Four discrete transition metal complexes involving pyridyl-substituted nitronyl nitroxide: Syntheses, crystal structures, and magnetic properties

Article abstract of DOI:10.1002/zaac.201300266

Four discrete metal-radical complexes, [Cu(p-MePh-COO)₂(NITpPy) ₂] (1), [Ni(m-MePhCOO)₂(NITpPy)₂(H ₂O)₂]·(CH₃-OH)₂ (2), [Mn(p-MePhCOO)₂(NITpPy)₂(

Full text of DOI:10.1002/zaac.201300266

ARTICLE
DOI: 10.1002/zaac.201300266
Four Discrete Transition Metal Complexes Involving Pyridyl-substituted
Nitronyl Nitroxide: Syntheses, Crystal Structures, and Magnetic Properties
Jie Zhou,[a][‡] Lin Du,[a][‡] Yong-Feng Qiao,[a] Yan Hu,[a] Peng Chen,[a] Bin Li,[a] and
Qi-Hua Zhao*[a]
Keywords: Magnetic properties; Nitronyl nitroxide radical; Copper; Nickel; Manganese
Abstract. Four discrete metal-radical complexes, [Cu(p-MePh-
COO)2(NITpPy)2] (1), [Ni(m-MePhCOO)2(NITpPy)2(H2O)2]· of the pyridine rings form three spin complexes, where toluates act as
(CH3-OH)2 (2), [Mn(p-MePhCOO)2(NITpPy)2(H2O)2] (3), and co-ligands. Weak antiferromagnetic interactions [JCu–Rad = –6.75 cm–1
[Mn(m-MePhCOO)2(NITpPy)2(H2O)2] (4) [NITpPy = 2-(4-pyridyl)-
(1), JCo–Rad = –4.15 cm–1 (2), JMn–Rad = –0.22 cm–1 (3), and JMn–Rad
4,4,5,5-tetramethyl-4,5-dihydro-1H-imidazolyl-1-oxyl-3-oxide] were –3.74 cm–1 (4)] were observed, spin polarization mechanism and or-
two radical ligands coordinated to the metal ions by the nitrogen atoms
=
synthesized and characterized by elemental analyses, IR spectroscopy,
PXRD, single-crystal X-ray diffraction, and magnetic susceptibility.
For the four complexes, the crystal structural analyses indicate that the
bital symmetry are used to explain the magnetic coupling in these
complexes.
to understand the magnetic exchange mechanism between
the metal and the organic radical but also to guide the
design of new organic radical ligands for the development
of novel molecular magnetic materials.[15,19] With
this in mind, we have synthesized four discrete metal-
radical complexes [Cu(p-MePhCOO)2(NITpPy)2] (1),
Introduction
In the field of molecular magnetic materials, much attention
has been paid to the assembly of different paramagnetic build-
ing blocks by reaction between radicals and metal complexes
with desired features. This so-called “metal-radical strategy”
initiated by Gatteschi and Rey in the late 1980s has proved to
be fascinating and fruitful.[1–5] Nitronyl nitroxides (NITR), as
organic radicals, have played an important role in this field
because most of them can act as not only good building blocks
but also stable spin carriers even when coordinated to metal
ions.[6–8] However, the weakly basic character of nitronyl ni-
troxides strongly limits their coordination ability.[9] One strat-
egy to overcome this coordination obstacle is using acidic cen-
tral metal atoms (metal β-diketonate systems),[10,11] another is
to develop functionalized nitronyl nitroxide radicals.[12,13] Be-
sides, co-ligands, such as carboxylates, azido, cyano, have
been used in recent years, supplying many heterospin systems
with interesting properties.[14–17] In order to understand the
magnetic interactions in these compounds, low dimensional
complexes, especially discrete molecules with a definite ar-
rangement, caught much attention for the fundamental studies
of magneto-structural correlations.[18] In particular, these are
useful to determine how structural factors affect the metal-
radical interactions. Such investigation is necessary not only
[Ni(m-MePhCOO)2(NITpPy)2(H2O)2]·(CH3OH)2
(2),
[Mn(p-MePhCOO)2(NITpPy)2(H2O)2] (3), and [Mn(m-
MePhCOO)2(NITpPy)2(H2O)2] (4), where two radical ligands
coordinate to metal ions by the nitrogen atoms of the pyridine
rings to form tri-spin systems. Herein the synthesis, structures,
and magnetic properties of the complexes are reported.
