Combined spectral experiment and theoretical calculation to study the interaction of 1,4-dihydroxyanthraquinone for metal ions in solution

Article abstract of DOI:10.1016/j.saa.2013.06.095

The interaction between 1,4-dihydroxyanthraquinone (1,4-DHA) and metal ions was studied by UV-Visible and fluorescence spectroscopies in solution. Time-dependent density functional theory calculations confirmed complex structures. The investigation results showed 1,4-DHA can selectively respond some metal ions and can be monitored by UV-Vis, fluorescence spectra and naked-eye. So 1,4-DHA has a potential application in the design of metal ions probe. More, as typical metal ions, Hg²⁺ and Er³⁺, their reaction abilities for 1,4-DHA were studied in detailed. Experimental results showed they have better response for 1,4-DHA. And theoretical calculation concluded that Er³⁺ easily reacts with 1,4-DHA over Hg²⁺ attributed to the low reaction energy of Er³⁺-1,4-DHA than Hg ²⁺-1,4-DHA.

Full text of DOI:10.1016/j.saa.2013.06.095

Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy 115 (2013) 772–777
Contents lists available at SciVerse ScienceDirect
Spectrochimica Acta Part A: Molecular and
Biomolecular Spectroscopy
journal homepage: www.elsevier.com/locate/saa
Combined spectral experiment and theoretical calculation to study
the interaction of 1,4-dihydroxyanthraquinone for metal ions in solution
Caixia Yin a, Jingjing Zhang a, Fangjun Huo b,
⇑
a Key Laboratory of Chemical Biology and Molecular Engineering of Ministry of Education, Institute of Molecular Science, Shanxi University, Taiyuan 030006, China
b Research Institute of Applied Chemistry, Shanxi University, Taiyuan 030006, China
h i g h l i g h t s
g r a p h i c a l a b s t r a c t
The statement: Hg2+ and Er3+, their reaction abilities for 1,4-DHA were studied by UV–Visible and fluo-
rescence spectroscopies in solution. They all have better response for 1,4-DHA in the spectra with distinct
and regular changes. And theoretical calculation concluded that Er3+ easily react with 1,4-DHA over Hg2+
attributed to the low reaction energy of Er3+-1,4-DHA than Hg2+-1,4-DHA.
ꢀ
The interaction between 1,4-
dihydroxyanthraquinone and metal
ions in solution was studied in
detailed.
ꢀ
ꢀ
1,4-Dihydroxyanthraquinone has
better response for Hg2+ and Er3+ over
other metal ions.
1,4-Dihydroxyanthraquinone has a
potential application in the design of
metal ions probe.
a r t i c l e i n f o
a b s t r a c t
Article history:
Received 1 April 2013
Received in revised form 23 June 2013
Accepted 27 June 2013
Available online 8 July 2013
The interaction between 1,4-dihydroxyanthraquinone (1,4-DHA) and metal ions was studied by UV–
Visible and fluorescence spectroscopies in solution. Time-dependent density functional theory calcula-
tions confirmed complex structures. The investigation results showed 1,4-DHA can selectively respond
some metal ions and can be monitored by UV–Vis, fluorescence spectra and naked-eye. So 1,4-DHA
has a potential application in the design of metal ions probe. More, as typical metal ions, Hg2+ and
Er3+, their reaction abilities for 1,4-DHA were studied in detailed. Experimental results showed they have
better response for 1,4-DHA. And theoretical calculation concluded that Er3+ easily reacts with 1,4-DHA
over Hg2+ attributed to the low reaction energy of Er3+-1,4-DHA than Hg2+-1,4-DHA.
Keywords:
1,4-DHA
Metal ions
UV–Visible
Ó 2013 Elsevier B.V. All rights reserved.
Naked-eye
Fluorescent
Theoretical calculation
Introduction
anthraquinone derivatives generally have the biological activity
and pharmacological effects, such as hemostatic, anti-bacterial
Anthraquinone, also called anthracenedione or dioxoanthra-
cene, is an aromatic organic compound with formula C14H8O2.
