Development of metal cyanurates: The example of barium cyanurate (BCY)

Article abstract of DOI:10.1002/ejic.201400014

Metal cyanurate compounds were prepared by means of solid-state metathesis reactions between a metal halide and an alkali cyanurate. Following this procedure, a mixture of BaCl₂ and K(OCN) was heated in a fused silica tube at 575 C to yield highly crystalline barium cyanurate. This reaction was analyzed by differential scanning calorimetry (DSC) measurements and involves a cyclotrimerization of cyanate ions to yield the cyclic cyanurate (O ₃C₃N₃)^3- ion. The crystal structure of Ba₃(O₃C₃N₃)₂ was refined by single-crystal X-ray diffraction, and the presence of cyanurate was verified by infrared spectroscopy.

Full text of DOI:10.1002/ejic.201400014

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DOI:10.1002/ejic.201400014
Development of Metal Cyanurates: The Example of
Barium Cyanurate (BCY)
[
a]
[a]
[b]
Markus Kalmutzki, Markus Ströbele, Holger F. Bettinger, and
H.-Jürgen Meyer*[
a]
Keywords: Cyanurates / Barium / Metathesis / Solid-state reactions / Density functional calculations
Metal cyanurate compounds were prepared by means of so-
lid-state metathesis reactions between a metal halide and an
alkali cyanurate. Following this procedure, a mixture of
measurements and involves a cyclotrimerization of cyanate
3–
ions to yield the cyclic cyanurate (O
3
C
3
N
3
)
ion. The crystal
structure of Ba (O was refined by single-crystal X-ray
3
3 3 3 2
C N )
BaCl
2
and K(OCN) was heated in a fused silica tube at 575 °C
diffraction, and the presence of cyanurate was verified by
infrared spectroscopy.
to yield highly crystalline barium cyanurate. This reaction
was analyzed by differential scanning calorimetry (DSC)
Introduction
reaction that has been reported for the preparation of many
nitride, carbide, or boride compounds, but fails for the
The discovery of new fields in chemistry is a great oppor- preparation of thermally labile compounds.
tunity to satisfy the growing demand for new high-perform-
Hence, moderate or less exothermic SSM reactions offer
ance materials. For this goal, new research strategies and perspectives for the preparation of thermally labile com-
synthetic methods are needed. One consideration for the pounds that are usually not accessible by classical solid-
development of new compounds is the employment of di- state reactions. After this method was successfully em-
verse anions. On this basis, compounds with complex ployed for preparations of boronitride and carbodiimide
3
–
2–
–
anions such as [NBN] , [NCN] , and [OCN] have been (cyanamide) compounds, its potential was recently demon-
prepared in our laboratory over the past few years. Most of strated again in the attempt to prepare new cyanate or cyan-
these compounds were synthesized by solid-state metathesis urate compounds.
1]
(
SSM) reactions.[ A quite large number of boronitride (ni-
Cyanurates have been reported in the literature for more
[
8,9]
tridoborate) compounds have been developed, including the than one hundred years;
however, no such compound
dinitridoborate ion.[ Unfortunately, many of them behave has been structurally characterized until LiSr(O C N ) and
2]
3
3
3
[
10]
hygroscopically and require handling under an inert gas, al- Li Sr F(O C N ) were reported very recently.
Both
3
2
3
3
3 2
though there are some interesting exceptions.
Many new inorganic carbodiimide (or cyanamide) com- (X = Cl, F). On this basis, more cyanurate compounds
compounds were prepared by treating Li(OCN) with SrX2
[
3,4]
pounds have been developed over the past decade.
Sev- would seem to be accessible in a straightforward manner.
In this work we describe the preparation, formation reac-
and magnetic properties. The dominant tion, crystal structure, and electronic structure of barium
eral of them are stable compounds and exhibit some excit-
[
4,5]
[6]
ing optical
method of synthesis for most of these compounds has been cyanurate (BCY).
SSM reactions.
