Synthesis, structure and luminescence properties of four novel terbium 2-fluorobenzoate complexes

Article abstract of DOI:10.1002/ejic.200500001

Four new complexes [Tb(2-FBA)₃·(2-HFBA)·H ₂O]₂ (1), {[Tb(2-FBA)₃·(4,4′-bpy) ·H₂O]₃}_n (2), [Tb(2-FBA) ₃·(2,2′-bpy)]₂ (3), and [Tb(2-FBA) ₃·phen·CH₃CH₂OH] ₂·[Tb(2-FBA)₃·phen]₂ (4) (2-HFBA: 2-fluorobenzoic acid; 4,4′-bpy: 4,4′-bipyridine; 2,2′-bpy: 2,2′-bipyridine; phen: 1,10-phenanthroline) have been synthesized and characterized by X-ray diffraction analysis. Complex 1 is a dimeric molecule with a one-dimensional supramolecular structure formed by hydrogen bonds. Complex 2 is an infinite one-dimensional polymer chain formed by bridging carboxylato groups; its 2D framework structure is formed by hydrogen bonds. The structure of complex 3 contains three independent binuclear molecules in the asymmetric unit. In two of them, two Tb³⁺ ions are held together by four 2-FBA groups, with two of them in a bidentate-bridging mode and the other two in a chelating-bridging mode. In the third, two Tb³⁺ ions are held together by four 2-FBA groups, all of which are in the bidentate-bridging mode. One 2-FBA group and one 2,2′-bpy chelate to one Tb³⁺ ion, resulting in coordination numbers of the central terbium ion of nine and eight, respectively. The structure of complex 4 contains two nonequivalent binuclear molecules in the asymmetric unit - [Tb(2-FBA)₃·phen· CH₃CH₂OH]₂ and [Tb(2-FBA)₃· phen]₂. In the former, the Tb³⁺ ion is surrounded by eight atoms, five O atoms from five 2-FBA groups, one O atom from one ethanol molecule and two N atoms from phen, and the 2-FBA groups act in monodentate and bridging coordination modes. In the latter, the Tb³⁺ ion is coordinated by nine atoms, seven O atoms from five 2-FBA groups and two N atoms of phen, and the 2-FBA groups link the Tb³⁺ ion in chelating, bridging, and chelating-bridging coordination modes. Complexes 1, 3, and 4 emit a bright green light under UV light in the solid state. There are four emission peaks in the luminescence spectra at 488, 543, 584, and 618 nm, corresponding to the ⁵D₄→⁷F₆, ⁵D₄→⁷F₅, ⁵D ₄→⁷F₄, and ⁵D ₄→⁷F₃ transitions, respectively, of the Tb³⁺ ion. Wiley-VCH Verlag GmbH & Co. KGaA, 2005.

Full text of DOI:10.1002/ejic.200500001

FULL PAPER
Synthesis, Structure and Luminescence Properties of Four Novel Terbium
2-Fluorobenzoate Complexes
Xia Li,[a] Zhuo-Yong Zhang,[a] and Ying-Quan Zou*[b]
Keywords: Fluorinated ligands / Luminescence / O ligands / Terbium
Four new complexes [Tb(2-FBA)3·(2-HFBA)·H2O]2 (1),
{[Tb(2-FBA)3·(4,4Ј-bpy)·H2O]3}n (2), [Tb(2-FBA)3·(2,2Ј-bpy)]2
(3), and [Tb(2-FBA)3·phen·CH3CH2OH]2·[Tb(2-FBA)3·phen]2
(4) (2-HFBA: 2-fluorobenzoic acid; 4,4Ј-bpy: 4,4Ј-bipyridine;
2,2Ј-bpy: 2,2Ј-bipyridine; phen: 1,10-phenanthroline) have
been synthesized and characterized by X-ray diffraction
analysis. Complex 1 is a dimeric molecule with a one-dimen-
sional supramolecular structure formed by hydrogen bonds.
Complex 2 is an infinite one-dimensional polymer chain
formed by bridging carboxylato groups; its 2D framework
bium ion of nine and eight, respectively. The structure of
complex 4 contains two nonequivalent binuclear molecules
in the asymmetric unit − [Tb(2-FBA)3·phen·CH3CH2OH]2
and [Tb(2-FBA)3·phen]2. In the former, the Tb3+ ion is sur-
rounded by eight atoms, five O atoms from five 2-FBA
groups, one O atom from one ethanol molecule and two N
atoms from phen, and the 2-FBA groups act in monodentate
and bridging coordination modes. In the latter, the Tb3+ ion
is coordinated by nine atoms, seven O atoms from five 2-FBA
groups and two N atoms of phen, and the 2-FBA groups link
structure is formed by hydrogen bonds. The structure of com- the Tb3+ ion in chelating, bridging, and chelating-bridging
plex 3 contains three independent binuclear molecules in the
asymmetric unit. In two of them, two Tb3+ ions are held to-
gether by four 2-FBA groups, with two of them in a biden-
tate-bridging mode and the other two in a chelating-bridging
mode. In the third, two Tb3+ ions are held together by four
2-FBA groups, all of which are in the bidentate-bridging
mode. One 2-FBA group and one 2,2Ј-bpy chelate to one
Tb3+ ion, resulting in coordination numbers of the central ter-
coordination modes. Complexes 1, 3, and 4 emit a bright
green light under UV light in the solid state. There are four
emission peaks in the luminescence spectra at 488, 543, 584,
and 618 nm, corresponding to the 5D4Ǟ7F6, 5D4Ǟ7F5,
5D4Ǟ7F4, and 5D4Ǟ7F3 transitions, respectively, of the Tb3+
ion.