One specific isomer, 9,10-dioxoanthracene, wherein the keto
groups are located on the central ring. It is a building block of many
dyes and is used in bleaching pulp for papermaking. Dyes
and anti-cancer [1]. For example, red dye having an anthraquinone
structure as a class of photosensitizers is ubiquitous in nature, and
it is also a constituent part of a variety of anti-cancer drugs, these
drugs target DNA and can damage DNA including physiological ac-
tive molecules induced by visible light exhibiting photosensitive
anti-cancer effects [2–7]. So, the biological and pharmaceutical sci-
ence of anthraquinones has received significant attention, with
derivatives showing a breadth of applicability (e.g., antibiotics
⇑
Corresponding author. Tel./fax: +86 351 7018329.
E-mail address: huofj@sxu.edu.cn (F. Huo).
1386-1425/$ - see front matter Ó 2013 Elsevier B.V. All rights reserved.
http://dx.doi.org/10.1016/j.saa.2013.06.095

C. Yin et al. / Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy 115 (2013) 772–777
773
and antitumor activity), the hydroxy-anthraquinone unit has been
identified as a key biologically active site in antitumor anthracy-
clines. As one of anthraquinone derivative, hydroxy-anthraquinone
is a naturally occurring genotoxic compound found in medicinal
plants, including Rubia tinctorium L [8,9]. The extraction from
Scutia myrtina has yielded three anthrone-anthraquinone deriva-
tives, a new bisanthrone-anthraquinone and the known aloesapo-
easily reacts with 1,4-DHA over Hg2+ attributed to the low reaction
energy of Er3+-1,4-DHA than Hg2+-1,4-DHA.
Experimental
Materials
nairn
I [10]. Most of these compounds, as they possessing
All chemicals and solvents were of analytical grade and bought
from Sigma–Aldrich or Beijing City without further purification.
Chromatography was carried out on silica gel (200–300 mesh).
Thin layer chromatography (TLC) was carried out using silica gel
GF254 plates with a thickness of 0.20–0.25 mm. Deionized water
antimicrobial, antiviral and anticancer properties [11,12], were
commonly used as biological fluorescent probes in cell imaging
microscopy [13]. In the 1990s, studying for biological redox anti-
cancer new drug AQ4N showed that the compounds combination
with anthraquinone structure and aliphatic N-oxides have broad
prospects in the creation of the anticancer compound. The 1,4-dihy-
droxyanthraquinone is critical structure in anthraquinone-based
anticancer new drug including AQ4N, including AQ4N, doxorubicin
[14–22]. It is well known that 1,4-dihydroxyanthraquinone (1,4-
DHA), commonly known as quinone Sin, its space structure is very
symmetry, and its color is obvious (when dissolved in different
solvents, it then show different colors, along with a strong fluores-
cence change). Based on its characteristics, in recent years, 1,4-DHA
can be used to synthesize various dyes and are common structural
subunits of many biologically active quinonoids namely, anthracy-
clines, dynemicins, mitoxantrones, anthraquinonesteroid hybrids,
and naphthacenedione organic dyes [23]. It also can be modified
into synthetic dyes intermediates, 1,4-diamino anthraquinone. In
addition, under certain condition, 1,4-dihydroxyanthraquinone
can be induced to self-assembly to form a metallo-supramolecular
coordination polymers [24–26] which demonstrate good selectivity
and binding for planar aromatic guests, small organic molecules
and transitional metal ions, such as methylene dichloride and irid-
ium [27–30]. 1,4-dihydroxyanthraquinone with multi coordinating
groups, can coordinate to many different metal ion (such as alkali
metal, alkaline earth metal, the third main group metals and tran-
sition metal) [31]. In view of this, the fluorescent complexes be-
tween hydroxy-anthraquinone and some rare earth ions in
applying to the fluorescence method determination have been
reported [32]. In this work, the interaction between 1,4-DHA and
metal ions was studied by UV–Visible, fluorescence spectroscopies
in solution. The results showed that Hg2+ and Er3+, all have better
response for 1,4-DHA in the spectra and color with distinct and
regular changes. And theoretical calculation concluded that Er3+
was used to prepare all aqueous solutions. The solutions of Hg2+
Er3+, Al3+, Ba2+, Cd2+, Zn2+, Cu2+, Mn2+, Ni2+, Co2+, Eu3+, La3+, Sm3+
,
,
Fe3+, Gd3+, Nd3+, Ho3+, Sn2+, Yb3+, Ce4+ and Zr3+ were prepared from
their chloride salts. The solution of Ag+ was prepared from nitrate
salt. The solution of VO2+ was prepared from their sulfate salt. All
spectroscopic measurements were performed in HEPES
(10 mmol/L, pH 7.0) buffer. HEPES buffer solutions were obtained
by adding 1 mol/L NaOH solution into 10 mmol/L aqueous HEPES
using a Mettler Toledo pH meter. 1,4-DHA was dissolved in abso-
lute EtOH to prepare the stock solutions with concentrations of
2.0 mmol/L.