This new or modified type of SSM reaction involves a
soft ignition that propagates through the sample. This stage
is supposed to involve the metathesis, which usually pro- Results and Discussion
duces an X-ray-amorphous product plus the crystalline me-
tathesis salt. A crystalline product is obtained after further Synthesis
heating by crystallization from a melt.[ This type of reac-
7]
tion is different to the well-known highly exothermic SSM
Inorganic cyanurates have been under discussion for dec-
ades but no example has been structurally verified until re-
cently. It is clear that cyanurate may be either prepared by
[
[
a] Institut für Anorganische Chemie, Universität Tübingen,
Auf der Morgenstelle 18, 72076 Tübingen, Germany
http://www.mnf.uni-tuebingen.de/fachbereiche/chemie/institute/
anorganische-chemie/institut/ag-meyer/startseite.html
b] Institut für Organische Chemie, Universität Tübingen,
Auf der Morgenstelle 18, 72076 Tübingen, Germany
–
trimerization of (OCN) ions, which is well-known in or-
[9]
ganic chemistry, or from the trianion of cyanuric acid,
which appears to be difficult to prepare, as has been shown
[
8,11]
in the past.
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Our preparations were guided by the employment of could be shown by powder XRD, which revealed no decom-
SSM reactions in which a reactive alkali cyanurate is com- position products.
bined with a metal halide. Previously, the employment of
Li(OCN) and SrCl (and SrF ) have yielded LiSr(O C N )
2
2
3
3
3
Thermal Analysis
and Li Sr F(O C N ) . From these reactions it became
3
2
3
3
3 2
clear to us that the employment of Li(OCN) is limited, be-
cause it shows decomposition effects above 475 °C with the
formation of carbonate as a decomposition product.
The synthesis of BCY was performed by SSM reaction
between BaCl2 and K(OCN) in the molar ration 1:2 at
[
12]
575 °C. The reaction is described by Equation (1). An ex-
Therefore, we decided to explore the usage of K(OCN). A
thermoanalytic study of K(OCN) performed in a differen-
tial thermal analysis (DTA) apparatus revealed a congruent
cess of K(OCN) is advantageous to provide a flux medium
in the reaction mixture, hence lowering the melting point of
the mixture as well as facilitating the crystallization of the
product. The formation reaction involves a cyclotrimeri-
zation of cyanate ions yielding cyanurate ions.
–1
melting at 329 °C upon heating (with a rate or 2 Kmin ).
The melt remained stable at least up to 525 °C (Figure 1).
Recrystallization upon cooling was observed at 329 °C.
Hence, K(OCN) showed sufficiently good performance –
even better than Li(OCN) – for employment in SSM reac-
tions. K(OCN) was fully preserved after the DTA run as
3
BaCl
2
+ 6 K(OCN) Ǟ Ba
3
(O
3
C
3
N
3
)
2
+ 6 KCl
(1)
We note here that an alternate description of reaction
equivalents of BaCl and 2 K(OCN) could be given to yield
2
Ba(OCN) . However, we prefer the formula Ba (O C N )
2
3
3
3
3 2
to express the presence of cyanurate ions in the structure, in
contrast to the yet unknown barium cyanate [Ba(OCN)2].[
The reaction given in Equation (1) was performed with a
quantitative conversion rate, as indicated by powder XRD
analysis displayed in Figure 2, and produced a highly crys-
talline product that was stable in air but started to decom-
pose when treated with water. Single crystals were selected
for an XRD crystal structure refinement. A comparison of
the observed XRD powder pattern and a theoretical pattern
calculated from single-crystal X-ray data is shown in Fig-
ure 2.
13]
The course of the reaction between BaCl and K(OCN)
2
in a 1:3 molar ratio was investigated by thermal studies.
Since K(OCN) melts near 329 °C, it appeared likely that it
acted not only as a reactant but also as a melt flux. Accord-
ing to a differential scanning calorimetry (DSC) study, the
reaction in Equation (1) readily proceeds in a small tem-
Figure 1. Differential thermal analysis of K(OCN) with melting
(329 °C) and recrystallization (293 °C) peaks.
Figure 2. Observed powder pattern of Ba
3
(O
3
C
3
N
3
)
2
(blue) in comparison to the theoretical pattern calculated from single-crystal X-ray
data (black). The stars mark reflections due to an excess amount of K(OCN) (green, PDF [8-471]) used in the reaction, and the metathesis
salt KCl (red, PDF [41-1476]).
