Metallomacrocyclic complexes by self-assembly of NiII and CuII Ions and chelating Bis(N-acylamidines)

Article abstract of DOI:10.1002/ejic.201101350

Bis(N-acylamidines) 1, which contain various rigid or flexible spacer units with different spatial orientations, are potent bis(bidentate) ligands for the coordination of metal ions. Treatment of 1 with Ni^II or Cu ^II salts gave two 2

Full text of DOI:10.1002/ejic.201101350

FULL PAPER
DOI: 10.1002/ejic.201101350
Metallomacrocyclic Complexes by Self-Assembly of NiII and CuII Ions and
Chelating Bis(N-acylamidines)[‡]
Juliana Isabel Clodt,[a] Roland Fröhlich,[a] and Matthias Eul,[b][‡‡] and
Ernst-Ulrich Würthwein*[a]
Keywords: Supramolecular chemistry / N,O ligands / Metallomacrocycles / Nickel / Copper
Bis(N-acylamidines) 1, which contain various rigid or flexible
spacer units with different spatial orientations, are potent
bis(bidentate) ligands for the coordination of metal ions.
Treatment of 1 with NiII or CuII salts gave two 2:2 (3) and
four 3:3 (4) metallomacrocycles by self-assembly. The struc-
tures of the hitherto unknown products were determined by
the geometry of the ligands that incorporate either linear or
bent spacers between the two binding sites. Complex 3b is
especially interesting due to its two vinyl subunits orientated
perpendicular to the plane of the molecule. Complexes 3 and
4 crystallize in planar layers with intercalated solvent mole-
cules (N,N-dimethylformamide, dimethyl sulfoxide). The mo-
lecular structures of five coordination compounds in the solid
state have been elucidated by X-ray diffraction.
even in the neutral form, and an additional coordination
site is offered at the central nitrogen atom. The synthesis
of 2:1 N-acylamidine/metal complexes was described by
Ley and Werner in 1913 as a reaction of the ligands with
metal(II) acetates.[23] This reaction yielded neutral 2:1 metal
complexes with anionic ligands, the structures of which
were proven to be trans complexes by Oehme and Pracejus
in 1969.[24] The first platinum(II) complex of a chelating N-
acylamidine has been recently reported.[25] We have pre-
viously described several types of metal complexes formed
from primary N-acylamidines and copper(II) or palladi-
um(II) salts.[14–16] In general, 2:1 metal complexes of 2 have
been found to have trans or cis arrangements (Scheme 1).
Introduction
The synthesis of metallomacrocycles by the self-assembly
of suitable ligands and metal ions is an important field of
current interest in supramolecular coordination chemistry,
not only from a structural point of view, but also with re-
spect to molecular containers, catalysis, recognition, and
magnetochemistry.[1–3] A large number of literature exam-
ples are based on pyridyl or bipyridyl units, which assemble
architectures such as triangles, squares, rectangles, polyhe-
dra, and cages.[4–6] Various synthetic approaches to design
supramolecular architectures have been discussed by Holli-
day and Mirkin.[5] The symmetry interaction approach,[7]
a
method to design metallomacrocycles based on chelating
ligands with two or more binding sites, has been widely
used by Saalfrank,[8–10] Lehn,[11,12] and Raymond[13] to as-
semble a variety of macrocyclic systems based on main-
group and transition-metal coordination compounds.
We have used this approach to generate new macrocyclic
complexes from bis(N-acylamidines) 1 as chelating ligands.
N-Acylamidines 2 are interesting nitrogen-rich mono-
dentate or bidentate ligands for metal-ion coordina-
tion.[14–20] Compared to β-imino ketones[21] and β-di-
imines,[22] the nitrogen atom in the central 3-position alters
the electronic structures at the binding sites considerably.
Furthermore, conjugation over all five atoms is observed
Scheme 1. Bis(N-acylamidines) 1, N-acylamidines 2, and 2:1 metal
complexes of primary 2 with cis and trans arrangements of the
ligands.
[‡] Unsaturated Hetero Chains, XXI. Part XX: Ref.[8]
[‡‡] Magnetic Measurements
[a] Organisch-Chemisches Institut, Westfälische Wilhelms-
Universität,
To the best of our knowledge, no examples of 2:2 or 3:3
metallomacrocycles or higher-order assemblies of 1 as li-
gands have been reported. The coordination geometry of
these ligands is expected to be similar to that of bis(β-diket-
ones) or bis(N-acylthioureas), which have been synthesized
Corrensstraße 40, 48149 Münster, Germany
Fax: +49-251-83-39772
E-mail: wurthwe@uni-muenster.de
[b] Institut für Anorganische und Analytische Chemie,
Westfälische Wilhelms-Universität,
Corrensstraße 38/30, 48149 Münster, Germany
1210
© 2012 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Eur. J. Inorg. Chem. 2012, 1210–1217

Metallomacrocyclic Complexes with NiII and CuII and Bis(N-acylamidines)
and studied with respect to their coordination behavior by sphere is tetrahedral or octahedral, and if the linker has
Reedijk et al.,[26] Köhler et al.,[27] Koch et al.,[28,29] and special steric properties. All these possibilities complicate
Ugur et al.[30] In this context, we were interested to learn, the prediction of the structures of such metal complexes.
which types of assemblies were formed by metal complex-
In this work, the coordination behavior of four different
ation of such bis(bidentate) bis(N-acylamidines) with bulky, primary bis(N-acylamidines) 1 towards nickel(II) and cop-
flexible, or rigid spacers of designed geometries. Such li- per(II) salts was examined (Scheme 3). The four ligands
gands have recently been synthesized in our laboratory for mainly differ with respect to their coordination geometry:
the first time.[31,32]
1a bears the sterically fixed, bent 1,3-adamantanediyl
spacer with a tetrahedral (109.5°) spatial orientation, which
allows bis(coordination) in a parallel orientation. Ligand
1b combines two flexible methylene units with a rigid (E)-
configured olefinic subunit within the 2-butenediyl spacer.
