Investigations on the structure diversity and thermal degradation behavior of CdII and ZnII thiocyanato coordination compounds based on 3-acetylpyridine as neutral co-ligand

Article abstract of DOI:10.1002/zaac.201200268

Reaction of Cd^II and Zn^II thiocyanate with 3-acetylpyridine leads to the formation of the new Cd^II and Zn ^II coordination compounds [Cd(NCS)₂(3-acetylpyridine) ₄] (1A), [Cd(NCS)₂(3-acetylpyridine)₂] _n (1B), [Cd(NCS)₂(3-acetylpyridine)]_n (1C) and [Zn(NCS)₂(3-acetylpyridine)₂] (2A). Compound 1A consists of discrete complexes, in which the metal centers are octahedrally coordinated by four terminal bonded N-donor co-ligands and two terminal N-bonded thiocyanato anions. In compound 2A the metal centers are only tetrahedrally coordinated by two terminal bonded N-donor co-ligands and two terminal N-bonded thiocyanato anions. In compound 1B the Cd^II cations are octahedrally coordinated by two terminal bonded N-donor co-ligands and four thiocyanato anions. The metal centers are linked by μ-1, 3 bridging thiocyanato anions into chains. In compound 1C the metal cations are octahedrally coordinated by two μ-1, 5 bridging 3-acetyl-pyridine ligands and four μ-1, 3 bridging thiocyanato anions building up a three-dimensional coordination network. Investigations on the thermal degradation behavior of all compounds using simultaneous differential thermoanalysis and thermogravimetry as well as X-ray powder diffraction and IR spectroscopy prove that on heating compound 2A decompose without the formation of 3-acetylpyridine-deficient intermediates. In contrast, for compound 1A a stepwise decomposition is observed, leading to the formation of the 3-acetylpyridine-deficient compound [Cd(NCS)₂(3- acetylpyridine)₂]_n (1B) which decomposes on further heating Copyright

Full text of DOI:10.1002/zaac.201200268

Job/Unit: Z12268
/KAP1
Date: 06-09-12 10:39:10
Pages: 9
ARTICLE
DOI: 10.1002/zaac.201200268
Investigations on the Structure Diversity and Thermal Degradation
II
II
Behavior of Cd and Zn Thiocyanato Coordination Compounds based on
-Acetylpyridine as Neutral Co-Ligand
3
[a]
[a]
[a]
Julia Werner, Jan Boeckmann, and Christian Näther*
II
II
Keywords: Coordination chemistry; Zn and Cd coordination compounds; Crystal structures; Thermochemistry
Abstract. Reaction of CdII and ZnII thiocyanate with 3-acetylpyridine 1,3 bridging thiocyanato anions into chains. In compound 1C the metal
II
II
leads to the formation of the new Cd and Zn coordination com-
cations are octahedrally coordinated by two μ-1,5 bridging 3-acetyl-
pyridine ligands and four μ-1,3 bridging thiocyanato anions building
pounds [Cd(NCS)
idine) (1B), [Cd(NCS)
acetylpyridine)
2
(3-acetylpyridine)
4
] (1A), [Cd(NCS)
(3-acetylpyridine)]
] (2A). Compound 1A consists of discrete complexes,
in which the metal centers are octahedrally coordinated by four ter-
minal bonded N-donor co-ligands and two terminal N-bonded thiocy-
2
(3-acetylpyr-
2
]
n
2
n
2
(1C) and [Zn(NCS) (3- up a three-dimensional coordination network. Investigations on the
2
thermal degradation behavior of all compounds using simultaneous
differential thermoanalysis and thermogravimetry as well as X-ray
powder diffraction and IR spectroscopy prove that on heating com-
anato anions. In compound 2A the metal centers are only tetrahedrally pound 2A decompose without the formation of 3-acetylpyridine-de-
coordinated by two terminal bonded N-donor co-ligands and two ter-
minal N-bonded thiocyanato anions. In compound 1B the Cd cations
ficient intermediates. In contrast, for compound 1A a stepwise decom-
position is observed, leading to the formation of the 3-acetylpyridine-
II
2 2 n
are octahedrally coordinated by two terminal bonded N-donor co-li- deficient compound [Cd(NCS) (3-acetylpyridine) ] (1B) which de-
gands and four thiocyanato anions. The metal centers are linked by μ-
composes on further heating
Introduction
N-donor co-ligands are thermally degraded, which enforces the
formation of intermediates, in which the metal atoms are
The development of strategies for a rational synthesis of
new coordination polymers that show cooperative magnetic
phenomena is still an active field of chemical research.[
For the preparation of such compounds paramagnetic metal
cations must be connected by small-sized ligands that can me-
diate magnetic exchange interactions. In this context our inter-
est has focused on the preparation of transition metal thio- and
selenocyanates in which the metal cations are linked by bridg-
ing thiocyanato anions. However, because in these compounds
the terminal coordination of the anionic ligand is usually pre-
ferred for hard metals like e.g. manganese, iron, cobalt, and
nickel, bridging compounds are less reported and their synthe-
[25–29]
linked by μ-1,3 bridging anionic ligands.
Most of these
compounds show cooperative magnetic phenomena and in
some of them a slow relaxation of the magnetization is ob-
1–14]
[30–34]
served.
Unfortunately, on thermal decomposition only microcrystal-
line powders of low crystallinity are obtained and therefore,
the structural identity of these compounds is difficult to prove.
