meta-phosphonobenzoic acid: A rigid heterobifunctional precursor for the design of hybrid materials

Article abstract of DOI:10.1002/ejic.200800483

Rigid meta-phosphonobenzoic acid 2 possesses two functional groups (phosphonic acid and carboxylic acid) both having the aptitude to associate with a metallic precursor to form hybrid materials. The hydrothermal reactions of compound 2 with MnCl₂·4H₂O or Co(NO ₃)₂·6H₂O produce, respectively, the isostructural layered materials M(H₂O)-(PO₃C ₆H₄CO₂H) (3, M = Mn; 4, M = Co) characterized by the presence of the free carboxylic acid groups in the interlayer space (space group P2₁/n). The reaction of Zn(CH₃COO) ₂·2H₂O with 2 produces two different materials depending on the pH of the reaction media. At low pH (pH < 4.1), the isostructural material Zn(H₂O)(PO₃C₆H ₄CO₂H) (5) is formed possessing Zn^II atoms octahedrally coordinated. At higher pH, generated by the addition of urea in the hydrothermal reaction, Zn₃(H₂O)₂)(PO ₃C₆H₄CO₂)₂ (6) is formed (orthorhombic; space group Pcan). In material 6, the phosphonic acid and the carboxylic acid groups are linked to the inorganic network. One of the two Zn^II centres is tetrahedrally coordinated and the other is surrounded by a trigonal bipyramid. Wiley-VCH Verlag GmbH & Co. KGaA, 2008.

Full text of DOI:10.1002/ejic.200800483

FULL PAPER
DOI: 10.1002/ejic.200800483
meta-Phosphonobenzoic Acid: A Rigid Heterobifunctional Precursor for the
Design of Hybrid Materials
Jean-Michel Rueff,*[a] Vincent Caignaert,[a] Sophie Chausson,[a] André Leclaire,[a]
Charles Simon,[a] Olivier Perez,[a] Loïc Le Pluart,[b] and Paul-Alain Jaffrès*[c]
Keywords: Phosphonates / Carboxylic acids / Hydrothermal synthesis / Acidity / Magnetic properties
Rigid meta-phosphonobenzoic acid 2 possesses two func-
tional groups (phosphonic acid and carboxylic acid) both
having the aptitude to associate with a metallic precursor to
form hybrid materials. The hydrothermal reactions of com-
pound 2 with MnCl2·4H2O or Co(NO3)2·6H2O produce,
respectively, the isostructural layered materials M(H2O)-
(PO3C6H4CO2H) (3, M = Mn; 4, M = Co) characterized by the
presence of the free carboxylic acid groups in the interlayer
space (space group P21/n). The reaction of Zn(CH3COO)2·
2H2O with 2 produces two different materials depending on
the pH of the reaction media. At low pH (pH Ͻ 4.1), the iso-
structural material Zn(H2O)(PO3C6H4CO2H) (5) is formed
possessing ZnII atoms octahedrally coordinated. At higher
pH, generated by the addition of urea in the hydrothermal
reaction, Zn3(H2O)2)(PO3C6H4CO2)2 (6) is formed (ortho-
rhombic; space group Pcan). In material 6, the phosphonic
acid and the carboxylic acid groups are linked to the inor-
ganic network. One of the two ZnII centres is tetrahedrally
coordinated and the other is surrounded by a trigonal bipyra-
mid.
(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim,
Germany, 2008)
rigid poly(carboxylic acid) precursors; thus, the use of rigid
phosphonic acid group represents also a great potential for
the construction of hybrid materials. 1,4-Benzenediphos-
phonic acid or 4.4Ј-biphenyldiphosphonic acid[12] were the
first rigid diphosphonic acids employed for the synthesis of
hybrid materials. More recently, 3D hybrid materials were
formed starting from the rigid 3,5-diphosphonophen-
ylphosphonic acid,[13] BINOL–diphosphonic acid,[14] or a
rigid dentritic tetraphosphonic acid.[15]In the last two cases,
microporous materials were formed. Finally, the use of rigid
heterobifunctional organic building blocks has been em-
ployed few times to form new hybrids. In these recent works
the metallic partner was calcium[16] or zinc[17] and the or-
ganic precursor was para-phosphonobenzoic acid or 5-
phosphonobenzene-1,3-dicarboxylic acid.
In this paper, we report the use of a heterobifunctional
organic precursor [3-phosphonobenzoic acid (2)] possessing
a rigid structure to synthesize hybrid materials involving
three different types of metallic precursors (Mn, Co and Zn
salts). We have investigated different conditions of synthesis
(e.g., variation of the pH), which control the number of
functional groups of the organic component linked to the
inorganic networks.
Introduction
Metal–organic frameworks (MOFs) or coordination net-
works,[1] synthesized from the reaction involving organic
molecules and metallic salts, have attracted much interest in
recent years owing to their potential applications in dif-
ferent areas including gas storage,[2] catalysis,[3] chiral sepa-
ration,[4] nonlinear optical materials[5] or drug storage.[6]
The rigidity of the organic precursor has a great influence
on the shape of the hybrid materials. For this reason, many
rigid dicarboxylates[7] have been employed as organic build-
ing blocks. As an illustration, bis(carboxylate) (e.g.
terephthalate) was selected to design porous materials when
engaged with either Zn4O[8] or Cr3O clusters.[9] The isoretic-
ular principle states that a variation of the length of the
rigid precursor can be exploited to tune the size of the
pores,[10] whereas the introduction of some flexibility in the
organic building block can prevent the formation of iso-
typic materials.[11] Many MOFs have been synthesized from
[a] Laboratoire CRISMAT, CNRS UMR 6508, ENSICAEN,
6 Blvd. Maréchal Juin, 14050 Caen Cedex, France
Fax: +33-2-31-95-16-00
E-mail: jean-michel.rueff@ensicaen.fr
[b] Laboratoire de Chimie Moléculaire et Thio-organique, EN-
SICAEN, Université de Caen Basse-Normandie, CNRS;
6 Blvd. Maréchal Juin, 14050 Caen, France
[c] Laboratoire CEMCA, CNRS UMR 6521, Université de Bret-
agne Occidentale,
Results and Discussion
Organic precursor 2 (Scheme 1) is readily synthesized in
multigram quantities starting from commercial 3-bromo-
benzoic acid. First, the methyl ester was synthesized follow-
ing the classical method of esterification. Then, methyl 3-
6 Avenue Le Gorgeu, 29238 Brest, France
Fax: +33-2-98-01-70-01
E-mail: pjaffres@univ-brest.fr
Supporting information for this article is available on the
WWW under http://www.eurjic.org or from the author.