Here, one may expect various types of bis(coordination).
Ligand 1c has a linear biphenyl spacer, which may be sub-
ject to internal rotation, and 1d contains a linear, inflexible
2,5-naphthlenediyl spacer. Ligands 1c and 1d allow bis-
(coordination) in a trigonal-planar (120°) orientation.
Ligands 1a and 1b were easily prepared from bis(N-acyl-
benzotriazoles) and N-phenylbenzamidine.[31] Ligands 1c
and 1d were synthesized by using diacyl dichlorides and
benzamidine as precursors.[32] The metal complexes (3 and
4) of these four ligands were generated by reaction of cop-
per or nickel salts with cis coordination within the individ-
ual complexes and syn orientation with respect to the two
binding sites. In general, 1a and 1b, with angled spacers,
assemble 2:2 metallomacrocycles 3a and 3b (Scheme 4),
whereas 1c and 1d, with linear spacers, led to triangular 3:3
metallomacrocycles 4a–d (Scheme 5).
Results and Discussion
The possibilities for the chelate binding of bis(N-acyl-
amidines) 1 in a square-planar coordination environment to
give syn and anti isomers with respect to the spatial orienta-
tion of the spacer groups are illustrated in Scheme 2. For
syn isomers metallomacrocycles, for instance triangles, are
expected, whereas anti isomers would lead to polymeric
chains. Furthermore, the macrocyclic structures will be dif-
ferent if the ligand is not linear but bent, if the coordination
Scheme 4. Self-assembly of 2:2 metallamacrocycles 3a and 3b from
bent 1a and 1b and nickel(II) salts.
In detail, 2:2 metallomacrocycles 3a and 3b were synthe-
sized from metal acetates and 1a and 1b in N,N-dimethyl-
formamide (DMF) at 40 °C in moderate to good yields
(Scheme 4). Both compounds were crystalline solids, and
their molecular structures were obtained by X-ray analysis.
Scheme 2. Superstructures arising from syn and anti arrangements
of the coordination sites for bis(N-acylamidine)metal complexes.
Scheme 3. Bis(N-acylamidines) 1a–d.
Eur. J. Inorg. Chem. 2012, 1210–1217
© 2012 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.eurjic.org
1211

J. I. Clodt, R. Fröhlich, M. Eul, E.-U. Würthwein
FULL PAPER
Scheme 5. Self-assembly of 3:3 metallamacrocycles 4a–d from linear 1c and 1d and nickel(II) and copper(II) salts.
In order to generate 3:3 metallomacrocycles 4a–d,
1 equiv. of 1c or 1d was treated with 1 equiv. of nickel(II)
acetate, copper(II) acetate, or [CuI(CH3CN)4]PF6 in DMF
at 40 °C. In the case of the copper(I) salt, during the reac-
tion copper(I) was oxidized to copper(II), most probably by
air, which was not excluded. Four 3:3 metallomacrocycles
4a–d were obtained in good yields (Scheme 5). Metallomac-
rocycle 4d was synthesized by two different ways, either by
using copper(I) hexafluorophosphate or copper(II) acetate.
Figure 1. Molecular structure 3a (left) and internal distances
The latter method gave the product in a higher yield.
These metallomacrocycles are only poorly soluble in po-
(right).
1
lar and nonpolar solvents; thus, H and 13C NMR spectra
Table 1. Selected (average) geometrical parameters for 3a.
could not be obtained.
Distances [Å]
Angles [°]
Torsional angles [°]
HN–C
HN–C–N
HN–C–N–C 1.326(4)
C–O
1.303(4)
1.353(4)
N–C–N 125.4(3)
C–N–C 120.5(3)
N–C–O 127.9(3)
C–O–Ni 126.7(2)
O–Ni–N 91.6(1)/176.4(1) O–Ni–N–C 6.5(3)
Ni–N–C 127.5(2) Ni–N–C–N 4.9(6)
N–C–N–C 2.9(6)
C–N–C–O 3.9(6)
N–C–O–Ni 2.5(5)
C–O–Ni–N 4.2(3)
Description of the Structures
The crystal structures of 3a, 3b, 4a, 4b, and 4d were de-
1.273(3)
1.848(2)
1.833(3)
termined by single-crystal X-ray diffraction. In order to O–Ni
Ni–N
generate crystals suitable for X-ray analysis, it was impor-
tant to cool DMF or dimethyl sulfoxide (DMSO) solutions
of the complexes very slowly to room temperature at a rate
of around 10 °C/h without stirring. The crystallization pro-
Selected bond lengths, bond angles, and torsion angles
cess started at ca. 80 °C. Other crystallization methods are for 3a (average of the two six-membered chelate rings),
described in the Experimental Section. Many of the crystals which are also typical for the other NiII complexes, are
contained intercalated solvent molecules (DMF, DMSO), listed in Table 1. The O–Ni and N–Ni bond lengths are
which could not be removed even by prolonged evaporation 1.848(2) and 1.833(3) Å, respectively, which are slightly
in vacuo.