In some cases the coordination mode of the anionic ligand – N-
terminal or bridging – can be determined by IR spectroscopy
analyzing the asymmetric CN stretching vibration but our pre-
vious investigations have shown that these values are strongly
[35–38]
influenced by e.g. the nature of the co-ligand.
Moreover,
sis is sometimes difficult to achieve or even impossible if the
synthesis is performed in the liquid state.[
using thermal decomposition as a synthetic tool intermediates
with bridging anions can only be expected if the octahedral
coordination is retained on ligand removal but one has to keep
in mind that also a transformation into tetrahedral coordinated
complexes might occur. In this context we reported on a very
efficient approach which might help to overcome these prob-
15–23]
Therefore, we
reported on an alternative approach for the synthesis of such
compounds which is based on thermal decomposition reac-
tions.[ Following our ideas octahedrally coordinated precur-
sor compounds based on paramagnetic transition metals with
terminally bonded thio- or selenocyanato anions and neutral
24]
II
lems. Using the chalcophilic metal cation Cd in the synthesis
ligand-deficient intermediates with bridging anions can easily
*
Prof. Dr. C. Näther
be crystallized in solution and identified by single crystal
Fax: +49-431-8801520
E-Mail: cnaether@ac.uni-kiel.de
structure analysis.[
39,40]
In several cases they are isotypic to
[
a] Institut für Anorganische Chemie
Christian-Albrechts-Universität zu Kiel
Max-Eyth-Straße 2
their paramagnetic counterparts, and the structures of the latter
can be determined by Rietveld refinement. In contrast to cad-
mium, zinc prefers a tetrahedral coordination and therefore the
preparation of such compounds can help in the identification
of possible tetrahedral intermediates. Even in those cases,
2
4118 Kiel, Germany
Supporting information for this article is available on the WWW
under http://dx.doi.org/10.1002/zaac.201200268 or from the au-
thor.
Z. Anorg. Allg. Chem. 0000, ᭿,(᭿), 0–0
© 0000 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
1

Job/Unit: Z12268
/KAP1
Date: 06-09-12 10:39:10
Pages: 9
J. Werner, J. Boeckmann, C. Näther
ARTICLE
where these intermediates are not isotypic to their paramag- Table 2. Stretching vibration νas(CN) for the thiocyanato anions and
ν
as(CO) for the acetyl group of the 3-acetylpyridine co-ligand in the
netic counterparts the comparison of their IR spectra can help
to unambiguously determine the coordination mode of the
infrared spectra of compounds 1A–1C and 2A.
paramagnetic intermediates. Finally, with cadmium thiocyan- Compound
ato different isomers including stable and metastable forms can
ν
as(CN) /cm–1
ν
as(CO) /cm–1
1
A
2043
2092
2096
2067
1684
1694
1671
1688
be prepared as shown in our previous work.[ This is the 1B
41]
1
2
C
A
reason why we are generally interested in the synthesis, struc-
tures and thermal behavior of these diamagnetic compounds.
In the course of systematic investigations we decided to inves-
II
II
tigate compounds based on Cd and Zn thiocyanate as well
as 3-acetylpyridine (3-Acpy), because this ligand is of current
interest for our project. According to a search in the CCDC
database (conquest Ver. 1.14, 2012) no compounds built up of
Furthermore, in compound 1C the ν˜ (CO) band is shifted
as
to lower wavenumbers, indicating that the acetyl group of the
co-ligand is involved in metal coordination, which is not the
case for the other compounds. Based on these results it can be
assumed that the Cd compound 1A consists of discrete com-
plexes in which the metal cations are octahedrally coordinated
by four 3-Acpy ligands and two terminal bonded thiocyanato
anions, whereas in the zinc compound 2A tetrahedral coordi-
nated discrete complexes with terminal coordinated thiocyan-
metal thiocyanates and this ligand are reported in literature.[
42]
Synthetic Investigations
In order to investigate if different crystalline phases can be ato anions should be present. In 1B the metal cations should be
prepared in solution, different ratios of the corresponding μ-1,3 bridged by the anionic ligands, whereas the coordination
metal salts and the N-donor co-ligand were reacted in water or topology of 1C should contain μ-1,3 bridging anions as well
pure co-ligand and the resulting precipitates were investigated as bridging 3-Acpy ligands.
by XRPD measurements (Table 1).
In further investigations crystallization experiments were
performed in order to characterize all compounds by single
crystal structure analysis.
Table 1. Crystalline phases that can be obtained if different ratios of
zinc and cadmium thiocyanate are reacted with 3-Acpy.
Ratio
Metal salt
Crystal Structures
3-Acpy
ZnII
CdII
The ligand-rich 1:4 (ratio metal salt to neutral co-ligand)
1
1
1
1
1
2
4
pure
10
6
4
2
2A
2A
2A
2A
2A
2A
2A
1A
1A
1A/1B
1B
1B
1B
1C
compound [Cd(NCS) (3-Acpy) ] (1A) crystallizes in the tri-
2
4
¯
clinic centrosymmetric space group P1 with two formula units
in the unit cell. The asymmetric unit consists of two crystallo-
graphically independent metal cations which are located on a
center of inversion, two thiocyanato anions as well as four 3-
Acpy ligands, all of them located in general position (Figure
1
1
1).
