Luminescence enhancement of the Tb(III) ion with the thenoyltrifluoroacetonate ligand acting as an efficient sensitizer

Article abstract of DOI:10.1016/j.inoche.2010.07.043

The synthesis, structural investigation, and photophysical properties of the complex [Tb(TTA)₂(NO₃)(TPPO)₂] are reported. Unlike the analog tris-diketonate complex [Tb(TTA)₃(TPPO) ₂], the new complex

Full text of DOI:10.1016/j.inoche.2010.07.043

Inorganic Chemistry Communications 13 (2010) 1391–1395
Contents lists available at ScienceDirect
Inorganic Chemistry Communications
journal homepage: www.elsevier.com/locate/inoche
Luminescence enhancement of the Tb(III) ion with the thenoyltrifluoroacetonate
ligand acting as an efficient sensitizer
a
a
b
c
Ercules E.S. Teotonio a, , Francisco A. Silva Jr , Dariston K.S. Pereira , Lidiaine M. Santo , Hermi F. Brito ,
Wagner M. Faustino d, Maria Cláudia F.C. Felinto e, Regina Helena Santos f, Rodolfo Moreno-Fuquen g,
Alan R. Kennedy h, Denise Gilmore h
⁎
a
Departamento de Química, Universidade Federal da Paraíba, 58051-970, João Pessoa, PB, Brazil
Departamento de Química, Universidade Federal de Goiás-Campus Catalão, UFG, 75704-020, Catalão, GO, Brazil
Instituto de Química, Universidade de São Paulo, 05508-900 São Paulo SP, Brazil
Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA 02138, USA
Instituto de Pesquisas Energéticas e Nucleares Travessa R 400 Cidade Universitária, São Paulo, SP CEP 05508-970, Brazil
Instituto de Química de São Carlos, USP, C.P. 780, 13560-970 São Carlos, SP, Brazil
Departamento de Química Universidad del Valle, Calle 13 Carrera 100, Cali, Colombia
WestCHEM, Department of Pure and Applied Chemistry, University of Strathclyde, 295 Cathedral Street, Glasgow G1 1XL, Scotland, UK
b
c
d
e
f
g
h
a r t i c l e i n f o
a b s t r a c t
Article history:
The synthesis, structural investigation, and photophysical properties of the complex [Tb(TTA)2(NO3)
(TPPO)2] are reported. Unlike the analog tris-diketonate complex [Tb(TTA)3(TPPO)2], the new complex
presents abnormally high luminescence intensity centered on the terbium ion. Our results clearly suggest a
higher energy transfer efficiency from the TTA antenna ligand to the Tb(III) ion in the bis-diketonate complex
compared with that in the tris-diketonate complex. A mechanism involving the increasing of triplet state
energy when one TTA ligand is replaced by the NO3− group in the first coordination sphere is suggested
and experimentally investigated to explain the anomalous luminescence properties of the new complex
[Tb(TTA)2(NO3)(TPPO)2].
Received 6 May 2010
Accepted 31 July 2010
Available online 6 August 2010
Keywords:
Terbium
Luminescence
Thenoyltrifluoroacetonate
Sensitizer
© 2010 Elsevier B.V. All rights reserved.
Energy transfer
The great interest in research on the luminescent coordination
compounds based on the trivalent lanthanide ions, Ln(III), as the
emitting centers is mainly due to the unique photophysical properties
presented by this kind of metal ion, including the narrow emission
bands arising from the intraconfigurational 4f–4f transitions and the
long excited state lifetimes (on the order of milliseconds) [1]. The
narrow emission bands of the Ln(III) ions are necessary to confer pure
(or highly monochromic) emission colors for applications in displays
[2–4], while their long lifetimes provide considerable intensities for
practical applications in time-resolved luminescence in medical
diagnosis [5–8].
However, the 4f–4f transitions, which are parity forbidden by
Laporte's rule, exhibit weak intensity in both their emission and
absorption spectra, with their molar absorption coefficients being on
the order of 1.0 M−1 cm−1. To overcome these low extinction
coefficients, indirect excitation is generally performed with chromo-
phoric organic ligands as antennae.