Synthesis of the complex
To a stirred solution of phthalic anhydride (1 mmoL) and boric
acid (25 mmoL), chlorophenol (1.2 mmoL) (dissolved in 5%, 20 g
sulfuric acid) was added dropwisely. Then the system was stirred
5 h at room temperature. The solution was poured into ice water
(400 g), and then heated to 85 °C for another 30 min. The reaction
mixture was filtered, and the solid was washed with water for sev-
eral times until it became neutral. After drying in high vacuum,
0.21 g (0.88 mmoL) pink power was obtained in a yield of 90%
(Fig. S1). The structure of complex was shown Fig. 1.
Physical measurements
The UV–Visible spectra were recorded on a Cary 50 Bio UV–Vis-
ible spectrophotometer in a 4.5 mL (1 cm in diameter) cuvette with
2 mL solution. Fluorescence spectra were measured on Cary Eclipse
fluorescence spectrophotometer. All data were treated with the
Fig. 1. (a) and (b) are UV–Vis absorbance values at 538 nm and fluorescence intensity at 532 nm of free 1,4-DHA (130 lmol/L) and 1,4-DHA (130 l
mol/L)-Er3+ under different
pH conditions, respectively.

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C. Yin et al. / Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy 115 (2013) 772–777
Origin 8.0 program. Absorption maxima, kmax, is given in nm. 1H
NMR, 13C NMR spectra were recorded on a Bruker AVANCE-
300 MHz and 75 MHz NMR spectrometer, respectively. Chemical
shifts are given in parts per million downfield from tetramethylsil-
ane (0.0 ppm) for spectra. ESI-MS was measured with a LC-MS
2010A (Shimadzu) instrument. The lightpink single crystal of
1,4-DHA was mounted on a glass fiber for data collection. Cell con-
stants and an orientation matrix for data collection were obtained
by least-squares refinement of diffraction data from reflections
within 2.24–27.47°, using a Bruker SMART APEX CCD automatic
sample was gradually titrated. All fluorescence spectra data were
recorded at 1 min after the ion addition.
Results and discussion
pH dependent of the compound
Figs. S3a and b and 1 show the UV–Vis and fluorescence spectra
of 1,4-DHA at different pH values. At pH 6 7, the absorption spec-
trum exhibits a broad band centered at 480 nm, and has a strong
emission at 538, 564 nm (Ex = 470), which resulted from fully
protonated. As has already been noticed in the UV–Vis and fluores-
cence spectra, at strong basic pH, 1,4-DHA is very unstable. When
the pH is raised from 9 to 13, the absorption at 480 nm decreases
and red-shift takes places up to the band centered at 532 and
572 nm. And the fluorescence intensity of 1,4-DHA decreases with
increasing pH. This large shift may be attributed to deprotonation
of the phenolic groups. Above facts demonstrated the solvent pro-
tonation and deprotonation effects. Fig. S3c and d are the UV–Vis
and fluorescence spectra of Er-1,4-DHA. The addition of Er3+ cannot
induce new peak in the range of pH 2–4. When pH is in the range of
8–13, after Er3+ addition, though, new peaks appear, they are irreg-
ular. In the range of 5–7, new peaks come and change regularly, ex-
cept for more weak absorbance intensity at pH 5.0. pH 6–7, the
fluorescence was quenched almost completely. However, in other
pH conditions, the fluorescence of 1,4-DHA cannot be quenched.
Therefore, the pH range of 6–7 is effective for this probe and neu-
tral pH was used for further studies.
diffractometer. Data were collected at 296 K using Mo K
a radiation
(k = 0.710713 Å) and the -scan technique, and corrected for the
x
Lorentz and polarization effects (SADABS) [33]. The structures
were solved by direct methods (SHELX97) [34], and subsequent
difference Fourier maps were inspected and then refined in F2
using a full-matrix least-squares procedure and anisotropic dis-
placement parameters.