shorter than those of nickel complexes of neutral N-acyl-
¯
Complex 3a crystallized in the triclinic space group P1 amidines as expected. These bond lengths are comparable
with one metallomacrocycle in the unit cell together with with 2:2 nickel macrocycles of bis(N-acylthioureas) and
four molecules of DMSO (Figure 1, Table 1). The two bis(N-acylisoureas).[33] The data reveal the expected elec-
nickel atoms are coordinated by two ligands to form tron delocalization within the chelate ring. The shortest Ni–
square-planar cis-N,O chelates from the deprotonated N- Ni distance is 6.44 Å.
acylamidine moieties. Small deviations from ideal square-
The crystal packing of 3a (Figure 2) is characterized by
planar geometry are observed with the NiII ion 0.009 Å a layered structure wherein intercalated DMSO and the
above the plane. The size of the cavity formed is given by metallomacrocycles are stacked on top of each other. Every
the distance between the two face-to-face adamantane units second DMSO molecule is connected to two amino protons
(3.8 Å) and the distance between two oxygen atoms of the of the metal complex by hydrogen bonding (2.24 and
same ligand (4.8 Å, Figure 1, right).
2.32 Å). The other solvent molecules are located in a layer
1212
www.eurjic.org
© 2012 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Eur. J. Inorg. Chem. 2012, 1210–1217

Metallomacrocyclic Complexes with NiII and CuII and Bis(N-acylamidines)
between two metallomacrocycles (Figure 2, bottom). There
is little interaction of the DMSO molecules with the NiII
ions as indicated by the Ni···S distance of 3.75 Å.
Figure 3. Molecular structure of 3b (left) and internal distances
(right).
Ni–Ni distance of 3.60 Å. The second layer completely co-
vers the cavity between two layers of the same arrangement.
Therefore, no channels were observed in the crystal struc-
ture. The structural parameters for the six-membered che-
late rings are similar to those of 3b.
Figure 2. Crystal packing of 3a (top) and hydrogen bonding be-
tween the layers with the intercalating DMSO molecules (bottom).
Most hydrogen atoms are omitted for clarity.
Complex 3b crystallized from the slow diffusion of di-
ethyl ether into a solution of DMF. It crystallized in the
monoclinic space group P21/n with two metallomacrocycles
in every unit cell together with four DMF molecules (Fig-
ure 3). Like 3a, the two four-coordinate nickel ions are
bridged by two deprotonated bis(N-acylamidines), which
results in approximately square-planar bidentate cis coordi-
nation with the NiII ion approximately 0.004 Å above the
plane. Interestingly, with respect to the geometry of the 2-
butene-1,4-diyl spacer unit, the two olefin groups of the two
ligands are orientated exactly parallel to each other (Fig-
ure 3, left) with the π orbitals arranged perpendicular to
the plane of the macrocycle, which suggests an additional
possibility for coordination inside the metallomacrocycle,
e.g. for late-transition metal ions. Thus, 1b unexpectedly
shows the same complexation behavior as 1a, which has a
Figure 4. Another view of the molecular structure of 3b (top) and
crystal packing (bottom). Solvent molecules are omitted for clarity.
Complex 4a (Figure 5) crystallizes in the triclinic space
¯
bent adamantane-1,3-diyl spacer, with the ability to posi- group P1 with four metallomacrocycles in the unit cell to-
tion the coordination sites in a parallel fashion. The dis- gether with 32 DMSO molecules. The three nickel ions are
tances between the opposing olefinic carbon atoms is 6.6 Å connected to three anionic N-acylamidine ligands in a
and that of the two oxygen atoms is 5.7 Å.
square-planar cis-N,O chelate coordination. A minor devia-
The crystal lattice of 3b is characterized by separate lay- tion from ideal square-planar geometry is observed as the
ers of the macrocycles, which are interconnected by DMF chelate rings are slightly twisted. The size of the internal
molecules (Figure 4, bottom). Thus, the oxygen atoms of cavity of the metallomacrocycle measured between the aro-
the DMF molecules are hydrogen-bonded to two cis-NH matic protons of the spacer unit is 6.3 and 6.9 Å (Figure 5,
groups of the chelates (NH···O 2.17 and 2.22 Å) and to the right). The biphenyl spacer units are almost coplanar with
oxygen atoms of the chelate of the next layer by the DMF the coordination sphere of the nickel atoms but display a
CH group [O···CH(DMF) 2.42 Å]. The crystal packing torsion angle within the biphenyl system of about 30°. The
(Figure 4, bottom) shows two different layers of metallo- planar macrocycles crystallize to form layers with an ap-
macrocycles stacked on top of each other with the shortest proximate distance of 3.6–3.8 Å. The bond lengths and
Eur. J. Inorg. Chem. 2012, 1210–1217
© 2012 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.eurjic.org
1213

J. I. Clodt, R. Fröhlich, M. Eul, E.-U. Würthwein
FULL PAPER
Figure 5. Molecular structure of 4a (left) and internal distances (right).
angles resemble those of 2:2 nickel macrocycles of bis(N- hydrogen bonds to each two of the NH groups of the che-
acylamidines) and are comparable to 3:3 nickel macrocycles lates (NH···O 2.16 and 2.44 Å). Similar to 4a, 4b crystallizes
of bis(N-acylthioureas) with phenyl spacer units.[27]
to form layers with distances of approximately 3.8 Å.