Results and Discussion
Crystal Structure Analysis
The four compounds are centrosymmetrical with the metal
atoms in the inversion center and all of them are in the triclinic
¯
space group P1.
[Cu(p-MePhCOO)2(NITpPy)2] (1)
The crystal structure of complex 1 is shown in Figure 1.
The CuII ion is four-coordinate in a square planar CuN2–O2
environment, which is occupied by two nitrogen atoms (N1,
N1A) from NITpPy ligands and two deprotonated p-toluate
oxygen atoms (O3, O3A). The Cu–N and Cu–O bond lengths
[1.9982(14) Å and 1.9893(13) Å] are comparable to those in
previously reported Cu-NITpPy complexes.[20] In NITpPy li-
gands, the N–O bond lengths are 1.270(2) Å [N(2)–O(1)] and
1.259(3) Å [N(3)–O(2)], which is intermediate among those
observed in copper complexes with coordinated NITpPy radi-
* Prof. Qi-Hua Zhao
Fax: +86-871-65035640
E-Mail: qhzhao@ynu.edu.cn
[a] Department of Chemistry
Yunnan University
Kunming, Yunnan 650091, P. R. China
[‡] These authors contributed equally to this work.
Supporting information for this article is available on the WWW
under http://dx.doi.org/10.1002/zaac.201300266 or from the au-
thor.
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Q.-H. Zhao et al.
ARTICLE
cals.[4,10] The fragment O1–N2–C6–N3–O2 is nearly planar, O3A) and two water oxygen atoms (O5, O5A), forming the
and forms a dihedral angle of 31.8° with the plane of the pyr- basal plane O3–O5–O3A–O5A [with the bond lengths of Ni1–
idine ring. It should be noted that the short distance (3.98 Å) O3 2.032(2) Å, Ni1–O5 2.062(2) Å]. The axial positions are
was observed between the two oxygen atoms of uncoordinated occupied by two nitrogen atoms (N1, N1A) from pyridyl rings
nitroxide groups of two adjacent radicals (Figure 2), similar to of NITpPy ligands with the bond length of Ni1–N1 2.122(3) Å.
the complex [Cu-(NITpPy)2(PhCOO)2],[20] which indicates All of the values are comparable to those in already reported
that there might be intermolecular interactions in complex 1.
analogous Ni-NITpPy complexes.[14,21,22] The dihedral angle
between the nitroxide group (O1–N2–C6–N3–O2) and the pyr-
idyl ring is 21.5°. The shortest intermolecular contact between
the nitroxide groups is 3.74 Å. Besides, methanol solvent mo-
lecules are present in the structure through hydrogen bonds
with the bond length 2.737 Å [O5···O6 (–x+1, –y + 1, –z)] and
2.670 Å [O6···O4 (–x+2, –y + 1, –z)] as shown in Figure S1
(Supporting Information).
Figure 1. ORTEP drawing of complex [Cu(p-MePhCOO)2(NITpPy)2]
(1) with the selected atom-labeling and 30% thermal ellipsoids. All
hydrogen atoms are omitted for clarity (#a –x+2, –y, –z+1).
Figure 3.
ORTEP
drawing
of
complex
[Ni(m-
MePhCOO)2(NITpPy)2(H2O)2]·(CH3OH)2 (2) with the selected atom-
labeling and 30% thermal ellipsoids. All hydrogen atoms and solvent
methanol molecules are omitted for clarity (#a –x+1, –y, –z+2).