II
These investigations clearly show that with Zn thiocyanate
and 3-Acpy only one crystalline phase 2A is formed. In con-
II
trast, with Cd thiocyanate three different crystalline phases
1
A–1C are obtained. Elemental analysis of these phases
yielding compositions of [Cd(NCS) (3-Acpy) ] for 1A,
2
4
[
[
Cd(NCS) (3-Acpy) ] for 1B, [Cd(NCS) (3-Acpy)] for 1C and
2 2 2
Zn(NCS) (3-Acpy) ] for 2A and X-ray powder diffraction
2
2
proves that 2A is not isotypic to 1B (Figure S1 in the Support-
ing Information).
To get some preliminary information on the coordination
mode of the thiocyanato anions and the 3-Acpy co-ligands, all
compounds were investigated by IR spectroscopy (Figure S2–
5
in the Supporting Information). In compounds with terminal
N-bonded thiocyanato anions the asymmetric ν˜ (CN) is ex-
as
–
1
pected at about 2050 cm , whereas for bridging anions
ν˜ as(CN) values of about 2100 cm– are expected.
1
[35]
For com-
pound 1A and 2A values for ν˜ (CN) are found, which are
as
Figure 1. Coordination sphere in one of the two independent com-
plexes of compound 1A with atom labeling. Symmetry code used to
generate equivalent atoms: A: –x, –y+1, –z+1. (an ORTEP plot of 1A
is shown in Figure S6 in the Supporting Information).
characteristic for terminal bonded thiocyanato anions (Table
–1
2
2
), whereas for 1B and 1C ν˜ (CN) is about 2100 cm (Table
), consistent with bridging anions.
as
2
www.zaac.wiley-vch.de
© 0000 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
Z. Anorg. Allg. Chem. 0000, 0–0

Job/Unit: Z12268
/KAP1
Date: 06-09-12 10:39:10
Pages: 9
CdII and ZnII Thiocyanato Coordination Compounds based on 3-Acetylpyridine
Each metal cation is coordinated by six nitrogen atoms of ato anions in a mutually trans orientation in a slightly distorted
two terminal bonded thiocyanato anions and four nitrogen octahedral coordination environment (Table 4).
atoms of terminal bonded 3-Acpy ligands within a slightly dis-
Table 4. Selected bond lengths /Å and angles /deg for 1B. Symmetry
codes: A: –x, –y+1, –z; B: x–1, y, z, C: –x+1, –y+1, –z.
torted octahedral coordination geometry. The metal–nitrogen
distances range between 2.258(2) and 2.4392(19) Å as well as
the angles around the metal cations range between 86.62(7)
and 93.38(7) ° (Table 3). The geometric parameters in both
crystallographically independent metal complexes are similar
Cd(1)–N(1)
Cd(1)–N(11)
Cd(1)–S(1B)
N(1)–Cd(1)–N(11)
N(1)–Cd(1)–N(11A)
N(1)–Cd(1)–S(1B)
N(1A)–Cd(1)–S(1B)
N(11)–Cd(1)–S(1B)
N(11)–Cd(1)–S(1C)
2.3056(15)
2.3856(15)
2.7346(5)
90.06(6)
89.94(6)
86.66(4)
93.34(4)
93.19(4)
86.81(4)
(
Table 3).
Table 3. Selected bond lengths /Å and angles /deg for both crystallo-
graphically independent metal complexes in compound 1A. Symmetry
code: A: –x, –y+1, –z+1.
Cd(1)–N(1)
Cd(1)–N(11)
Cd(1)–N(21)
Cd(2)–N(2)
Cd(2)–N(31)
Cd(2)–N(41)
N(1)–Cd(1)–N(11)
N(1)–Cd(1)–N(11A)
N(1)–Cd(1)–N(21)
N(1)–Cd(1)–N(21A)
N(11)–Cd(1)–N(21)
N(11)–Cd(1)–N(21A)
N(2)–Cd(2)–N(31)
N(2)–Cd(2)–N(31B)
N(2)–Cd(2)–N(41)
N(2)–Cd(2)–N(41B)
N(31)–Cd(2)–N(41)
N(31)–Cd(2)–N(41B)
2.262(2)
2.384(2)
2.378(2)
2.258(2)
2.360(2)
2.439(2)
91.27(8)
88.73(8)
90.20(8)
89.80(8)
93.13(8)
86.87(8)
90.39(8)
89.61(8)
87.12(8)
92.88(8)
93.38(7)
86.62(7)
The cadmium cations are μ-1,3 bridged via the thiocyanato
anions into chains which elongate the crystallographic a axis.
The Cd···Cd intrachain distance amounts to 5.7902(2) Å
whereas the shortest interchain Cd···Cd distance amounts to
8
.8051(3) Å. This structural motif is frequently observed in
[43]
thiocyanato coordination polymers.
It must be noted that a
similar topology is found in the related azide compounds of
[
44–45]
composition [M(N ) (3-Acpy) ] (M = Mn, Cd).
In con-
3
2
2 n
trast to 1B, in the Cd azide compound the metal atoms are
linked by pairs of μ-1,1 bridging anionic ligands, whereas in
the manganese compound the metal centers are connected via
pairs of alternating μ-1,1 and μ-1,3 bridging anionic ligands.