The antenna effect in lanthanide coordination compounds depends
on the electromagnetic energy absorption from the ligand that
transfer energy to the excited 2S + 1LJ states of the Ln(III) ion, which
decay radiatively with photon emission. Based on the energy of the
triplet state (T) of the organic ligands, there could be four different
situations: i) The ligand T state is located below the emitter 2S + 1LJ
levels of the Ln(III) ion. In this case, the metal ion cannot easily accept
energy from the first excited triplet states (T1) of the organic ligands
(diketonates) via the intramolecular ligand-to-metal energy transfer.
For example, the Gd(III) ion has its first excited level, 6P7/2, located at
one higher than the T state of the organic ligands; ii) The ligand T
states have energies very close to the excited 2S + 1LJ states. For this
situation, there is a competitive balance between the non-radiative
donation and the retrodonation (T↔2S + 1LJ), which makes the Ln(III)
ions exhibit low luminescence intensities; iii) The donor ligand T state
is considerably more energetic than the main acceptor excited 2S + 1LJ
state of the Ln(III) ion, minimizing the retrodonation (T←2S + 1LJ)
processes; and iv) The ligand T states have energies largely above the
main acceptor excited states of the central metal ion. Some works
have determined that the energy gap between the lowest singlet and
triplet excited states of the ligand around 5000 cm−1 and the triplet
⁎
Corresponding author. Tel.: +55 83 3216 7591; fax: +55 83 3216 7437.
E-mail address: teotonioees@quimica.ufpb.br (E.E.S. Teotonio).
1387-7003/$ – see front matter © 2010 Elsevier B.V. All rights reserved.
doi:10.1016/j.inoche.2010.07.043

1392
E.E.S. Teotonio et al. / Inorganic Chemistry Communications 13 (2010) 1391–1395
state at least 3500 cm−1 more energetic than the acceptor 2S + 1LJ
level, is one of the better energetic conditions to obtain the
coordination compounds with higher luminescence intensities cen-
tered on the Ln(III) ions [9–15].
ligand via an oxygen atom to the Tb(III) ion is indicated by the shift of
the stretching frequency ν(P=O) from 1200 cm−1 in the non-
coordinate TPPO to around 1180 cm−1 in the Tb(III) complexes. The
IR spectrum of the [Tb(TTA)2(NO3)(TPPO)2] complex also displays
two absorption bands around 1175 and 1136 cm−1 assigned to the
NO−3 group acting as chelate with the C2V symmetry.
Single crystals of the [Tb(TTA)2(NO3)(TPPO)2] complex grown in
hexagonal form were obtained after evaporation of solvents from the
mother solution at room temperature (298 K) over 48 h. It is important
to report that no sign of deterioration during storage under ordinary
laboratory atmospheric conditions was observed. X-ray diffraction data
indicate that this coordination compound crystallizes in the triclinic
system with the P1 space group symmetry [26-30]. As can be seen in
Several kinds of antenna ligands have been successfully synthe-
sized during the last decade to obtain new, highly luminescent
complexes for photonic applications as either optical probes in clinical
analyses or emitter layers in organic light-emitting devices (OLEDs).
The β-diketonate ligands are among the most largely investigated
[13–15]. Previous works have shown that β-diketonate complexes
containing aromatic or a combination of aromatic and aliphatic
substituent groups are very efficient antennae for the Eu(III) ion.
These include thenoyltrifluoroacetonate (TTA), dibenzoylmethanate
(DBM), benzoylacetonate (BA), and naphtoylacetonates (1NTFA and
2NTFA) [16,17]. For the Tb(III) ion, often the aliphatic diketonates are
better antennae than the aromatic ones. But, some aromatic
diketonates with methoxy and fluor substituents can present ideal
energy to tune the T states for efficient intramolecular energy transfer
from the ligand to the Tb(III) ion [15].
The points discussed above are based on the similarity between the T
state energy values in both the tris and tetrakis diketonate complexes. In
fact, X-rays of the structures of these lanthanide, coordination
compounds have shown that the β-diketonate ligands coordinate in an
analogous mode. The differences between the Ln(III)–O(β-diketonate)
distances for these two complexes are around 0.02 Å [18,19]. Conse-
quently, significant changes in the electronic charge distributions
between the tris and tetrakis chelate rings are not expected to take
place. However, for some Eu(III) compounds with DBM and TTA ligands
containing phosphine oxide (TPPO) as a second kind of ligand, the T state
energies change considerably [20–22].
