obvious hysteresis loops for all the three
compounds. The hysteresis loops of BrDHA are shown in Fig. 4
as an illustrative example and the others are given in Fig. S1 in
the ESI.† The summarized results (Table 2) indicated that all the
three compounds indeed displayed obvious ferroelectric
behavior with remnant polarization (Pr) between 31.8 and
Compound
Ps (mC cmꢀ2
)
Pr (mC cmꢀ2
)
Ec (kV cmꢀ1
)
ClDHA
BrDHA
NODHA
44.3–74.5
49.4–69.0
61.5–86.5
44.3–74.5
31.8–45.9
38.2–52.5
2.63–4.73
3.28–4.63
2.81–3.63
34.5 mC cmꢀ2, and coercive field (Ec) between 2.63–4.73 kV cmꢀ1
.
The saturation spontaneous polarization (Ps) was between 44.3
and 86.5 mC cmꢀ2, which was close to that of typical inorganic
indicating the presence of a phase transition (Fig. 5a). The peak
slightly moves toward lower temperature and the height
decreases with increasing frequency. As shown in Fig. 5b,
a relaxation process was also observed, indicating that dielectric
loss changes with temperature at different frequencies.
17
single crystal ferroelectric materials such as BaTiO3,16 PbTiO3
etc. More importantly, as shown in Table 2, the Ps values are
directly related to the substituents of the aromatic aldehydes.
With the increase in electron-withdrawing properties of the
substituents from –Br to –Cl and then –NO2, the Ps values or the
ferroelectric properties gradually increased. This provides us
a useful message that the ferroelectricity of dehydroabietylamine
Schiff bases can be easily tuned through the variation of the
substituents of the aromatic aldehydes.
Conclusions and perspectives
In this paper, three dehydroabietylamine Schiff bases have been
synthesized by using dehydroabietylamine and aromatic alde-
hydes with different electron-withdrawing substituents. The
ferroelectric, dielectric and NLO properties are reported for the
first time in cheap natural biomass resource dehydroabietylamine
derivatives. The results demonstrate that the ferroelectricity can
be tuned through the substituents of the aromatic aldehyde. With
the increase in electron-withdrawing properties of the
To further confirm the ferroelectricity of ClDHA, BrDHA and
NODHA, the ferroelectric properties of powdered samples in
pellets were also investigated at room temperature (Fig. S2 in the
ESI†). The observed hysteresis loops and the low leakage
currents (less than 10ꢀ7 A cmꢀ2; Fig. S3 in the ESI†) indicated
that the three compounds indeed display obvious ferroelectric
behavior and the observed hysteresis loops were clearly due to
ferroelectricity. The saturation spontaneous polarization (Ps) of
powdered samples are much smaller than the corresponding
single crystal samples, the reason should be due to the irregular
arrangement of the polar direction in powdered samples. In
addition, the leakage currents of single crystal samples are also
lower than 10ꢀ7 A cmꢀ2 (Fig. S4 in ESI†).
Dielectric properties
Due to the structural similarity of the three compounds, only
ClDHA was selected to investigate the dielectric properties. The
temperature dependence of the dielectric constant and dielectric
loss of ClDHA were measured at various frequencies in the range
of 100–106 Hz. A dielectric constant peak appears at about 390 K
Fig. 5 (a, top) Temperature dependence of the dielectric constant e0 (real
part) of ClDHA at various frequencies (100–106 Hz). (b, bottom)
Temperature dependence of the dielectric loss e00/e0, where e00 and e0 are
the imaginary and real parts of the dielectric constant for ClDHA, at
various frequencies (100–106 Hz).
Fig. 4 Electric hysteresis loops of BrDHA recorded on a Ferroelectric
Tester Precision Premier II made by Radiant Technologies, Inc., at r.t.
for single crystal samples along the b axis at different settings of electric
field.
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R. Kawajiri, T. Mitani and T. Shimoda, J. Am. Chem. Soc., 2005,
127, 17598; (f) L. Song, S.-W. Du, J.-D. Lin, H. Zhou and T. Li,
Cryst. Growth Des., 2007, 7, 2268; (g) Y.-M. Xie, J.-H. Liu,
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C.-Z. Lu, Cryst. Growth Des., 2008, 8, 3914.
5 (a) G. Rijnders and D. H. V. Blank, Nature, 2005, 433, 369; (b)
H. N. Lee, H. M. Christen, M. F. Chisholm, C. M. Rouleau and
D. H. Lowndes, Nature, 2005, 433, 395; (c) C. C. Homes, T. Vogt,
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substituents from –Br to –Cl and then –NO2, the Ps values or the
ferroelectric properties gradually increased. It can be predicted
that these properties can be further improved by replacing the
substituents with groups with higher electron-withdrawing
properties, such as –F, –CF3 etc. or with multiple electron-
withdrawing groups. Further studies on the improvement of the
ferroelectricity of pure organic compounds are still under way in
our laboratory.
6 (a) S. Horiuchi and Y. Tokura, Nat. Mater., 2008, 7, 357; (b)
R. Kumai, S. Horiuchi, Y. Okimoto and Y. Tokura, J. Chem.
Phys., 2006, 125, 084715; (c) S. Horiuchi, R. Kumai and Y. Tokura,
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and Y. Tokura, J. Am. Chem. Soc., 2005, 127, 5010; (e) E. Collet,
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Acknowledgements
This work was supported by China Postdoctoral Science Foun-
dation (20090451189), Natural Science Foundation of Jiangxi
Province (2007GZH1667), Department of Education of Jiangxi
Province (Grant GJJ10536) and Open Funds of State Key
Laboratory of Coordination Chemistry of Nanjing University.
7 (a) S. Horiuchi, R. Kumai and Y. Tokura, Chem. Commun., 2007,
2321; (b) K. Noda, I. Kenji, K. Atsushi, H. Toshihisa, Y. Hirofumi
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