The most ligand-deficient 1:1 compound [Cd(NCS) (3-Ac-
2
py)] (1C) crystallizes in the monoclinic non-centrosymmetric
n
space group Pc with two formula units in the unit cell. The
asymmetric unit consists of one cadmium cation, two thiocyan-
ato anions and one 3-Acpy ligand all of them located in gene-
ral positions. The metal cations are coordinated by three nitro-
gen atoms of two μ-1,3 bridging thiocyanato anions and one
μ-1,5 bridging 3-Acpy ligand, two sulfur atoms of two adja-
cent μ-1,3 bridging thiocyanato anions as well as one oxygen
atom of one μ-1,5 bridging 3-Acpy ligand all in mutually trans
orientation within a slightly distorted octahedral geometry
The ligand-deficient 1:2 compound [Cd(NCS) (3-Acpy)2]n
1B) crystallizes in the monoclinic centrosymmetric space
2
(
group P2 /c with two formula units in the unit cell. The asym-
1
metric unit consists of one metal cation, which is situated on
a center of inversion as well as of one 3-Acpy and one thiocy-
anato ligand in general positions (Figure 2).
(Figure 3).
The metal–nitrogen distances range between 2.288(4) and
2.349(4) Å and the angles around the metal cations range be-
tween 88.10(14) and 174.81(7) ° (Table 5). The metal cations
are connected via μ-1,3 bridging thiocyanato anions into lay-
ers, that are located in the bc plane (Figure 4: top). These
layers consist of 16-membered M-NCS rings, in which each
metal cation is only linked by one single anionic ligand.
The layers are connected by μ-1,5 bridging 3-Acpy ligands
into a three-dimensional network. Interestingly, all oxygen
atoms of the acetyl substituent point in the direction of the a
axis, which clearly shows the non-centrosymmetric arrange-
ment of the building blocks (Figure 4: bottom).
Figure 2. Molecular structure of compound 1B with atom labeling. For
clarity the disordered oxygen atom of the acetyl group is not shown.
Symmetry transformations used to generate equivalent atoms: A: –x,
It must be noted that a similar coordination topology was
never observed before in a metal thiocyanato coordination
polymer. However, a few examples of 12-membered respec-
tively 16-membered M–NCS (M = Cd, Mn) rings can be found
in the Cambridge Structural Database, but obviously exhibit a
–y+1, –z; B: x–1, y, z, C: –x+1, –y+1, –z. (an ORTEP plot of 1B is
shown in Figure S7 in the Supporting Information).
The metal cation is coordinated by four nitrogen atoms of different coordination topology.[46–48] It must also be men-
two 3-Acpy ligands and two μ-1,3 bridging thiocyanato anions tioned that a compound with a 24-membered Cd-NCS-mem-
and two sulfur atoms of two adjacent μ-1,3 bridging thiocyan- bered rings was reported recently.[
49]
Z. Anorg. Allg. Chem. 0000, 0–0
© 0000 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
www.zaac.wiley-vch.de
3

Job/Unit: Z12268
/KAP1
Date: 06-09-12 10:39:10
Pages: 9
J. Werner, J. Boeckmann, C. Näther
ARTICLE
Figure 3. Molecular structure of compound 1C with atom labeling.
Symmetry transformations used to generate equivalent atoms: A: x,
–y+1, z–1/2; B: x–1, y, z–1; C: x, –y, z–1/2. (an ORTEP plot of 1C is
shown in Figure S8 in the Supporting Information).
Table 5. Selected bond lengths /Å and angles /deg for 1C. Symmetry
codes: A: x, –y+1, z–1/2; B: x–1, y, z–1; C: x, –y, z–1/2.
Cd(1)–N(1A)
Cd(1)–N(2)
2.288(4)
2.299(4)
Cd(1)–N(11)
2.349(4)
Cd(1)–O(11B)
2.474(4)
Cd(1)–S(1)
Cd(1)–S(2C)
2.6621(16)
2.6870(17)
174.60(19)
90.92(14)
85.67(15)
93.68(13)
174.81(7)
94.17(15)
89.39(15)
88.10(14)
91.71(13)
N(1A)–Cd(1)–N(2)
N(1A)–Cd(1)–N(11)
N(1A)–Cd(1)–O(11B)
N(1A)–Cd(1)–S(1)
S(1)–Cd(1)–S(2C)
N(2)–Cd(1)–N(11)
N(2)–Cd(1)–O(11B)
N(2)–Cd(1)–S(1)
N(2)–Cd(1)–S(2C)
Figure 4. Crystal structure of compound 1C with view of the layers
along the a axis (top) and of the three-dimensional coordination net-
work in the direction of the crystallographic c axis (bottom) (an OR-
TEP plot of 1C is shown in Figure S5 in the Supporting Information).
Thermoanalytical Investigations
In order to prove if ligand-deficient compounds are also ac-
cessible by thermal decomposition, the ligand-rich 1:4 com-
pound [Cd(NCS) (3-Acpy) ] (1A) and the 1:2 compound
2
4
The ligand-deficient 1:2 compound [Zn(NCS) (3-Acpy) ] [Zn(NCS) (3-Acpy) ] (2A) were investigated for their thermal
2
2
2
2
(
2A) crystallizes in the monoclinic centrosymmetric space degradation behavior. On heating compound 1A two mass
group C2/c with four formula units in the unit cell. The asym- steps are observed in the TG curve, which are accompanied
metric unit consists of one metal cation situated on a twofold with endothermic events in the DTA curve at 99 °C, 136 °C
rotation axis as well as one thiocyanato anion and one 3-Acpy and 159 °C (Figure 6). The DTG curve for 1A shows that the
co-ligand in general positions (Figure 5). The metal cations are first mass step is well resolved whereas the second mass step
coordinated by four nitrogen atoms of two terminal N-bonded is poorly resolved. The experimental mass loss in the first step
thiocyanato anions and two terminal bonded 3-Acpy co-li- of 35.6% is in good agreement with that calculated for the
gands in a slightly distorted tetrahedron (Figure 5). The metal- removal of two molecules 3-Acpy (Δmcalc. = –34.0%) and giv-
nitrogen distances are 1.9349(18) and 2.0421(16) Å and the ing evidence for the formation of a ligand-deficient compound
angles around the metal cations range between 104.00(7) and of composition [Cd(NCS) (3-Acpy) ] (Figure 6). The experi-
2
2 n
1
23.56(12) ° (Table 6).