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perature interval between 284 and 295 °C (Figure 3). The (B O ) ion with three exocyclic oxygen atoms.[14] The crys-
3–
3
6
reaction can be assumed to be initiated by a coincidence of tal structure of BCY contains a cyanurate ion (Figure 4)
an exothermic ignition of the reaction and the melting of that occupies general positions with its O, C, and N atoms
K(OCN). This is displayed in Figure 3 with the exothermic (Table 1). The cyanurate ring is almost planar and shows
effect (Figure 3, peak 1; 284 °C onset, 315 °C offset) due to an average angle between three adjacent atoms of 119.1°,
the ignition of the metathesis, which is superimposed by an which matches quite well with the corresponding angle re-
endothermic effect (Figure 3, peak 2; 295 °C) caused by the ported for cyanuric acid (122.42°). The relatively large tor-
melting of the mixture of starting materials. During this sion angle of 3.88° (compared to 0.39° in cyanuric acid)
process the cyclotrimerization of cyanate ions into cyan- might be caused by matrix effects.
urate is expected to take place before an endothermic effect
in the DSC (Figure 3, peak 3; 338 °C) indicates the melting
of the product mixture. Upon cooling, two exothermic ef-
fects represent the recrystallization of the reaction products
(Figure 3, peak 4; 303 °C) and a mixture of K(OCN) and
KCl (Figure 3, peak 5; 259 °C).
Figure 4. Cyanurate ion of BCY.
Table 1. Atom positions and isotropic displacement parameters
2
–1
[
pm ϫ10 ] of Ba
3 3 3 3 2
(O C N ) .
[
a]
Atom Wyckoff site
x
y
z
U
eq
Ba1
Ba2
O1
N1
C1
12c
6a
36f
36f
36f
0
0
0
0
0.3511(1) 25(1)
1/4 27(1)
0.3976(8) 0.0707(8) 0.0370(1) 46(1)
0.1753(1) 0.2095(1) 0.0393(2) 36(1)
0.9669(1) 0.1680(1) 0.0388(2) 31(1)
2
Figure 3. DSC of a 1:3 molar mixture of BaCl and K(OCN).
[a] Ueq is defined as one-third of the trace of the orthogonalized
The occurrence of the cyanate cyclotrimerization was in- U tensor. All atoms occupy 18b sites.
ij
vestigated in more detail by interrupting the reaction just
at the temperature observed for the exothermic ignition. At
this stage SSM reactions (e.g., of carbodiimides) have al-
ways shown X-ray-amorphous products plus the metathesis
salt, and until now there has been no structural proof of
the identity of a product that has been formed in the exo-
The average C–N bond length in the cyanurate ion of
BCY (135 pm) is only slightly shorter than the one reported
for solid cyanuric acid (136 pm), in which three hydrogen
atoms are located at the nitrogen atoms. Both bond lengths
are relatively close to the value expected for a C–N double
bond (130 pm) rather than for a C–N single bond (147 pm).
The average C–O bond in BCY [127.9(8) pm] is longer than
the value found in solid cyanuric acid (121 pm), which is
[
7]
thermic process. Hence, the trimerization reaction of
–
(
OCN) can be studied in more detail on the basis of the
DSC measurements. For this purpose, a (1:3 molar) sample
mixture of BaCl and K(OCN) was heated to 300 °C (heat-
2
–
close to the expected value for a C–O double bond (122 pm)
1
ing rate 2 Kmin ) and then rapidly cooled. An infrared
spectrum was recorded on this sample at room temperature.
The vibration bands can be clearly assigned to stretching
[15]
(Figure 4).
Terminal oxygen atoms in the structure of
BCY play a dominant role in the connectivity with sur-
rounding cations, as will be shown later.
vibrations ν(C N ) as well as bending vibrations δ(C N )
3
3
3
3
These findings suggest that the three negative charges of
the cyanurate ion are partially located on the terminal oxy-
gen atoms, but some delocalization of negative charge
throughout the ring can be assumed.
characteristic of the cyanurate ion. These vibrations ap-
peared to be similar to those of BCY samples that were
prepared according to the reaction in Equation (1).
3–
The (O C N ) ring, displayed in Figure 4 is located per-
3
3
3
pendicular to the threefold rotation axis. The presence of
this large planar ion introduces a layered character into the
crystal structure (Figure 5).
Crystal Structure
Ba (O C N ) (BCY) crystallizes in the trigonal space
The in-plane arrangement of cyanurate ions follows the
3
3
¯
3
3 2
group R3c with six formula units (Table 4) and is isotypic motif of a closest-packed layer, as displayed in Figure 6,
with the structure of α-Ba(B O ), which contains the cyclic with barium ions situated above and below.