Eur. J. Inorg. Chem. 2008, 4117–4125
© 2008 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
4117

J.-M. Rueff, P.-A. Jaffrès et al.
FULL PAPER
(diethoxyphosphoryl)benzoate (1) was obtained by a modi-
fied Tav’s method for the phosphonation of a halogenoaro-
matic substrate. This reaction takes place at a temperature
higher than 180 °C by treating 3-bromobenzoate with tri-
ethylphosphite in the presence of a catalytic amount of
nickel bromide. It must be noted that this reaction must be
carried out with care. Indeed, the addition rate of triethyl-
phosphite must be slow, especially at the beginning, because
an induction period is observed, which is followed by an
exothermic reaction. After purification by distillation, com-
pound 1 was isolated in a yield ranging from 70 to 85%. In
the last step, the ester functional groups were hydrolyzed by
heating compound 1 at reflux in the presence of concen-
trated HCl. Compound 2 was isolated without further puri-
fication in a quasiquantitative yield.
Figure 1. (a) Projection along c of the crystal structure of 2. Dashed
lines symbolized O–H hydrogen bonds. (b) Projection along b of
the slices located around y = 1/2.
Scheme 1. Synthetic pathway for compound 2.
Single crystals of compound 2 were isolated and charac-
terized by single-crystal X-ray diffraction (Table 3 and Sup-
porting Information). The peculiar arrangement of the
functional -COOH and -H2PO3 groups in the meta position
of the benzene ring can be clearly identified. In the crystal
structure, H2PO3C6H4CO2H molecules form slices, shifted
by 1/2 along the c axis and stacked along the b axis (see
Figure 1b). As shown in Figure 1a, within these slices,
molecules are linked together two by two through their
functional -COOH groups. Molecules are packed to have
the -COOH functionalities in a face-to-face position form-
ing hydrogen bonds (intermolecular O–H distances close to
1.6 Å; encircled in Figure 1b). The juxtaposition of these
supramolecular dimeric units leads to the formation of rib-
bons along the c direction. A more complex hydrogen-
bonding scheme can be evidenced between the -H2PO3
groups, which ensures the cohesion of the global structure
linking both the ribbons and slices together. Let us call –,
0 and + the ribbon as a function of their position along a
(Figure 1b). The 0 ribbon of one slice is linked to the +
and – ribbons of the adjacent slices through strong hydro-
gen bonds acting between the -H2PO3 groups (intermo-
lecular O–H distances close to 1.6 Å); these O–H bonds are
schematized and encircled in Figure 1a. This strong en-
were repeated with the addition of urea, which, as reported
in Table 1, increased the final pH of the solution. According
to these conditions of synthesis, three crystal structures
(compounds 3, 4, 6) were resolved from single-crystal dif-
fraction studies and one structure (compound 5) from pow-
der diffraction. Of note, the powder X-ray diffraction analy-
ses of the solid recovered after the hydrothermal treatment
point out that the products were phase pure.
Table 1. Summary of the hydrothermal syntheses of materials 3–6.
The syntheses were carried out with compound
0.49 mmol) in water (15 mL) heating at 160 °C for 40 h.
2
(0.1 g,
Entry Inorganic
Precursor
Urea
[equiv.]
Initial Final
pH[b] pH[c]
Material[d]
CN[e]
(1.5 equiv.)[a]
1
2
3
4
5
6
7
8
MnCl2
1.5
1.5
none
1.5
1.5
none
1.5
1.7
4.3
4.3
1.7
4.4
4.3
4.2
4.1
5.7
5.7
4.1
6.2
6.2
3.9
5.4
4.1
Mn(H2O)(LH)
Mn(H2O)(LH)
Mn(H2O)(LH)
Co(H2O)(LH)
Co(H2O)(LH)
Co(H2O)(LH)
Zn3(H2O)2(L)2
Zn(H2O)(LH)
3
3
3
4
4
4
6
5
Mn(OAc)2
Mn(OAc)2
Co(NO3)2
Co(OAc)2
Co(OAc)2
Zn(OAc)2
Zn(OAc)2
none
[a] MnCl2 = MnCl2·4H2O; Mn(OAc)2 = Mn(CH3COO)2·2H2O;
twined supramolecular boundary results in the 3D charac- Co(NO3)2 = Co(NO3)2·6H2O; Co(OAc)2 = Co(CH3COO)2·4H2O;
Zn(OAc)2 = Zn(CH3COO)2·2H2O. [b] Measured 15 min after stir-
ter observed for the material.
ring the substrates in water. [c] Measured at the opening of the
Rigid bifunctional organic precursor 2 was used as a rea-
pressured vessel. [d] LH = PO3C6H4CO2H. [e] CN = Compound
gent in a hydrothermal synthesis in association with three
number.
different metallic salts. Because the pH of the reaction me-
dium can have a great influence on the nature of the species
Table 3 summarizes the crystal parameters and the data
present in solution and therefore an influence on the struc- used for the structure refinements of compounds 2, 3, 4, 5
ture of the hybrid materials formed, the pH of the solutions and 6. The unit cell volumes of the isotypic compounds (3,
were measured before the closure of the autoclaves and at 4 and 5) with Mn to Zn decrease from 918.42 to 884.25 Å3
their opening as reported in Table 1. Most of the reactions in accordance with the contraction of the radii of the transi-
4118
www.eurjic.org
© 2008 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Eur. J. Inorg. Chem. 2008, 4117–4125

meta-Phosphonobenzoic Acid: A Precursor for the Design of Hybrid Materials
tion element of the same row when the atomic number in-
creases. These compounds consist of inorganic layers inter-
leaved regularly with organic layers (Figure 2). The organic
part is characterized by the presence of supramolecular di-
meric units involving two carboxylic acid groups bearing by
two molecules covalently bonded to two distinct inorganic
layers. In materials 3 and 4, the Mn2+ or Co2+ ions are
bonded to the oxygen atoms of the phosphonate groups.
The polyhedra of coordination around the transition ele-
ments are completed with water molecules in order to form
an octahedron of oxygen atoms around each transition
metal. This octahedron is distorted and the deformation
varies according to the nature of the divalent ion; for Co2+
there are five bonds shorter than 2 Å and a long one of
2.408 Å, for Mn2+ three short bonds around 2.12 Å, two
medium bonds around 2.21 Å and one very long bond of
Figure 3. X-ray diffraction data recorded on powder from
2.505 Å are observed.