mental mass loss in the second step of 27.6% is much lower
4
www.zaac.wiley-vch.de
© 0000 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
Z. Anorg. Allg. Chem. 0000, 0–0

Job/Unit: Z12268
/KAP1
Date: 06-09-12 10:39:10
Pages: 9
CdII and ZnII Thiocyanato Coordination Compounds based on 3-Acetylpyridine
In order to verify the nature of the intermediate formed, ad-
ditional TG measurements were performed and stopped after
the first mass step. Elemental analysis of the residue obtained
support the assumption of the formation of a ligand-deficient
1
:2 compound of composition [Cd(NCS) (3-Acpy) ] and
2 2
XRPD investigations of this residue clearly prove that com-
pound 1B has formed in this reaction (Figure 7).
Figure 5. Molecular structure of compound 2A with atom labeling.
Symmetry transformations used to generate equivalent atoms: A: –x+1,
y, –z+1/2. (an ORTEP plot of 2A is shown in Figure S9 in the Support-
ing Information).
Table 6. Selected bond lengths /Å and angles /deg for 2A. Symmetry
code: A: –x+1, y, –z+1/2.
Zn(1)–N(1)
Zn(1)–N(11)
1.9349(18)
2.0421(16)
N(1)–Zn(1)–N(11)
N(1)–Zn(1)–N(11A)
N(1)–Zn(1)–N(1A)
N(11)–Zn(1)–N(11A)
104.00(7)
107.15(7)
123.56(12)
110.83(9)
Figure 7. Experimental XRPD pattern of the residue obtained after the
first mass step in thermal decomposition of compound 1A (A), to-
gether with calculated XRPD for compound 1B (B).
For compound 2A two poor resolved mass steps are ob-
served, which are accompanied with endothermic events in the
DTA curve. The experimental mass loss is not in reasonable
agreement for the loss of one or two 3-Acpy co-ligands and
the overall reaction must be more complicated (Figure S10 in
the Supporting Information).
Conclusions
II
II
In this contribution we investigated Zn and Cd thiocyan-
ato coordination polymers based on 3-acetylpyridine as neutral
N-donor co-ligand for their crystal structures and their thermal
degradation behavior. Investigations using different ratios of
the corresponding metal salts and the neutral N-donor co-li-
gand 3-Acpy resulted in the formation of two new coordination
compounds of composition [Cd(NCS) (3-Acpy) ] (1A) and
2
4
II
[
Zn(NCS) (3-Acpy) ] (2A). If the 1:4 Cd compound 1A is
2 2
thermally decomposed, a ligand-deficient intermediate of com-
position [Cd(NCS) (3-Acpy) ] (1B) can be isolated after the
2
2 n
first mass step, which decomposed on heating. Moreover, from
our synthetic work a further compound of composition
[
Cd(NCS) (3-Acpy)] (1C) was detected. In its crystal struc-
2 n
ture a 3D coordination network is found, which has never been
observed before in such thiocyanato coordination polymers.
Summarizing, we have shown that, with cadmium as counter
cation, coordination polymers with μ-1,3-bridging thiocyanato
anions can be easily prepared in solution, which for the para-
Figure 6. DTG, TG and DTA curves for compound 1A. Heating
–1
rate = 1 K·min ; given are the mass change /% and the peak tempera-
ture T /°C.
P
than expected for the removal of the remaining 3-Acpy li- magnetic metals manganese, iron, cobalt and nickel is fre-
gands.
quently difficult to achieve.
Z. Anorg. Allg. Chem. 0000, 0–0
© 0000 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
www.zaac.wiley-vch.de
5

Job/Unit: Z12268
/KAP1
Date: 06-09-12 10:39:10
Pages: 9
J. Werner, J. Boeckmann, C. Näther
ARTICLE
Elemental Analysis of the Residue Obtained in the Thermal De-
composition: Isolated in the first heating step (see thermoanalytical
investigations) of compound 1A. Calculated for the ligand-deficient
Experimental Section
Synthesis: ZnSO
4 2 4 2
·H O and CdSO ·8/3H O were obtained from
Merck, Ba(NCS) ·3H
2
2
O and 3-acetylpyridine were obtained from Alfa compound 1B: C16H N O S
Aesar. Solvents were used without further purification. Crystalline
14 4 2 2
Cd (470.84): calcd. C 40.82, H 3.00, N
11.90; S 13.62, found C 40.78, H 2.92, N 11.86, S 13.42%.
powders of compounds 1A–2B were prepared by stirring the reactants
in appropriate solvents at room temperature. The residues were filtered Differential Thermal Analysis and Thermogravimetry: The DTA-
off and washed with mother liquor and dried in air. The purity of all TG measurements were performed in a dynamic nitrogen atmosphere
(
purity: 5.0) in Al
2 3
O crucibles using a STA-409CD thermobalance
compounds was checked by X-ray powder diffraction and elemental
analysis (Figures S11–14 in the Supporting Information).
from Netzsch. All measurements were performed with a flow rate of
7
–
1
5 mL·min and were corrected for buoyancy and current effects. The
instrument was calibrated using standard reference materials.