¯
Complex 4b crystallized in the trigonal space group R3
The magnetic properties of 4b in the solid state were
with six metallomacrocycles per unit cell together with 18 measured in the temperature range of 3–300 K. The com-
DMSO molecules (Figure 6). The structural properties of pound is essentially diamagnetic, which indicates that there
this C3-symmetrical complex are similar to those of 4a. is no significant interaction of the interlayer DMSO mole-
Square-planar coordination spheres of the nickel atoms cules with the nickel(II) ions. On the basis of these measure-
were found. The average N–Ni–O angle is 91.2(1)°, which ments, the nickel(II) ions can be described as square-
leads to a small deviation from ideal square-planar geome- planar.[34]
try with the nickel atom approximately 0.019 Å above the
Crystals of 4d suitable for X-ray analysis were obtained
plane. This is also indicated by the torsion angles within the from [Cu(CH3CN)4]PF6 and 1d but not from CuII salts. The
chelate ring system, which are between 1.6(8) and 8.2(8)° reactants were stirred in DMF in the presence of air so that
and show substantial deviations from the ideal planar che- the copper(I) salt was oxidized. The slightly yellow solution
late ring system compared to 4a, where all of the torsion slowly turned blue on formation of copper(II). Slow dif-
angles are less than 5(6)°. The shortest distance between the fusion of diethyl ether into the solution led to red crystals
aromatic protons of the two different ligands in the inside of 4d. Complex 4d crystallized in the triclinic space group
¯
of the metallomacrocycle is 4.5 Å (Figure 6, right).
P1 with two metallomacrocycles in the unit cell together
The naphthalene units are coplanar with the nickel coor- with a minimum of six molecules of DMF. Due to the pres-
dination spheres, whereas the phenyl substituents of the N- ence of these solvent molecules, the structure could not be
acylamidines are tilted [–21.1(6) and –40.9(6)°]. Three of refined with high precision (R1 = 0.1011, Figure 7). The
the DMSO molecules are connected to the macrocycle by three copper atoms are interconnected by three deproton-
Figure 6. Molecular structure of 4b (left) and internal distances (right).
1214
www.eurjic.org
© 2012 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Eur. J. Inorg. Chem. 2012, 1210–1217

Metallomacrocyclic Complexes with NiII and CuII and Bis(N-acylamidines)
Figure 7. Molecular structure of 4d (left) and internal distances (right).
337 nm, 3 ns. CHN elemental analysis was performed with a Ele-
mentar Vario El III apparatus.
ated N-acylamidine ligands in a square-planar cis-N,O co-
ordination. Again, we observed small deviations from the
ideal square-planar geometry, as the CuII ion is located
0.047 Å below the plane of the complex.
General Procedure (GP) for the Synthesis of 3a and 4a–d: A solution
of metal acetate (0.1 mmol) in DMF (2 mL) was stirred at 40 °C
until the metal salt had dissolved. The ligand (0.1 mmol) dissolved
in DMF (2 mL) at 40 °C was added dropwise over 10 min, and
the mixture was stirred at 40 °C for 30 min. The metal complex
precipitated immediately or on cooling to room temperature. The
solid was collected by filtration and washed with a small amount
of DMF. The products were purified as stated below.
The internal distances of the metallomacrocycle are 6.2
and 7.8 Å, measured between the aromatic protons of the
spacer unit (Figure 7, right). The biphenyl spacer units are
almost coplanar with the coordination sphere of the copper
atoms but are tilted by about 25° within the biphenyl sys-
tem. The average O–Cu and N–Cu bond lengths are
1.918(3) and 1.919(3) Å, respectively, which are slightly
longer than those of 4a as expected. The bond lengths of
the N-acylamidine moieties reveal the expected electron de-
localization within the chelate rings.
cis-[Ni{(1a–2H)-N,O}]2 (3a): Adamantane-1,3-dicarboxylic acid
bis(1-amino-1-phenylmethylideneamide) (1a, 42.8 mg (0.100 mmol)
and Ni(OAc)2·4H2O (24.7 mg, 0.100 mmol) were treated according
to the GP. Recrystallization from DMSO gave orange crystals.
Yield: 36.2 mg (0.037 mmol, 75%). M.p. Ͼ300 °C. IR (ATR): ν =
˜
3069 (vw), 2932 (w), 2903 (m), 2853 (w), 1591 (m), 1545 (s), 1479
(m), 1452 (s), 1429 (m), 1414 (m), 1377 (s), 1350 (m), 1325 (m),
1308 (s), 1258 (m), 1240 (m), 1140 (w), 1103 (w), 1030 (w), 1003
(w), 957 (w), 918 (w), 793 (w), 758 (w), 704 (s), 685 (vs) cm–1. MS
(MALDI, matrix DCTB {trans-2-[3-(4-tert-butylphenyl)-2-methyl-
2-propenylidene]malononitrile}): m/z = 969–976 [C52H52N8Ni2O4
+ H]+. C52H52N8Ni2O4 (970.4): calcd. C 64.36, H 5.40, N 11.55;
found C 64.11, H 5.38, N 11.52.