The main role of the TPPO ligand is to substitute the water
molecules in Ln(III) complexes, minimizing the non-radiative pro-
cesses. It is important to mention that phosphine and phosphine oxide
ligands have large cone angles that influence both the number of the
ligands around the metal ion and the effectiveness of the overlap
between the metal ion and the ligand wave functions. In our previous
paper, we determined the energetic positions of the singlet (S) and
triplet (T) states arising from the TTA ligand in bis-TTA and tris-TTA
complexes of the Gd(III) and Eu(III) ions [20]. The energy values of
the TTA triplet states were estimated from the shortest wavelength
based on the emission bands corresponding to the T→S0 transitions
(0–0 phonon). The energy values of the excited S states were taken as
the longest wavelength from the absorption spectra corresponding to
the S0 →S transition (0–0 phonon). The data showed that the excited
levels of the TTA ligand are higher in bis-TTA complexes than in tris-
TTA ones.
In this paper, we describe the synthesis [23,24], characterization
[25], structure [26] and optical properties, of a new, unusual, highly
luminescent complex of terbium(III) with the thenoyltrifluoroaceto-
nate ligand acting as the luminescence sensitizer [Tb(TTA)2(NO3)
(TPPO)2]. The emission spectral profile and the experimental emission
quantum yield obtained for this complex have been discussed in
comparison with the similar tris-diketonate complex with the formula
[Tb(TTA)3(TPPO)2].
The terbium bis-complex of the formula [Tb(TTA)2(NO3)(TPPO)2]
has been prepared by the reaction of Tb(NO3)3⋅5H2O, HTTA (thenoyltri-
fluoroacetone) and TPPO (triphenylphosphine oxide) in a 1:2:2 ratio in
methanol [23], while the tris-complex [Tb(TTA)3(TPPO)2] was prepared
by direct reaction of TbCl3⋅6H2O, HTTA and TPPO in a 1:3:2 ratio in
ethanol [24]. The experimental results are in good agreement with the
calculated data, confirming that the complexes present the following
stoichiometries [Tb(TTA)2(NO3)(TPPO)2] and [Tb(TTA)3(TPPO)2].
The IR spectra of the Tb(III) complexes show two strong
absorption bands at 1688 and 1557 cm−1 attributed to νs(C=O)
and νas(C=O) vibrational stretching modes, suggesting that the TTA
ligand acts as a chelate ligand. Moreover, the coordination of the TPPO
Fig. 1. (a) ORTEP drawing (50% of probability) displaying the X-ray structure of [Tb
(TTA)2(NO3)(TPPO)2] complex; (b) coordination polyhedron of Tb3+ ion: Bond
lengths: Tb1–O1 2.235(4), Tb1–O2 2.278(4), Tb1–O5 2.342(4), Tb1–O6 2.347(4),
Tb1–O4 2.354(4), Tb1–O3 2.362(4), Tb1–O7 2.453(4), Tb1–O8 2.454(4). Bond angles:
O1–Tb1–O2 155.89(12),O1–Tb1–O5 79.90(15), O2–Tb1–O5 80.57(15), O1–Tb1–O6
95.01(15), O2–Tb1–O6 92.25(14), O5–Tb1–O6 71.98(14), O1–Tb1–O4 93.44(14), O2–
Tb1–O4 95.34(14), O5–Tb1–O4 147.16(13), O6–Tb1–O4 140.86(13), O1–Tb1–O3 82.00
(15), O2–Tb1–O3 79.57(14), O5–Tb1–O3 75.60(13), O6–Tb1–O3 147.45(12). (c) Part of
the crystal structure of the [Tb(TTA)2(NO3)(TPPO)2] complex, showing the crystal chain
in the [101] direction. (d) Part of the crystal structure of [Tb(TTA)2(NO3)(TPPO)2],
showing the crystal growth in the [001] direction.