(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim,
Germany, 2005)
bridging-chelating modes. Consequently, the complexes are
often mononuclear, dinuclear dimers, polymeric chains, or
Introduction
Most terbium complexes emit intense green fluorescence network structures. Generally, lanthanide complexes with
and have potential applications in fluorescent probes and only a monoacid form coordination polymers with bridging
in electroluminescent devices.[1,2] The luminescent inten- carboxylato groups, such as [Nd(3-CH3C6H4COO)3] and
sities of lanthanide complexes depend on their ligands, and [Tb(3-CH3C6H4COO)3],[5]
[Nd(2-CH3OC6H4COO)3·
some lanthanide carboxylate complexes have good lumines- 4H2O],[6]
[Eu(4-CH3C6H4COO)3],[7]
and [Eu(2,3-
cent properties. This kind of lanthanide complex has been DMOBA)3]n (2,3-DMOBA = 2,3-dimethoxybenzoate).[8]
studied in recent years due to the variety of structural types However, lanthanide complexes with a monoacid and 1,10-
and potential applications in catalysis and luminescent phenanthroline (phen) or 2,2Ј-bipyridine (2,2Ј-bpy) are
probes, etc.[1–4] We are interested in the structural chemistry commonly dimeric molecules with a bridging linkage of the
of these complexes. Many structural studies on lanthanide carboxylato groups, such as in [Eu(4-CH3C6H4-
carboxylate complexes have been reported. In lanthanide COO)3(phen)],[9]
[Sm2(4-CH3C6H4COO)6(2,2Ј-bpy)2],[10]
monocarboxylate complexes, the carboxylate groups are co- [Eu(m-CH3C6H4COO)3(phen)](H2O),[11] and [Eu2(3,4-
ordinated simultaneously to the lanthanide ion in different DMBA)6·(phen)2] (3,4-DMBA = 3,4-dimethylbenzoate).[12]
modes, namely monodentate, chelating, bridging, and In these complexes, the phen or 2,2Ј-bpy ligand coordinates
to the metal in a chelating mode to form a stable five-mem-
bered ring. Lanthanide carboxylate complexes containing
2,2Ј-bpy or phen have interesting structures, with both high
stability and intense fluorescence.[9–12] 4,4Ј-Bipyridine (4,4Ј-
[a] Department of Chemistry Capital Normal University,
bpy), however, coordinates to the metal with one or two N
atoms, and is weaker than phen or 2,2Ј-bpy. In this paper
terbium and 2-fluorobenzoic acid (2-HFBA) have been
used to synthesize a new complex [Tb(2-FBA)3·(2-HFBA)·
Beijing 100037, People’s Republic of China
[b] Department of Chemistry Beijing Normal University,
Beijing 100875, People’s Republic of China
Fax: +86-1062208564
E-mail: zouyq@263.net
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DOI: 10.1002/ejic.200500001
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FULL PAPER
H2O]2 (1). When 4,4Ј-bpy, 2,2Ј-bpy, or phen was added to
the complexes, new mixed-ligand terbium complexes with
interesting structures were obtained, namely {[Tb(2-FBA)3·-
(4,4Ј-bpy)·H2O]3}n (2), [Tb(2-FBA)3·(2,2Ј-bpy)]2 (3), and
[Tb(2-FBA)3·phen·CH3CH2OH]2·[Tb(2-FBA)3·phen]2 (4).
Crystal analysis showed that complex 1 is a dimeric mole-
cule, whereas complex 2 is a polymer in which 4,4Ј-bpy co-
ordinates to Tb3+ ion and the 2-FBA groups coordinate
to the Tb3+ ion in only one bidentate-bridging mode. The
structure of complex 3 contains three independent binuclear
molecules, and the structure of complex 4 contains two
nonequivalent binuclear molecules. These structural fea-
tures are rare in lanthanide carboxylate complexes. Com-
plexes 1, 3, and 4 emit intense green fluorescence.
Results and Discussion
Structural Description of [Tb(2-FBA)3·(2-HFBA)·H2O]2 (1)
The structure of complex 1 is shown in Figure 1 (part a),
which shows that the Tb3+ ion is coordinated by seven oxy-
gen atoms from 2-FBA groups, one oxygen atom from one
2-HFBA ligand, and one oxygen atom from water, giving a
coordination number of nine. The two Tb3+ ions are linked
together by four bridging carboxylato groups to form a cen-
trosymmetric dimeric unit, which is rare for lanthanide car-
boxylate complexes. The majority of known lanthanide
complexes containing a monoacid display a one-dimen-
sional polymer chain, such as in [Tb(3-CH3C6H4COO)3],[5]
[Nd(2-CH3OC6H4COO)3·4H2O],[6]
and
[Eu(2,3-
DMOBA)3]n.[8] The distance between two Tb3+ ions is
3.951(3) Å (Table 1). All the 2-FBA groups are coordinated
to the Tb3+ ion and can be classified into three different
coordination modes: the carboxylato groups O5–C15–O6
are in a chelating mode, in which two O atoms coordinate
to the same Tb3+ ion, the carboxylato groups O1–C1–O2
are in a bridging mode, in which two O atoms coordinate
to two different Tb3+ ions to form a bidentate bridge, and
the carboxylato groups O3–C8–O4 are in a chelating-bridg-
ing mode, in which two O atoms chelate one Tb3+ ion and
one of them also simultaneously links to another Tb3+ ion,
forming a tridentate bridge. The 2-HFBA ligand binds in a
monodentate mode through a single oxygen atom to the
Tb3+ ion. It is not common to observe a monodentate car-
boxylic acid ligand coordinated to a lanthanide center. The
Tb–O bonds have an average length of 2.436 Å and the O–
Tb–O bond angles lie in the range 50.2(2)–148.7(3)°. There
is a bonding water molecule (O9) at a distance of 2.410(7) Å
to the Tb3+ ion, which takes part in hydrogen bonds with
the coordinated oxygen of carboxylato groups and the flu-
orine atoms in the benzene ring [O9–H9A···O5 (–x + 1,
Figure 1. Molecular structure of complex 1 (a) and the packing
diagram viewed along the b-axis (b). All hydrogen atoms have been
omitted for clarity; the thermal ellipsoids are shown at the 30%
probability level.
–y, –z + 2) with d(O9···O5) = 2.754 Å and ЄO9–H9A–O5 dimensional supramolecular chain (Figure 1, part b). This
= 166.16°; O9–H9B···F2 (–x + 1, –y, –z + 2) with d(O9···F2) case is different from the three complexes with a one-dimen-
= 3.047 Å and ЄO9–H9B–F2 = 153.38°] to form a one- sional polymeric structure mentioned above.
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Four Novel Terbium 2-Fluorobenzoate Complexes
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Table 1. Bond lengths [Å] and angles [°] for complex 1.
different from the complex [Tb2(O2CPh)6(4,4Ј-bpy)]n,[1] in
which 4,4Ј-bpy bridges two different metals with two N
atoms. Complex 2 is also different from the complexes
{[Eu(m-MOBA)3·2H2O]1/2(4,4Ј-bpy)}ϱ (m-MOBA = m-
Tb(1)–O(3)#1[a]
Tb(1)–O(2)#1
Tb(1)–O(9)
Tb(1)–O(7)
Tb(1)–O(3)
2.316(8)
2.333(8)
2.410(7)
2.462(9)
2.668(8)
Tb(1)–O(1)
Tb(1)–O(6)
Tb(1)–O(4)
Tb(1)–O(5)
2.329(8)
2.409(8)
2.426(8)
2.546(8)
methoxybenzoate)[13]
and
{[Eu(α-FURA)3·2H2O]·
NO3·(4,4Ј-Hbpy)}ϱ (α-FURA = α-furoate),[14] in which the
4,4Ј-bpy molecule does not coordinate to the metal. Lan-
thanide carboxylate complexes containing coordinated 4,4Ј-
bpy are less common due to the weak coordination of 4,4Ј-
bpy in this kind of complex.
