Influence of Structural Anisotropy on Mesogenity of Eu(III) Adducts and Optical Properties of Vitrified Films Formed on their Base

Article abstract of DOI:10.1021/acs.inorgchem.5b01617

A new series of europium adducts with the general formula Eu(CPDk_3-CnH2n+1)₃Phen, where CPDk_3-CnH2n+1 denotes β-diketones and Phen is 1,10-phenanthroline, was synthesized. The obtained mesogenic complexes were heated to the temperatures of the isotropic liquid state and then cooled. The complexes having short CH₃ and C₂H₅ substituents crystallized upon cooling, and the complexes with longer substituents from C₃H₇ to C₆H₁₃ underwent a glass transition with the formation of optically transparent amorphous films. Inside the series the complexes with C₇H₁₅ and C₈H₁₇ substituents exhibited a unusual smectic C mesomorphism for lanthanidomesogens. On the basis of quantum-chemical simulations and the results of small-angle X-ray scattering the dependence between the anisotropy of Eu(III) complexes with various ligand environments and their supramolecular organization was found. The synthesized Eu(III) complexes in the solid state show intense red photoluminescence upon irradiation by ultraviolet light (λ_max - 337 nm).

Full text of DOI:10.1021/acs.inorgchem.5b01617

Article
pubs.acs.org/IC
Influence of Structural Anisotropy on Mesogenity of Eu(III) Adducts
and Optical Properties of Vitrified Films Formed on their Base
Andrey A. Knyazev,*,† Aleksandr S. Krupin,† Elena Yu. Molostova,† Ksenia A. Romanova,†
and Yuriy G. Galyametdinov†,‡
†Physical and Colloid Chemistry Department, Kazan National Research Technological University, 420015 Kazan, Russia
‡Kazan E. K. Zavoisky Physical-Technical Institute, Russian Academy of Sciences, 420029 Kazan, Russia
S
* Supporting Information
ABSTRACT: A new series of europium adducts with the
general formula Eu(CPDk3-CnH2n+1)3Phen, where
CPDk3-CnH2n+1 denotes β-diketones and Phen is 1,10-
phenanthroline, was synthesized. The obtained mesogenic
complexes were heated to the temperatures of the isotropic
liquid state and then cooled. The complexes having short CH3
and C2H5 substituents crystallized upon cooling, and the
complexes with longer substituents from C3H7 to C6H13
underwent a glass transition with the formation of optically
transparent amorphous films. Inside the series the complexes
with C7H15 and C8H17 substituents exhibited a unusual smectic
C mesomorphism for lanthanidomesogens. On the basis of
quantum-chemical simulations and the results of small-angle X-ray scattering the dependence between the anisotropy of Eu(III)
complexes with various ligand environments and their supramolecular organization was found. The synthesized Eu(III)
complexes in the solid state show intense red photoluminescence upon irradiation by ultraviolet light (λmax − 337 nm).
widely used in modern nanotechnologies, such as spin coating,
vacuum deposition, and elaboration of molecular layers by the
Langmuir−Blodgett method.
INTRODUCTION
■
At present, many research groups are engaged in the synthesis
and investigation of lanthanide complexes,1,2 which have great
potential as materials for optoelectronic devices, organic light
emitting diodes, flat and flexible displays,3−5 optical fiber
components,6,7 luminescent biological probes,8,9 hybrid phos-
phors,10 and solar batteries.11,12
The anisotropic geometry of the molecules of mesogenic
lanthanide complexes in combination with their glass-forming
ability at ambient temperatures makes it possible to obtain a
source of polarized luminescent light with controlled polar-
ization and radiation intensity. The observed ability of
mesogenic complexes to form optically transparent films
could be used in the future in the development of components
of transparent organic light-emitting diodes and light panels. In
the present work, the syntheses of new coordination
compounds of lanthanides with mesogenic properties are
described; their liquid crystalline properties are discussed, and
theoretical calculations of their molecular geometry with the
purpose of understanding the mechanisms of self-organization
in the mesophase are performed. We have determined that
films of some of the obtained samples are transparent in the
visible spectral range. The effects of the molecular geometry
and the particular ways of intermolecular interactions and
supramolecular self-assembly of the complexes on their
luminescent and optical properties are investigated.