Conclusions
We have demonstrated that the bis(bidentate) bis(N-acyl-
amidines) 1, which incorporate various spacer units, are
well suited for the preparation of supramolecular architec-
tures by self-assembly. We obtained two 2:2 metallomacro-
cycles (3a and 3b) from the bent 1a and 1b. The structure
of 3b is surprising, as – in spite of the (E) configuration of
the alkenyl moieties – the two π bonds are located perpen-
dicular to the molecular plane, which creates a cavity with
internal π-donor properties. Furthermore, four 3:3 metallo-
macrocycles 4a–d were obtained, which are characterized
by planar structures and often crystallized in layers with
intercalated solvent molecules (DMF, DMSO). Further
work directed towards the synthesis of 3D coordination
compounds based on N-acylamidine ligands is underway.
X-ray Crystal Structure Analysis of 3a:[35] C52H52N8Ni2O4·
4C2H6OS, M = 1282.95, orange crystal, 0.40ϫ0.15ϫ0.07 mm, a
= 10.4056(4), b = 12.3064(7), c = 13.0618(4) Å, α = 64.856(3), β =
83.375(3), γ = 86.827(2)°, V = 1503.99(11) Å3, ρcalcd. = 1.416 gcm–3,
μ = 0.826 mm–1, empirical absorption correction (0.734 Յ T Յ
¯
0.944), Z = 1, triclinic, space group P1 (No. 2), λ = 0.71073 Å, T
= 223(2) K, ω and φ scans, 17245 reflections collected (Ϯh, Ϯk,
Ϯl), [(sinθ)/λ] = 0.66 Å–1, 7092 independent (Rint = 0.064) and 4484
observed reflections [I Ն 2σ(I)], 380 refined parameters, R = 0.061,
wR2 = 0.177, max. (min.) residual electron density 0.72 (–1.07)
eÅ–3, hydrogen atoms at N1 found from difference fourier calcula-
tions, others calculated and refined as riding atoms.
cis-[Ni{(1b–2H)-N,O}]2 (3b):
A solution of Ni(OAc)2·4H2O
Experimental Section
(24.7 mg, 0.100 mmol) in DMF (2 mL) was stirred at 40 °C until
the metal salt had dissolved. (E)-Hex-3-enedioic acid bis(1-amino-
1-phenylmethylideneamide) (1b, 34.8 mg, 0.100 mmol) dissolved in
DMF (2 mL) at 40 °C was added dropwise to the metal salt solu-
tion over 10 min, and the mixture was stirred for 30 min. Slow dif-
fusion of diethyl ether (5 mL) into the DMF solution led to red
Materials and Methods: IR spectra were recorded with a Varian
3100 FTIR spectrometer by using a Specac Golden Gate Single
Reflection ATR sampling system. MALDI MS data were recorded
with Lazarus IIIDE (Organic Institut, Münster) or Reflex IV
(Bruker Daltonics, Bremen) instruments by using an N2 laser,
Eur. J. Inorg. Chem. 2012, 1210–1217
© 2012 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.eurjic.org
1215

J. I. Clodt, R. Fröhlich, M. Eul, E.-U. Würthwein
FULL PAPER
¯
crystals of 3b within a week. The crystals were collected by fil-
(0.883 Յ T Յ 0.975), Z = 6, trigonal, space group R3 (No. 148), λ
tration and dried under vacuum. Yield: 16.6 mg (0.020 mmol,
= 0.71073 Å, T = 223(2) K, ω and φ scans, 18683 reflections col-
40%). M.p. 140 °C (decomposition). IR (ATR): ν = 3217 (w), 2930
lected (Ϯh, Ϯk, Ϯl), [(sinθ)/λ] = 0.66 Å–1, 6280 independent (Rint
˜
(vw), 1653 (m), 1553 (s), 1408 (vs), 1342 (m), 1256 (w), 1101 (w), = 0.050) and 4664 observed reflections [I Ն 2σ(I)], 342 refined
1049 (w), 1028 (w), 926 (w), 824 (w), 779 (m), 754 (w), 737 (w), parameters, R = 0.0601, wR2 = 0.136, max. (min.) residual electron
675 (s), 665 (s), 615 (s) cm–1. MS (MALDI): m/z = 809.1
density 0.94 (–0.37) eÅ–3; hydrogen atoms at N1 and N18 were
found from difference fourier calculations, others were calculated
and refined as riding atoms.
[C40H36N8Ni2O4 + H]+.
X-ray Crystal Structure Analysis of 3b:[35] C40H36N8Ni2O4·
2C3H7NO, M = 956.38, orange crystal, 0.35ϫ0.25ϫ0.03 mm, a =
10.5711(2), b = 16.8185(3), c = 15.5769(2) Å, β = 90.504(1)°, V
= 2769.31(8) Å3, ρcalcd. = 1.147 gcm–3, μ = 0.729 mm–1, empirical
absorption correction (0.785 Յ T Յ 0.979), Z = 2, monoclinic,
space group P21/n (No. 14), λ = 0.71073 Å, T = 223(2) K, ω and φ
scans, 20639 reflections collected (Ϯh, Ϯk, Ϯl), [(sinθ)/λ] =
0.66 Å–1, 6462 independent (Rint = 0.046) and 5410 observed reflec-
tions [I Ն 2σ(I)], 297 refined parameters, R = 0.059, wR2 = 0.183,
max. (min.) residual electron density 0.57 (–0.52) eÅ–3; other sol-
vents (probably diethyl ether) could not be refined in a chemically
meaningful way, therefore, the SQUEEZE routine was used, hydro-
gen atoms at N1 and N12 were found from difference fourier calcu-
lations, others were calculated and refined as riding atoms.