Characterization of compound
1H NMR (300 MHz, 25 °C, CDCl3): d 7.25 (d, 2H), 7.80 (t, 1H),
8.29 (t, 1H), 12.84 (s, 2H); 13C NMR (75 MHz, CDCl3): d 113.46,
127.75, 130.07, 134.16, 135.19, 158.52, 187.58; Elemental analysis
(calcd.%) for
C14H8O4: C, 70.00; H, 3.36, Found: C, 70.02;
H, 3.32. Electrospray ionization mass spectra (ESI-MS) m/z
239.17, [probe-H]+. Crystal data for C14H8O4: crystal size:
0.16 ꢁ 0.15 ꢁ 0.09, monoclinic, space group P21/n (No. 11).
a = 10.283(3) Å, b = 6.0486(17) Å, c = 16.500(5) Å, b = 95.805°,
V = 1021.0(5) Å3, Z = 4, T = 173 K, hmax = 27.47°, 6912 reflections
measured, 2329 unique (Rint = 0.0424) Final residual for 165
Selectivity over metal ions
parameters and 2329 reflections with I > 2
wR2 = 0.1599 and GOF = 1.195 (Fig. S2).
r(I): R1 = 0.0667,
The effect of a wide range of environmentally and physiologi-
cally-active metal ions on 1,4-DHA was investigated using the
UV–Vis spectra of solutions containing 1,4-DHA and these metal
ions in the HEPES (10 mmol/L) pH 7.0 aqueous buffer. The results
Measurement procedure
showed that metal ions such as Ag+, Al3+, Ba2+, Cd2+, Zn2+, Cu2+
Mn2+, Ni2+, Co2+, Eu3+, La3+, Sm3+, Fe3+, Gd3+, Nd3+, Ho3+, Sn2+
,
,
The UV–Vis procedures were shown as follows: into a 10 mmol/
L, pH 7.0 HEPES buffer solution containing 130.0 mol/L 1,4-DHA,
ion sample was gradually titrated. All UV–Vis spectra data were re-
corded at 1 min after the ion addition.
The fluorescence procedures were as follows: into a 10 mmol/L,
pH 7.0 HEPES buffer solution containing 7.0 lmol/L 1,4-DHA, ion
l
Yb3+, Ce4+, VO2+, Zr3+ et al. did not respond as well as Hg2+ and
Er3+ do. Namely: some metal ions could not induced UV/Vis or fluo-
rescence spectra to change distinctly and regularly (Figs. S4 and
S5). Some metal ions, although made UV/Vis or fluorescence spec-
tra take place some variations, precipitations were produced
Fig. 2. (a) UV–Vis spectra of 1,4-DHA (130 l
mol/L) in HEPES (10 mmol/L, pH = 7.0) upon addition of various concentrations of Er3+ (0–3 equiv); (b) fluorescence spectra of 1,4-
DHA (7
l
M) in the presence of various concentrations of Er3+ (0–3 equiv) in HEPES (10 mM, pH 7.0) (kex ¼ 470 nm, slit: 5 nm/5 nm). Inset: time-dependent UV–Vis
absorbance of probe at 480 nm in the presence of 10 equiv Er3+
.

C. Yin et al. / Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy 115 (2013) 772–777
775
quickly. It is a pity that some metal ions could not form stable
complexes in aqueous solution at all. The UV–Vis and fluorescence
color change photographs for all kinds of metal ions were showed
in supporting information Fig. S6.
the addition of Er3+ caused changes in the fluorescence spectra;
i.e. a remarkable quenching of the broad emission band centered
at 538, 564 nm was observed. Simultaneously, a visual fluores-
cence change (from brilliant yellow to colorless) for 1,4-DHA was
observed under illumination with a UV 365 nm lamp.
UV–Vis and fluorescence spectra of detecting Er3+
UV–Vis and fluorescence spectra of detecting Hg2+
As a typical lanthanide metal ion, Er3+ was used to further
examine response of 1,4-DHA by the UV–Vis. Fig. 2a shows the
changes in the UV–Vis spectra when Er3+ was added to HEPES
We also carried out a detailed investigation on the 1,4-DHA rec-
ognition to Hg2+. Fig. 3a shows the regular change in the UV–Vis
spectra when Hg2+ was added to HEPES (10 mmol/L, pH 7.0) solu-
(10 mmol/L, pH 7.0) solution containing 1,4-DHA (130 lmol/L).