Zn(H2O)(PO3C6H4CO2H) (5). The vertical dashes correspond to
the calculated position of the peaks, the bottom line to the differ-
ence between experimental and calculated pattern.
Figure 4. (a) The pseudoperovskite layer; (b) view of the
[M2+PO6C]ϱ layer.
Figure 2. Projection of the structure of M(H2O)(PO3C6H4CO2H)
along the a axis (3, M = Mn; 4, M = Co; 5, M = Zn).
hybrid materials, compounds 3, 4 and 5 are 2D with regard
to the inorganic (I2) part owing to the infinite metal–oxy-
gen–metal networks in two directions (ac planes). Along to
The structure of material 5 (M = Zn) was obtained from the c axis, the organic molecules are bonded together
powder X-ray diffraction study (Figure 3). In material 5, through supramolecular links. Regarding the stability and
which is isostructural with materials 3 and 4, the coordina- the role of these supramolecular links to explain the pack-
tion of Zn2+ is similar to the cobalt ones with five short ing of materials 3, 4 and 5, we conclude that the hydrogen
distances and one very long one. The phosphorus atoms are bonds have a crucial role in describing the global dimen-
surrounded by three oxygen atoms and one carbon atom sionality of these materials (Table 2). The organic molecules
that form a tetrahedron around it. In the structures of 3, 4 are bonded together (supramolecular link) along the b di-
and 5, the octahedra share corners leading to a pseudoper- rection, which is orthogonal to those involved describing
ovskite layer (Figure 4a). The PO3C tetrahedra share one the inorganic networks. Therefore, the organic part is 1D.
edge with the MO6 octahedra leading to MPO7C and one Materials 3, 4 and 5 can therefore be classified in the cat-
corner with another octahedron (Figure 4b). This arrange- egory I2O1, which corresponds to 3D materials. It should
ment is similar to the VPO8 units seen in the Li2VO2PO4 be noted that compound 5 can also be obtained without
frameworks or within the layers of MII(RPO3)·H2O series hydrothermal treatment by stirring an aqueous solution of
reported in the literature.[18]
2 with ZnII acetate salt at room temperature. Following this
This latter bonding distorts the perovskite layer by a procedure, a microcrystalline powder is obtained. Syntheses
drastic tilt of the octahedra versus the plane containing the performed in aqueous solution at room temperature with
metals. Following the nomenclature proposed by Chee- MnII and CoII acetate salts and compound 2 do not result
tham, Rao and Feller[1] to describe the dimensionality of in materials 3 and 4. However, when the mother solution is
Eur. J. Inorg. Chem. 2008, 4117–4125
© 2008 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.eurjic.org
4119

J.-M. Rueff, P.-A. Jaffrès et al.
FULL PAPER
Table 2. The hydrogen-bonding networks in 2, 3 and 4.
H2PO3C6H4CO2H (2)
H11···O22 1.55(1) Å O11–H11···O22 173(1)°
O11–H11 1.00(1) Å
O13–H12 0.97(1) Å
O15–H17 0.98(1) Å
O21–H21 0.94(1) Å
O23–H22 1.08(1) Å
O24–H27 1.00(1) Å
O11···O22 2.541(4) Å
O13···O12 2.594(5) Å
O15···O14 2.627(4) Å
O21···O22 2.570(4) Å
O23···O12 2.543(5) Å
O24···O25 2.624(4) Å
H12···O12 1.62(1) Å
H17···O14 1.66(1) Å
H21···O22 1.63(1) Å
H22···O12 1.47(1) Å
H27···O25 1.62(1) Å
O13–H12···O12 175(1)°
O15–H17···O14 172(1)°
O21–H21···O22 172(1)°
O23–H22···O12 176(1)°
O24–H27···O25 180(1)°
Mn(H2O)(PO3C6H4CO2H) (3)
O6–H61 0.81(2) Å
O6–H62 0.86(2) Å
O4–H41 0.79(3) Å
H61···O1 2.21(2) Å
H62···O2 2.03(2) Å
H41···O5 1.88(3) Å
O6–H61···O1 138(1)°
O6–H62···O2 167(2)°
O4–H41···O5 172(2)°
O6···O1 2.871(1) Å
O6···O2 2.877(1) Å
O4···O5 2.659(2) Å
Co(H2O)(PO3C6H4CO2H) (4)
O6–H61 0.76(3) Å
O6–H62 0.87(3) Å
O4–H41 0.93(6) Å
H61···O1 2.19(3) Å
H62···O2 2.07(3) Å
H41···O5 1.77(6) Å
O6–H61···O1 147(3)°
O6–H62···O2 166(3)°
O4–H41···O5 167(5)°
O6···O1 2.856(1) Å
O6···O2 2.924(1) Å
O4···O5 2.677(3) Å
heated whilst stirring at 70 °C for several hours, material 3
is obtained as a light-brown precipitate with a yield of 40%.
All our trials to obtain material 4 by this way were unfruit-
ful.
Increasing the pH during the synthesis of 6 by the ad-
dition of urea in the course of the hydrothermal treatment
(Table 1, Entry 7) leads to a framework very different from
the three previous compounds owing to the ability of the
Zn2+ ion to adopt other coordination than octahedral. All
the oxygen atoms belonging to the phosphonate organic
molecule are bonded to zinc atoms and three independent
zinc ions are observed. The first one (Zn1) is tetrahedrally
coordinated to oxygen atoms, which are also bonded to the
phosphorus atoms of the phosphonates. The others (Zn2
and Zn3) are surrounded by five oxygen atoms forming a
trigonal bipyramid: two oxygen atoms of the phosphonate
group, two from the carboxylate group and one water mole-
cule. The framework is made of inorganic columns sur-
rounded by organic columns and vice versa (Figure 5).
Figure 6. (a) The inorganic chain running along the a axis; (b) inor-
ganic chain shown down the a axis.
The organic columns, also running along the a axis, are
made of isolated phosphonate groups. In this structure,
each molecule 2 is bonded to six zinc atoms (Figure 7). Re-
garding the dimensionality of compound 6, the contri-
bution of the inorganic network is one (I1), as the inorganic
part is composed of chains running along the a axis. These
inorganic chains are bonded together with the organic
molecules along the b direction, but also along the c axis.
Therefore, the contribution of the organic part to the di-
Figure 5. Projection along the a axis of the structure of Zn3-
(H2O)2(PO3C6H4CO2)2 (6).