Among coordination compounds of lanthanides, mesogenic
lanthanide complexes or lanthanidomesogens are of particular
interest due to their potential applications as advanced
multifunctional materials.13−16 Mesomorphic properties in
these kinds of compounds are accompanied by anisotropy of
their magnetic and optical properties, allowing one to create
luminescent materials that emit polarized monochromatic
light.17,18 There is an interest in developing lanthanide-
containing liquid crystals, mainly because of the unique
magnetic properties of some of the trivalent ions of the
lanthanide series.19,20 As has been shown earlier,21−25
lanthanidomesogens under the influence of external stimuli
(magnetic fields, electric fields, and laser irradiation) or
orienting agents are capable of forming homogeneous,
supramolecularly organized media on the macroscopic scale.
The important advantage of mesogenic lanthanide complexes is
their increased solubility in organic solvents and capability to
incorporate, in view of some structural resemblance, namely,
the anisotropic form and the presence of terminal alkyl chains,
into the structure of the conductive conjugated polymers.26 It
allows one to prepare hybrid film materials by the methods
Received: May 16, 2015
© XXXX American Chemical Society
A
DOI: 10.1021/acs.inorgchem.5b01617
Inorg. Chem. XXXX, XXX, XXX−XXX

Inorganic Chemistry
Article
Scheme 1. Synthesis of Tris(β-diketonate) Europium Adducts with 1,10-Phenanthroline
decomposition over a wider temperature range (ΔT = 80 °C).
The new compounds have transition temperatures about 40 °C
lower in comparison with literature data (Table 1).
Phase transition temperatures of the synthesized lanthanide
complexes and temperature ranges of the existence of
mesophases (ΔT), which are determined by the polarizing
polythermal microscopy, are given in Table 1.
RESULTS AND DISCUSSION
■
A new series of europium adducts with the general formula
Eu(CPDk3‑CnH2n+1)3Phen, where CPDk3‑CnH2n+1 denotes β-
diketones and Phen is 1,10-phenanthroline, have been
synthesized in accordance with Scheme 1.
The special modifications of known methods have been
applied to the synthesis of complexes, which have been
developed earlier in our group27 by taking into consideration
the specific solubility of the initial ligands and reaction products
containing long hydrocarbon chains. The composition and
structure of the obtained compounds have been confirmed by
data of elemental analysis and mass spectrometry and by the
method of IR spectroscopy.
The obtained mesogenic complexes were heated to the
temperatures of the isotropic liquid state, and then, depending
on the length of alkyl substituents, complexes with short CH3
and C2H5 substituents crystallized upon cooling and complexes
with longer substituents from C3H7 to C6H13 underwent a glass
transition with the formation of optically transparent
amorphous films. The obtained films are stable and remain
transparent at room temperature over several months. Such
kind of vitrified films have been described in the literature.28
Complexes with C7H15 and C8H17 substituents exhibited
smectic C mesomorphism (Figure 1). At the present time
As seen from the data in Table 1, an increase in the length of
the alkyl substituent in β-diketone, starting from C3H7 in the
complex Eu(CPDk3‑C3H7)3Phen, gives rise to a sharp decrease
in the melting point and to the formation of amorphous
products in the syntheses, rather than crystals. A further
increase in the length of the alkyl substituent in the case of the
C7H15 and C8H17 radicals promotes the formation of the
smectic C mesophase and leads to an increase in the
temperature of the isotropic liquid transition.
For determining relationships between the molecular
structure of complexes and their supramolecular organization,
the X-ray diffraction analysis data are quite helpful. However,
the presence of a large number of long alkyl substituents in the
structures of complexes does not allow one to grow a single
crystal, since amorphous products are formed in the synthesis,
as has been shown above. Therefore, we have tried preliminarily
to estimate the sizes of molecules by quantum chemistry
methods. A quantum-chemical simulation of Ln(III) complexes
with various ligand environments makes it possible to foresee
and afterward to synthesize compounds with obviously
predictable mesomorphic properties. Such a prediction can be
made on the basis of the value of geometric anisotropy: i.e., the
ratio of the long inertial axis of a molecule to its short inertial
axis in the ellipsoid of revolution (l/d).
The geometries of eight isomers of the studied complexes
with different arrangements of β-diketones relative to the plane
formed by the 1,10-phenanthroline ligand and europium ion
were considered. Probable isomers of the europium complexes
are represented in Table S1 in the Supporting Information for
the example of the Eu(CPDk3‑C8H17)3Phen complex. On the
basis of the calculations of the equilibrium geometries for the
isomer 5 with the energetically most advantageous arrangement
of the ligands in the complex was chosen for further
calculations of the geometric anisotropy values. In this isomer
the long alkyl chains (−C8H17) in β-diketones have a crosswise
arrangement and do not sterically hinder each other.