With increasing Er3+ concentration (0–3 equiv.), a broad band
centered at 480 nm gradually decreased and a new broad band
centered at 525, 560 nm appeared, and the solution changed color
from yellow to amaranth. A well-defined isosbestic point was
noted at 500 nm, which may indicate the formation of single
new species. The changes in the fluorescence spectra of probe
tion containing 1,4-DHA (130
centration (0–2 equiv.),
l
mol/L). With increasing Hg2+ con-
broad band centered at 480 nm
a
gradually decreased and a new band at 550 nm appeared, and
the solution changed color from yellow to flesh pink color. A
well-defined isosbestic point was noted at 523 nm, which may
indicate the formation of single new species. The changes in the
1,4-DHA (7.0
l
mol/L) upon addition Er3+ (0–21
l
mol/L) in HEPES
fluorescence spectra of probe 1,4-DHA (7.0
lmol/L) in the presence
buffer are displayed in Fig. 2b (kex = 470 nm). As it can be seen,
of Hg2+ (0–2 equiv) in HEPES buffer are displayed in Fig. 3b
Fig. 3. (a) UV–Vis spectra of 1,4-DHA (130 l
mol/L) in HEPES (10 mmol/L, pH = 7.0) upon addition of various concentrations of Hg2+ (0–2 equiv); (b) fluorescence spectra of
1,4-DHA (7
l
M) in the presence of various concentrations of Hg2+ (0–2 equiv) in HEPES (10 mmol/L, pH 7.0) (kex ¼ 470 nm, slit: 5 nm/5 nm). Inset: time-dependent UV–Vis
absorbance of probe at 480 nm in the presence of 10 equiv Hg2+
.
2.365
2.128
2.494
2.419
2.464
2.417
2.403
2.395
2.128
2.371
(a)
(b)
Fig. 4. The structures of Hg-1,4-DHA (a) and Er-1,4-DHA (b) obtained by theoretical calculation.

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C. Yin et al. / Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy 115 (2013) 772–777
Scheme 1. Structure and thermal ellipsoids of probe are drawn at the 50% probability level.
(kex = 470 nm). As it can be seen, the addition of Hg2+ caused
changes in the fluorescence spectra; i.e. a remarkable quenching
of the broad emission band centered at 538, 564 nm was observed.
Simultaneously, a visual fluorescence change (from brilliant yellow
to colorless) for 1,4-DHA was observed under illumination with a
UV 365 nm lamp.
Conclusion
In conclusion, we have reported the interaction between 1,4-
DHA with anthraquinone structure and metal ions by UV–Vis, fluo-
rescence in solution. The investigation results showed 1,4-DHA can
selectively respond some metal ions accompanying UV–Vis, fluo-
rescence spectra changes, as well as color change monitored by
naked-eye. More, as typical metal ions, Hg2+ and Er3+, their reaction
abilities for 1,4-DHA were studied in detailed. They all have better
response for 1,4-DHA in the spectra with distinct and regular
changes. And theoretical calculation concluded that Er3+ easily re-
act with 1,4-DHA over Hg2+ attributed to the low reaction energy of
Er3+-1,4-DHA than Hg2+-1,4-DHA. So 1,4-DHA has a potential appli-
cation in the design of metal ions probe. This result provided a the-
oretical basis for anthraquinone and its derivatives will be
designed as optical probes in the future.
Time-dependence in the detection process of Hg2+and Er3+
Time-dependent modulations in the UV–Vis spectra of 1,4-DHA
was monitored in the presence of 10 equiv. of Hg2+, and Er3+
,
respectively. The kinetic study showed that the reaction was com-
plete within 10, and 60 s for Er3+, and Hg2+ respectively, indicating
that 1,4-DHA reacts rapidly to Er3+ than Hg2+ under the experimen-
tal conditions (Fig. 3 inset).
Acknowledgments
Theoretical predictions
The work was supported by the National Natural Science Foun-
dation of China (Nos. 21072119, and 21102086), the Shanxi Prov-
ince Science Foundation for Youths (No. 2012021009-4), the
Shanxi Province Foundation for Returnee (No. 2012-007), the Taiy-
uan Technology star special (No. 12024703), Program for the Top
Young and Middle-aged Innovative Talents of Higher Learning
Institutions of Shanxi and CAS Key Laboratory of Analytical Chem-
istry for Living Biosystems Open Foundation (ACL201304).