The inorganic columns running along the a axis are
made of ZnO5 bipyramids and ZnO4 and PO3C tetrahedral
sharing corners (Figure 6a,b).
Figure 7. The surrounding of the two independent PO3C6H4CO2
molecules present in material 6.
4120
www.eurjic.org
© 2008 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Eur. J. Inorg. Chem. 2008, 4117–4125

meta-Phosphonobenzoic Acid: A Precursor for the Design of Hybrid Materials
mensionality of compound 6 is two. Hence, compound 6 compounds. In contrast, compound 6 forms needles with
can be classified in the category I1O2 forming a 3D struc- an average size of 200 µm ϫ50 µm. This observation is con-
ture. The contribution of organic part to the dimensionality sistent with the absence of a layered organization in this
of material 6 is increased compared to that of material 3 or compound.
4. Such organization can be explained by the linkage be-
The thermogravimetric curves (see Supporting Infor-
tween the two functional groups present on organic precur- mation) of compounds 3, 4, 5 and 6 exhibit an initial mass
sor 2 and the inorganic part. Moreover, this 3D organiza- loss between room temperature and 330 °C, which is in
tion arises from the rigidity of the organic precursor, which good agreement with the departure of the coordinated
is locked into a bent shape owing to the presence of the water molecules present in the structure: 5.8% for one H2O
functional groups in the meta position on the aromatic ring. in C7H7MnO6P (theoretical loss: 6.6%), 7% for one H2O
From these structural studies we noticed that when ZnII in C7H7CoO6P (theoretical loss: 6.5%), 4.9% for two H2O
salts are engaged with organic molecule 2, the pH of the in C14H12Zn3O12P2 (theoretical loss: 5.7%) and 6.4% for
reaction media has a remarkable effect on the structural one H2O in C7H7ZnO6P (theoretical loss: 6.3%). After this
organization of the hybrids formed. At low pH, compound dehydration process, a series of several more mass losses are
5 is formed exclusively, as only the phosphonic acid is observed, which are attributed to the decomposition of the
linked to the inorganic network, whereas the carboxylic ac- compound and the formation of Mn2P2O7 for C7H7MnO6P,
ids are engaged into a dimeric unit through hydrogen bond- Co2P2O7 for C7H7CoO6P, Zn3(PO4)2 for C14H12Zn3O12P2
ing. This observation can be justified by the fact that the and Zn2P2O7 for C7H7ZnO6P. These final materials
phosphonic acid is first ionized in water due to its lower were identified by X-ray diffraction and their formation is
pKa. Therefore, the phosphonate salt must have a greater in good agreement with the total weight of loss: 44%
reactivity with the metallic precursor in comparison to the for C7H7MnO6P, 43% for C7H7CoO6P, 40% for
carboxylic acid group. In contrast, when the pH of the reac- C14H12Zn3O12P2 and 45% for C7H7ZnO6P.
tion media increases during the hydrothermal synthesis by
The IR spectra of materials 3, 4, 5 and 6 are depicted in
the transformation of urea into ammonia, the carboxylic Figure 8. The resemblance between the IR spectra of com-
acid is also deprotonated leading in that case to the forma- pounds 3, 4 and 5 was expected in view of their structural
tion of compound 6, which is characterized by the implica- similarities. The broad signal between 2500 and 3600 cm–1
tion of the two groups (phosphonic and carboxylic) in the and the strong peak around 1700 cm–1 are characteristic of
inorganic network. Therefore, a pH dependent chemioselec- the presence of the hydrogen bonds between the carboxylic
tivity is observed leading to the formation of materials 5 or acid groups, resulting from the dimeric carboxylic acid unit
6, which can be synthesized selectively. It is worth noting into the interlayer space. As expected, these signals are dra-
that the influence of the condition of reactions, including matically reduced in the IR spectra of material 6 owing to
the addition of basic compounds, can modify the structure the absence of hydrogen bonds.
of the resulting materials.[19] If the pH plays an important
role in the case of the synthesis of material 5 and 6, it ap-
pears to have no influence when cobalt or manganese salts
are used as inorganic precursors. Indeed, even in presence
of urea (Table 1, Entries 1, 2, 4 and 5), layered materials 3
or 4 are exclusively formed. The pH of the final solution
can reach a value of 6.2 (Table 1, Entry 5) without any evi-
dence for the formation of a phase in which the two func-
tional groups would be linked to the inorganic network.
The influence of the composition of the inorganic salt has
also been studied, as the counter anion can have an influ-
ence on the pH of the reaction media. For instance, when
Co(NO3)·6H2O (Table 1, Entry 4) or Co(CH3COO)2·4H2O
Zn3(H2O)2(PO3C6H4COO)2 (6).
(Table 1, Entry 5) are used the initial pH, respectively 1.7
Figure 8. Infrared spectra of Mn(H2O)(PO3C6H4COOH) (3),
Co(H2O)(PO3C6H4COOH) (4), Zn(H2O)(PO3C6H4COOH) (5) and
and 4.4, were noticeably different, whereas the final pH was
Magnetic measurements were performed with a SQUID
identical (6.2). In both cases, the same layered material 4 is magnetometer on an assembly of Mn(H2O)(PO3C6H4-
formed. Similar behaviour is observed when manganese COOH) and Co(H2O)(PO3C6H4COOH) unoriented small
salts are used (Table 1, Entries 1 and 2). Therefore, the crystals. In Figure 9, the magnetization is shown for both
chemioselectivity when Mn or Co salts are used is not pH compounds.
dependent in the range of pH of 4 to 6.2.
A fitting by the Curie law gives that the Mn compound
The SEM characterizations (see Supporting Information) presents a moment of 5.97 µB/Mn and an extrapo-
are consistent with the single X-ray structures of com- lation temperature θ = –72 K for a Neel temperature of TN
pounds 3, 4, 5 and 6. Indeed, platelets of average size 50 µm = 22.5 K. The ratio θ/TN ≈ 3 corresponds to 3 first Mn
ϫ50 µm for 3, 100 µm ϫ100 µm for 4 and 2 µm ϫ2 µm for neighbours in the structure, which does not correspond to
5 are observed by SEM. These characteristics are in good any physical neighbours. An alternative fitting procedure
agreement with the existence of a layered structure for these with a Fisher law[20] (for 1D chains) modified to introduce
Eur. J. Inorg. Chem. 2008, 4117–4125
© 2008 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.eurjic.org
4121

J.-M. Rueff, P.-A. Jaffrès et al.