[Mn(p-MePhCOO)2(NITpPy)2(H2O)2] (3) and
[Mn(m-Me-PhCOO)2(NITpPy)2(H2O)2] (4)
Complexes 3 and 4 are similar to that of 2, the mainly differ-
ence is they do not contain solvent methanol molecules. The
crystal structures are shown in Figure 4 and Figure 5, respec-
tively. The MnII ions are located at an inversion center and
adopt distorted octahedral arrangement. The equatorial plane
is formed by four oxygen atoms, where two of which come
from two toluate anions and the other two from two water
molecules. The apical positions are occupied by two nitrogen
Figure 2. The packing plot of 1, the adjacent distance /Å of the
NITpPy oxygen atoms is shown. For clarity, all hydrogen atoms and
methyl of the NITpPy ligands are omitted.
atoms from pyridine rings of NITpPy ligands. The Mn–Owater
Mn–Otoluate and Mn–N bond lengths are 2.225(2), 2.127(2),
,
[Ni(m-MePhCOO)2(NITpPy)2(H2O)2]·(CH3OH)2 (2)
An ORTEP drawing of complex 2 is illustrated in Figure 3. and 2.311(3) Å for 3, and 2.196(2), 2.126(2), and 2.344(3) Å
The NiII ion adopts a slightly distorted octahedral arrangement, for 4. In the NITpPy ligands, the N–O bond lengths are
coordinated by two deprotonated m-toluate oxygen atoms (O3, 1.275(4) Å [N(2)–O(1)] and 1.265(4) Å [N(3)–O(2)] in com-
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Transition Metal Complexes withPyridyl-substituted Nitronyl Nitroxide
plex 3, whereas the corresponding values in 4 are equal to were performed on powdered crystalline samples in a 1000 Oe
1.275(4) Å. The dihedral angle between the O1–N2–C6–N3– field in the 2 K to 300 K range. The χM and χMT vs. T plots
O2 fragment and the pyridine ring is 29.1° and 28.0° in 3 and of the four complexes are shown in Figure 6, Figure 7, Fig-
4, respectively. The shortest intermolecular contact between ure 8, and Figure 9, respectively. The purity of the samples
the nitroxide groups are 3.82 Å for 3 and 3.84 Å for 4, as was confirmed by a comparison of experimental and simulated
shown in Figure S2 and Figure S3 (Supporting Information).
powder X-ray diffraction (Figure S4, Supporting Information).
Figure 6. Temperature dependence of the χMT (Δ) and χM (᭺) product
at 1000 Oe for complex 1, the solid lines correspond to the theoretical
fits.
Figure 4.
ORTEP
drawing
of
complex
[Mn(p-
Magnetic Properties for Complex 1
MePhCOO)2(NITpPy)2(H2O)2] (3) with the selected atom-labeling and
30% thermal ellipsoids. All hydrogen atoms are omitted for clarity
(#a –x+1, –y, –z+1).
According to the χMT vs. T plots of 1, the χMT value is
equal to 1.16 cm3·K·mol–1 at room temperature, close to the
value (1.12 cm3·K·mol–1) expected for three uncoupled spins
of S = 1/2 for one copper atom and two nitronyl nitroxide
radical ligands. Overall, χMT decreases with decreasing tem-
perature. At higher temperature, the χMT decreases very slowly
with the decrease of the temperature, while at lower tempera-
ture χMT decreases sharply to 0.09 cm3·K·mol–1 around 2.0 K,
which indicates the existence of antiferromagnetic spin ex-
change interactions in the complex. The magnetic data were
ˆ
ˆ
ˆ
ˆ
ˆ
fitted into isotropic model H = –2J(SCuSR + SCuSR). For radi-
cal-CuII-radical complexes, the theoretical expression of mag-
netic susceptibility is:
where J is the interaction parameter between CuII and each
radical ligand. The intermolecular interactions were considered
using the mean-field approximation, where z is the number of
neighbors and jЈ is the intermolecular coupling constant.