The structure of coordination compound Hg-1,4-DHA was opti-
mized by using the density functional theory (DFT) method imple-
mented in the Dmol3 program [35]. The widely used generalized
gradient approximation (GGA) corrected the Perdew–Wang 1991
(PW91) functional [36,37] was adopted. The valence electrons
functions were expanded into a set of numerical atomic orbitals
by a double-numerical basis with polarization functions (DNP)
[38]. The inner electrons of mercury atoms are kept frozen and re-
placed by an effective core potential (ECP), and other atoms in this
study are treated with an all-electron basis set. The tolerances of
energy, force, and displacement convergence were 2 ꢁ 10ꢂ5
hartree, 4 ꢁ 10ꢂ3 hartree/Å, and 5 ꢁ 10ꢂ3 Å, respectively. The equi-
librium structures of Hg-1,4-DHA and Er-1,4 DHA are shown in
Fig. 4. It can be seen that it is four coordination by the O atoms
from two (1,4-DHA) for Hg2+, however, for Er3+, was coordinated
by three 1,4-DHA molecular and three H2O. The bond lengths of
Hg–O are 2.395, 2.128, 2.128 and 2.403 Å, respectively. The bond
lengths of Er–O are 2.371, 2.365, 2.417, 2.419, 2.494, 2.464 Å,
respectively. The reaction energy of forming Hg-1,4-DHA is
150.59 kJ/mol (according to the reaction: Hg + 2(1,4-DHA) = Hg-
1,4-DHA + H2), while the reaction energy of forming Er-1,4 DHA
is ꢂ1176.66 kJ/mol (according to the reaction: Er + 3(1,4-
DHA)+3H2O = Er-1,4-DHA + 3/2H2). We can see that the later reac-
tion is exothermal, which implies that the reaction is favorable
from thermodynamics. This is consistent that tervalent rare earth
ions have high affinity on anion radical of quinones comparing
with divalent metal ions [39]. In addition, the structure of Er-1,4-
DHA-3NO3 is obtained using the larger smearing value in order
to converge, which is shown in Fig. S7 (see Scheme 1).
Appendix A. Supplementary material
Supplementary data associated with this article can be found, in
the online version, at http://dx.doi.org/10.1016/j.saa.2013.06.095.
References
[1] G. Meazza, F.E. Dayan, D.E. Wedge, J. Agric. Food Chem. 51 (2003) 3824–3828.
[2] W. Yin, Z. Ou, Y. Gao, P. Hao, C. Guo, Z. Wang, Acta Chim. Sinica 68 (2010)
1343–1348.
[3] G.B. Schuster, Acc. Chem. Res. 33 (2000) 253–260.
[4] M. Wainwright, Curr. Bioact. Compd. 3 (2007) 252–261.
[5] X.F. Zhang, J.F. Xiang, M.Y. Tian, Y.L. Tang, Chin. Sci. Bull. 54 (2009) 1374–1386.
[6] D. Shen, Y.X. Lu, X.L. Zhang, H.P. Sun, F. Zhang, Chin. J. Nosocomiol. 10 (2008)
1368–1370.
[7] D. Ly, Y. Kan, B. Armitage, G.B. Schuster, J. Am. Chem. Soc. 118 (1996) 8747–
8748.
[8] T. Tanaka, H. Kohno, M. Murakami, R. Shimada, S. Kagami, Oncol. Rep. 7 (2000)
501–508.
[9] R.G. Balasingham, C.F. Williams, H.J. Mottram, M.P. Coogan, S.J.A. Pope,
Organometallics 31 (2012) 5835–5843.
[10] Y. Hou, S. Cao, P.J. Brodie, M.W. Callmander, F. Ratovoson, E.A. Rakotobe, V.E.
Rasamison, M. Ratsimbason, J.N. Alumasa, P.D. Roepe, D.G.I. Kingston, Bioorg.
Med. Chem. 17 (2009) 2871–2876.

C. Yin et al. / Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy 115 (2013) 772–777
777
[11] M. Demeunynck, Antitumor acridines, Expert Opin. Ther. Pat. 14 (2004) 55–70.