E.E.S. Teotonio et al. / Inorganic Chemistry Communications 13 (2010) 1391–1395
1393
Fig. 1 (continued).
Fig 1a, the Tb(III) ion is coordinated by eight oxygen atoms belonging to
two monodentate TPPO ligands, two bidentate TTA− anions and one
bidentate nitrate group. There are no significant structural differences
between the [Ln(TTA)2(NO3)(TPPO)2] complexes containing Sm(III),
Eu(III) and Tb(III) ions owing to the closeness of their ionic radii of
1.079, 1.066 and 1.040 , respectively [18,20]. The shortest Tb–O
distance (Fig. 1b) occurs with the oxygen atom of the TPPO ligand and
the longest with the oxygen atom of the TTA ligand. One interesting
feature is that the values of the two distances Tb–O for the same TTA
molecule are very close. These X-ray data are different from those for
the tris-complex [Ln(TTA)3(TPPO)2] in which the Ln–O distances
close to the thyophen substituent group are much longer than those
close to the CF3. This behavior apparently mimics the greater steric
effect between TTA and TPPO ligands compared with the bis-complex
[Tb(TTA)2(NO3)(TPPO)2]. Fig. 1b displays the coordination polyhe-
dron TbO8 for the [Tb(TTA)2(NO3)(TPPO)2] compound containing a
distorted dodecahedron geometry with the D2d point group.
590 nm, under emission on the 5D4→7F5 transition at 545 nm, are given
in Fig. 2a. The spectrum of the [Tb(TTA)2(NO3)(TPPO)2] compound
contains two, overlapped, intense, broaden bands corresponding to the
S0→S1 transition of the TTA ligands. Excitation of the spectrum also
displays weak narrow absorption bands in the spectral range from 450
to 500 nm that are assigned to the 4f8-intraconfigurational transitions:
7F6→5L6 (339 nm), 7F6→5L9 (350 nm), 7F6→5L10 (369 nm), 7F6→5G6
(376 nm), 7F6→5D3 (380 nm) and 7F6→5D4 (488 nm). These optical
data show that the TTA ligand must also be considered an efficient
antenna for sensitizing the luminescence intensity of the Tb(III) ion in
the bis-complex.
a) [Tb(TTA)2(NO3)(TPPO)2] b) [Tb(TTA)3(TPPO)2]
This crystal structure contains no classical hydrogen bonds.
However, this system has other interactions, such as the S–H...F, C–
H…F and CH...O interactions, which define its crystal growth. In a
first substructure, a molecular interaction between the S and
F atoms is observed. Indeed, the S1A atom in the molecule at
(x, y, z) acts as a hydrogen bond donor to the F5 atom in the
molecule at (x−1,+y−1,+z−1) with an S…F distance of 3.159 Å
generating a chain growing in the [101] crystallographic direction
(Fig. 1c). In a second substructure, the C29 atom in the molecule
acts as a hydrogen bond donor to the O7 atom in the symmetrically-
related molecule (x−1,+y−1,+z, symmetry operation) with a C…O
distance of 3.216 Å; simultaneously, the C30 atom makes a hydrogen
bond with the F6 atom with a C…F distance of 3.263 Å. These
interactions are generated along the [001] direction (Fig. 1d).
250 300 350 400 450 500
250 300 350 400 450 500
λ (nm)
λ (nm)
Fig. 2. Excitation spectra of the (a) [Tb(TTA)2(NO3)(TPPO)2] and (b) [Tb(TTA)3(TPPO)2]
complexes in solid state recorded at liquid nitrogen temperature with emission
monitored at 550.8 nm.