cis-[Cu{(1d–2H)-N,O}]3 (4c): Naphthalene-2,6-dicarboxylic acid
bis(1-amino-1-phenylmethylideneamide) (1d, 42.0 mg, 0.100 mmol)
and Cu(OAc)2 (18.1 mg, 0.100 mmol) were treated according to the
GP. The precipitate was collected by filtration and washed with
DMF (2 mL), toluene (2 mL), and pentane (2 mL) to give a brown
solid. Yield: 45.3 mg (0.031 mmol, 94%). M.p. Ͼ300 °C. IR (ATR):
ν = 3325 (w), 3267 (w), 3065 (vw), 2922 (vw), 2884 (vw), 1665 (m),
˜
1589 (w), 1543 (s), 1470 (m), 1454 (s), 1422 (s), 1383 (s), 1350 (vs),
1256 (m), 1234 (m), 1198 (m), 1188 (m), 1115 (m), 1092 (m), 1055
(m), 1028 (m), 1001 (w), 924 (m), 827 (m), 797 (m), 762 (vs), 689
(s), 660 (m) cm–1. MS (MALDI, matrix DCTB): m/z = 1443–1450
[C78H54N12Cu3O6 + H]+. C78H54N12Cu3O6 (1446.0): calcd. C
64.79, H 3.76, N 11.62; found C 64.38, H 3.76, N 11.58.
cis-[Ni{(1c–2H)-N,O}]3 (4a): Biphenyl-4,4Ј-dicarboxylic acid bis(1-
amino-1-phenylmethylideneamide) (1c, 44.6 mg,0.100 mmol) and
Ni(OAc)2·4H2O (24.7 mg, 0.100 mmol) were treated according to
the GP. In order to obtain crystals, the solid was recrystallized from
DMSO to give orange crystals. Yield: 45.5 mg (0.028 mmol, 84%).
cis-[Cu{(1c–2H)-N,O}]3 (4d). Method 1: Ligand 1c (44.6 mg,
0.100 mmol) and Cu(OAc)2 (18.1 mg, 0.100 mmol) were treated ac-
cording to the GP. The precipitate was collected by filtration and
washed with DMF (2 mL), toluene (2 mL), and pentane (2 mL).
Yield: 45.1 mg (0.029 mmol, 88%). Method 2: Ligand 1c (44.6 mg,
0.100 mmol) was dissolved in DMF (1 mL) and added dropwise to
a solution of [Cu(CH3CN)4]PF6 (37.2 mg, 0.100 mmol) in DMF
(1 mL). On stirring for 15 min, the solution slowly turned blue due
to the formation of copper(II). Slow diffusion of diethyl ether into
the solution led to red crystals of 4d within a week. The crystals
were collected by filtration and dried under vacuum. Yield: 26.0 mg
M.p. Ͼ 300 °C. IR (ATR): ν = 3304 (w), 3061 (w), 1607 (vw), 1589
˜
(w), 1566 (m), 1533 (m), 1495 (w), 1452 (m), 1423 (s), 1404 (m),
1369 (vs), 1302 (m), 1271 (m), 1246 (m), 1180 (m), 1157 (m), 1057
(w), 1028 (m), 1003 (m), 847 (m), 810 (m), 795 (m), 756 (s), 704
(vs), 644 (m), 629 (m) cm–1. MS (MALDI): m/z = 1509.3
[C84H60N12Ni3O6 + H]+. C84H60N12Ni3O6 + 1.5 DMSO (1626.7):
calcd. C 64.23, H 4.28, N 10.33; found C 64.25, H 4.21, N 10.54.
(0.017 mmol, 50%). M.p. Ͼ300 °C. IR (ATR): ν = 3314 (vw), 3063
˜
(vw), 2926 (vw), 2870 (vw), 1661 (m), 1589 (m), 1568 (m), 1535 (s),
1495 (m), 1454 (s), 1425 (s), 1406 (m), 1366 (vs), 1256 (m), 1231
(m), 1180 (m), 1155 (m), 1096 (m), 1028 (w), 1003 (m), 934 (w),
851 (m), 795 (m), 754 (s), 745 (m), 708 (s), 660 (m) cm–1. MS
X-ray Crystal Structure Analysis of 4a:[35] C84H60N12Ni3O6·
8C2H6OS, M = 2134.59, orange crystal, 0.40ϫ0.30ϫ0.05 mm, a
= 15.5954(2), b = 22.4297(3), c = 30.5163(5) Å, α = 91.203(1), β =
93.253(1), γ = 102.921(2)°, V = 10381.3(3) Å3, ρcalcd. = 1.366 gcm–3,
μ = 0.766 mm–1, empirical absorption correction (0.749 Յ T Յ
(MALDI, matrix DCTB): m/z = 1546–1550 [C84H60N12Cu3O6
+
Na]+. C84H60Cu3N12O6 + 0.5 DMF (1557.8): calcd. C 65.80, H
4.10, N 11.22; found C 65.64, H 4.04, N 10.97.
¯
0.963), Z = 4, triclinic, space group P1 (No. 2), λ = 0.71073 Å, T
= 223(2) K, ω and φ scans, 58596 reflections collected (Ϯh, Ϯk,
Ϯl), [(sinθ)/λ] = 0.59 Å–1, 35585 independent (Rint = 0.069) and
24804 observed reflections [I Ն 2σ(I)], 2499 refined parameters, R
= 0.123, wR2 = 0.330, max. (min.) residual electron density 3.61
(–2.46) eÅ–3; hydrogen atoms were calculated and refined as riding
atoms, solvent molecules were refined with geometrical and ther-
mal restraints, weakly diffracting crystals of poor quality.