Cd(NCS)
2.566 g, 10 mmol) were stirred in water (100 mL). The white precipi-
tate of BaSO was filtered off and the water was removed from the
2 2 2 4 2
: Ba(NCS) ·3H O (3.076 g, 10 mmol) and CdSO ·8/3H O
(
Single-Crystal Structure Analysis: The investigations were per-
formed with the imaging plate diffraction system (IPDS-1 for 1A, 2A
4
filtrate by heating. The final product was dried by 80 °C. The homo-
geneity of the product was investigated by Xray powder diffraction
and elemental analysis.
and IPDS-2 for 1B, 1C) with Mo-K -radiation from STOE & CIE. The
α
structure solution was performed with direct methods using SHELXS-
[
50]
2
97,
and structure refinements were performed against F using
[
50]
SHELXL-97.
All non-hydrogen atoms were refined with aniso-
tropic displacement parameters. The hydrogen atoms were positioned
with idealized geometry and were refined with fixed isotropic displace-
Zn(NCS)
1.795 g, 10 mmol) were stirred in water (100 mL). The white precipi-
tate of BaSO was filtered off and the water was removed from the
filtrate by heating. The final product was dried by 80 °C. The homo-
geneity of the product was investigated by Xray powder diffraction
and elemental analysis.
2 2 2 4 2
: Ba(NCS) ·3H O (3.076 g, 10 mmol) and ZnSO ·H O
(
ment parameters [Uiso(H)
= 1.2·Ueq(Caromatic) and Uiso(H) =
4
1.5·Ueq(Caliphatic)] using a riding model. For compound 1B the oxygen
atom of the acetyl group is disordered over two sites with occupancies
of 60 and 40% and was refined using a split model. The crystal of
compound 1C is racemically twinned and therefore, a twin refinement
was performed (BASF parameter: 0.52 (4)). The structure can also be
1
refined in the centrosymmetric space group P2 /c but in this case the 3-
acetylpyridine ligand is disordered around a center of inversion, which
clearly shows that space group Pc is correct.
2
Synthesis of Compound 1A: Cd(NCS) (57.1 mg, 0.25 mmol) and 3-
acetylpyridine (163.7 mg, 1.50 mmol) were stirred in water (1.5 mL)
for 3 d. Yield: 88.7%. Single crystals suitable for single crystal X-ray
diffraction were prepared by slow evaporation of the filtrate.
Moreover, inspection of the crystal packing clearly shows that no cen-
ter of inversion can be present. Details of the structure determination
are given in Table 7.
C
30
H
28
N
6
O
4
S
2
Cd (713.12): calcd. C 50.53, H 3.96, N 11.78, S 8.99;
found C 49.96, H 3.96, N 11.45, S 8.42%.
CCDC-866924 (1A), CCDC- -866923 (1B), CCDC- -866922 (1C) and
CCDC-866925 (2A) contain the supplementary crystallographic data
for this paper. These data can be obtained free of charge from the
Cambridge Crystallographic Data Centre via http://www.ccdc.cam.ac.uk/.
2
Synthesis of Compound 1B: Cd(NCS) (57.1 mg, 0.25 mmol) and 3-
acetylpyridine (54.6 mg, 0.50 mmol) were stirred in water (1.5 mL)
for 3 d. Yield: 90.2%. Single crystals suitable for single crystal X-ray
diffraction were prepared by slow evaporation of the filtrate.
C
16
H
14
N
4
O
2
S
2
Cd (470.84): calcd. C 40.82, H 3.00, N 11.90; S 13.62,
X-ray Powder Diffraction (XRPD): XRPD experiments were per-
formed using a STOE Transmission Powder Diffraction System
found C 40.84, H 2.82, N 11.98, S 13.38%.
(
α
STADI P) with Cu-K -radiation (λ = 1.5406 Å) that is equipped with
Synthesis of Compound 1C: Cd(NCS)
2
(228.6 mg, 1.00 mmol) and
a linear position-sensitive detector (Δ2θ = 6.5–7° simultaneous; scan
range overall = 2–130°) from STOE & CIE and an Image Plate Detec-
tor (scan range overall = 0–127°).
3-acetylpyridine (27.3 mg, 0.25 mmol) were stirred in water (1.5 mL)
for 3 d. Yield: 87.6%. Single crystals suitable for single crystal X-ray
diffraction were prepared by the same method but without stirring.
After 3 d, colorless well-shaped single crystals were obtained.
Spectroscopy: IR spectra were recorded with an Alpha IR spectrome-
ter from Bruker equipped with a Platinum ATR QuickSnap™ sampling
C
9
H
7
N
3
2
OS Cd (349.71): calcd. C 30.91, H 2.02, N 12.02, S 18.34;
–
1
module between 4000–375 cm .
found C 30.62, H 1.67, N 11.74, S 18.10%.
Supporting Information (see footnote on the first page of this article):
Calculated XRPD patterns, IR spectra and ORTEP plots of compounds
1A–1C and 2A. DTG, TG and DTA curves for 2A. Experimental and
calculated XRPD patterns for compounds 1A–1C and 2A.
2
Synthesis of Compound 2A: Zn(NCS) (45.4 mg, 0.25 mmol), and 3-
acetylpyridine (272.9 mg, 2.50 mmol) were stirred in water (1.5 mL)
for 3 d. Yield: 85.2%. Single crystals suitable for single crystal X-ray
diffraction were prepared by slow evaporation of the filtrate.