χM = χЈ / [1 – (2zjЈχЈ / Ng2β2)]
The best fit parameters were obtained with g = 2.04, J =
–6.75 cm–1, zJЈ = –3.34 cm–1, and the agreement factor (R) is
3.2ϫ10–5 [R = ∑ (χMcalcd – χMobsd)2 / (χMobsd)2]. The negative
value confirms weak intramolecular antiferromagnetic cou-
pling between the square-planar coordinated copper (II) and
two coordinated NITpPy as expected.
Figure 5.
ORTEP
drawing
of
complex
[Mn(m-
MePhCOO)2(NITpPy)2(H2O)2] (4) with the selected atom-labeling and
30% thermal ellipsoids. All hydrogen atoms are omitted for clarity
(# a –x, 1–y, 1–z).
Magnetic Properties
In order to understand the magneto-structural correlations in
To analyze the exchange coupling in the three spin systems, complex 1, it is necessary to consider the involved magnetic
variable-temperature magnetic susceptibility measurements orbitals of the CuII ions and the 2pπ orbitals on the pyridine
Z. Anorg. Allg. Chem. 2014, 363–369
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365

Q.-H. Zhao et al.
ARTICLE
Table 1. Selected structural and magnetic parameters for Cu-NITpPy compounds.
Compound
δa) /°
J /cm–1
Reference
[Cu(p-MePhCOO)2(NITpPy)2]
[Cu(FOD)2(NITpPy)]
31.8
29.5
–6.75
–2.0
this work
[26]
[Cu(NITpPy)2(PhCCO2)2 (H2O)2]
[Cu(NIT4Py)2(DTB)2(H2O)2]
[Cu(Cl2CCO2)2(NITpPy)2(H2O)]
14.36
12.5
10.08
–10.89
–8.89
–11.5
[20]
[27]
[28]
a) δ is defined by the pyridine ring and ONCNO plane.
rings. McConnell’s spin distribution mechanism[23] is also in- 1.1ϫ10–4. The fitting results confirm that weak intramolecular
troduced, which is shown in Scheme 1. According to this antiferromagnetic coupling between NiII and NITpPy (Fig-
model, a spin distribution would induce a contrary spin on the ure 7).
adjacent atom due to the spin polarization. A large positive
spin density is located on the NO groups lead to negative spin
density at nitrogen atoms of pyridine.[24,25] For complex 1, the
O–N–C–N–O mean plane containing the unpaired electron of
the radical makes an angle of 30° with the N1–Cu–N1A plane,
and the angle between the N–Cu–N plane and the plane of the
pyridine ring is 39°. These geometrical parameters favor a
weak overlap of the π* magnetic orbital of the radical with
the dx2–y2 magnetic orbital of the CuII ion leading the weak
antiferromagnetic CuII-nitroxide interaction (J = –6.75 cm–1).
Compared to the structure and magnetism of other Cu-NITpPy
complexes (Table 1), totally, the larger the value of the dihe-
dral angle is, the harder the spin polarization can occur, and
the weaker the magnetic coupling is.
Figure 7. Temperature dependence of the χMT (Δ) and χM (᭺) product
at 1000 Oe for complex 2, the solid lines correspond to the theoretical
fits.
For complex 2, the antiferromagnetic interaction between
NiII and NITpPy radicals was explained in detail in
the literature[22] by spin polarization mechanism.[23,29] The
J (–4.15 cm–1) value is comparable to the reported discrete
Scheme 1. The spin polarization mechanism for intramolecular mag-
netic couping in 1.
complex [Ni(salox)2(NIT4Py)2] (–2.51 cm–1)[22] and one-di-
mensional complexes, {[Ni(NITpPy)2(obb)(H2O)2]·1.5H2O}n
(–3.74 cm–1)[30] and {[Ni(NITpPy)2(TCB)(H2O)]·2H2O}n
(–5.0 cm–1).[31]
Magnetic Properties for Complex 2
At room temperature, the χMT is 2.16 cm3·K·mol–1, which is
higher than the (1.75 cm3·K·mol–1) expected for an uncoupled
system with one NiII ion (S = 1) and two NITpPy (S = 1/2).