X-ray Crystal Structure Analysis of 4d:[35] C84H60Cu3N12O6·
3C3H7NO, M = 1743.35, red crystal, 0.40ϫ0.35ϫ0.10 mm, a =
13.3524(2), b = 13.4896(3), c = 25.5935(6) Å, α = 79.232(1), β =
76.486(1), γ = 79.531(1)°, V = 4357.08(16) Å3, ρcalcd. = 1.329 gcm–3,
μ = 0.792 mm–1, empirical absorption correction (0.742 Յ T Յ
¯
0.925), Z = 2, triclinic, space group P1 (No. 2), λ = 0.71073 Å, T
= 223(2) K, ω and φ scans, 58467 reflections collected (Ϯh, Ϯk,
Ϯl), [(sinθ)/λ] = 0.66 Å–1, 20282 independent (Rint = 0.071) and
14756 observed reflections [I Ն 2σ(I)], 1118 refined parameters, R
= 0.075, wR2 = 0.210, max. (min.) residual electron density 1.14
(–0.89) eÅ–3; other solvents could not be identified in a chemically
meaningful way, therefore the SQUEEZE routine was used, hydro-
gen atoms at N1 were found from difference fourier calculations,
others were calculated and refined as riding atoms, some phenyl
groups show disorder (refined for C12E–C17E).
cis-[Ni{(1d–2H)-N,O}]3 (4b): Naphthalene-2,6-dicarboxylic acid
bis(1-amino-1-phenylmethylideneamide) (1d, 42.0 mg 0.100 mmol)
and Ni(OAc)2·4H2O (24.7 mg, 0.100 mmol) were treated according
to the GP. In order to obtain crystals suitable for X-ray analysis,
the solid was recrystallized from DMSO to give orange crystals.
Yield: 37.0 mg (0.026 mmol, 78%). M.p. Ͼ300 °C. IR (ATR): ν =
˜
3059 (vw), 3026 (vw), 1601 (vw), 1587 (w), 1537 (s), 1456 (m), 1425
(m), 1391 (s), 1354 (s), 1261 (m), 1242 (m), 1200 (m), 1184 (m),
1146 (w), 1117 (m), 1051 (w), 1028 (w), 1001 (w), 966 (w), 918 (m),
822 (w), 770 (s), 691 (vs) cm–1. MS (MALDI, matrix DCTB): m/z
= 1429–1431 [C78H54N12Ni3O6 + H]+. C78H54N12Ni3O6 (1431.4):
calcd. C 65.45, H 3.80, N 11.74; found C 64.93, H 3.89, N 11.67.
Acknowledgments
X-ray Crystal Structure Analysis of 4b:[35] C78H54N12Ni3O6· We are grateful to cand. chem. Thomas Bucher for experimental
3C2H6OS, M = 1665.85, orange crystal, 0.15ϫ0.12ϫ0.03 mm, a
= 26.2897(4), c = 19.8066(4) Å, V = 11855.3(3) Å3, ρcalcd.
1.400 gcm–3, μ = 0.853 mm–1, empirical absorption correction
help and Dr. Christof Wigbers for preliminary experiments in this
field. We thank Prof. Dr. R. W. Saalfrank, Erlangen, for helpful
discussions. This work was supported by the International Re-
=
1216
www.eurjic.org
© 2012 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Eur. J. Inorg. Chem. 2012, 1210–1217

Metallomacrocyclic Complexes with NiII and CuII and Bis(N-acylamidines)
[21] I.-M. Lee in Focus on Organometallic Chemistry Research (Ed.:
search Training Group 1444 Münster–Amsterdam (DFG) and the
Fonds der Chemischen Industrie (Frankfurt).
M. A. Casto), Nova Science Publishers, Inc. New York, Chapt.
5, p. 133, 2005.
[22] L. Bourget-Merk, M. F. Lappert, J. R. Severn, Chem. Rev.
2002, 102, 3031–3066.
[1]
E. Zangrando, M. Casanova, E. Alessio, Chem. Rev. 2008, 108,
[23] H. Ley, F. Werner, Ber. Dtsch. Chem. Ges. 1913, 46, 4040–4049.
[24] G. Oehme, H. Pracejus, Z. Chem. 1969, 9, 140–141.
[25] T. B. Anisimova, N. A. Bokach, K. V. Luzyanin, M. Haukka,
V. Yu. Kukushkin, Dalton Trans. 2010, 39, 10790–10998.
[26] G. Aromi, P. Gamez, J. Reedijk, Coord. Chem. Rev. 2008, 252,
964–989.
[27] R. Köhler, R. Kirmse, R. Richter, J. Siehler, E. Hoyer, Z.
Anorg. Allg. Chem. 1986, 537, 133–144.
[28] K. R. Koch, S. A. Bourne, A. Coetzee, J. Miller, J. Chem. Soc.,
Dalton Trans. 1999, 3157–3161.
4979–5013 and references cited therein.
[2]
[3]
J. M. Lehn, Science 2002, 295, 2400–2403.
G. F. Swiegers, T. J. Malefetse, Coord. Chem. Rev. 2002, 225,
91–121.