Figure 1. Schlieren texture of the smectic C mesophase of
Eu(CPDk3‑C7H15)3Phen at 130 °C (magnification 500×).
The highest contribution to the value of geometric
anisotropy of a molecule is brought by the length of terminal
alkyl substituents of ligands. While the anisometry of molecules
in purely organic liquid crystals increases with an increase in the
length of alkyl substituents, an increase in the length of alkyl
substituents in the investigated complexes leads to a
simultaneous increase in both the length and width, i.e. short
this is a unique example of an unusual Sc phase for
lanthanidomesogens and the first example for β-diketonate
adducts. In addition, attempts to obtain derivatives of
lanthanide complexes exhibiting the Sc phase have been
described in the literature.13,16,29,30 Only two successful samples
of complexes with Schiff bases are known (Table 1, entries 9−
16).31,32 As follows from Table 1, the mesophase exists without
B
DOI: 10.1021/acs.inorgchem.5b01617
Inorg. Chem. XXXX, XXX, XXX−XXX

Inorganic Chemistry
Article
Table 1. Values of Geometric Anisotropy of Eu(CPDk3‑CnH2n+1)3Phen Molecules and Temperatures of Phase Transitions and
Temperature Ranges of the Existence of Mesophases
a
b
entry
complex
l, Å
d, Å
l/d
temp of phase transition, °C
1
Eu(CPDk3‑CH3)3Phen
Eu(CPDk3‑C2H5)3Phen
Eu(CPDk3‑C3H7)3Phen
Eu(CPDk3‑C4H9)3Phen
Eu(CPDk3‑C5H11)3Phen
Eu(CPDk3‑C6H13)3Phen
Eu(CPDk3‑C7H15)3Phen
Eu(CPDk3‑C8H17)3Phen
[La(LH)L2(NO3)]31
[Pr(LH)L2(NO3)]31
[Nd(LH)L2(NO3)]31
[Eu(LH)L2(NO3)]31
[Gd(LH)L2(NO3)]31
[Ho(LH)L2(NO3)]31
[Er(LH)L2(NO3)]31
[Pr(L1H2)3NO3](NO3)2
30.9
30.9
30.9
30.8
30.8
30.9
30.9
30.8
13.8
13.9
14.0
15.3
15.8
16.4
17.6
19.4
2.24
2.22
2.21
2.01
1.95
1.88
1.76
1.59
Cr 256 I
2
Cr 221 I
3
g 133 I
4
g 114 I
5
g 110 I
6
g 78 I
7
g 55 Sc 135 I
g 55 Sc 113 I
Cr 94 Sc 161 dec
Cr 93 Sc 159 dec
Cr 93 Sc 166 dec
Cr 92 Sc 158 dec
Cr 93 Sc 158 dec
Cr 91 Sc 157 dec
Cr 92 Sc 168 dec
Cr 113 Sf 173 Sc 240 dec
8
9
10
11
12
13
14
15
16
32
a
L − 4-({3-hydroxy-4-[(octadecylimino)methyl]phenoxy}carbonyl)phenyl 4-(hexyloxy)benzoate; L1 − N,N′-bis(4-hexadecyloxysalicylidene)-
b
diaminoethane. Legend: Cr, crystal; I, isotropic liquid; g, vitrified film; Sc, smectic C mesophase; Sf, smectic F mesophase; dec, decomposition;.
Figure 2. Optimized structures and geometry parameters of some Eu(CPDk3‑CnH2n+1)3Phen complexes.
axis of the ellipsoid of rotation, of molecules. However,
according to the results of quantum-chemical calculations, an
increase in the length of alkyl substituents in β-diketones
(Table 1) gives rise to a decrease in the anisometry of
molecules of the complexes. In contrast to the complexes
described earlier33 with the Bpy17‑17 ligand (5,5′-dimethyl-2,2′-
bipyridine), the length of which brings a crucial contribution to
the overall geometric anisotropy of molecules of the complexes,
the anisometry of the complexes with 1,10-phenanthroline
depends on the molecular sizes of β-diketones to a greater
extent. Though the l/d value for the majority of known organic
calamitic liquid crystals lies in a range from 4 to 8, it reaches
values of 1.76 and 1.59 in the case of the Eu-
(CPDk3‑C7H15)3Phen and Eu(CPDk3‑C8H17)3Phen complexes,
respectively, and, in spite of this fact, they exhibit liquid
crystalline phases in a rather broad temperature range. One of
the possible explanations for such a difference in the behavior
of lanthanide-containing metallomesogens and conventional
organic liquid crystals is a participation in the lateral
intermolecular interactions between complexes of lanthanide
ions.34 According to the computational data (Figure 2), the
geometry of molecules becomes more branched on transition
to the longer hydrocarbon radicals. This results in the reduction
of intermolecular ligand−ligand and Ln−Ln interactions and, as
follows from Table 1 data, the melting temperatures of
complexes decrease as the substituent length grows. When
the length of the substituent becomes longer (i.e., with the long
alkyl chains −C7H15 and −C8H17), the relation between
intermolecular attraction and anisometry become optimal for
forming liquid crystal ordering; thus, mesophases can be
formed at smaller anisometric values.