O(3)#1–Tb(1)–O(1) 78.1(3)
O(1)–Tb(1)–O(2)#1 135.3(3)
O(3)#1–Tb(1)–O(2)#1 73.6(3)
O(3)#1–Tb(1)–O(6)
O(2)#1–Tb(1)–O(6)
O(1)–Tb(1)–O(9)
O(6)–Tb(1)–O(9)
O(1)–Tb(1)–O(4)
O(6)–Tb(1)–O(4)
O(3)#1–Tb(1)–O(7)
O(2)#1–Tb(1)–O(7)
O(9)–Tb(1)–O(7)
O(3)#1–Tb(1)–O(5)
O(2)#1–Tb(1)–O(5)
O(9)–Tb(1)–O(5)
O(7)–Tb(1)–O(5)
O(1)–Tb(1)–O(3)
O(6)–Tb(1)–O(3)
O(4)–Tb(1)–O(3)
O(5)–Tb(1)–O(3)
100.3(3)
77.6(3)
74.6(3)
85.6(3)
79.5(3)
126.6(3)
73.9(3)
128.0(3)
72.7(3)
139.9(3)
72.4(3)
72.1(3)
112.4(3)
68.4(3)
148.7(3)
50.2(2)
112.3(3)
O(1)–Tb(1)–O(6)
142.0(3)
O(3)#1–Tb(1)–O(9) 141.5(3)
O(2)#1–Tb(1)–O(9) 143.9(3)
O(3)#1–Tb(1)–O(4) 125.5(3)
O(2)#1–Tb(1)–O(4) 89.5(3)
Table 2. Bond lengths [Å] and angles [°] for complex 2.
O(9)–Tb(1)–O(4)
O(1)–Tb(1)–O(7)
O(6)–Tb(1)–O(7)
O(4)–Tb(1)–O(7)
O(1)–Tb(1)–O(5)
O(6)–Tb(1)–O(5)
O(4)–Tb(1)–O(5)
75.3(3)
73.7(3)
69.6(3)
142.5(3)
141.9(3)
52.0(3)
74.7(3)
Tb(1)–O(6)#1[a]
Tb(1)–O(5)
Tb(1)–O(2)#2
Tb(1)–O(7)
O(6)#1–Tb(1)–O(3)
O(3)–Tb(1)–O(5)
O(3)–Tb(1)–O(1)
O(6)#1–Tb(1)–O(2)#2 78.13(14)
O(5)–Tb(1)–O(2)#2 142.85(14)
O(6)#1–Tb(1)–O(4)#2 133.69(15)
O(5)–Tb(1)–O(4)#2 74.71(15)
O(2)#2–Tb(1)–O(4)#2 95.84(16)
O(3)–Tb(1)–O(7)
O(1)–Tb(1)–O(7)
O(4)#2–Tb(1)–O(7)
O(3)–Tb(1)–N(1)
O(1)–Tb(1)–N(1)
O(4)#2–Tb(1)–N(1)
2.470(4)
2.487(4)
2.504(4)
2.566(4)
99.78(15)
143.71(14)
75.50(15)
Tb(1)–O(3)
Tb(1)–O(1)
Tb(1)–O(4)#2
Tb(1)–N(1)
2.476(4)
2.504(4)
2.513(4)
2.851(5)
O(6)#1–Tb(1)–O(5)
O(6)#1–Tb(1)–O(1)
O(5)–Tb(1)–O(1)
O(3)–Tb(1)–O(2)#2
O(1)–Tb(1)–O(2)#2
O(3)–Tb(1)–O(4)#2
O(1)–Tb(1)–O(4)#2
O(6)#1–Tb(1)–O(7)
O(5)–Tb(1)–O(7)
O(2)#2–Tb(1)–O(7)
O(6)#1–Tb(1)–N(1)
O(5)–Tb(1)–N(1)
O(2)#2–Tb(1)–N(1)
O(7)–Tb(1)–N(1)
83.05(14)
142.84(14)
80.72(14)
71.70(14)
131.55(14)
122.08(14)
72.77(16)
71.31(15)
73.95(15)
127.62(16)
68.34(15)
71.85(15)
71.50(15)
129.25(15)
O(3)#1–Tb(1)–O(3) 75.3(3)
O(2)#1–Tb(1)–O(3) 71.4(3)
O(9)–Tb(1)–O(3)
O(7)–Tb(1)–O(3)
117.5(3)
134.9(3)
[a] Symmetry transformations used to generate equivalent atoms:
#1 –x + 2, –y, –z + 2.
72.88(14)
72.15(15)
135.85(17)
142.93(15)
135.20(15)
66.29(15)
Structural Description of {[Tb(2-FBA)3·(4,4Ј-bpy)·H2O]3}n
(2)
The structure of complex 2 is shown in Figure 2 (part a),
which shows that each terbium ion is connected by six oxy-
gen atoms from six 2-FBA groups, one oxygen atom from
water, and one nitrogen atom from a 4,4Ј-bpy molecule. The
2-FBA groups coordinate the terbium ion in only a biden-
tate-bridging mode. Complexes in which carboxylato
groups coordinate a metal in only one coordination mode,
[a] Symmetry transformations used to generate equivalent atoms:
#1 –x + 1, –y + 1, –z + 1; #2 –x, –y + 1, –z + 1.
Structural Description of [Tb(2-FBA)3·(2,2Ј-bpy)]2 (3)
The structure of complex 3 is shown in Figure 3 (a, b
such
as
[Nd(3-CH3C6H4CO2)3][5]
and
[Eu(4-
CH3C6H4COO)3].[7] in which the carboxylato groups adopt and c). It is dimeric and, interestingly, there are three inde-
only one bridging-chelating mode, are not common. Two pendent molecules in the asymmetric unit, in which each
adjacent Tb3+ ions are connected by four bridging O1–C1– molecular unit is dimeric with an inversion center. Each
O2 and O3–C8–O4 groups to form a dimeric unit. These Tb13+ ion is coordinated by nine atoms, seven oxygen
dimeric units are linked by two simple bridging carboxylato atoms from five 2-FBA groups and two nitrogen atoms of
groups (O5–C15–O6) to form a one-dimensional polymer one 2,2Ј-bpy ligand (Figure 3, part a). They adopt a dis-
chain along the [1,0,0] direction. The distances between two torted monocapped square-antiprism arrangement, with
adjacent Tb3+ ions in the polymer chain are 4.269 Å atoms O3, O5, O4A, and O6A forming the upper and O1,
(Tb1···Tb1A) within the dimeric unit and 5.637 Å between O2, N1, and N2 the lower square-planes with a dihedral
the dimeric units (Table 2). The Tb1A···Tb1···Tb1B angle is angle between them of 4.4°; atom O4 caps the upper plane.