FULL PAPER
a pH dependent chemioselectivity is observed. At low pH,
material 5, isostructural with materials 3 and 4, is formed.
At higher pH, material 6 is formed in which both functional
groups (phosphonic acid and carboxylic acid) are engaged
in the inorganic network leading to a I1O2 3D network.
The structure of this material is governed by the rigidity of
organic building block 2. This study illustrates that the use
of a heterobifunctional organic precursor can produce ma-
terials in which carboxylic acid groups are not engaged with
the inorganic networks, resulting in the obtained functional
materials. Further studies are presently engaged to achieve
postchemical transformations based on the reactivity of the
carboxylic acid groups present in these materials. For in-
stance, the introduction of amines in the interlayer space of
compound 5 is presently studied. In contrast, with certain
metallic precursors (Zn) and at controlled pH, rigid bifunc-
tional organic precursor 2 can produce original hybrid
structures.
Figure 9. Magnetization vs. temperature obtained in zero field co-
oled process under 3000 G for Mn(H2O)(PO3C6H4COOH) (top)
and Co(H2O)(PO3C6H4COOH) (bottom). The corresponding fit-
ting parameters are given in the text.
Experimental Section
General: All compounds were fully characterized by 1H, 13C and
31P NMR spectroscopy (Bruker AC 300 spectrometer). The follow-
ing abbreviations were used: s singlet, d doublet, t triplet, q quadru-
plet, qt quintuplet, m multiplet. Mass spectra were recorded with
a QTOF Micro (Waters), ionization electrospray positive (ESI),
lockspray PEG, infusion introduction (5 µL/min), source tempera-
ture 80 °C, desolvatation temperature 120 °C. Elemental analyses
were recorded with an automatic apparatus CHNS-O Thermo-
Quest. Thermogravimetric analyses (TGA) were recorded at the
rate of 2 °C/min from room temperature to 700 °C in air or under
an atmosphere of nitrogen by using a SETARAM TGA 92 appara-
tus.
an interchain coupling provides a smaller moment 5.40 µB/
Mn and an extrapolation temperature θ = –45 K for a Neel
temperature of TN = 22.5 K. The ratio θ/TN corresponds to
2 first Mn neighbours within the chain, which seems rea-
sonable. The smaller value of the moment can be due to
the inappropriate extrapolation of this model. The values
of about 5.97 µB/Mn corresponds exactly to what is ex-
pected for 5/2 moments of Mn2+ with no quench of L. The
values of TN, θ and µB are in good agreement with the
values found in the literature for similar layered Mn2+ phos-
phonates (alkyl or phenyl).[21,22] The isotypic cobalt com-
pound presents a moment of 3.53 µB and TN = 6.5 K, θ =
–13 K. The ratio θ/TN = 2 confirms the isotypic character
of the structures. The value of 3.53 µB corresponds to fully
quenched value of the L moment, which is classical for
Co2+. Slightly smaller than the value of µB described in the
literature for Co2+ phenyl phosphonate, the difference can
be easily explained by the temperature range used for the
fitting model.[20]
Methyl 3-(Diethoxyphosphoryl)benzoate (1): NiBr2 (1.87 g;
8.55 mmol), methyl-3-bromobenzoate (23.00 g, 106.9 mmol) and
mesitylene (16 mL) were placed under a nitrogen atmosphere in a
two-necked, round-bottom flask fitted with a reflux condenser and
an additional funnel. The suspension was heated at 180 °C and
triethylphosphite (26.63 g, 160 mmol) was carefully added dropwise
over 45 min. At the end of the addition, the solution was heated at
180 °C for 2 h. After cooling at room temperature, the volatiles,
including the solvent, were removed in vacuo. Water (150 mL) was
added to the residue, and the mixture was extracted with ethyl ether
(2ϫ75 mL). The organic phase was then washed with brine
(3ϫ40 mL), dried with MgSO4, filtered and concentrated in vacuo
to produce an orange viscous oil. Purification by distillation under
high vacuum (10 mTorr) was achieved in a Kugelrohr oven
(180 °C), which produced a colourless viscous oil (23.27 g; 80%
Conclusions
1
3
yield). H NMR (300.13 MHz,CDCl3): δ = 1.26 (t, J = 7.1 Hz, 6
H, CH3CH2O), 3.87 (s, O-CH3), 3.95–4.18 (m, 4 H, CH2-O-P), 7.49
The use of rigid heterobifunctional compound 2 to de-
sign hybrid materials produces either I2O1 or I1O2 3D struc-
tures depending on the type of inorganic precursors in-
volved and, in the case of ZnII salt as inorganic source, the
pH of the reaction media. When Mn or Co salts are em-
ployed (materials 3 and 4), the single phosphonic acid
group of compound 2 is engaged in the inorganic network,
demonstrating the chemioselectivity of the hybrid construc-
tion. This construction is not pH dependent in the pH
3
4
3
(td, J = 7.6 Hz, JHP = 4.0 Hz, CH5), 7.94 (ddt, JHP = 12.9 Hz,
3J = 7.6 Hz, J = 1.3 Hz, CH4), 8.15 (dq, 3J = 7.8 Hz, 4JHH = 5JHP
4
= 1.3 Hz, CH6), 8.40 (dt, JHP = 13.7 Hz, J = 1.3 Hz, CH2) ppm.
31P NMR (121.49 MHz, CDCl3): δ = 18.10 ppm. 13C NMR
(75.47 MHz,CDCl3): δ = 16.22 (d, J = 6.4 Hz), 52.26 (s), 62.28 (d,
J = 5.5 Hz), 128.63 (d, J = 6.4 Hz), 129.00 (d, J = 165.1 Hz), 130.63
(d, J = 9.5 Hz), 132.71 (d, J = 10.9 Hz), 133.21 (d, J = 3.0 Hz),
135.88 (d, J = 10.0 Hz), 166.00 (d, J = 2.0 Hz) ppm. HRMS (ES-
3
4
range studied. When ZnII salt is used as inorganic source, TOF): calcd. for C12H18O5P [M + H]+ 273.0892; found 273.0884.
4122 Eur. J. Inorg. Chem. 2008, 4117–4125
www.eurjic.org
© 2008 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim

meta-Phosphonobenzoic Acid: A Precursor for the Design of Hybrid Materials
3-Phosphonobenzoic Acid (2): Compound 1 (22.12 g; 81.25 mmol)
and concentrated HCl (37% in water, 300 mL) were mixed, and the
solution was heated at reflux for 21 h. The solution was concen-
trated in vacuo, and the resulting solid was dried in vacuo to pro-
duce 2 (16.05 g; 98% yield). Single crystals suitable for X-ray stud-
ies were directly isolated after a slow cooling of the acidic solution.