The phase transition temperatures determined by the POM
method have been confirmed by the DSC method, as illustrated
in Figure 3 on an example of the Eu(CPDk3‑C7H15)3Phen
complex. As seen from the given thermogram (Figure 3), two
characteristic peaks corresponding to the transition from the
crystal to a liquid crystalline phase (55 °C) and from the liquid
crystalline phase to the isotropic liquid state (134 °C) appear
Figure 3. DSC thermogram of the Eu(CPDk3‑C7H15)3Phen complex
during heating and cooling.
C
DOI: 10.1021/acs.inorgchem.5b01617
Inorg. Chem. XXXX, XXX, XXX−XXX

Inorganic Chemistry
Article
upon heating of the sample. Upon cooling, the sample is
vitrified with preservation of the molecular packing adopted in a
mesophase (the molecular packing of the smectic C phase), as
can be concluded from the absence of crystallization peaks on
the thermogram.
Using the ability of the investigated adducts to form glasses
with preservation of the molecular packing upon cooling, the
vitrified phases of the Eu(CPDk3‑CnH2n+1)3Phen complexes have
been investigated by the method of small-angle X-ray scattering
at ambient temperatures.
The X-ray diffraction pattern of a vitrified film of the
Eu(CPDk3‑C7H15)3Phen complex that is recorded at room
temperature contains two peaks at 2θ = 3.97° and 2θ = 7.92°
(Figure 4), which correspond to the first and second reflections
Using the data of small-angle X-ray scattering (Figure 4), the
packing of molecules in the smectic C phase was simulated.
According to the performed calculations, the length of an
Eu(CPDk3‑C7H15)3Phen molecule equals 30.9 Å (Table 1) and
exceeds the interlayer spacing distance (28.5 Å). Hence, it can
be assumed that interpenetration of the alkyl substituents of β-
diketone molecules belonging to neighboring layers takes place
upon packing of the molecules in the mesophase (Figure 5).
The Eu(III) complexes with CPDk3‑C3H7−CPDk3‑C6H13 β-
diketones are amorphous substances in the solid state at room
temperature. As seen from the diffractogram (Figure 6), a film
of Eu(CPDk3C6H13)3Phen upon cooling from the isotropic
liquid state is vitrified at ambient temperatures with the
formation of an amorphous low-ordered structure.
Figure 6. Diffractogram of Eu(CPDk3‑C6H13)3Phen complex at 25 °C
after cooling from an isotropic liquid.
Figure 4. Diffractogram of Eu(CPDk3‑C7H15)3Phen complex at 25 °C
after cooling from an isotropic liquid.
Thin homogeneous films were prepared on the basis of
Eu(CPDk3‑C6H13)3Phen, by cooling the sample from its
isotropic liquid state between quartz plates. The Eu-
(DBM)3Phen complex (DBM = 1,3-diphenyl-1,3-propane-
dione) was used as the reference sample. The film thickness
was about 10 μm. The photographic images of the prepared
films are shown in Figure 7.
of the interlayer spacing equal to 28.5 Å. The diffractogram is
typical for a smectic C mesophase.35 This is confirmed by
preservation of the smectic C mesophase packing in a vitrified
film of the complex, as can be observed by the polarizing optical
microscopy method.
Figure 5. Model of packing of Eu(CPDk3‑C7H15)3Phen according to quantum-chemical simulations (the length of the molecule) and small-angle X-
ray diffraction (interlayer distance).
D
DOI: 10.1021/acs.inorgchem.5b01617
Inorg. Chem. XXXX, XXX, XXX−XXX

Inorganic Chemistry
Article
Figure 7. Photographic images of the prepared films of Eu-
(CPDk3‑C6H13)3Phen (left) and Eu(DBM)3Phen (right) complexes
between quartz plates (in cm).