159.1°, and the Tb–Ocarboxyl distances range from The 2-FBA ligands act in chelating, bridging, and chelat-
2.470(4) Å to 2.513(4) Å, with a mean value of 2.492 Å. The ing-bridging modes. Two Tb1 ions are held together by four
O–Tb–O bond angles are in the range 71.70(14)– 2-FBA groups, with two of them in a bidentate bridging
143.71(14)°, and the Tb–Owater bond length is 2.566(4) Å. mode, and the other two in a chelating-bridging mode. In
The 4,4Ј-bpy ligand coordinates to Tb3+ ion through one addition, each terbium ion is also chelated by one 2-FBA
N atom. There is a bonding nitrogen atom (N1) of 4,4Ј-bpy group and one 2,2Ј-bpy ligand. The Tb1···Tb1A distance is
at a distance of 2.851(5) Å to the Tb3+ ions. The two pyridyl 4.137 Å (Table 3). The Tb1–O bond lengths range from
rings are not coplanar, and have a dihedral angle of 146.0°. 2.28(8) to 2.91(9) Å, with an average length of 2.459 Å. It
The uncoordinated N atom of 4,4Ј-bpy forms a hydrogen is reasonable that the Tb1–O4 distance, 2.91 Å, of the tri-
bond with coordinated water [O7–H7A···N2B, with dentate bridging carboxylato group is the largest due to
d(O7···N2B) = 2.857 Å and ЄO7–H7A–N2B = 170.0°]. Ad- O3–C18–O4–Tb1 being an unstable four-membered ring.
jacent 1D chains are interlinked by these hydrogen bonds to This feature has been observed in other lanthanide carbox-
form a two-dimensional supramolecular network structure ylate complexes. The O–Tb1–O angles vary considerably in
along the [1,0,1] direction (Figure 2, part b). Complex 2 is the range 53.00(3)–150.00(3)°, but they are not uncommon
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Figure 2. Molecular structure of complex 2 (a) and the packing diagram (b). All hydrogen atoms have been omitted for clarity; the
thermal ellipsoids are shown at the 30% probability level.
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Four Novel Terbium 2-Fluorobenzoate Complexes
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for lanthanide carboxylate complexes. The 2,2Ј-bpy ligand the terbium ion in chelating and bidentate-bridging coordi-
coordinates to the Tb3+ ion in a conventional chelation nation modes. Obviously, the structures given in Figure 3
mode with two N atoms, forming a five-membered ring. (part b) and Figure 3 (part a) are different with respect to
The two pyridyl rings of the 2,2Ј-bpy ligand are not copla- the different linking modes of the four 2-FBA groups to the
nar and form a dihedral angle of 12.2° in the dimer. The two terbium ions. The Tb2···Tb2A distance is 4.260 Å. The
Tb1–N bond lengths are similar, with an average value of Tb2–O distances vary in the range 2.35(7) to 2.48(8) Å,
2.56 Å, and the N–Tb1–N bond angle is 62(3)°.
with an average value of 2.372 Å, and the O–Tb2–O angles
Each Tb23+ ion is eight-coordinate, with six oxygen range from 53.00(3) to 149.00(3)°. The average Tb2–N dis-
atoms from five 2-FBA groups and two nitrogen atoms tance is 2.53 Å and the N–Tb2–N angle is 62(4)°. The dihe-
from one chelating 2,2Ј-bpy ligand (Figure 3, part b). The dral angle between the two pyridyl rings of the 2,2Ј-bpy
two terbiums in the dimer are held together by four 2-FBA molecule is 6.0°.
groups, all with a bidentate-bridging coordination mode,
As shown in Figure 3 (part c), the Tb33+ ion is coordi-
and each terbium ion is further bonded to one chelating 2- nated by nine atoms, seven oxygen atoms from five 2-FBA
FBA group and one 2,2Ј-bpy molecule. Thus, each terbium groups and two nitrogen atoms of one 2,2Ј-bpy ligand. The
ion has a distorted square-antiprism coordination geometry coordination polyhedron of the Tb33+ ion is a distorted
with O7, O8, N3, and N4 forming one square face and O9, monocapped square-antiprism, which is quite similar to
O11, O10A, and O12A the other. The dihedral angle be- that of the Tb13+ ion in Figure 3 (part a) but differs from
tween the two faces is 4.6°. The 2-FBA ligands coordinate that of the Tb2 ion in Figure 3 (part b). The distance be-
Figure 3. Molecular structures of the complex 3. (a), (b), and (c) show three different structures. All hydrogen atoms have been omitted
for clarity; the thermal ellipsoids are shown at the 30% probability level.
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Table 3. Bond lengths [Å] and angles [°] for complex 3.
tween the two central terbium ions (Tb3···Tb4) is 3.951 Å.
The average Tb3–O and Tb3–N bond lengths are 2.436 Å
and 2.56 Å, respectively. The O–Tb3–O angles range from
53.00(3) to 144.00(3)°; the N–Tb3–N angle is 63(3)°. The
two pyridyl rings of 2,2Ј-bpy in the dimer are not coplanar,
and have a dihedral angle of 10.1°.
Tb(1)–O(4)#1[a]
Tb(1)–O(5)
Tb(1)–O(1)
Tb(1)–N(2)
Tb(1)–O(4)
Tb(2)–O(10)#2
Tb(2)–O(11)
Tb(2)–O(7)
Tb(2)–N(3)
Tb(3)–O(16)
Tb(3)–O(18)
Tb(3)–O(19)
Tb(3)–N(5)
Tb(4)–O(22)
Tb(4)–O(20)
Tb(4)–O(24)
2.28(8)
2.37(7)
2.42(7)
2.55(11)
2.91(9)
2.32(8)
2.37(8)
2.48(7)
2.54(10)
2.36(7)
2.44(9)
2.48(8)
2.57(8)
2.34(7)
2.37(7)
2.44(8)
2.56(9)
2.58(7)
76(3)
Tb(1)–O(6)#1
Tb(1)–O(3)
Tb(1)–O(2)
Tb(1)–N(1)
Tb(2)–O(12)#2
Tb(2)–O(9)
Tb(2)–O(8)
Tb(2)–N(4)
Tb(3)–O(21)
Tb(3)–O(14)
Tb(3)–O(17)
Tb(3)–N(6)
Tb(3)–O(20)
Tb(4)–O(15)
Tb(4)–O(23)
Tb(4)–O(13)
Tb(4)–N(7)
2.36(8)
2.41(9)
2.46(7)
2.58(9)
2.27(9)
2.35(8)
2.44(8)
2.52(11)
2.35(7)
2.37(7)
2.45(8)
2.56(8)
2.60(8)
2.35(8)
2.43(8)
2.48(8)
2.58(8)
The structure of complex 3 contains three independent
centrosymmetric units [Figure 3, parts a–c]. Figure 3 (part
b) is different from Figure 3 (part a) or Figure 3 (part c)
owing to the different bonding mode of the carboxyl
groups, similar to the previously reported complex [Eu2(p-
CH3C6H4COO)(phen)2], which contains two nonequivalent
binuclear molecules.[9] The mean Tb1–O distance (2.459 Å)
in Figure 3 (part a) is longer than that of Tb2–O (2.372 Å)
in Figure 3 (part b), and the distance between the central
metal ions Tb1···Tb1A (4.137 Å) in Figure 3 (part a) is
shorter than that of Tb2···Tb2A (4.260 Å) in Figure 3 (part
b). A similar feature in the following discussion for complex
4 can be found due to the different bonding mode of the
carboxyl groups. The Tb1–O mean distance in Figure 3
(part a) is close to that of Tb3–O (2.436 Å) in Figure 3 (part
c), and the distance between the central metal ions
Tb1···Tb1A in Figure 3 (part a) is close to that of Tb3···Tb4
(3.951 Å) in Figure 3 (part c) due to the similar coordina-
tion environments of Tb13+ and Tb33+. The corresponding
O–Tb–O bond angles for the three molecules are in agree-
ment with each other. For coordinated 2,2Ј-bpy, the two
pyridyl rings are not coplanar in the complex, although the
Tb–N bond lengths and the N–Tb–N bond angles for the
three molecules are in good agreement.