Upon cooling, χMT decreases regularly, approaching a mini-
mum around 2 K with χMT = 0.083 cm3·K·mol–1. In the case
of χM vs. T, the χM increases with the decrease of the tempera-
ture until getting a maximum at 10 K, then decreases sharply
down with the temperature decreasing. All the above magnetic
behaviors suggest the existence of antiferromagnetic interac-
tion in the system. The magnetic data were fitted into isotropic
Magnetic Properties for Complexes 3 and 4
At room temperature, the χMT are 5.06 and 5.00 cm3·K·mol–1
for complexes 3 and 4, respectively, slightly lower than the
value expected for an uncoupled system with one MnII ion
(S = 5/2) and two NITpPy (S = 1/2) (5.12 cm3·K·mol–1). For
complex 3, the χMT value decreases when the system is cooled
down, this is similar to those in complexes 1 and 2. In complex
4, the χMT values are approximately a constant with the lower-
ing of the temperature to 6 K, and sharply decrease below 6 K.
The above magnetic behaviors indicate the existence of antifer-
romagnetic spin exchange interactions in complexes 3 and 4.
Therefore, the temperature dependence of the magnetic suscep-
tibility of the molecular were analyzed on the following equa-
ˆ
ˆ
ˆ
ˆ ˆ
model H = –2J(SNiSR + SNiSR) with the theoretical expression
of magnetic susceptibility:
ˆ
ˆ
ˆ
The best fit parameters were obtained with g = 2.15, J = tion deduced from the spin Hamiltonian H = –2J(SMnSR
–4.15 cm–1, zJЈ = –3.91 cm–1. The agreement factor (R) is
+
ˆ
S
ˆ
MnSR) for a symmetric three-spin system:
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Transition Metal Complexes withPyridyl-substituted Nitronyl Nitroxide
to the MnII ions through the pyridyl-N. According to Table 2,
there are two opposite signs of magnetic interactions (ferro-
magnetic and antiferromagnetic). For MnII-NITpPy com-
pounds, the MnII ion has three magnetic orbitals with π sym-
metry (dxy, dxz, and dyz) that are able to overlap with the mag-
netic π* orbital of the pyridine ring, leading to the antiferro-
magnetic interaction coupling, and two σ symmetry orbitals
(dx2–y2, dz2), which are orthogonal to the magnetic orbital of the
radical leading to ferromagnetic interaction. The nature of the
interaction is the result of a balance between two opposite con-
tributions, and the predominant interaction governs the sign
and the magnitude of the overall magnetic interaction. There-
fore, antiferromagnetic interactions in complexes 3 and 4 may
be rationalized in terms of larger contributions from the π or-
bital on the metal center (dxy, dxz, and dyz) than from the σ
orbitals (dx2–y2, dz2).
The best fit parameters were obtained with g = 1.99, J =
–0.22 cm–1, zJЈ = –0.003 cm–1, R = 4.3ϫ10–5 for 3, g = 1.99,
J = –3.74 cm–1, zJЈ= –0.079 cm–1 R = 3.8ϫ10–3 for 4. The
magnetic results show that the existence of very weak antifer-
romagnetic spin exchange interactions in 3 and 4 (Figure 8 and
Figure 9).
The weak intermolecular antiferromagnetic exchange inter-
actions revealed by the negative zJЈ in the four complexes can
also be explained by the relative arrangement of the stacked
NITpPy groups, where two adjacent NITpPy groups stack to
form a structure with parallel arrangements, the short distances
between the Oradical atoms of the N–O groups with the adjacent
metal atoms are 3.98, 3.74, 3.82, and 3.84 Å, respectively, so
σ-type overlaps (SOMO–SOMO overlaps) of the nitronyl ni-
troxide π* orbitals from the adjacent radicals can occur and
favor the intermolecular antiferromagnetic interactions.[35,36]
Figure 8. Temperature dependence of the χMT (Δ) and χM (᭺) product
at 1000 Oe for complex 3, the solid lines correspond to the theoretical
fits.