The light absorption intensity data of a film of the
Eu(DBM)3Phen complex containing crystalline inclusions and
of a vitrified Eu(CPDk3‑C6H13)3Phen film are given in Figure 8.
Figure 9. Excitation (dashed line) and emission (solid line) spectra of
the film of the Eu(CPDk3C6H13)3Phen adduct.
are in the range 0.54−0.56 ms, which is typical for Eu(III)
complexes with β-diketones.38
CONCLUSION
■
New mesogenic Eu(III) complexes containing ligands with
multiple bonds have been synthesized. The obtained complexes
are capable of undergoing a glass transition upon cooling from
the isotropic liquid state with the formation of the supra-
molecularly organized media, which preserve the ordered
arrangement of the Eu(III) ions created in the smectic C
mesophase. By the methods of quantum chemistry and X-ray
diffraction analysis, the relationship between the geometric
anisotropy of molecules of the complexes, their intermolecular
interaction, and supramolecular organization of the formed
mesophases has been established. It is shown that some of the
synthesized lanthanidomesogen entities are vitrified, forming
optically isotropic films, which exhibit effective luminescence in
the red spectral range.
Figure 8. Light transmittance of Eu(CPDk3‑C6H13)3Phen and Eu-
(DBM)3Phen complexes.
EXPERIMENTAL SECTION
■
As seen from the spectra, the intensity of the transmitted light
in the range from 400 to 700 nm strongly depends on the
aggregate state of the substance in a film. The relative intensity
of the transmitted light of a vitrified film of the amorphous
Eu(CPDk3‑C6H13)3Phen complex reaches 98%, which exceeds
by 5 times the same parameter for a film of the Eu(DBM)3Phen
complex containing crystalline inclusions.
General Information. The optical textures and temperatures of
phase transitions were determined on an Olympus BX-51 polarizing
microscope equipped with a LINKAM high-precision heating system.
The IR spectra were recorded on a Bruker-IFS66VIS spectrometer
1
using samples suspended in Vaseline oil or in KBr tablets. H NMR
spectra were recorded with Bruker Avance 300 and Bruker Avance 400
spectrometers (operating at 300 and 400 MHz). The mass spectra
were obtained using a Bruker Esquire LC-Ion Trap Mass
Spectrometer. The X-ray diffraction studies were performed on a
DRON-2 diffractometer using Fe Kα radiation with λ 1.93728 Å. DSC
measurements were made on a Mettler-Toledo DSC 1 Star module in
a heating−cooling mode at a scan rate of 10 K/min. The luminescence
spectra were registered on a Varian Cary Eclipse spectrofluorimeter.
The absolute quantum yield of the complexes in the solid state was
determined following a standard technique using a specially designed
setup equipped with an integrating sphere 105 mm in diameter coated
with MgO, a light diode (380 nm, 10 mW) as an excitation source, and
an FEU62 photomultiplier as a detector.39
Synthetic Procedures. The β-diketone ligands (abbreviated
CPDk3‑R) with different lengths of the alkyl terminal substituents (R
= CH3−C8H17) were synthesized according to the method of Adams
and Hauser.40 To the stirred solution of the ketone (0.05 mol) in 100
mL of absolute ether, cooled to 10 °C, was added a suspension of
sodium amide in toluene (0.1 mol). After 5 min the calculated amount
of ester R-COOC2H5 (0.1 mol) in 100 mL of absolute ether was
added over 20 min, and the stirring was continued for 6 h. After 20 mL
of water was added, the mixture was neutralized with dilute
The synthesized Eu(III) complexes in the solid state show
intense red photoluminescence upon irradiation by ultraviolet
light (λmax 337 nm). The difference in structure and
luminescence properties in the series of complexes under
investigation are negligible. Typical excitation and emission
spectra of the Eu(CPDk3C6H13)3Phen adduct are shown in
Figure 9 as an example. The maximum luminescence intensity
corresponds to a wavelength of 612 nm.36 The observed well-
5
resolved peaks can be attributed to transitions from the D0
level of the excited state to the 7FJ sublevels of the ground-state
multiplet (J = 0−4). The ratio of the electric dipole transition
intensity to the magnetic dipole transition intensity ((5D0 →
37
7
7F2)/(5D0 → F1)) is 11.5. The complexes display relatively
high luminescence efficiency among the Eu(III) mesogenic
complexes with β-diketones; the absolute quantum yield is 30−
32% and does not depends on the length of the alkyl chains.