Excitation spectra of the [Tb(TTA)2(NO3)(TPPO)2] and the
[Tb(TTA)3(TPPO)2] complexes recorded at 77 K in the range 250–

1394
E.E.S. Teotonio et al. / Inorganic Chemistry Communications 13 (2010) 1391–1395
The more significant photoluminescent property difference ob-
served between the complexes studied in this work is that the [Tb
(TTA)2(NO3)(TPPO)2] compound in the solid state exhibits strong
green luminescence under UV radiation at room temperature,
whereas the [Tb(TTA)3(TPPO)2] complex shows a very weak intensity
(Fig. 3b). The latter only shows significant luminescence intensity at a
low temperature (77 K), probably because of the decreasing thermal
deactivation processes. Another distinction between the bis and tris-
TTA complexes is that the emission spectrum of the [Tb(TTA)3
(TPPO)2] complex at low temperature displays a broaden band
assigned to the phosphorescence of the TTA ligand.
a)[Tb(TTA)2(NO3)(TPPO)2] b)[Tb(TTA)3(TPPO)2]
To obtain quantitative information about the luminescence of the
[Tb(TTA)2(NO3)(TPPO)2] complex, the experimental, luminescence
quantum yield (qx) was determined with the method developed by
Brill and Veenis at Philips Research Laboratories [31,32]. The standard
phosphor used was sodium salicylate, whose emission spectrum
contains a large broaden band around 425 nm, with a q value of 60%.
Based on this method, the emission quantum yield of [Tb(TTA)2(NO3)
(TPPO)2] is 38.5% ( 10%). Actually, the emission quantum yield for
the [Tb(TTA)3(TPPO)2] complex was not determined owing to its very
weak luminescence intensity at room temperature. These data clearly
demonstrate that there is a considerable increase of the luminescence
intensity for the Tb(III) bis-TTA complex compared with the tris-TTA
one. According to our previous work [20], this behavior may
be explained by the energy gap between the ligand centered
triplet state and the metal center, which is higher in the bis-TTA
complex (ΔE≅1200 cm−1) than in the similar tris-TTA complexes
(ΔE≅160 cm−1). Consequently, the retrodonation T←2S + 1LJ pro-
cesses play a minor role in the non-radiative, relaxation pathways of
the emitting level of the [Tb(TTA)2(NO3)(TPPO)2] compound, pro-
ducing a strong green luminescence emission. Fig. 4 shows the energy
level diagram including the triplet state energy of the TTA ligand in
the bis and tris complexes and the main energy transfer pathway from
the TTA ligand to the Tb(III) ion [33]. The photographs in Fig. 4 show
the luminescence of the bis and tris complexes at room temperature
under irradiation at around 390 nm with a UV lamp.
450 500 550 600 650 700 750
450 500 550 600 650 700 750
λ (nm)
λ (nm)
Fig. 3. Emission spectra of the (a) [Tb(TTA)2(NO3)(TPPO)2] and (b) [Tb(TTA)3(TPPO)2]
complexes in solid state recorded at liquid nitrogen temperature under excitation at
350 nm.
The excitation spectrum of the [Tb(TTA)3(TPPO)2] complex
(Fig. 2b) at liquid nitrogen temperature also displays the absorption
bands corresponding to the S0 →S1 transition. This band is observed
because the thermal quenching of the emitting state decreases when
the temperature is lowered.
The emission spectrum of the [Tb(TTA)2(NO3)(TPPO)2] complex in
the solid state, recorded in the range of 420 to 720 nm at liquid
nitrogen temperature under excitation at the TTA transitions
(350 nm), is shown in Fig. 3a. This emission spectrum exhibits
characteristic narrow emission bands that are assigned to the 4f8–4f8
transitions of the Tb(III) ion, emanating from the emitting 5D4 level to
the 7FJ (J=0, 1, 2, 3, 4, 5 or 6) levels, where the most intense
corresponds to the 5D4 →7F5 transition taking place around 545 nm.
An important feature to be observed is the nonexistence of broaden
bands arising from the TTA-centered transitions, indicating that
intramolecular energy transfer from the TTA ligands to the Tb(III) ion
is operative.
The increase in the triplet state energy observed for the [Ln(TTA)2
(NO3)(TPPO)2] complexes, where Ln=Eu(III), Gd(III) and Tb(III), is
6P7/2
30
S1
S1
T
5D4
T
20
10
7F0
1
2
3
4
5
6
8S7/2
0
S0
S0
Gd3+ (4f7)
Tb3+(4f8)
tris -TTA
bis-TTA
Fig. 4. Energy level diagram for the TTA ligand and lanthanide ions (Gd3+ and Tb3+) in the [Tb(TTA)2(NO3)(TPPO)2] and [Tb(TTA)3(TPPO)2] complexes showing the most probable
intramolecular ligand-to-metal energy mechanism. The photographs were obtained after UV irradiation.