C
16
H
14
N
4
O
2
S
2
Zn (349.71): calcd. C 45.34, H 3.33, N 13.22, S 15.13;
Acknowledgment
found C 44.72, H 3.13, N 13.22, S 14.08%.
This project was supported by the Deutsche Forschungsgemeinschaft
Elemental Analysis: CHNS analysis was performed using an EURO (Project No. NA 720/3–1) and the State of Schleswig-Holstein. We
EA elemental analyzer, fabricated by EURO VECTOR Instruments
and Software.
thank Professor Dr. Wolfgang Bensch for access to his experimental
facility. Special thanks to Inke Jeß for the single crystal measurements.
6
www.zaac.wiley-vch.de
© 0000 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
Z. Anorg. Allg. Chem. 0000, 0–0

Job/Unit: Z12268
/KAP1
Date: 06-09-12 10:39:10
Pages: 9
CdII and ZnII Thiocyanato Coordination Compounds based on 3-Acetylpyridine
Table 7. Selected crystal data and details on the structure determinations for the compounds 1A–1C and 2A.
compound
1A
1B
1C
2A
formula
MW /g·mol–1
crystal system
space group
a /Å
b /Å
c /Å
α /°
β /°
C
30
H
28CdN
6
O
4
S
2
C
16
H
14CdN
4
O
2
S
2
C
9
H
7
CdN
3
OS
2
16 14 4 2 2
C H N O S Zn
423.80
monoclinic
C2/c
22.3035(19)
4.9288(2)
18.6395(15)
90.000
118.839(9)
90.000
1794.9(2)
180
713.10
triclinic
P1
11.0640(9)
11.5262(9)
13.8111(12)
68.997(9)
74.361(10)
78.915(10)
1574.4(2)
200
470.83
monoclinic
P2
349.70
monoclinic
Pc
¯
1
/c
5.7902(2)
18.3942(7)
8.8051(3)
90.00
93.154(3)°.
90.000
936.38(6)
293
7.9268(5)
9.8740(5)
7.8131(5)
90.000
108.318(5)
90.000
580.54(6)
293
γ /°
V /Å3
T /K
Z
D
μ /mm
2
2
2
4
–3
calc /g·cm
1.504
0.871
1.670
1.405
2.001
2.220
1.568
1.618
–
1
θmax /deg
28.00
29.20
29.18
28.12
measured refl.
13982
0.0450
7387
6111
396
0.0405
0.1146
1.026
17690
0.0343
2517
2156
126
0.0229
0.0525
1.078
9575
0.0268
2905
2564
147
0.0220
0.0427
1.066
7712
0.0434
2157
1695
115
0.0312
0.0841
1.027
R
int
unique reflns.
refl.[F Ͼ 4σ(F
parameters
[F Ͼ 4σ(F
[all data]
0
0
)]
R
1
0
0
)]
wR
2
GOF
Δρmax/min/e·Å–3
1.189/–1.836
0.427/–0.453
0.442/–0.400
0.401/–0.416
[
[
21] R. Sekiya, S.-i. Nishikiori, CrystEngComm 2011, 13, 6405–6414.
22] J. M. Shi, J. N. Chen, C. J. Wu, J. P. Ma, J. Coord. Chem. 2007,
60, 2009–2013.
References
[
1] D. Braga, L. Maini, M. Polito, L. Scaccianoce, G. Cojazzi, F.
Grepioni, Coord. Chem. Rev. 2001, 216, 225–248.
2] S. L. James, Chem. Soc. Rev. 2003, 32, 276–288.
3] C. Janiak, Dalton Trans. 2003, 2781–2804.
[23] D. Vujovic, H. G. Raubenheimer, L. R. Nassimbeni, Dalton
Trans. 2003, 631–637.
[24] C. Näther, J. Greve, J. Solid State Chem. 2003, 176, 259–265.
[
[
[
4] D. Maspoch, D. Ruiz-Molina, J. Veciana, J. Mater. Chem. 2004, [25] M. Wriedt, I. Jeß, C. Näther, Eur. J. Inorg. Chem. 2009, 1406–
1
4, 2713–2723.
5] D. Maspoch, D. Ruiz-Molina, J. Veciana, Chem. Soc. Rev. 2007,
6, 770–818.
1413.
[
[
[
[
[
[
[
[
[
[
[
[
[
[
[
[
[26] M. Wriedt, C. Näther, Dalton Trans. 2009, 10192–10198.
[27] M. Wriedt, C. Näther, Eur. J. Inorg. Chem. 2010, 3201–3211.
3
6] D. Gatteschi, R. Sessoli, Angew. Chem. Int. Ed. 2003, 42, 268– [28] M. Wriedt, C. Näther, Chem. Commun. 2010, 46, 4707–4709.
2
97.
7] X.-Y. Wang, Z.-M. Wang, S. Gao, Chem. Commun. 2008, 281–
94.
8] S. R. Batten, K. S. Murray, Coord. Chem. Rev. 2003, 246, 103–
30.
9] L. Bogani, A. Vindigni, R. Sessoli, D. Gatteschi, J. Mater. Chem.
008, 18, 4750–4758.
10] H. L. Sun, Z. M. Wang, S. Gao, Coord. Chem. Rev. 2010, 254,
081–1100.
[29] M. Wriedt, S. Sellmer, C. Näther, Inorg. Chem. 2009, 48, 6896–
6903.