The values of the fluorescence lifetime (see Figure S1 in the
Supporting Information) of synthesized lanthanide complexes
E
DOI: 10.1021/acs.inorgchem.5b01617
Inorg. Chem. XXXX, XXX, XXX−XXX

Inorganic Chemistry
Article
hydrochloric acid and extracted with ether. The solvent was
evaporated from the ether solution and the residue dissolved in the
minimum volume of ethanol. The β-diketone was recrystallized twice
from this ethanol solution. Yields, elemental analysis, and melting
points have been described previously.33
Tris[1-(4-(4-propylcyclohexyl)phenyl)undecane-1,3-
dionato](1,10-phenanthroline)europium(III): General Proce-
dure. An alcoholic solution of EuCl3·6H2O (0.015 g, 0.04 mmol)
was slowly dropped into a stirred hot alcoholic solution containing
0.078 g (0.12 mmol) of β-diketone, 0.008 g (0.04 mmol) of 1,10-
phenanthroline, and 0.005 g (0.125 mmol) of KOH. The light yellow
precipitate that formed was isolated by hot filtration, washed with hot
alcohol, and dried under vacuum. Further, the product was dissolved in
toluene, and the obtained solution was filtered off and evaporated to
dryness under vacuum.
Theoretical Calculations. Quantum-chemical simulation of the
equilibrium geometry of complexes was performed using the Priroda
06 software41,42 by the DFT method with the PBE exchange
correlation functional.43 The properties of lanthanide-containing
systems should be simulated by taking into account relativistic effects.
Therefore, the rL11 relativistic basis set was applied for lanthanides
and the rL1 basis set for other atoms,44 which are analogues of the cc-
pVDZ and cc-pCVDZ correlation-consistent double-ζ basis sets of
Dunning, respectively. Calculations were carried out in the gas phase
without symmetry constraints. The geometry of the coordination
polyhedron of complexes was adopted from the Cambridge Structural
Database, which contains the X-ray diffraction analysis data for similar
compounds without alkyl substituents.45−47
(5) Katkova, M. A.; Bochkarev, M. N. Dalton Trans. 2010, 39, 6599−
6612.
(6) Bunzli, J.-C. G.; Eliseeva, S. V. J. Rare Earths 2010, 28, 824−842.
̈
(7) Hasegawa, Y.; Wada, Y.; Yanagida, S. J. Photochem. Photobiol., C
2004, 5, 183−202.
(8) Eliseeva, S. V.; Bunzli, J.-C. G. Chem. Soc. Rev. 2010, 39, 189−
̈
227.
(9) Bunzli, J.-C. G. Chem. Lett. 2009, 38, 104−109.
̈
(10) Carlos, L. D.; Ferreira, R. A. S.; de Zea Bermudez, V.; Julian
́
-
Lopez, B.; Escribano, P. Chem. Soc. Rev. 2011, 40, 536−549.
́
(11) Shen, J.; Li, Z. Q.; Cheng, R.; Luo, Q.; Luo, Y. D.; Chen, Y. W.;
Chen, X. H.; Sun, Z.; Huang, S. M. ACS Appl. Mater. Interfaces 2014, 6,
17454−17462.
(12) MacDougall, S. K. W.; Ivaturi, A.; Marques-Hueso, J.; Kramer,
K. W.; Richards, B. S. Sol. Energy Mater. Sol. Cells 2014, 128, 18−26.
(13) Binnemans, K.; Gorller-Walrand, C. Chem. Rev. 2002, 102,
̈
2303−2345.
(14) Donnio, B.; Guillon, D.; Deschenaux, R.; Bruce, D. W. In
Comprehensive coordination chemistry II; McCleverty, J. A., Meyer, J. J.,
Eds.; Elsevier Science: Amsterdam, 2003; Vol. 7, pp 357−627.
(15) Torroba, J., Bruce, D. W. In Comprehensive Inorganic Chemistry
II: From Elements to Applications, 2nd ed.; Elsevier: Amsterdam, 2013;
Vol. 8, pp 837−917.10.1016/B978-0-08-097774-4.00824-X
(16) Binnemans, K. In Handbook on the Physics and Chemistry of Rare
Earths; Elsevier: Amsterdam, 2013, Vol. 43, pp 1−158.10.1016/B978-
0-444-59536-2.00001-5
(17) Driesen, K.; Moors, D.; Beeckman, J.; Neyts, K.; Gorller-
Walrand, C.; Binnemans, K. J. Lumin. 2007, 127, 611−615.