[12] P. Belmont, J. Bosson, T. Godet, M. Tiano, Anti-Cancer Agents Med. Chem. 7
(2007) 139–169.
[13] A. Silvestri, G. Barone, G. Ruisi, M.T.L. Giudice, S. Tumminello, J. Inorg. Biochem.
98 (2004) 589–594.
[22] H.P. Laurence, Anthraquinone anti-cancer compounds with (Disubstituted-
Amino-N-Oxide) alkylamino substituent: GB, 2234283[P], 1991-01-05.
[23] D. Mal, S. Ray, I. Sharma, J. Org. Chem. 72 (2007) 4981–4984.
[24] N.C. Gianneschi, M.S. Masar, C.A. Mirkin, Acc. Chem. Res. 38 (2005) 825–837.
[25] J.A. Thomas, Chem. Soc. Rev. 36 (2007) 856–868.
[14] R.E. Airley, J.E. Monghan, I.J. Stratford, Pharma. J. 26 (2000) 666–673.
[15] L.H. Patterson, S.R. McKeown, K. Ruparelia, J.A. Double, M.C. Bibby, S. Cole, I.J.
Stratford, Brit. J. Cancer 82 (2000) 1984–1990.
[16] A. Yakkundi, V. McErlane, M. Murray, H.O. McCarthy, C. Ward, C.M. hughes,
L.H. Patterson, D.G. Hirst, S.R. Mckeowm, T. Robson, Cancer Gene Ther. 13
(2006) 598–605.
[26] S.J. Lee, W. Lin, Acc. Chem. Res. 41 (2008) 521–537.
[27] Y.F. Han, W.G. Jia, W.B. Yu, G.X. Jin, Chem. Soc. Rev. (2009) 3419–3434.
[28] Y.F. Han, Y.J. Lin, G.X. Jin, Dalton Trans. 40 (2011) 10370–10375.
[29] P.J. Lusby, Inorg. Chem. 108 (2012) 292–314.
[30] Y.F. Han, H. Li, G.X. Jin, Chem.Commun. 46 (2010) 6879–6890.
[31] P.H. Merrell, Inorg. Chim. Acta 32 (1979) 99–102.
[17] B.G. Siim, K.O. Hicks, S.M. Pullen, V. Zijl, L. Pierre, W.A. Denny, W.R. Wilson,
Biochem. Pharmacol. 60 (2000) 969–978.
[18] H.S. Huang, J.F. Chiou, Y. Fong, C.C. Hou, Y.C. Lu, J.Y. Yang, Yaou, J. Med. Chem.
46 (2003) 3300–3307.
[32] F.G. Sanchez, C.C. Blanco, A.H. Bayona, Talanta 34 (1987) 345–350.
[33] G.M. Sheldrick, SADABS, University of Gottingen, Germany, 1997.
[34] G.M. Sheldrick, Program for the Refinement of Crystal Structure, University of
Goettingen, Germany, 1997.
[19] H.P. Laurence, K.P. Paul, H. Tesdale-Spittle, A preparation of anthraquinone
derivatives, Useful as Antitumor Agents: WO, 2005061453 [P], 2005-07-07.
[20] P. Jang, J. Chen, Preparation and anticancer activity of anthraquinone
derivatives: TW, 401405 [P], 2000-08-11.
[35] B. Delley, J. Chem. Phys. 113 (2000) 7756–7764.
[36] J.P. Perdew, K. Burke, M. Ernzerhof, Phys. Rev. Lett. 77 (1996) 3865–3868.
[37] J.P. Perdew, K. Burke, Y. Wang, Condens. Matter Mater. Phys. 54 (1996) 16533–
16539.
[21] R.M. Phillips, M. Jaffar, D.J. Maitland, P.M. Loadman, S.D. Shnyder, G. Steans,
P.A. Cooper, A. Race, A.V. Patterson, I.J. Stratfotd, Biochem. Pharmacol. 68
(2004) 2107–2116.
[38] Y. Inada, H. Orita, J. Comput. Chem. 29 (2008) 225–232.
[39] S.R. Miller, D.A. Gustowski, Z. Chen, G.W. Gokel, L. Echegoyen, A.E. Kaifer,
Macro. Syst. Anal. Chem. 60 (1988) 2021–2024.