Tb(4)–N(8)
Tb(4)–O(14)
O(4)#1–Tb(1)–O(6)#1
O(6)#1–Tb(1)–O(5)
O(6)#1–Tb(1)–O(3)
O(4)#1–Tb(1)–O(1)
O(5)–Tb(1)–O(1)
O(4)#1–Tb(1)–O(2)
O(5)–Tb(1)–O(2)
O(1)–Tb(1)–O(2)
O(6)#1–Tb(1)–N(2)
O(3)–Tb(1)–N(2)
O(2)–Tb(1)–N(2)
O(6)#1–Tb(1)–N(1)
O(3)–Tb(1)–N(1)
O(2)–Tb(1)–N(1)
O(4)#1–Tb(1)–O(4)
O(5)–Tb(1)–O(4)
O(1)–Tb(1)–O(4)
N(2)–Tb(1)–O(4)
O(12)#2–Tb(2)–O(10)#2
O(10)#2–Tb(2)–O(9)
O(10)#2–Tb(2)–O(11)
O(12)#2–Tb(2)–O(8)
O(9)–Tb(2)–O(8)
O(12)#2–Tb(2)–O(7)
O(9)–Tb(2)–O(7)
O(8)–Tb(2)–O(7)
O(10)#2–Tb(2)–N(4)
O(11)–Tb(2)–N(4)
O(7)–Tb(2)–N(4)
O(10)#2–Tb(2)–N(3)
O(11)–Tb(2)–N(3)
O(7)–Tb(2)–N(3)
O(21)–Tb(3)–O(16)
O(16)–Tb(3)–O(14)
O(16)–Tb(3)–O(18)
O(21)–Tb(3)–O(17)
O(14)–Tb(3)–O(17)
O(21)–Tb(3)–O(19)
O(14)–Tb(3)–O(19)
O(17)–Tb(3)–O(19)
O(16)–Tb(3)–N(6)
O(18)–Tb(3)–N(6)
O(19)–Tb(3)–N(6)
O(16)–Tb(3)–N(5)
O(18)–Tb(3)–N(5)
O(19)–Tb(3)–N(5)
O(21)–Tb(3)–O(20)
O(14)–Tb(3)–O(20)
O(17)–Tb(3)–O(20)
N(6)–Tb(3)–O(20)
O(22)–Tb(4)–O(15)
O(15)–Tb(4)–O(20)
O(15)–Tb(4)–O(23)
O(22)–Tb(4)–O(24)
O(20)–Tb(4)–O(24)
O(22)–Tb(4)–O(13)
O(20)–Tb(4)–O(13)
O(24)–Tb(4)–O(13)
O(15)–Tb(4)–N(8)
O(23)–Tb(4)–N(8)
O(13)–Tb(4)–N(8)
O(15)–Tb(4)–N(7)
O(23)–Tb(4)–N(7)
O(13)–Tb(4)–N(7)
O(22)–Tb(4)–O(14)
O(20)–Tb(4)–O(14)
O(24)–Tb(4)–O(14)
N(8)–Tb(4)–O(14)
O(4)#1–Tb(1)–O(5)
O(4)#1–Tb(1)–O(3)
O(5)–Tb(1)–O(3)
O(6)#1–Tb(1)–O(1)
O(3)–Tb(1)–O(1)
O(6)#1–Tb(1)–O(2)
O(3)–Tb(1)–O(2)
O(4)#1–Tb(1)–N(2)
O(5)–Tb(1)–N(2)
O(1)–Tb(1)–N(2)
O(4)#1–Tb(1)–N(1)
O(5)–Tb(1)–N(1)
O(1)–Tb(1)–N(1)
N(2)–Tb(1)–N(1)
O(6)#1–Tb(1)–O(4)
O(3)–Tb(1)–O(4)
O(2)–Tb(1)–O(4)
N(1)–Tb(1)–O(4)
O(12)#2–Tb(2)–O(9)
O(12)#2–Tb(2)–O(11)
O(9)–Tb(2)–O(11)
O(10)#2–Tb(2)–O(8)
O(11)–Tb(2)–O(8)
O(10)#2–Tb(2)–O(7)
O(11)–Tb(2)–O(7)
O(12)#2–Tb(2)–N(4)
O(9)–Tb(2)–N(4)
O(8)–Tb(2)–N(4)
O(12)#2–Tb(2)–N(3)
O(9)–Tb(2)–N(3)
O(8)–Tb(2)–N(3)
N(4)–Tb(2)–N(3)
O(21)–Tb(3)–O(14)
O(21)–Tb(3)–O(18)
O(14)–Tb(3)–O(18)
O(16)–Tb(3)–O(17)
O(18)–Tb(3)–O(17)
O(16)–Tb(3)–O(19)
O(18)–Tb(3)–O(19)
O(21)–Tb(3)–N(6)
O(14)–Tb(3)–N(6)
O(17)–Tb(3)–N(6)
O(21)–Tb(3)–N(5)
O(14)–Tb(3)–N(5)
O(17)–Tb(3)–N(5)
N(6)–Tb(3)–N(5)
O(16)–Tb(3)–O(20)
O(18)–Tb(3)–O(20)
O(19)–Tb(3)–O(20)
N(5)–Tb(3)–O(20)
O(22)–Tb(4)–O(20)
O(22)–Tb(4)–O(23)
O(20)–Tb(4)–O(23)
O(15)–Tb(4)–O(24)
O(23)–Tb(4)–O(24)
O(15)–Tb(4)–O(13)
O(23)–Tb(4)–O(13)
O(22)–Tb(4)–N(8)
O(20)–Tb(4)–N(8)
O(24)–Tb(4)–N(8)
O(22)–Tb(4)–N(7)
O(20)–Tb(4)–N(7)
O(24)–Tb(4)–N(7)
N(8)–Tb(4)–N(7)
O(15)–Tb(4)–O(14)
O(23)–Tb(4)–O(14)
O(13)–Tb(4)–O(14)
N(7)–Tb(4)–O(14)
75(3)
121(3)
77(3)
129(3)
82(3)
77(3)
79(3)
79(3)
132(3)
90(3)
81(3)
131(3)
85(3)
150(3)
93(3)
144(3)
140(3)
53(3)
78(3)
150(3)
74(3)
137(3)
138(3)
105(3)
75(3)
74(3)
70(3)
62(3)
68(3)
68(2)
46(2)
126(3)
141(3)
76(3)
127(3)
82(3)
82(3)
81(3)
81(3)
132(3)
53(3)
79(3)
75(3)
74(3)
136(3)
72(3)
97(3)
137(3)
72(2)
88(3)
71(3)
74(3)
80(3)
125(2)
142(3)
140(3)
83(3)
76(3)
77(3)
73(3)
71(3)
66(3)
74(2)
130(3)
119(3)
137(3)
76(3)
74(3)
85(3)
92(3)
90(3)
125(3)
139(3)
78(3)
114(2)
139(3)
78(3)
125(3)
76(3)
138(3)
139(3)
88(3)
149(3)
144(3)
138(3)
101(3)
147(3)
80(3)
71(3)
62(4)
80(3)
124(3)
88(3)
128(3)
53(3)
90(3)
144(3)
78(3)
145(3)
74(3)
136(3)
145(3)
114(3)
63(3)
74(3)
158(3)
51(2)
114(3)
74(3)
126(3)
74(3)
128(3)
54(3)
81(3)
144(3)
141(3)
143(3)
84(3)
78(3)
147(3)
68(3)
63(3)
67(3)
135(3)
51(2)
113(3)
Structural Description of a phen-Containing Terbium 2-
Fluorobenzoate Complex with Two Different Compositions,
[Tb(2-FBA)3·phen·CH3CH2OH]2 and [Tb(2-FBA)3·phen]2
(4)
The structure of complex 4 is shown in Figure 4 (parts a
and b). Obviously, the structure of complex 4 contains two
nonequivalent binuclear molecules, namely [Tb(2-FBA)3·
phen·CH3CH2OH]2 (Figure 4, part a) and [Tb(2-FBA)3·
phen]2 (Figure 4, part b); both dimers are centrosymmetric.