(18) Gao, R.; Zhao, M.; Guan, Y.; Fang, X.; Li, X.; Yan, D. J. Mater.
Chem. C 2014, 2, 9579−9586.
(19) Binnemans, K.; Galyametdinov, Y. G.; Van Deun, R.; Bruce, D.
W.; Collinson, S. R.; Polishchuk, A. P.; Bikchantaev, I.; Haase, W.;
Prosvirin, A. V.; Tinchurina, L.; Litvinov, I.; Gubajdullin, A.;
Rakhmatullin, A.; Uytterhoeven, K.; Van, L. J. Am. Chem. Soc. 2000,
122, 4335−4344.
(20) Chakraborty, J.; Ray, A.; Pilet, G.; Chastanet, G.; Luneau, D.;
Ziessel, R. F.; Charbonniere, L. J.; Carrella, L.; Rentschler, E.; El
̀
ASSOCIATED CONTENT
* Supporting Information
■
S
The Supporting Information is available free of charge on the
ACS Publications website at DOI: 10.1021/acs.inorg-
chem.5b01617.
CHN analysis data and yields, optimized structures of
isomers of the Eu(CPDk3‑C8H17)3Phen complex, lumi-
nescence decay curves, and NMR and mass spectrometry
data (PDF)
Fallahe, M. S.; Mitra, S. Dalton Trans. 2009, 46, 10263−10272.
(21) Galyametdinov, Y. G.; Knyazev, A. A.; Dzhabarov, V. I.;
Cardinaels, T.; Driesen, K.; Gorller-Walrand, C.; Binnemans, K. Adv.
Mater. 2008, 20, 252−257.
(22) Knyazev, A. A.; Molostova, E. Y.; Krupin, A. S.; Heinrich, B.;
Donnio, B.; Haase, W.; Galyametdinov, Y. G. Liq. Cryst. 2013, 40,
857−863.
AUTHOR INFORMATION
Corresponding Author
*A.A.K.: tel, +7 843 231 41 77; e-mail, knjazev2001@mail.ru.
■
Author Contributions
(23) Dzhabarov, V. I.; Knyazev, A. A.; Nikolaev, V. F.;
Galyametdinov, Y. G. Russ. J. Phys. Chem. A 2011, 85, 1450−1453.
(24) Lapaev, D. V.; Nikiforov, V. G.; Safiullin, G. M.; Lobkov, V. S.;
Salikhov, K. M.; Knyazev, A. A.; Galyametdinov, Y. G. Opt. Mater.
2014, 37, 593−597.
The manuscript was written through contributions of all
authors. All authors have given approval to the final version of
the manuscript.
Notes
(25) Bunzli, J.-C. G. Acc. Chem. Res. 2006, 39, 53−61.
̈
The authors declare no competing financial interest.
(26) Lapaev, D. V.; Safiullin, G. M.; Lobkov, V. S.; Salikhov, K. M.;
Knyazev, A. A.; Galyametdinov, Y. G. Russ. J. Phys. Chem. 2005, 79,
S33−S38.
ACKNOWLEDGMENTS
■
Financial support was provided by a grant from the RSF (No.
14-13-00758). Quantum-chemical calculations were performed
using the facilities of the Joint Supercomputer Center of
Russian Academy of Sciences and the Supercomputing Center
of Lomonosov, Moscow State University.48
(27) Knyazev, A. A.; Galyametdinov, Y. G.; Goderis, B.; Driesen, K.;
Goossens, K.; Gorller-Walrand, C.; Binnemans, K.; Cardinaels, Th.
̈
Eur. J. Inorg. Chem. 2008, 2008, 756−761.
(28) Binnemans, K.; Jongen, L.; Gorller-Walrand, C. Phys. Chem.
̈
Chem. Phys. 2001, 3, 4796−4799.
(29) Terazzi, E.; Suarez, S.; Torelli, S.; Nozary, H.; Imbert, D.;
REFERENCES
Mamula, O.; Rivera, J.-P.; Guillet, E.; Ben
́
ech, J.-M.; Bernardinelli, G.;
■
Scopelliti, R.; Donnio, B.; Guillon, D.; Bunzli, J.-C. G.; Piguet, C. Adv.
̈
(1) Feng, J.; Zhang, H. Chem. Soc. Rev. 2013, 42, 387−410.
(2) Binnemans, K. Chem. Rev. 2009, 109, 4283−4374.