Conclusions
Four discrete metal-radical complexes of the formula
[Cu(p-MePhCOO)2(NITpPy)2] (1), [Ni(m-MePhCOO)2(NI-
TpPy)2(H2O)2]·(CH3OH)2
(2),
[Mn(p-MePhCOO)2(NIT-
pPy)2(H2O)2] (3) and [Mn(m-MePhCOO)2(NITpPy)2(H2O)2]
(4) were prepared and characterized. For the four complexes,
the crystal structural analyses indicate that the two radical li-
gands are coordinated to the metal ions by the nitrogen atoms
of the pyridine rings to form three spin complexes. Orbital
symmetry and spin polarization mechanism are used to explain
the magnetic coupling in these complexes. They are of signifi-
cance for understanding the magnetostructural correlations. It
is known that small changes in the coordination of the nitronyl
nitroxide and metal have a large influence in the magnetic
properties. More correlations are necessary to research in fu-
ture, which will be helpful for the development of novel mo-
Figure 9. Temperature dependence of the χMT (Δ) and χM (᭺) product
at 1000 Oe for complex 4, the solid lines correspond to the theoretical
fits.
Table 2 summarizes selected magnetic parameters for lecular magnetic materials. Thus, we are working on the syn-
MnII-NITpPy compounds where NITpPy radicals coordinate thesis of different metal-radical complexes.
Table 2. Selected magnetic parameters for MnII-NITpPy compounds, where NITpPy radicals coordinate to the MnII ions through the pyridyl-N.
Compound
J /cm–1
g
Reference
[Mn(PNN)2(PhCOO)2(H2O)2]
Mn(NITpPy)2[Ag(CN)2]2
{[MnAu2(CN)4(NITpPy)2(H2O)2]}n
Mn(Phtfac)2(NITpPy)2
[Mn(p-MePhCOO)2(NITpPy)2(H2O)2]
[Mn(m-MePhCOO)2(NITpPy)2(H2O)2]
3.1
5.2
–1.94
3.0
–0.22
–3.74
2.00
2.00
2.00
1.96
1.99
1.99
[15]
[32]
[33]
[34]
this work
this work
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367

Q.-H. Zhao et al.
ARTICLE
56.20, H 6.51, N 9.36%; found: C 56.43, H 6.33, N 9.43%. IR (KBr):
ν˜ = 3427.1 br, 2978.4 m, 1606.7 m [νas(CO2)], 1379.2 s [ν(NO)],
1057.7 m, 753.7 m cm–1.
Experimental Section
General: All chemicals used were of reagent grade and used without
further purification. 2-(4-pyridyl)-4,4,5,5-tetramethylimida-zoline-1-
oxyl-3-oxide (NITpPy) was prepared according to the methods de-
scribed previously.[37,38] The contents of carbon, hydrogen, and nitro-
gen were determined by a Vario-EL III element analyzer. Fourier trans-
form infrared spectra were recorded using KBr disks with an FTS-40
infrared spectrometer in the 4000–400 cm–1 region. The phase purity
of the samples was investigated by powder X-ray diffraction (PXRD)
measurements carried out with a Bruker D8 Advance diffractometer
equipped with Cu-Kα radiation (λ = 1.5406 Å) at a scan speed of
1°·min–1. Simulations of the PXRD patterns were obtained using sin-
gle-crystal data and processed by the Mercury v1.4 program, which is
available free of charge through the internet at http://www.iucr.org.
Variable-temperature susceptibility measurements of crystalline sam-
ples were performed with a Quantum Design MPMS-XL SQUID mag-
netometer. Diamagnetic corrections were performed from Pascal’s con-
stants, and an experimental correction for a sample holder was also
applied.
[Mn(m-MePhCOO)2(NITpPy)2(H2O)2] (3): Complex 3 was synthe-
sized in a manner similar to that of 1 only by replacing copper p-
toluate with manganese p-toluate. C40H50MnN6O10 calcd: C 57.90, H
6.07, N 10.13%; found: C 58.13, H 5.81, N 9.92%. IR (KBr): ν˜ =
3427.0 w, 1614.0 s [νas(CO2)], 1408.0 s [νs(CO2)], 1375.2 s [ν(NO)],
1057.7 m, 753.76 w cm–1.