Figure 4 (part a) shows that four 2-FBA groups function
as a bridge and connect two terbium ions to form a dimeric
molecule with a Tb1···Tb1A separation of 4.423 Å. Each
Tb13+ ion is further bonded to a monodentate 2-FBA
group, one chelated phen, and one ethanol molecule to give
a coordination number of eight. The Tb13+ ion is in a dis-
torted square-antiprism arrangement in which the dihedral
angle between the top (atoms O1, O5, O2A, O6A) and bot-
tom (atoms O3, O7, N1, N2) planes is 3.0°. The 2-FBA
groups link the Tb13+ ion in monodentate and bidentate-
bridging coordination modes. The Tb1–O(carboxyl) dis-
tances are in the range 2.30(4) to 2.43(4) Å, with an average
distance of 2.348 Å, and the O–Tb1–O(carboxyl) angles
range from 72.90(13) to 144.9(13)° (Table 4). The bond
length for the oxygen atom of the ethanol molecule to the
terbium ion is 2.575 Å. The coordinated ethanol molecules
74(3)
75(3)
136(3)
110(3)
70(3)
74(3)
75(3)
158(3)
117(3)
[a] Symmetry transformations used to generate equivalent atoms:
#1 –x, –y + 1, –z; #2 –x + 1, –y + 1, –z + 1.
2914
© 2005 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.eurjic.org
Eur. J. Inorg. Chem. 2005, 2909–2918

Four Novel Terbium 2-Fluorobenzoate Complexes
FULL PAPER
Figure 4. Molecular structures of complex 4. (a) and (b) show two different structures. All hydrogen atoms have been omitted for clarity;
the thermal ellipsoids are shown at the 30% probability level.
form hydrogen bonds with uncoordinated carboxyl oxygen
Figure 4 (part b) shows that the Tb23+ ion is surrounded
atoms (O7–H7···O4, with an O7···O4 distance of 2.578 Å by nine atoms, seven oxygen atoms from five 2-FBA groups
and O7–H7···O4 angle of 136.18°). The phen ligand acts as and two nitrogen atoms from one phen molecule. The
a typical chelating ligand coordinating to the terbium ion, Tb23+ ion is in a distorted monocapped square-antiprism
with an average Tb1–N distance of 2.43 Å and N–Tb1–N configuration. Atoms O10, O12, O11A, and O13A and O8,
angle of 63.7(16)°.
O9, N3, and N4 form the upper and lower square-planes,
Eur. J. Inorg. Chem. 2005, 2909–2918
www.eurjic.org
© 2005 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
2915

X. Li, Z.-Y. Zhang, Y.-Q. Zou
FULL PAPER
Table 4. Bond lengths [Å] and angles [°] for complex 4.
of central ion and coordination mode of carboxylato
groups are different. The differences result in different dis-
tances of Tb–O(carboxyl) and Tb···Tb. The mean Tb2–O-
(carboxyl) distance of 2.439 Å in Figure 4 (part b) is longer
than that of Tb1–O(carboxyl) (2.348 Å) in Figure 4 (part
a), and the distance between the central metal ions
(Tb2···Tb2A) (3.985 Å) in Figure 4 (part b) is shorter than
that between Tb1 and Tb1A (4.423 Å) in Figure 4 (part a).
A similar feature was observed in complex 3. The fact that
Ln3+ ions are bridged by chelating-bridging carboxylato
groups results in a larger Ln–O distance and a smaller Ln–
Ln distance.
Figure 3 (parts a, b and c) and Figure 4 (part b) exhibit
common structures of lanthanide carboxylate complexes
with 2,2Ј-bpy or phen, in which the carboxylate groups co-
ordinate to lanthanide in different modes, such as mono-
dentate, chelating-bidentate, bidentate-bridging, and triden-
tate-bridging. Generally, ternary lanthanide complexes con-
taining a monoacid and 2,2Ј-bpy or phen are centrosym-
metric dimers with a coordination number at the metal of
eight or nine. The structure of eight-coordinate complexes
is the same as that in Figure 3b, where two metal ions are
linked together by four carboxylato groups with a biden-
tate-bridging coordination mode, and each metal ion is also
chelated by one carboxylato group and one 2,2Ј-bpy or
phen molecule, such as in [Sm2(4-CH3C6H4COO)6(2,2Ј-
bpy)2],[10] [Eu(m-CH3C6H4COO)3(phen)](H2O),[11] and
[Eu2(3,4-DMBA)6(phen)2].[12] The structure of nine-coordi-
nate complexes is the same as those in Figure 3 (parts a and
c) and Figure 4 (part b), where two metal ions are linked
together by four carboxylato groups with bidentate-bridg-
ing and chelating-bridging modes, and each metal ion is
also chelated by one carboxylato group and one 2,2Ј-bpy
or phen ligand, such as in [Eu(2,3-DMOBA)3·bpy]2 (2,3-
DMOBA = 2,3-dimethoxybenzoate),[15] [Ln2(O2CCH3)6-
(phen)2] (Ln = Ce, Gd),[16] and [La2(propionato)6(2,2Ј-
bpy)2].[17] Eight- or nine-coordinate complexes are formed
depending on the different bridges over the two central me-
tal ions of the four carboxyl groups, namely whether the
four carboxylato groups are all in a bidentate-bridging
Tb(1)–O(5)
2.30(4)
2.36(4)
2.37(4)
2.55(5)
2.30(4)
2.36(4)
2.44(4)
2.55(5)
2.71(4)
74.5(14)
80.2(14)
Tb(1)–O(1)
Tb(1)–O(2)#1
Tb(1)–O(7)
Tb(1)–N(2)
Tb(2)–O(10)
Tb(2)–O(9)
Tb(2)–O(8)
Tb(2)–N(3)
2.34(4)
2.37(4)
2.43(4)
2.60(5)
2.34(4)