(3) Comby, S.; Bunzli, J.-C. G. In Handbook on the Physics and
Chemistry of Rare Earths; Gschneidner, K. A., Bunzli, J.-C. G.,
Pecharsky, V. K., Eds.; Elsevier Science: Amsterdam, 2007; Vol. 37, pp
Funct. Mater. 2006, 16, 157−168.
(30) Terazzi, E.; Torelli, S.; Bernardinelli, G.; Rivera, J.-P.; Benech, J.-
̈
M.; Bourgogne, C.; Donnio, B.; Guillon, D.; Imbert, D.; Bunzli, J.-C.
G.; Pinto, A.; Jeannerat, D.; Piguet, C. J. Am. Chem. Soc. 2005, 127,
̈
̈
888−903.
217−470.
(31) Lodewyckx, K.; Van Deun, R.; Binnemans, K. Mater. Sci. Eng., C
2001, 18, 217−221.
(4) Quirino, W. G.; Legnani, C.; Cremona, M.; Lima, P. P.; Junior, S.
A.; Malta, O. L. Thin Solid Films 2006, 494, 23−27.
F
DOI: 10.1021/acs.inorgchem.5b01617
Inorg. Chem. XXXX, XXX, XXX−XXX

Inorganic Chemistry
Article
(32) Kumari, S.; Singh, A. K.; Kumar, K. R.; Sridhar, B.; Rao, T. R.
Inorg. Chim. Acta 2009, 362, 4205−4211.
(33) Dzhabarov, V. I.; Knyazev, A. A.; Strelkov, M. V.; Molostova, E.
Y.; Schustov, V. A.; Haase, W.; Galyametdinov, Y. G. Liq. Cryst. 2010,
37, 285−291.
(34) Serrano, J. L. Metallomesogens, Synthesis, Properties and
Applications; Wiley-VCH: Weinheim, Germany, 1996.
(35) Demus, D.; Goodby, J.; Gray, G. W.; Spiess, H.-W.; Vill, V.
Handbook of Liquid Crystals: Fundamentals; Wiley-VCH: Weinheim,
Germany, 1998; pp 638−640.
(36) Moore, E. G.; Samuel, A. P. S.; Raymond, K. N. Acc. Chem. Res.
2009, 42, 542−552.
(37) Graffion, J.; Cattoen, X.; Man, M. W. C.; Fernades, V. R.; Andre,
́
̈
P. S.; Ferreira, R. A.; Carlos, L. D. Chem. Mater. 2011, 23, 4773−4782.
(38) Binnemans, K. In Handbook on the Physics and Chemistry of Rare
Earths; Gschneidner, K. A., Jr., Bunzli, J.-C. G., Pecharsky, V. K., Eds.;
̈
Elsevier Science: Amsterdam, 2005; Vol. 35, pp 107−272.
(39) Romanova, K. A.; Datskevich, N. P.; Taidakov, I. V.;
Vitukhnovskii, A. G.; Galyametdinov, Y. G. Russ. J. Phys. Chem. A
2013, 87, 2108−2111.
(40) Adams, J. T.; Hauser, C. R. J. Am. Chem. Soc. 1944, 66, 1220−
1222.
(41) Laikov, D. N. Chem. Phys. Lett. 1997, 281, 151−156.
(42) Laikov, D. N. Priroda: Electronic Structure Code Version 6, 2006.
(43) Perdew, J. P.; Burke, K.; Ernzerhof, M. Phys. Rev. Lett. 1996, 77,
3865−3868.
(44) Laikov, D. N. Chem. Phys. Lett. 2005, 416, 116−120.
(45) Yu, J.; He, X.-Q.; Zhou, Z.-Y.; Liu, L. Chin. J. Struct. Chem. 1989,
8, 187−191.
(46) Qian-Ling, G.; Zhu, W.-X.; Guo, R.; Yan, X.; Wang, R.-J. Chin. J.
Chem. 2003, 21, 211−215.
(47) Guo, J.-F.; Zhang, H.-J.; Fu, L.-S.; Meng, Q.-G. Chin. J. Inorg.
Chem. 2004, 20, 543−546.
(48) Voevodin, V. V.; Zhumatiy, S. A.; Sobolev, S. I.; Antonov, A. S.;
Bryzgalov, P. A.; Nikitenko, D. A.; Stefanov, K. S.; Voevodin, V. V.
Practice of “Lomonosov” Supercomputer. Open Systems J. 2012, 7,
36−39; http://www.osp.ru/os/2012/07/13017641/ (in Russian).
G
DOI: 10.1021/acs.inorgchem.5b01617
Inorg. Chem. XXXX, XXX, XXX−XXX