1 equiv.) was added dropwise to a stirred aqueous solution (60 mL)
of Zn(CH3COO)2·2H2O (0.488 g, 2.22 mmol, 1.5 equiv.). After
30 min, a white precipitate started to be formed. The solution was
stirred for 3 d, and the precipitate was then recovered by filtration,
washed with water, rinsed with absolute ethanol and dried in air.
X-ray diffraction confirmed that the compound synthesized by this
way has the same structure as that obtained by hydrothermal syn-
3
1H NMR (300.13 MHz, D2O): δ = 7.38 (m, CH5), 7.77 (dd, JHP
= 12 Hz, 3J = 7 Hz, CH4), 7.89 (d, 3J = 8 Hz, CH6), 8.10 (dd, 3JHP thesis (0.385 g, 91% yield). IR (KBr): ν = 3374, 3340, 3093, 3006,
˜
4
= 14 Hz, J = 1 Hz, CH2) ppm. 31P NMR (121.49 MHz, D2O): δ 2898, 2855, 2690, 2609, 2573, 1698, 1635, 1599, 1584, 1484, 1430,
= 14.81 ppm. 13C NMR (75.47 MHz, D2O): δ = 129.32 (d, J =
1403, 1314, 1270, 1159, 1109, 1077, 1018, 1000, 979, 920, 912, 829,
14.5 Hz), 130.9 (d, J = 14.8 Hz), 131.72 (d, J = 11.4 Hz), 132.30 779, 749, 735, 679 cm–1. TGA (in air): 6.5% weight loss at about
(d, J = 184.0 Hz), 133.11 (d, J = 12.8 Hz), 135.51 (d, J = 10.5 Hz),
250 °C (6.3% of water calculated). C7H7O6PZn (283.48): calcd. C
169.80 (s) ppm. C7H7O5P (202.1): calcd. C 41.60, H 3.49; found C
29.66, H 2.49; found C 29.21, H 3.0.
41.92, H 3.67. IR (KBr): ν = 3079, 2890, 2845, 2681, 2572, 2292,
˜
Preparation of Zn3(H2O)2(PO3C6H4COO)2 (6): In a 50-mL PTFE
insert was dissolved 3-phosphonobenzoic acid (0.2 g, 0.98 mmol,
1 equiv.) in permuted water (15 mL). To this solution was added
Zn(CH3COO)2·2H2O (0.327 g, 1.48 mmol, 1.5 equiv.) and urea
(0.089 g, 1.48 mmol, 1.5 equiv.). The insert was transferred into a
Berghof pressure digestion vessel and heated from room tempera-
ture to 160 °C over 18 h and then further heated at 160 °C for 40 h
and cooled to room temperature over 18 h. After filtration, the re-
sulting compound obtained as white crystallites was washed with
water, rinsed with absolute ethanol and dried in air (0.240 g, 86%
1700, 1679, 1603, 1581, 1449, 1407, 1320, 1273, 1163, 1111, 1085,
1014, 956, 853, 829, 755, 734, 687, 661 cm–1.
Preparation of Mn(H2O)(PO3C6H4COOH) (3) and Co(H2O)-
(PO3C6H4COOH) (4) by Hydrothermal Synthesis: In a 50-mL
PTFE insert was dissolved 3-phosphonobenzoic acid (0.2 g,
0.98 mmol, 1 equiv.) in permuted water (15 mL). To this solution
was added the desired transition metal salt [1.5 equiv.;
MnCl2·4H2O (0.294 g, 1.48 mmol) for
3 or Co(NO3)2·6H2O
(0.432 g, 1.48 mmol) for 4] and urea (0.089 g, 1.48 mmol,
1.5 equiv.). The insert was transferred into a Berghof pressure di-
gestion vessel and heated from room temperature to 160 °C over
18 h and then further heated at 160 °C for 40 h and cooled to room
temperature over 18 h. After filtration, the resulting compounds,
obtained as light brown (for 3) or purple (for 4) crystallites, were
washed with water, rinsed with absolute ethanol and dried in air.
yield). IR (KBr): ν = 3375, 3317, 3268, 3224, 3182, 3059, 1717,
˜
1700, 1684, 1653, 1613, 1587, 1567, 1559, 1542, 1507, 1497, 1474,
1456, 1429, 1397, 1278, 1228, 1176, 1111, 1097, 1076, 1050, 1031,
1002, 975, 881, 825, 764, 754, 695, 667 cm–1. TGA (in air): 4.9%
weight loss at about 315 °C (5.7% of water calculated).
C14H12O12P2Zn3 (630.33): calcd. C 26.68, H 1.92; found C 26.64,
H 2.44.
Compound 3: Yield: 0.198 g (73%). IR (KBr): ν = 3448, 3378, 3095,
˜
3003, 2894, 2852, 2686, 2602, 2567, 1699, 1598, 1583, 1483, 1428,
1403, 1311, 1269, 1158, 1109, 1091, 1002, 984, 920, 910, 827, 749,
732, 683, 659 cm–1. TGA (under N2): 5.8% weight loss at about
310 °C (6.6% of water calculated). C7H7MnO6P (273.04): calcd. C
30.79, H 2.58; found C 30.29, H 2.71.