2.42(4)
2.50(4)
2.65(5)
Tb(1)–O(6)#1[a]
Tb(1)–O(3)
Tb(1)–N(1)
Tb(2)–O(13)#2
Tb(2)–O(11)#2
Tb(2)–O(12)
Tb(2)–N(4)
Tb(2)–O(13)
O(5)–Tb(1)–O(1)
O(1)–Tb(1)–O(6)#1
O(1)–Tb(1)–O(2)#1
O(5)–Tb(1)–O(3)
O(6)#1–Tb(1)–O(3)
O(5)–Tb(1)–O(7)
O(6)#1–Tb(1)–O(7)
O(3)–Tb(1)–O(7)
O(1)–Tb(1)–N(1)
O(2)#1–Tb(1)–N(1)
O(7)–Tb(1)–N(1)
O(1)–Tb(1)–N(2)
O(2)#1–Tb(1)–N(2)
O(7)–Tb(1)–N(2)
O(5)–Tb(1)–O(6)#1
O(5)–Tb(1)–O(2)#1
121.5(13)
78.3(13)
72.9(13)
84.3(14)
140.6(13)
75.3(14)
136.6(13)
138.6(15)
79.0(15)
98.4(14)
78.2(15)
133.3(15)
71.5(14)
122.9(14) O(6)#1–Tb(1)–O(2)#1
83.6(13) O(1)–Tb(1)–O(3)
144.9(13) O(2)#1–Tb(1)–O(3)
143.4(14) O(1)–Tb(1)–O(7)
72.5(13)
73.2(13)
146.9(15) O(6)#1–Tb(1)–N(1)
74.4(14)
73.9(15)
145.2(15) O(6)#1–Tb(1)–N(2)
70.7(14) O(3)–Tb(1)–N(2)
118.6(14) N(1)–Tb(1)–N(2)
O(2)#1–Tb(1)–O(7)
O(5)–Tb(1)–N(1)
O(3)–Tb(1)–N(1)
O(5)–Tb(1)–N(2)
63.7(16)
O(13)#2–Tb(2)–O(10) 77.7(14)
O(13)#2–Tb(2)–O(11)#2 74.3(14)
O(10)–Tb(2)–O(11)#2 135.2(13) O(13)#2–Tb(2)–O(9)
O(10)–Tb(2)–O(9) 75.0(13) O(11)#2–Tb(2)–O(9)
O(13)#2–Tb(2)–O(12) 123.9(14) O(10)–Tb(2)–O(12)
O(11)#2–Tb(2)–O(12) 80.2(15) O(9)–Tb(2)–O(12)
155.7(16) O(10)–Tb(2)–O(8)
143.5(14)
141.9(13)
87.5(15)
78.7(14)
125.3(15)
52.5(14)
90.0(18)
76.2(17)
130.9(19)
72.9(15)
126.2(16)
153.5(16)
62(2)
O(13)#2–Tb(2)–O(8)
O(11)#2–Tb(2)–O(8)
O(12)–Tb(2)–O(8)
O(10)–Tb(2)–N(4)
O(9)–Tb(2)–N(4)
O(8)–Tb(2)–N(4)
O(10)–Tb(2)–N(3)
O(9)–Tb(2)–N(3)
O(8)–Tb(2)–N(3)
90.5(14)
70.1(15)
O(9)–Tb(2)–O(8)
O(13)#2–Tb(2)–N(4)
138.1(18) O(11)#2–Tb(2)–N(4)
94.4(17)
67.7(19)
75.7(16)
77.2(15)
O(12)–Tb(2)–N(4)
O(13)#2–Tb(2)–N(3)
O(11)#2–Tb(2)–N(3)
O(12)–Tb(2)–N(3)
103.1(16) N(4)–Tb(2)–N(3)
O(13)#2–Tb(2)–O(13) 74.7(14)
O(11)#2–Tb(2)–O(13) 73.0(13)
O(10)–Tb(2)–O(13)
O(9)–Tb(2)–O(13)
O(8)–Tb(2)–O(13)
66.3(13)
114.5(13)
119.4(14)
134.1(15)
O(12)–Tb(2)–O(13)
N(4)–Tb(2)–O(13)
50.0(13)
148.3(17) N(3)–Tb(2)–O(13)
[a] Symmetry transformations used to generate equivalent atoms:
#1 –x + 2, –y + 2, –z; #2 –x + 1, –y, –z + 1.
respectively, with a dihedral angle between them of 8.2°; mode or two of them are in a bidentate-bridging mode and
atom O13 caps the upper plane. The 2-FBA ligands act in the other two in a chelating-bridging mode. The phen or
chelating, bidentate-bridging, and chelating-bridging 2,2Ј-bpy molecule coordinates to the metal in conventional
modes. Two terbium ions are connected by four 2-FBA chelation through two N atoms to form a five-membered
groups − two bidentate-bridging and two chelating-bridg- ring. However, although the two phenyl rings are coplanar
ing − to give a Tb2···Tb2A distance of 3.985 Å. In addition, in the phen complexes since this molecule is rigid, the two
each terbium ion is chelated by one 2-FBA group and one pyridyl rings are not coplanar in 2,2Ј-bpy complexes since
phen ligand. Obviously, Figure 4 (part b) is unlike Figure 4 this is a flexible ligand.
(part a) but quite similar to Figure 3 (part a) and Figure 3
(part c). The Tb2–O bond lengths range from 2.30(4) to
2.71(4) Å, with an average distance of 2.439 Å, and the O–
Tb2–O angles range from 52.5(14) to 155.7(16)°. The phen
molecule chelates the terbium ion with an average Tb2–N
Fluorescence Spectra
bond length of 2.60 Å and N–Tb2–N angle of 62(2)°.
The complexes 1, 3, and 4 emit a bright-green light in
However, there are very few cases where two molecules the solid state under UV light. Fluorescence was observed
with two different compositions and structures exist in an in the range of 400–700 nm by selective excitation at
asymmetric unit. By comparing Figure 4 (part b) with Fig- 353 nm, as shown in Figure 5 (parts a, b, and c). There are
ure 4 (part a), their formulas, the coordination environment four main emission peaks in the luminescence spectra at
2916
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Eur. J. Inorg. Chem. 2005, 2909–2918

Four Novel Terbium 2-Fluorobenzoate Complexes
FULL PAPER
488, 543, 584, and 618 nm, corresponding to the transition
between the first excited state (5D4) and the ground-state
multiplet (7F6–3) of the Tb3+ ion, namely 5D4Ǟ7F6,
Conclusion
The complexes discussed above were constructed based
on terbium and 2-fluorobenzoic acid, with 4,4Ј-bpy, 2,2Ј-
bpy, or phen acting as co-ligands to generate terbium com-
plexes with various structures. Complex 1 is a dimeric mole-
cule, unlike the majority of known lanthanide complexes
containing a monoacid, which are one-dimensional poly-
mers. Complex 2 is one of the very few lanthanide com-
plexes containing a coordinated 4,4Ј-bpy molecule, complex
3 contains three independent binuclear molecules, and com-
plex 4 contains two different binuclear molecules. Several
other structural features of these complexes are of particu-
lar importance. In particular, complexes 1, 3, and 4 exhibit
good fluorescence properties.