E.E.S. Teotonio et al. / Inorganic Chemistry Communications 13 (2010) 1391–1395
1395
[16] J. Yuan, S. Sueda, R. Somazawa, K.E. Matsumoto, K.A. Matsumoto, Chem. Lett.
32 (2003) 492.
[17] F.J. Steemers, W. Verboom, D.N. Reinhoudt, E.B. Vandertol, J.W. Verhoven, J. Am.
Chem. Soc. 117 (1995) 9408.
[18] Y.J. Fu, T.K.S. Wong, Y.K. Yan, X. Hu, J. Alloy. Compd. 358 (2003) 235.
[19] X.F. Chen, S.H. Liu, C.Y. Duan, Y.H. Xu, X.Z. You, J. Ma, N.B. Min, Polyhedron 17 (1998)
1883.
[20] E.E.S. Teotonio, G.M. Fett, H.F. Brito, W.M. Faustino, G.F. de Sá, M.C.F.C. Felinto, R.H.A.
Santos, J. Lumin. 128 (2008) 190.
probably because the shorter Ln–O(β-diketonate) distances tend to
decrease the electronic conjugation of the chelate ring, improving the
energy match between the excited T state of the TTA ligand and the
emitting 4DJ levels of the Tb(III) ion.
Another remarkable characteristic of the [Tb(TTA)2(NO3)(TPPO)2]
complex is its triboluminescence trait of exhibiting green emission
light when its crystals are triturated. This spectroscopic behavior
occurs by indirect excitation of the ligands as follows: i) breaking of
the crystals, ii) excitation of the ligand, iii) transfer of energy from the
ligand to the Tb(III) ion and iv) emission from the terbium ion [20].
In summary, the optical data of the [Tb(TTA)2(NO3)(TPPO)2]
complex demonstrated that the TTA ligand efficiently sensitizes the
luminescence of the Tb(III) ion in the bis-diketonate form. The Ln–O
(β-diketonate) bond distances obtained for the bis and tris-TTA
complexes reflect their energy gap between the ligand centered,
triplet level and the 5D4 level of the Tb(III) ion and, consequently,
their luminescent properties. The photoluminescent properties of the
[Tb(TTA)2(NO3)(TPPO)2] complex in a solid state at room tempera-
ture indicate that this coordination compound can be used as a green
luminescent layer in organic light emitter devices (OLEDs), among
other photonic devices.
[21] N.I. Steblevskaya, V.E. Karasev, R.N. Shchelokov, J. Inorg. Chem. 29 (1984) 2230.
[22] V.E. Karasev, I.N. Botova, Russ. J. Inorg. Chem. 33 (1988) 2257.
[23] Synthesis of the Tb(TTA)2(NO3)(TPPO)2: One equivalent of Tb(NO3)3·6H2O (0.61 g,
1.7x10−3 mol) in 10 mL of methanol was added to a solution containing three
equivalents of HTTA (1.00 g, 6.7x10−3 mol) and two equivalents of TPPO in 40 mL of
methanol by dropping (under stirring). The resultant solution was in standby for
two days, forming crystals, which were filtered, washed with cooled methanol to
remove the excess of ligand and dried in a vacuum desiccator with an 80% yield of
the [Tb(TTA)2(NO3)(TPPO)2] complex. C52H38F6NO9P2S2Tb (1219.85): calcd. Tb3+
,
13.03; C, 51.20; H, 3.14; N, 1.15 Found: Eu3+, 13.07; C, 51.02; H, 3.17; N, 1.29. IR
(KBr, cm–1): 3058 (w), 1625 (s), 1606(s), 1574 (m), 1537 (s), 1502 (s), 1464 (s),
1439 (m), 1412 (s), 1385 (w), 1360 (m), 1306 (s), 1246 (m), 1230(m), 1161 (s),
1138 (s), 1094 (m), 1028 (m), 930 (w), 860 (w), 785 (m), 727 (s), 690(m), 640(w),
580 (w), 540(s).