XRD Investigations: XRD investigation was performed by using
Mo-Kα radiations on a Kappa CCD (Bruker Nonius) diffractometer
equipped with a CCD (charge coupled device) detector. Large Ω-
and Φ-scans were used to both control the crystalline quality of
different samples and determine the unit cell parameters. Single
crystals of suitable size were then selected. Considering the cell pa-
rameters and the spot size (i.e. mosaicity) suitable data collection
strategies have been defined. A scanning angle of 0.8° and a Dx
(detector–sample distance) value of 34 mm were chosen; Φ- and Ω-
scans were used. To collect a great number of weak reflections, but
avoiding any detector saturation by reflections of strong intensity,
different exposure times were used to collect the data. The dif-
fracted intensities were collected up to θ = 40°. Following the sym-
metry of the crystal, one independent monoclinic or orthorhombic
space was scanned. Plots of reciprocal lattice planes assembled
from these series of experimental frames are sufficiently accurate
to obtain an overall view of the reciprocal space. The conditions
limiting the possible reflections were then observed and the possible
space groups identified. The EvalCCD software[23] was used to ex-
tract reflections from the collected frames and reflections were
merged and rescaled as a function of the exposure time. Data were
corrected from absorption by using the Sadabs program[24] devel-
oped for scaling and correction of area detector data. Structural
models were built up from Patterson map analysis (heavy atoms
method) for 3, 4 and 6 and with superflip[25] by using charge-flip-
ping methods for phase 2. The model was subsequently introduced
in the refinement program Jana2006,[26] and all the atomic posi-
tions were refined and anisotropic atomic displacement parameters
(ADP) were considered for all the atoms. At this step of the refine-
ment, the hydrogen atoms can be located. The decreasing law of
the diffusion factor as a function of sinθ/λ implies that the main
contribution of the hydrogen atoms to the diffracted intensity is
condensed in the beginning of the diffraction patterns. Difference
Compound 4: Yield: 0.101 g (38%). IR (KBr): ν = 3412, 3379, 3092,
˜
2990, 2895, 2855, 2723, 2690, 2611, 2573, 1697, 1627, 1599, 1584,
1486, 1431, 1404, 1317, 1270, 1159, 1111, 1005, 992, 975, 920, 831,
749, 736, 679 cm–1. TGA (in air): 7% weight loss at about 195 °C
(6.5% of water calculated). C7H7CoO6P (277.04): calcd. C 30.35,
H 2.55; found C 30.33, H 2.69.
Preparation of Compound 3 by Soft Chemistry: An aqueous solu-
tion (30 mL) of 3-phosphonobenzoic acid (0.6 g, 2.96 mmol,
1 equiv.) was added to a stirred aqueous solution (20 mL) of
Mn(CH3COO)2·4H2O (1.09 g, 4.47 mmol, 1.5 equiv.). The solution
was stirred overnight. The white precipitate formed was filtered,
washed with water, rinsed with absolute ethanol and dried in air.
X-ray diffraction confirmed that the compound synthesized by this
way has the same structure as that obtained by hydrothermal syn-
thesis (0.66 g, 810% yield).
Preparation of Zn(H2O)(PO3C6H4COOH) (5) Hydrothermal Syn-
thesis: In a 50-mL PTFE insert was dissolved 3-phosphonobenzoic
acid (0.1 g, 0.49 mmol, 1 equiv.) in distilled water (15 mL). To this
solution was added Zn(CH3COO)2·2H2O (0.162 g, 1.48 mmol,
1.5 equiv.). The insert was transferred into a Berghof pressure di-
gestion vessel and heated from room temperature to 160 °C over
18 h and then further heated at 160 °C for 40 h and cooled to room
temperature over 18 h. After filtration, the resulting compound ob-
tained as a white powder was washed with water, rinsed with abso-
lute ethanol and dried in air (0.095 g, 68% yield).
Preparation of Compound 5 by Soft Chemistry: An aqueous solu-
tion (30 mL) of 3-phosphonobenzoic acid (0.3 g, 1.48 mmol,
Eur. J. Inorg. Chem. 2008, 4117–4125
© 2008 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.eurjic.org
4123

J.-M. Rueff, P.-A. Jaffrès et al.
FULL PAPER
Table 3. Summary of crystal data, intensity measurement and structure refinement for H2PO3C6H4CO2H (2), [Mn(H2O)(PO3C6H4CO2H)]
(3), [Co(H2O)(PO3C6H4CO2H)] (4), [Zn(H2O)(PO3C6H4CO2H)] (5) and [Zn3(H2O)2(PO3C6H4CO2)2] (6).
2
3
4
5[a]
6
Molecular formula
Formula mass
Laue class
Space group
a [Å]
b [Å]
c [Å]
C7H7O5P
202.10
2/m
C2 (14)
34.839(3)
6.9003(4)
6.9606(5)
98.557(7)
654.69(16)
4
C7H7O6PMn
273.04
2/m
P21/n (14)
4.9742(3)
31.9775(1)
5.7936(2)
94.593(4)
918.43(7)
4
C7H7O6PCo
277.03
2/m
P21/n (14)
4.9119(3)
32.316(5)
5.7481(8)
93.859(9)
910.35(15)
4
C7H7O6PZn
283.48
2/m
P21/n (14)
4.8727(2)
32.0216(2)
5.6948(2)
95.6714(4)
884.215(8)
4
C14H12O12P2Zn3
630.33
[mm]m
Pcan (60)
7.7731(4)
14.344(2)
36.246(8)
90.
β [°]
Cell volume [Å3]
Z
4041.4(9)
8
Density
1.622
0.318
1.974
1.616
2.0207
2.065
2.130
2.0712
3.753
µ [mm–1]
Tmin
Tmax
0.7771
0.9409
16874
5426
3564
0.7871
0.9309
25611
16624
0.7766
0.9440
9169
7419
2935
0.7732
0.9255
35122
16651
Measured reflections
Independent data
Independent data with
[IϽ3σ]
781
3739
3087
Temp. data collect. [°C]
Secondary extinction
Number of variables
R(Fo)
21
–
234
0.054
0.043
21
0.006(8)
165
0.0280
0.0291
21
1.1(2)
165
0.0321
0.0363
21
21
0.006(2)
311
0.0622
0.0678
0.069
Rw
[a] Data from powder diffraction (see Figure 3).
[2]
a) J. L. C. Rowsell, A. R. Millard, K. S. Park, O. M. Yaghi, J.
Am. Chem. Soc. 2004, 126, 5666–5667; b) R. E. Morris, P. A.
Wheatley, Angew. Chem. Int. Ed. 2008, 47, 4966–4981; c) G.
Ferey, Chem. Soc. Rev. 2008, 37, 191–214.
P. M. Forster, A. K. Cheetham, Top. Catal. 2003, 24, 79–86.
D. Bradshaw, T. J. Prior, E. J. Cussen, J. B. Claridge, M. J. Ros-
seinsky, J. Am. Chem. Soc. 2004, 126, 6106–6114.
O. R. Evans, W. B. Lin, Acc. Chem. Res. 2002, 35, 511–522.
P. Horcajada, C. Serre, M. Vallet-Regi, M. Sebban, F. Taulelle,
G. Férey, Angew. Chem. Int. Ed. 2006, 45, 5974–5978.
a) N. L. Rosi, J. Kim, M. Eddaoudi, B. Chen, M. O’Keeffe,
O. M. Yaghi, J. Am. Chem. Soc. 2005, 127, 1504–1518; b) P.
Rabu, J.-M. Rueff, Z. L. Huang, S. Angelov, J. Souletie, M.