[Mn(p-MePhCOO)2(NITpPy)2(H2O)2] (4): Complex 4 was synthe-
sized in a manner similar to that of 1 only by replacing copper p-
toluate with manganese m-toluate. C40H50MnN6O10 calcd: C 57.90, H
6.07, N 10.13%; found: C 57.48, H 6.23, N 10.05%. IR (KBr): ν˜ =
3426.8 w, 1602.24 m [νas(CO2)], 1546.0 m, 1379.8 s [ν(NO)], 1320.7
w, 758.9 w cm–1.
Crystallographic Data Collection and Refinement: The selected sin-
gle crystal with suitable dimensions was mounted on a glass fiber and
used for X-ray diffraction analyses. Crystallographic data were col-
lected at 293 K with a Bruker Smart AXS CCD diffractometer with
graphite-monochromated Mo-Kα radiation (λ = 0.71073 Å). Empirical
absorption corrections were carried out using the SADABS program.
The structures were solved by direct methods using SHELXS-97 pro-
gram[39] and refined on F2 by the full-matrix least-squares technique
by using SHELXL-97 software.[40] All non-hydrogen atoms were lo-
cated using difference Fourier syntheses and were finally refined with
anisotropic displacement parameters. All the hydrogen atoms of the
organic ligands were placed by geometrical considerations and iso-
tropically refined with fixed U values by using a riding model. The
details of the crystallographic data collection and refinement param-
Preparation of [Cu(p-MePhCOO)2(NITpPy)2] (1): Complex 1 was
synthesized by adding a solution of NITpPy (0.2 mmol) in CH2Cl2
(10 mL) to a solution of copper p-toluate (0.1 mmol) in methanol
(10 mL) in a dropwise manner. The mixture was stirred for 1 h at
ambient temperature and filtered. The clear blue filtrate was kept in
the dark and was slowly evaporated at room temperature. Two weeks
later, dark-blue crystals suitable for X-ray analysis were obtained.
C40H46CuN6O8: calcd. C 59.88; H 5.78; N 10.47%; found: C 59.72,
H 5.41, N 10.91%. IR (KBr): ν˜ = 3426.9 w, 2983.7 w, 1605.8 s
[νas(CO2)], 1554.4 w, 1374.7 s [ν(NO)], 1317.2 w, 769.3 m cm–1.
[Ni(m-MePhCOO)2(NITpPy)2(H2O)2]·(CH3OH)2 (2): Complex 2
was synthesized in a manner similar to that of 1 only by replacing eters are summarized in Table 3. The main bond lengths and angles
copper p-toluate with nickel m-toluate. C42H58N6NiO12: calcd. C are presented in Table 4.
Table 3. Crystallographic and data collection parameters for complexes 1–4.