[24] Syntheses of the Tb(TTA)3(TPPO)2: Terbium chloride (0.56 g, 1.5 mmol) aqueous
solution was added to a solution of thenoyltrifluoroacetone (1.0 g, 4.5 mmol) and
triphenylphosphine oxide (0.83 g, 3.0 mmol) in 30 mL of ethanol. Subsequently, the
pH was adjusted to 6 using a 0.01 mol⋅L–1 NaOH solution. The formed precipitate was
filtered, washed with 10 mL of ethanol and dried in a vacuum. C60H42F9O8P2S3Tb
(1379.02): calcd. Tb3+, 11.52; C, 52.26; H, 3.07; Found: Eu3+, 11.23; C, 52.02; H, 3.16.
IR (KBr, cm–1): 3059 (w), 1614 (s), 1574 (m), 1537 (s), 1500 (s), 1477 (s), 1458 (m),
1414 (s), 1381 (w), 1354 (m), 1308 (s), 1232 (m), 1184 (s), 1124 (s), 1063 (m),
932 (w), 856 (m), 783 (m), 748 (m), 721 (s), 692(m), 642 (w), 579 (m), 540 (s).
[25] Experimental: Elemental analyses of the carbon, hydrogen and nitrogen of
the complexes were performed on a Perkin-Elmer model 2400 microanalyzer. The
Ln(III) ion contents were performed by complexometric titration with EDTA.
Acknowledgements
This work was supported by the CNPq (Conselho Nacional de
Desenvolvimento Científico e Tecnológico) Brazilian Agencies,
RENAMI project (Brazilian Molecular and Interfaces Nanotechnology
Network), inctINAMI (CNPq), CNPq-FACEPE-PRONEX, CAPES and
FAPESP (Fundação de Amparo à Pesquisa do Estado de São Paulo).
RMF also acknowledges the Universidad del Valle, Colombia.
Infrared spectra were recorded in KBr pellets on
a Bomen model MB-102
spectrophotometer in the range of 4000 to 400 cm–1. Steady-state excitation and
emission spectra at room
( 298 K) and liquid nitrogen temperatures were
recorded at an angle of 22.5o (front face) with a spectrofluorimeter (SPEX-
Fluorolog 2) with a double grating 0.22 m monochromator (SPEX 1680) and a 450
W Xenon lamp as an excitation source. All spectra were recorded using a detector
mode correction. The luminescence decay curves of the emitting levels were
Appendix A. Supplementary material
measured using
a phosphorimeter SPEX 1934D accessory coupled to the
spectrofluorometer. The TL spectrum measured at room temperature was
recorded with a USB4000 spectrometer fitted with a grating blazed at 500 nm
with 600 grooves per mm, 3648-element linear CCD-array detector (Ocean
Optics, Inc.).
The crystallographic data of the [Tb(TTA)2(NO3)(TPPO)2] complex
has been deposited with the Cambridge Crystallographic Data Centre
as a supplementary publication no. CCDC 770932 Copies of the data
can be obtained free of charge upon application to CCDC, 12 Union
Road, Cambridge CB2 1EZ, UK [Fax: int. code +44(1223)336-033; E-
mail:deposit@ccdc.cam.ac.uk]. Supplementary data to this article can
be found online at doi:10.1016/j.inoche.2010.07.043.
[26] Crystallographic data for Tb(TTA)2(NO3)(TPPO)2
: Empirical formula
C52H38TbF6NO9P2S2, Formula weight=1219.81, Temperature (K)=123(2),
Wavelength (Å)=0.71073 (Å), Crystal system, space group Triclinic, P1, Unit
cell dimensions a=10.9224(7) (Å), b=11.6539(7) (Å), c=12.4000(8) (Å),
α=102.481(5) (o), β=102.285(6) (o), γ=117.618(6) (o), V=1273.00(19)
(Å3), Z=1, Dc=1.591 (gd cm−3). Absorption coefficient=1.612 (mm–1), F
(000)=610, Limiting indices −15≤h≤12, −15≤k≤16, −16≤l≤17, Reflec-
tions collected/unique=9580/ 6254 [R(int) =0.034], Refinement method Full-
matrix least-squares on F2, Data/restraints/parameters=7844/141/672, Good-
ness-of-fit on F2=0.888, Final R indices [IN2 (I)] R1=0.0421, wR2=0.0676, R
indices (all data) R1=0.0567. X-ray crystallography data were collected on an
References
[1] J.-C.G. Bünzli, G.R. Choppin, Lanthanide Probes in Life, Chemical and Earth
Sciences: Theory and Practice, Elsevier, Amsterdam, 1989, Chapter 7.