M. Fujita, K. Ogura, Coord. Chem. Rev. 1996, 148, 249–264;
M. Fujita, Chem. Soc. Rev. 1998, 27, 417–425.
B. J. Holliday, C. A. Mirkin, Angew. Chem. 2001, 113, 2076–
2097.
J. M. Lehn, Supramolecular Chemistry, VCH, Weinheim, New
York, Basel, Cambridge, Tokyo, 1995.
S. Leininger, B. Olenyuk, P. J. Stang, Chem. Rev. 2000, 100,
853–908.
R. W. Saalfrank, I. Bernt, E. Uller, F. Hampel, Angew. Chem.
1997, 109, 2596; Angew. Chem. Int. Ed. Engl. 1997, 36, 2482–
2485.
R. W. Saalfrank, R. Burak, S. Reihs, N. Low, F. Hampel, H. D.
Stachel, J. Lentmaier, K. Peters, E. M. Peters, H. G.
von Schnering, Angew. Chem. 1995, 107, 1085; Angew. Chem.
Int. Ed. Engl. 1995, 34, 993–995.
[4]
[5]
[6]
[7]
[8]
[29] O. Hallale, S. R. Bourne, K. R. Koch, CrystEngComm 2005, 7,
161–166.
[30] D. Ugur, H. Arslan, N. Külcü, Russ. J. Coord. Chem. 2006, 32,
669–675.
[31] J. I. Clodt, V. D. Hack, R. Fröhlich, E.-U. Würthwein, Synthe-
sis 2010, 1485–1492.
[32] J. I. Clodt, C. Wigbers, R. Reiermann, R. Fröhlich, E.-U.
Würthwein, Eur. J. Org. Chem. 2011, 3197–3298.
[33] U. Schröder, L. Beyer, R. Richter, J. Angulo-Cornejo, M. Cas-
tillo-Montoya, M. Lino-Pacheco, Inorg. Chim. Acta 2003, 353,
59–67.
[34] Above 270 K, the thermal variation of the molar susceptibility
exceeds the value of the product χMT = 0.375 emuKmol–1.
With regard to the number of three nickel(II) atoms per mole-
cule, we interpret this observation by the presence of a small
amount of a paramagnetic impurity.
[35] Data sets were collected with Nonius KappaCCD diffractome-
ters, equipped with a rotating anode generator. Programs used:
data collection COLLECT (Nonius B. V., 1998), data re-
duction Denzo-SMN (Z. Otwinowski, W. Minor, Methods En-
zymol. 1997, 276, 307–326), absorption correction SORTAV
(R. H. Blessing, Acta Crystallogr., Sect. A 1995, 51, 33–37;
R. H. Blessing, J. Appl. Crystallogr. 1997, 30, 421–426) and
Denzo (Z. Otwinowski, D. Borek, W. Majewski, W. Minor,
Acta Crystallogr., Sect. A 2003, 59, 228–234), structure solu-
tion SHELXS-97 (G. M. Sheldrick, Acta Crystallogr., Sect. A
1990, 46, 467–473), structure refinement SHELXL-97 (G. M.
Sheldrick, Acta Crystallogr., Sect. A 2008, 64, 112–122), graph-
ics SCHAKAL (E. Keller, University of Freiburg, 1997).
CCDC-854332 (for 3a), -854333 (for 3b), -854334 (for 4a),
-854335 (for 4b), and -854336 (for 4d) contain the supplemen-
tary crystallographic 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.
Received: December 2, 2011
[9]
[10]
R. W. Saalfrank, H. Maid, A. Scheurer, Angew. Chem. 2008,
120, 8924–8956; Angew. Chem. Int. Ed. 2008, 47, 8794–8824.
[11] P. N. W. Baxter, J. M. Lehn, G. Baum, D. Fenske, Chem. Eur.
J. 1999, 5, 102–112.
[12] P. N. W. Baxter, J. M. Lehn, B. O. Kneisel, G. Baum, D. Fenske,
Chem. Eur. J. 1999, 5, 113–120.
[13] D. L. Caulder, K. N. Raymond, Acc. Chem. Res. 1999, 32, 975–
982.
[14] J. K. Eberhardt, R. Fröhlich, E.-U. Würthwein, J. Org. Chem.
2003, 68, 6690–6694.
[15] J. K. Eberhardt, R. Fröhlich, S. Venne-Dunker, E.-U.
Würthwein, Eur. J. Inorg. Chem. 2000, 1739–1743.
[16] J. K. Eberhardt, T. Glaser, R.-D. Hoffmann, R. Fröhlich, E.-
U. Würthwein, Eur. J. Inorg. Chem. 2005, 1175–1181.
[17] C. Wigbers, J. Prigge, Z. Mu, R. Fröhlich, L. Chi, E.-U.
Würthwein, Eur. J. Org. Chem. 2011, 861–877.
[18] J. C. J. Bart, J. W. Bassi, M. Calcaterra, M. Pieroni, Inorg.
Chim. Acta 1978, 28, 201–210.
[19] M. J. Carney, P. J. Walsh, F. J. Hollander, R. G. Bergman, Or-
ganometallics 1992, 11, 761–777.
[20] K. Hiraki, Y. Kinoshita, J. Kinoshita-Kawashima, H. Kawano,
J. Chem. Soc., Dalton Trans. 1996, 291–298.
Published Online: February 8, 2012
Eur. J. Inorg. Chem. 2012, 1210–1217
© 2012 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.eurjic.org
1217