1
2
3
4
Empirical formula
Formula weight
C40H46N6O8Cu
802.37
C42H58N6O12Ni
897.65
C40H50N6O10Mn
829.80
C40H50N6O10Mn
829.80
Temperature /K
293(2)
293(2)
293(2)
293(2)
Crystal size /mm
Crystal system
space group
0.26ϫ0.22ϫ0.18
triclinic
P1
0.25ϫ0.16ϫ0.12
triclinic
P1
0.36ϫ0.24ϫ0.16
triclinic
P1
0.28ϫ0.19ϫ0.12
triclinic
P1
¯
¯
¯
¯
a /Å
b /Å
c /Å
α /°
6.8781(6)
11.7287(10)
12.4815(10)
94.5490(10)
99.7110(10)
91.1190(10)
988.79(14)
1
7.5693(11)
12.3692(19)
12.5228(19)
88.092(2)
81.119(2)
87.894(2)
1907.3(2)
1
6.8576(9)
12.3631(16)
12.9831(17)
89.466(2)
89.740(2)
76.530(2)
1070.4(2)
1
7.2254(11)
10.0729(16)
14.178(2)
82.881(2)
83.672(2)
85.885(2)
1015.9(3)
1
β /°
γ /°
Volume /Å3
Z
Dcalc /g·cm–3
1.347
0.611
421
1.288
0.484
476
1.287
0.369
437
1.356
0.389
437
Absorption coefficient /mm–1
F(000)
Limiting indices
–8 Յ h Յ 8
– 13 Յ k Յ 13
– 14 Յ l Յ 14
3504 / 0 / 250
99.6
–9 Յ h Յ 9
–16 Յ k Յ 16
–16 Յ l Յ 16
5268 / 0 / 284
99.6
–6 Յ h Յ 9
–14 Յ k Յ 15
–16 Յ l Յ 16
4769 / 0 / 264
98.5
–8 Յ h Յ 7
–11 Յ k Յ 11
–15 Յ l Յ 16
3524 / 0 / 264
98.5
Data/restraints/ parameters
Completeness to θ = 25.00 /%
Goodness-of-fit on F2
1.084
1.049
1.054
1.043
Final R indices [I Ͼ 2σ(I)]
R indices (all data)
0.0325, 0.0872
0.0384, 0.0888
0.232 and –0.240
0.0613, 0.1260
0.1171, 0.1574
0.310 and –0.483
0.0634, 0.1683
0.0933, 0.1993
0.368 and –0.548
0.0546, 0.1362
0.0792, 0.1567
0.488 and –0.501
Largest diff. peak and hole /e·Å–3
368
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© 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
Z. Anorg. Allg. Chem. 2014, 363–369

Transition Metal Complexes withPyridyl-substituted Nitronyl Nitroxide
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Table 4. Selected bond lengths /Å and angles /° for complexes 1–4.
1
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Cu(1)–N(1)
N(2)–O(1)
1.9982(14)
1.270(2)
Cu(1)–O(3)
N(3)–O(2)
1.9893(13)
1.259(3)
2
Ni(1)–O(3)
Ni(1)–N(1)
N(3)–O(2)
O(3)–Ni(1)–N(1)
2.032(2)
2.122(3)
1.276(4)
89.90(9)
Ni(1)–O(5)
N(2)–O(1)
O(3)–Ni(1)–O(5)
O(5)–Ni(1)–N(1)
2.062(2)
1.273(4)
88.56(9)
92.08(9)
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Mn(1)–O(3)
Mn(1)–N(1)
N(3)–O(2)
2.127(2)
2.311(3)
1.265(4)
Mn(1)–O(5)
N(2)–O(1)
O(5)–Mn(1)–N(1)
O(3)–Mn(1)–N(1)
2.225(2)
1.275(4)
93.13(9)
90.08(10)
O(3)–Mn(1)–O(5) 89.55(9)
4
Mn(1)–O(3)
Mn(1)–N(1)
N(3)–O(2)
2.196(2)
2.344(3)
1.275(4)
Mn(1)–O(4)
N(2)–O(1)
O(3)–Mn(1)–N(1)
O(4)–Mn(1)–N(1)
2.126(2)
1.275(4)
92.53(8)
90.11(9)
O(4)–Mn(1)–O(3) 87.21(8)
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Crystallographic data (excluding structure factors) for the structures in
this paper have been deposited with the Cambridge Crystallographic
Data Centre, CCDC, 12 Union Road, Cambridge CB21EZ, UK.
Copies of the data can be obtained free of charge on quoting the de-
pository numbers CCDC-940021, -940022, -940023, and -940024
(Fax: +44-1223-336-033; E-Mail: deposit@ccdc.cam.ac.uk, http://
www.ccdc.cam.ac.uk).
Supporting Information (see footnote on the first page of this article):
The packing plots of complexes 2, 3 and 4 are revealed in Figure S1
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Acknowledgements
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This work was supported by the National Natural Science Foundation
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Received: May 28, 2013
Published Online: September 20, 2013
Z. Anorg. Allg. Chem. 2014, 363–369
© 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
www.zaac.wiley-vch.de
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