Drillon, Polyhedron 2001, 20, 1677–1685; c) N. Guillou, C. Liv-
age, G. Férey, Eur. J. Inorg. Chem. 2006, 24, 4963–4978.
H. Li, M. Eddaoudi, M. O’Heeffe, O. M. Yaghi, Nature 1999,
402, 276–279.
G. Férey, C. Mellot-Draznieks, C. Serre, F. Millange, J. Dutour,
S. Surblé, I. Margiolake, Science 2005, 309, 2040–2042.
M. Eddaoudi, D. B. Moler, H. Li, B. Chen, T. M. Reineke, M.
O’Keeffe, O. M. Yaghi, Acc. Chem. Res. 2001, 34, 319–330.
T. Devis, O. Davis, M. Valls, J. Marrot, F. Couty, G. Férey, J.
Am. Chem. Soc. 2007, 129, 12614–12615.
Fourier series were then performed in the 0Յsinθ/λՅ0.5 interval.
The analysis of the observed maxima of density allowed the loca-
tion of all the hydrogen atoms. The atomic position of the hydrogen
atoms were refined but their ADP were considered as isotropic and
fixed to 0.038 Å2. The FullProf program[27] was used to refine the
structure of compound 5. The sample was loaded in a thin capillary
(Ø = 0.3 mm) to avoid preferential orientation, and the data were
registered with a Bruker D8 diffractometer up to 90° (2θ) by using
the Cu-Kα1 wavelength. Bond length constraints were applied on
the organic moiety during the refinement. The final reliability fac-
[3]
[4]
[5]
[6]
[7]
tors were: RWP = 5.34%, REXP = 2.64% (χ2 = 4.04) and RBragg
=
8.05%. Table 3 summarizes the structure refinement data for com-
pounds 2, 3, 4, 5 and 6
CCDC-686731 (for 4), -686732 (for 3), -686733 (for 6), -686734
(for 2) and -686735 (for 5) contain the supplementary crystallo-
graphic data for this paper. These data can be obtained free of
charge from The Cambridge Crystallographic Data Centre via
www.ccdc.cam.ac.uk/data_request/cif.
[8]
[9]
[10]
[11]
[12]
[13]
Supporting Information (see footnote on the first page of this arti-
cle): Molecular structure of H2PO3C6H4CO2H in the solid state;
SEM characterization of compounds 3, 4, 5 and 6; TGA curves of
3, 4, 5 and 6.
G. Alberti, U. Costantino, F. Marmottini, R. Vivani, P. Zap-
pelli, Angew. Chem. Int. Ed. Engl. 1993, 32, 1357–1359.
a) D. J. Kong, J. Zon, A. McBee, A. Clearfield, Inorg. Chem.
2006, 45, 977–986; b) G. B. Hix, V. Caignaert, J.-M. Rueff, L.
Le Pluart, J. E. Warren, P. A. Jaffrès, Cryst. Growth Des. 2007,
7, 208–211.
Acknowledgments
The authors would like to thank Ms. Hélène Rousselière and Dr.
Alain Pautrat from the Laboratoire de Cristallographie et Science
des Matériaux, Caen, France, for their precious help. We thank
the Service de RMN, UFR Sciences et Techniques, Université de
Bretagne Occidentale, Brest for recording the NMR spectroscopic
data.
[14]
[15]
A. Hu, H. W. Ngo, W. Lin, J. Am. Chem. Soc. 2003, 125,
11490–11491.
a) M. V. Vasylyev, E. J. Wachtel, R. Popovitz-Biro, R. Neum-
ann, Chem. Eur. J. 2006, 12, 3507–3514; b) J. M. Taylor, A. H.
Mahmouhdkhani, G. K. H. Shimizu, Angew. Chem. Int. Ed.
2007, 46, 795–798; c) M. Vasylyev, R. Neumann, Chem. Mater.
2006, 18, 2781–2783.
[16]
a) J. Svoboda, V. Zima, L. Benes, K. Melanova, M. Vlcek,
Inorg. Chem. 2005, 44, 9968–9976; b) S. Bauer, N. Stock, J.
Solid State Chem. 2007, 180, 3111–3120.
[1] A. K. Cheetham, C. N. R. Rao, R. K. Feller, Chem. Commun.
2006, 46, 4780–4795.
4124
www.eurjic.org
© 2008 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Eur. J. Inorg. Chem. 2008, 4117–4125

meta-Phosphonobenzoic Acid: A Precursor for the Design of Hybrid Materials
[17] Z. Chen, Y. Zhou, L. Wenig, C. Yuan, D. Zhao, Chem. Asian
J. 2007, 2, 1549–1554.
[23] A. J. M. Duisenberg, EvalCCD Thesis, University of Utrecht,
The Netherlands, 1998.
[18] a) G. Cao, H. Lee, V. M. Lynch, T. Mallouk, Inorg. Chem.
1988, 27, 2781–2785; b) K. J. Martin, P. J. Squattrito, A.
Clearfield, Inorg. Chim. Acta 1989, 155, 7–9.
[19] S. Drumel, P. Janvier, P. Bardoux, M. Bujoli-Doeuff, B. Bujoli,
Inorg. Chem. 1995, 34, 148–156.
[24] G. M. Sheldrick, SADABS: Program for Empirical Absorption
Correction of Area Detector Data, University of Göttingen,
Germany, 1996.
[25] L. Palatinus, G. Chapuis, J. Appl. Crystallogr. 2007, 40, 786–
790.
[20] J. C. Bonner, M. E. Fisher, Phys. Rev. 1964, 135, 3A, A640–
[26] V. Petricek, M. Dusek, L. Palatinus, Jana2006: Structure Deter-
mination Software Programs, Institute of Physics, Praha, Czech
Republic, 2006.
[27] J. Rodriguez-Carvajal, Phys. B 1993, 192, 55–69.
Received: May 14, 2008
658.
[21] S. G. Carling, P. Day, D. Visser, R. K. Kremer, J. Solid State
Chem. 1993, 106, 111–119.
[22] J. Le Bideau, C. Payen, B. Bujoli, P. Palvadeau, J. Rouxel, J.
Magn. Magn. Mater. 1995, 140–144, 179–1720.
Published Online: August 5, 2008
Eur. J. Inorg. Chem. 2008, 4117–4125
© 2008 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.eurjic.org
4125