[2] T. Justel, H. Nikol, C. Ronda, Angew. Chem. 110 (1998) 3250.
[3] J. Kido, Y. Okamoto, Chem. Rev. 102 (2002) 2357.
[4] H. Wang, P. He, S. Liu, J. Shi, M. Gong, Inorg. Chem. Commun. 13 (2010) 145.
[5] F.R. Richardson, Chem. Rev. 82 (1982) 541.
‘Oxford Diffraction Gemini S’ Kappa CCD diffractometer with
a graphite-
monochromated Mo Kα radiation (λ=0.71073 Å) at 123(2) K. The orientation
matrix and cell dimensions were determined by least-square refinement of the
angular positions of all reflections. Data were corrected for absorption and
Lorentz polarization effects. The structure of the [Tb(TTA)2·(NO3)(TPPO)2]
complex was solved by the standard Patterson heavy atom method, followed by
the normal difference Fourier technique. Space group, structure solution,
refinement, molecular graphics and geometrical calculation have been carried
out with the SHELXL-97 [27], ORTEP 3 [28], Mercury [29] and PARST [30]
programs.
[6] I. Hammila, J. Alloy. Compd. 225 (1995) 480.
[7] J. Yuan, K. Matsumoto, H. Kimura, Anal. Chem. 70 (1998) 596.
[8] I. Hemmilä, T. Stahlberg, P. Mottran In, Bioanalytical Applications of Labeling
Technologies Immunoassays, Wallac, Turku, 1994.
[9] H.F. Brito, O.L. Malta, M.C.F.C. Felinto, E.E.S. Teotonio, Luminescence phenomena
involving metal enolates, in: J. Zabicky (Ed.), The Chemistry of Metal Enolates,
John Willey & Sons Ltd, 2009, pp. 131–184, chapter 3.
[10] E.E.S. Teotonio, H.F. Brito, M.C.F.C. Felinto, C.A. Kodaira, O.L. Malta, J. Coord. Chem.
56 (2003) 913.
[11] E.E.S. Teotonio, G.M. Fett, H.F. Brito, C.A. Trindade, M.C.F.C. Felinto, Inorg. Chem.
Commun. 10 (2007) 867.
[12] G.F. de Sá, O.L. Malta, C. de Mello Donegá, A.M. Simas, R.L. Longo, P.A. Santa-Cruz,
E.F. da Silva Jr, Coord. Chem. Rev. 196 (2000) 165.
[13] S. Sata, M. Wada, Bull. Chem. Soc. Jpn 43 (1970) 1955.
[14] W.F. Sager, N. Filipescu, F.A. Serafin, J. Phys. Chem. 64 (1964) 1092.
[15] N. Filipescu, W.F. Sager, F.A. Serafin, J. Phys. Chem. 68 (1964) 3324.
[27] G.M. Sheldrick, Acta Crystallogr. A64 (2008) 112.
[28] L.J. Farrugia, J. Appl. Crystallogr. 30 (1997) 565.
[29] C.F. Macrae, P.R. Edgington, P. McCabe, E. Pidcock, G.P. Shields, R. Taylor, M.
Towler, J. van de Streek, J. Appl. Crystallogr. 39 (2006) 453.
[30] M. Nardelli, J. Appl. Crystallogr. 28 (1995) 659.
[31] A. Brill, W.J. Veenis, J. Res. Natl Bur. Stand. 80A (1976) 401.
[32] A. Brill, W.J. Veenis, Philips J. Res. 33 (1978) 124.
[33] O.L. Malta, H.F. Brito, J.F.S. Menezes, F.R.G. Silva, C.M. Donega, S. Alves, Chem. Phys.
Lett. 282 (1998) 233.