2
4
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A sequence of twelve identical cyanurate layers that are
shifted differently within the ab plane makes up for the long
c axis of the unit cell. Barium ions occupy two distinct posi-
tions in the structure of BCY. They alternate in interlayer
spaces created by the arrangement of cyanurate ions (Fig-
ure 5). Both barium ions have sixfold coordination environ-
ments with oxygen atoms of six surrounding cyanurate ions.
Ba1 is situated on a threefold axis that has a distorted trigo-
nal-antiprismatic environment with two distinct Ba1–O
distances at 276.8(5) pm (3ϫ) and 288.2(5) pm (3ϫ)
(Table 2). Moreover, there are three nitrogen contacts
[dN1–Ba1 = 297.1(6) pm] that may be included in the coordi-
nation environment to result in a ninefold coordination for
Ba1. Ba2 is situated on a threefold inversion axis, sur-
rounded in a trigonal-prismatic fashion by six oxygen atoms
with Ba2–O distances of 264.0(5) pm (6ϫ), as shown in
Figure 7.
Table 2. Selected bond lengths [pm], multiplicities (nϫ), and angles
3 3 3 3 2
[°] in the structure of Ba (O C N ) .
Ba1–O1
Ba2–O1
Ba1–N1
O1–C1
C1–N1
276.8(5) (3ϫ), 288.2(5) (3ϫ)
264.0(5) (6ϫ)
297.1(6) (3ϫ)
127.9(8)
134.8(1), 1.35(1)
C1–N1–C1
N1–C1–N1
O1–C1–N1
115.9(6)
124.1(6)
116.4(7), 119.6(7)
3 3 3 3 2
Figure 5. Unit cell of Ba (O C N ) projected along the b axis em-
phasizing the alternating sequence of Ba1 and Ba2 ions along the
c axis.
Figure 6. Motif of a closest-packed layer of (O
below (small gray) the layer.
3
C
3
N
3
)3– ions in the structure of Ba
(O C N ) with barium ions above (large gray) and
3 3 3 3 2
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3 3 3 3 2
Figure 7. Perspective view of the structure of Ba (O C N ) showing the sixfold coordination environment of barium ions by oxygen
atoms. Ba1 (left) exhibits a trigonal-antiprismatic environment, and Ba2 (right) is coordinated in a trigonal-prismatic manner.
MO Calculations
The cyanurate ion corresponds to a minimum of D3h
symmetry at the BBLYP/6-311+G* level of theory with C–
N distances of 136.7 pm and C–O distances of 128.1 pm.
Computation of the harmonic vibrational frequencies gives
–
1
–1
a very strong band at 1394 cm (EЈ, I = 7428 kmmol )
–
1
–1
and weaker ones at 1408 cm (EЈ, I = 454 kmmol ) and
–
1
–1
1
128 cm (EЈ, I = 65 kmmol ) that correspond to CN
stretching vibrations ν(C N ). The out-of-plane bending vi-
3
3
–
1
–1
bration δoop(C N ) is at 833 cm (A ЈЈ, I = 129 kmmol ),
3
3
2
whereas the in-plane bending vibration δ (C N ) is at
ip
3
3
–
1
–1
5
74 cm (EЈ, I = 47 kmmol ).
The electronic configuration involves six occupied π or-
bitals that result from the bonding and antibonding combi-
nation of the three p lone pairs of the oxygen atoms and
the three π orbitals of the heterocycle (see Figures 8 and 9).
A set of degenerate π orbitals (π and π ) are the highest
5
6
occupied molecular orbitals (HOMO). These have one
nodal plane that bisects the six-membered ring and an anti-
bonding interaction with the O(p) orbitals.
Figure 8. The π molecular orbitals of the cyanurate anion as com-
The corresponding MOs with a bonding interaction be- puted at the B3LYP/6-311+G* level of theory.
tween the ring π orbitals and the O(p) orbitals are lower in
energy (π and π ). In addition, there is one π orbital (π )
without a nodal plane and small coefficients of O(p),
2
3
1
Infrared Spectroscopy
whereas the antibonding combination of the ring π orbital
An infrared spectrum of BCY was recorded between
–1
and the in-phase O(p) comprises π (see Figures 8 and 9).
4000 and 400 cm . Stretching vibrations ν(C N ) are to be
4
3 3
–1
These MOs resemble those of benzene, but include in found between 1060 and 1411 cm ; bending vibrations
addition contributions of the π lone pairs of the oxygen δoop(C N ) are at 830–860 cm–1 and δ (C N ) at
3
3
ip
3
3
atoms. Natural population analysis[ arrives at a charge of 590 cm .