5D4Ǟ7F5, D4Ǟ7F4, and D4Ǟ7F3, respectively. The most
intense emission band is at 543 nm. The luminescence spec-
tra of complexes 1 and 3 are similar to that of complex 4.
The splits observed in the emission bands correspond to
5D4Ǟ7F6, 5D4Ǟ7F5. Shoulder peaks at 486 nm, 542 and
548 nm were observed. The nonluminescence of complex 2
may be due to 4,4Ј-bpy coordinating in a monodentate
manner, which means that the ligand-to-metal energy trans-
fer processes are not effective.
5
5
Experimental Section
Fluorescence Spectroscopy: Fluorescence spectra were measured on
an F-4500 FL spectrophotometer in the solid state at room tem-
perature.
[Tb(2-FBA)3·(2-HFBA)·H2O]2
(1):
2-Fluorobenzoic
acid
(1.5 mmol) was dissolved in the appropriate amount of ethanol.
The pH of the solution was controlled in the range 6–7 by addition
of 2 m NaOH solution. An ethanolic solution of TbCl3·6H2O
(0.5 mmol) was then added dropwise. The mixture was heated un-
der reflux with stirring for 3 h. Single crystals were obtained from
the mother liquor after a month at room temperature. Yield:
0.0969 g (26.39%). C56H38F8O18Tb2 (1468.7): calcd. C 45.80, H
2.61; found C 45.39, H 3.00.
[Tb(2-FBA)3·(4,4Ј-bpy)·H2O]n (2): 2-Fluorobenzoic acid (1.5 mmol)
was dissolved in the appropriate amount of ethanol. The pH of the
solution was controlled in the range 6–7 by addition of 2 m NaOH
solution. An ethanolic solution of 4,4Ј-bipyridine (0.5 mmol) and
an ethanolic solution of TbCl3·6H2O (0.5 mmol) were then added
dropwise, successively. The mixture was heated under reflux with
stirring for 2 h. Single crystals were obtained from the mother
liquor after seven weeks at room temperature. Yield: 0.1200 g
(31.98%). C62H44F6N4O14Tb2 (1500.9): calcd. C 49.62, H 2.96, N
3.73; fC 51.18, H 3.06, N 4.32.
[Tb(2-FBA)3·(2,2Ј-bpy)]2 (3): When 2,2Ј-bpy was used instead of
4,4Ј-bpy, complex 3 was obtained. Yield: 0.1959 g (53.50%).
C124H80F12N8O24Tb4 (2929.64): calcd. C 50.84, H 2.75, N 3.82;
found C 50.82, H 3.06 N, 3.80.
[Tb(2-FBA)3·phen]2 and [Tb(2-FBA)3·phen·CH3CH2OH]2 (4): When
phen was used instead of 4,4Ј-bpy, complex 4 was obtained. Yield:
0.1983 g (50.89%). C136H92F12N8O26Tb4 (3117.9): calcd. C 52.39,
H 2.97, N 3.59; found C 52.75, H 2.69, N 3.61.
X-ray Crystallographic Study: X-ray crystal data collection for the
complexes was performed on a Bruker Smart 1000 CCD dif-
fractometer with monochromated Mo-Kα radiation (λ = 0.71073 Å)
at 293 K (Table 5). Semi-empirical absorption corrections were ap-
plied using the SADABS program. All calculations were carried
out with SHELXS-97 and SHELXL-97.[18,19] The structures were
solved by direct methods and refined on |F|2 by full-matrix least-
squares methods.
CCDC-250512, -250511, -250513, and -250514 (for 1–4, respectively)
contain the supplementary crystallographic data for this paper. These
data can be obtained free of charge from The Cambridge Crystallo-
graphic Data Centre via www.ccdc.cam.ac.uk/data_request/cif.
Figure 5. The fluorescence spectra of complexes 1 (a; λexc
353 nm), 3 (b; λexc = 353 nm), and 4 (c; λexc = 353 nm).
=
Eur. J. Inorg. Chem. 2005, 2909–2918
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© 2005 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
2917

X. Li, Z.-Y. Zhang, Y.-Q. Zou
FULL PAPER
Table 5. Crystal data and structure refinement for complexes 1–4.
Compound
1
2
3
4
Empirical formula
Formula mass
Crystal system
Space group
Unit-cell dimensions
a [Å]
b [Å]
c [Å]
α [°]
β [°]
C56H38F8O18Tb2
1468.70
C62H44F6N4O14Tb2
1500.85
C124H80F12N8O24Tb4
2929.64
C136H92F12N8O26Tb4
3117.86
triclinic
triclinic
triclinic
triclinic
¯
¯
¯
¯
P1
P1
P1
P1
1
2
1
2
9.100(7)
9.745(3)
11.281(4)
21.845(7)
22.213(7)
93.142(6)
90.885(6)
91.585(6)
5463(3)
11.261(3)
12.627(4)
22.746(7)
81.154(5)
78.244(5)
80.697(5)
3100.3(16)
1
11.548(9)
13.600(11)
110.625(12)
92.949(13)
91.065(13)
1334.8(18)
1
12.770(4)
13.312(4)
113.134(4)
104.747(5)
97.008(5)
1426.6(8)
1
γ [°]
Volume [Å3]
Z
2
dcalcd. [gcm–3]
T [K]
1.827
293(2)
1.747
293(2)
1.781
293(2)
1.670
293(2)
λ [Å]
0.71073
2.732
720
0.71073
2.550
740
0.71073
2.659
2880
0.71073
2.350
1540
μ [mm–1]
F(000)
Limiting indices
–7 Յ h Յ 10
–13 Յ k Յ 13
–15 Յ l Յ 16
6908/4692
R(int.) = 0.0547
R1 = 0.0688
wR2 = 0.1678
R1 = 0.0980
wR2 = 0.1919
–7 Յ h Յ 11
–14 Յ k Յ 15
–15 Յ l Յ 15
7414/4992
R(int.) = 0.0191
R1 = 0.0377
wR2 = 0.1123
R1 = 0.0455
wR2 = 0.1223
0.939 and –0.736
–12 Յ h Յ 13
–25 Յ k Յ 25
–20 Յ l Յ 26
28575/19190
R(int.) = 0.173
R1 = 0.0790
wR2 = 0.1671
R1 = 0.1686
wR2 = 0.2039
2.692 and –3.145
–7 Յ h Յ 13
–14 Յ k Յ 15
–25 Յ l Յ 27
16241/10893
R(int.) = 0.0283
R1 = 0.0382
wR2 = 0.0778
R1 = 0.0685
wR2 = 0.0982
0.833 and –0.649
Reflections collected/unique
Final R indices [I Ͼ 2σ(I)]
R indices (all data)
Largest diff. peak and hole [eÅ–3] 2.576 and –2.742
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Received January 2, 2005
Published Online: June 21, 2005
2918
© 2005 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
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Eur. J. Inorg. Chem. 2005, 2909–2918