2
[30] J. Boeckmann, C. Näther, Dalton Trans. 2010, 39, 11019–11026.
[31] J. Boeckmann, C. Näther, Chem. Commun. 2011, 47, 7104–7106.
[32] J. Boeckmann, M. Wriedt, C. Näther, Chem. Eur. J. 2012, 18,
5284–5289.
[33] S. Wöhlert, J. Boeckmann, M. Wriedt, C. Näther, Angew. Chem.
Int. Ed. 2011, 50, 6920–6923.
[34] S. Wöhlert, C. Näther, Cryst. Growth Des. 2012, in press.
[35] R. A. Bailey, S. L. Kozak, T. W. Michelsen, W. N. Mills, Coord.
Chem. Rev. 1971, 6, 407–445.
1
2
1
11] W. X. Zhang, W. Xue, J. B. Lin, Y. Z. Zheng, X. M. Chen, Crys-
tEngComm 2008, 10, 1770–1776.
12] B. Gil-Hernandez, P. Gili, J. K. Vieth, C. Janiak, J. N. Sanchiz, [36] R. J. H. Clark, C. S. Williams, Spectrochim. Acta 1966, 22, 1081–
Inorg. Chem. 2010, 49, 7478–7490.
13] H. A. Habib, J. Sanchiz, C. Janiak, Dalton Trans. 2008, 4877–
1090.
[37] P. O. Kinell, B. Strandberg, Acta Chem. Scand. 1959, 13, 1607–
4
884.
14] H. A. Habib, J. Sanchiz, C. Janiak, Dalton Trans. 2008, 1734–
744.
1622.
[38] L. Shen, Y.-Z. Xu, J. Chem. Soc., Dalton Trans. 2001, 3414–
3414.
1
15] S. Gerber, H. Gröger, J. Ensling, P. Gütlich, H. Krautscheid, An-
gew. Chem. Int. Ed. 2005, 44, 7787–7790.
16] J. Tercero, C. Diaz, J. Ribas, J. Mahia, M. Maestro, X. Solans, J.
Chem. Soc., Dalton Trans. 2002, 2040–2046.
[39] I. Jeß, J. Boeckmann, C. Näther, Dalton Trans. 2012, 41, 228–
236.
[40] J. Boeckmann, I. Jeß, T. Reinert, C. Näther, Eur. J. Inorg. Chem.
2011, 5502–5511.
17] R. Vicente, A. Escuer, J. Ribas, X. Solans, M. Font-Bardia, Inorg.
Chem. 1993, 32, 6117–6118.
18] M. A. Porai-Koshits, G. N. Tishchenko, Crystallogr. Rep. 1960,
[41] S. Wöhlert, J. Boeckmann, I. Jess, C. Näther, Cryst. Eng. Comm.
2012, accepted.
[42] F. Allen, Acta Crystallogr., Sect. B 2002, 58, 380–388.
[43] S. Banerjee, B. Wu, P.-G. Lassahn, C. Janiak, A. Ghosh, Inorg.
Chim. Acta 2005, 358, 535–544.
[44] A. Escuer, R. Vicente, M. A. S. Goher, F. A. Mautner, Inorg.
Chem. 1997, 36, 3440–3446.
[45] M. A. S. Goher, F. A. Mautner, K. Gatterer, M. A. M. Abu-Yous-
4
, 239.
19] H. Cai, Y. Guo, Y. Li, J.-G. Li, Acta Crystallogr., Sect. A 2007,
3, m936–m938.
20] Y. Jin, Y.-X. Che, J.-M. Zheng, J. Coord. Chem. 2007, 60, 2067–
074.
6
2
Z. Anorg. Allg. Chem. 0000, 0–0
© 0000 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
www.zaac.wiley-vch.de
7

Job/Unit: Z12268
/KAP1
Date: 06-09-12 10:39:10
Pages: 9
J. Werner, J. Boeckmann, C. Näther
ARTICLE
sef, A. M. A. Badr, B. Sodin, C. Gspan, J. Mol. Struct. 2008, 876,
99–205.
46] J. N. McElearney, L. L. Balagot, J. A. Muir, R. D. Spence, Phys.
Rev. B 1979, 19, 306–317.
47] A. Ouchi, M. Taniguchi, Bull. Chem. Soc. Jpn. 1988, 61, 3347–
[48] H.-L. Sun, B.-Q. Ma, S. Gao, S. R. Batten, Cryst. Growth Des.
2006, 6, 1261–1263.
1
[
49] A. Tahli, J. K. Maclaren, I. Boldog, C. Janiak, Inorg. Chim. Acta
[
[
2011, 374, 506–513.
[
50] G. M. Sheldrick, Acta Crystallogr., Sect. A 2008, 64, 112–122.
3349.
Received: June 08, 2012
Published Online: ᭿
8
www.zaac.wiley-vch.de
© 0000 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
Z. Anorg. Allg. Chem. 0000, 0–0

Job/Unit: Z12268
/KAP1
Date: 06-09-12 10:39:10
Pages: 9
CdII and ZnII Thiocyanato Coordination Compounds based on 3-Acetylpyridine
J. Werner, J. Boeckmann, C. Näther* .............................. 1–9
Investigations on the Structure Diversity and Thermal Degra-
II
II
dation Behavior of Cd and Zn Thiocyanato Coordination
Compounds based on 3-Acetylpyridine as Neutral Co-Ligand
Z. Anorg. Allg. Chem. 0000, 0–0
© 0000 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
www.zaac.wiley-vch.de
9