16]
–1 [9,17]
Some vibration bands corresponding to the
–
–0.89 on O, –0.83 on N, and +0.72 on C.
(OCN) ion are also present in the spectrum owing to the
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Figure 9. Schematic orbital interaction diagram of the cyanurate anion (not drawn to scale).
3–
excess amount of K(OCN) used in the reaction. The finger- (α-BBO) in which the smaller (O C N ) ion is substituted
3
3
3
3–
print region of the IR spectrum of Ba (O C N ) is dis- by (O B O ) .
3
3
3
3 2
3
3
3
played in Figure 10; the assignment of the vibrational bands
is shown in Table 3.
The reaction performs well in its own K(OCN) flux as
we have shown in DSC studies of the reaction. The reaction
starts with a soft ignition near the melting point of
K(OCN) to produce an X-ray-amorphous material. Similar
reactions were previously reported by us with Li (CN ) to
2
2
yield carbodiimide compounds. In the case of K(OCN), a
trimerization takes place during the reaction to yield the
3–
cyclic (O C N ) ion. The formation of this ion at about
3
3
3
300 °C just after the ignition process of the reaction was
demonstrated by infrared spectroscopy. This confirms one
of our previous assumptions for SSM reactions. The ig-
nition involves the metathesis reaction and the following
melting process serves to generate a highly crystalline pow-
der of the product.
Experimental Section
Preparations: K(OCN) was prepared by heating a mixture of urea
(
2 3
Ͼ99% Merck) and K (CO ) (99%, Merck) in a 2.5:1 ratio (total
3 3 3 3 2
Figure 10. Fingerprint region of the IR spectrum of Ba (O C N ) .
mass ca. 2.5 g) in a corundum vessel. The mixture was slowly
heated to 100 °C and remained at this temperature for 3 h. Then
the mixture was slowly heated to 130 °C (decomposition of urea)
within 30 min, where it remained for 30 min, followed by slow heat-
ing to 275 °C, where it remained for about 30 min to get rid of
decomposition products of urea (biuret) before it was cooled to
–
1
3 3 3 3 2
Table 3. Vibrational frequencies [cm ] of Ba (O C N ) .
δip(C
3
N
3
)
590
δ
oop(C
3
N
3
)
830–860
693
1060–1411
620
ν(BaO)
ν(C
3
N
3
)
room temperature. Commercial BaCl
schmidt A.-G., Essen) was dried under vacuum at 150 °C for 2 h.
Both starting materials, BaCl and K(OCN), were identified as sin-
(anhydrous, Th. Gold-
2
δ(C=O)
2
gle-phase materials according to powder X-ray diffraction (XRD).
All procedures of the preparation including the mixing of starting
materials and loading of silica tubes were performed in a glovebox
Conclusion
3 3 3 3 2
under dry argon. Ba (O C N ) (BCY) was prepared from a care-
The novel compound Ba (O C N ) (BCY) was synthe-
sized by means of a solid-state metathesis reaction and rep-
3
3
3
3 2
fully ground mixture of BaCl with an excess amount of K(OCN)
2
following a 1:3 molar ratio. This mixture was fused into a silica
resents the first binary cyanurate. The crystal structure of ampoule under vacuum, heated to 575 °C within about 4 h, and
BCY was refined isotypically to the structure of α-Ba(B O ) kept at this temperature for 48 h before it was cooled to room tem-
2
4
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perature with the natural cooling rate of the furnace. The ampoules
were opened in air and the crystalline product was inspected by
XRD. Powder XRD patterns indicated high conversion rates of
reactions by showing only reflections of the product (BCY), the
metathesis salt (KCl), and K(OCN), which was used in an excess
for_deposited_data.html] on quoting the depository number CSD-
426619 (BCY). Reaction products were inspected by powder XRD
with a Stadi-P (STOE, Darmstadt) powder diffractometer with ger-
manium-monochromated Cu-Kα1 radiation. The powder pattern
recorded for the reported reaction indicates high conversion rates
by showing reflections that belong to BCY, the co-produced me-
tathesis salt (KCl), and K(OCN), which was used in an excess
amount as a flux medium. The powder pattern of BCY was indexed
amount as a flux medium. The crystal structure of Ba
was refined by single-crystal XRD.
3 3 3 3 2
(O C N )
Thermal Analysis: Differential thermal analyses (DTA) were per-
formed with a Netzsch Jupiter, STA 449 F3 apparatus. Samples
were fused into homemade silica containers with typical total
masses of 100 mg. Measurements of K(OCN) were performed be-
tween room temperature and 525 °C with heating and cooling rates
with a trigonal unit cell and the following parameters: a =
3
7
08.4(3) pm, c = 4026(1) pm, β = 120°, V = 1750.0(1) Å .
Computational Details: The cyanurate ion was investigated by using
[19]
hybrid density functional theory (B3LYP) in conjunction with a
6-311+G* basis set as implemented in Gaussian 09.[21] As multi-
ply charged anions are unstable towards loss of electrons in the gas
phase, the computations simulated a water solution with the help
of a polarizable continuum model.[
–1
[20]
of 2 Kmin . DSC measurements were also performed with a
Netzsch Jupiter, STA 449 F3 apparatus. Samples with typical total
masses of 30 mg were enclosed into gold-plated stainless steel con-
tainers. Measurements were performed under argon between room
temperature and 475 °C with a heating and cooling rate of
22]
–1
Infrared Spectra: Vibrational spectra were recorded with a Bruker
2
Kmin .
X-ray Crystallography: A single crystal of Ba
was measured with a single-crystal X-ray diffractometer (STOE-
IPDS) at room temperature (T = 293 K) using Mo-K radiation (λ
0.71073 Å). The structure refinement and solution were per- Acknowledgments
formed with direct methods (SHELXS) and least-squares refine-
–
1
Tensor 27 FTIR spectrometer within the range of 400–4000 cm
by using KBr pellets.
3
3 3 3 2
(O C N ) (BCY)
α
=
2
[18]
ments on F (SHELXL).
The crystal structure of BCY was re-
This research was supported by the Deutsche Forschungsgemein-
fined on a transparent single crystal (ca. 0.08ϫ0.08ϫ0.06 mm) schaft (Bonn) in the framework of the SSM reactions project
within the range Θ = 3.06–26.04°. A total number of 5715 collected
reflections was corrected for Lorentz and polarization effects
(ME914/25-1). Support of M. K. by the Landesgraduiertenför-
derung of the Science Ministry of Baden-Württemberg (Universität
Tübingen) is gratefully acknowledged.
(
(
STOE IPDS Software) and reduced to 389 independent reflections
int = 0.0701). Some results and final R values for BCY are shown
R
in Table 4. The atom positions of BCY are given in Table 1. Se-
lected bond lengths and angles of BCY are collected in Table 2.
Further details of the crystal structure investigations may be ob-
tained from the Fachinformationszentrum Karlsruhe, 76344 Egg-
enstein-Leopoldshafen, Germany [Fax: (+49)7247-808-666; E-mail:
[
1] a) H.-J. Meyer, Dalton Trans. 2010, 39, 5973–5982; b) K. Gib-
son, M. Ströbele, B. Blaschkowski, J. Glaser, M. Weisser, R.
Srinivasan, H.-J. Kolb, H.-J. Meyer, Z. Anorg. Allg. Chem.
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[
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Largest diff. peak/hole [eÅ ]
1296.
Eur. J. Inorg. Chem. 0000, 0–0
7
© 0000 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim

Job/Unit: I40014
/KAP1
Date: 24-04-14 16:55:41
Pages: 9
www.eurjic.org
FULL PAPER
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Received: January 7, 2014
Published Online: ᭿
Eur. J. Inorg. Chem. 0000, 0–0
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© 0000 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim

Job/Unit: I40014
/KAP1
Date: 24-04-14 16:55:42
Pages: 9
www.eurjic.org
FULL PAPER
Barium Cyanurate
M. Kalmutzki, M. Ströbele,
H. F. Bettinger, H.-J. Meyer* ........... 1–9
Development of Metal Cyanurates: The
Example of Barium Cyanurate (BCY)
Keywords: Cyanurates / Barium / Metath-
esis / Solid-state reactions / Density func-
tional calculations
The binary metal cyanurate Ba
was synthesized by a solid-state metathesis
reaction, and the nature of the cyanurate
3
(O
3
C
3
N
3
)
2
ion was examined by density functional
methods.
Eur. J. Inorg. Chem. 0000, 0–0
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© 0000 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim