Magneto-structural versatility of copper(ii)-3-phenylpropionate coordination polymers with N-donor coligands

Article abstract of DOI:10.1039/c5dt03401a

A novel series of copper(ii) coordination polymers [Cu₂(O₂CC₈H₉)₄(pyz)]_n (1), [Cu₂(O₂CC₈H₉)₄(dps)]_n (2), {[Cu(O₂

Full text of DOI:10.1039/c5dt03401a

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Lloret, M. Julve, J. Cano and M. V. Marinho, Dalton Trans., 2015, DOI: 10.1039/C5DT03401A.
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Graphical abstract
From copper(II) and the conformational flexible 3-phenylpropionate anion a series of
paddle-wheel and other SBU (secondary building units) coordination polymers can be
originated with rigid and flexible N-donor ligands. Magneto-structural correlations are
exploited in five new compounds.

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Ligand effects on the structural and magnetic versatility in a new
family of oneꢀdimensional copper(II)ꢀ3ꢀphenylpropionate coordination
polymers with Nꢀdonor aromatic bridging ligands
a
b
c
c
Nathália R. de Campos, Marcos A. Ribeiro, Willian X. C. Oliveira, Daniella O. Reis,
,c
a
d
Humberto O. Stumpf,* Antônio C. Doriguetto, Flávia C. Machado, Carlos B.
e
f
f
f,g
,a
Pinheiro, Francesc Lloret, Miguel Julve, Joan Cano, and Maria V. Marinho*
a
Instituto de Química, Universidade Federal de Alfenas, Campus Sede, Alfenas, MG
37130ꢀ000, Brazil. Eꢀmail: mvmarinho09@gmail.com
b
Instituto de Química, Universidade Estadual de Campinas, Laboratório de Química de
Coordenação, SP 13083ꢀ970, Brazil
c
Departamento de Química – ICEx, Universidade Federal de Minas Gerais, Campus
Pampulha, Belo Horizonte, MG 31270ꢀ901, Brazil. Eꢀmail: stumpf@ufmg.br
d
Departamento de Química – ICE, Universidade Federal de Juiz de Fora, Campus
Universitário s/n, Martelos, Juiz de Fora, MG 36036ꢀ330, Brazil
e
Departamento de Física, Universidade Federal de Minas Gerais, Av Antônio Carlos,
6627, 31270ꢀ901, Belo Horizonte, MG, Brazil
f
Instituto de Ciencia Molecular – Departament de Química Inorgànica, Universitat de
València, C/ Catedrático José Beltrán 2, 46980 Paterna, València, Spain
g
Fundació General de la Universitat de València (FGUV), Universitat de València,
46010 València, Spain
†
Electronic supplementary informaꢀon (ESI) available: Experimental and calculated powder X-ray
diffraction (PXRD) patterns for 1-5, TG and DTA plots for 1-5 , crystallographic drawings of the structures
of 1-5, and theoretical calculations data for 5. CCDC 1409932 (1), 1409933 (2), 1409934 (3), 1409935 (4),
and 1409936 (5). For ESI and crystallographic data in CIF or other electronic format see DOI:
1
0.1039/x0xx00000x
1

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Abstract
A novel series of copper(II) coordination polymers of [Cu
2
(O
2
CC
8
H
9
)
4
(pyz)]
n
(1),
(3),
[
Cu
2
(O
2
CC
8
H
9
)
4
(dps)]
n
(2),
{[Cu(O
2
CC
8
H
9
)
2
(dps)(H O)]·H
2
2
O}
n
{
[NaCu(O CC H ) (bpm)(NO )]·H O} (4), and [Cu (O CC H ) (OH) (bpp) ] (5)
2 8 9 2 3 2 n 4 2 8 9 6 2 2 n
ꢀ
[
O
2
CC
8 9
H = 3ꢀphenylpropionate anion, pyz = pyrazine, dps = di(4ꢀpyridyl)sulfide, bpm
=
2,2’ꢀbipyrimidine, and bpp = 1,3ꢀbis(4ꢀpyridyl)propane] have been synthesized and
magnetoꢀstructurally investigated. Compounds 1 and 2 belong to a large group of
copper(II) carboxylates where bisꢀmonodentate pyz (1) and dps (2) ligands connect the
II
2
paddleꢀwheel [Cu
(ꢀꢀO
2
CC
8
H
9
)
4
] units leading to alternating copper(II) chains. The
II
structure of 3 consists of uniform chains of transꢀ[Cu (O
2
CC
8
H
9
2
) ] units linked by the
bisꢀmonodentate dps ligand. Compound 4 consists of heterobimetallic chains where
I
2
II
2
[
Na
Cu
2 8 9 4 3 2
(ꢀꢀO CC H ) (NO ) ] units are doubly bridged by bisꢀbidentate bpm ligands.
Compound 5 is also a chain compound whose structure is made up by tetranuclear
II
4
[
Cu
(ꢀ
3
ꢀOH)
2
2 8 9 4 2 8 9 2
(ꢀꢀO CC H ) (O CC H ) ] units which are doubly bridged by bisꢀ
monodenate bpp ligands. The magnetic properties were investigated in the temperature
range 1.8–300 K. Strong antiferromagnetic interactions across the quadruple synꢀsyn
ꢀ1
carboxylate are observed in 1 and 2 [J = –378 (1) and –348 cm (2)] whereas a weak
ferromagnetic coupling through the double outꢀofꢀplane oxo(carboxylate) bridge occurs
–1
in 4 [J = +2.66 cm ], the spin Hamiltonian being defined as H = –J S
1
· S
2 1 2
with S = S
ꢀ1
=
SCu = ½. A quasi Curie law is observed for 3 (θ = ꢀ0.36 cm ), the bisꢀmonodentate
dps ligand being a very poor mediator of magnetic interactions. The analysis of the
magnetic properties of 5 is quite complex because of the presence of two
crystallographically independent tetracopper(II) units with singleꢀꢀꢀhydroxo, diꢀꢀꢀ
hydroxo, ꢀ
each one. The nature and values of the magnetic couplings for 5 obtained by fit
intermediate, strong and weak antiferromagnetic interactions for the three former
3
ꢀhydroxo and singleꢀꢀꢀhydroxo plus double syn,syn carboxylate bridges in
(
exchange pathways respectively, and intermediate ferromagnetic interactions for the
latter one) were substantiated by DFT type calculations.
2

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Introduction
The chemistry of copper(II)ꢀcarboxylate systems has been thoroughly
1
investigated since the early 1970s due to their diverse structural and specific
2
,3
properties. Their use as building blocks, specially those containing dicopper(II) units
4
in the field of molecular magnetism, has been highly rewarding. The search for new
carboxylateꢀcontaining oligonuclear copper(II) compounds, from diꢀ to triꢀ and
tetranuclear complexes, which are able to act as secondary building units (SBUs) for the
construction of metalꢀorganic frameworks (MOFs) is still a challenge field for synthetic
5
chemists envisaging the preparation of multifunctional magnetic materials.
The carboxylate group can adopt different coordination modes in its metal
2a,4,6
complexes, as illustrated in Chart 1.
Among them, the syn,syn one has afforded a
very large family of paddle wheelꢀtype dinuclear complexes whose core consists of
6
gꢀh
tetrakis(ꢀꢀcarboxylatoꢀ
κO:
κO’)dicopper(II) units.
In contrast, the carboxylate
complexes where the carboxylate adopts the bisꢀmonodentate bridging mode are less
2
a
common. The diversity of bridging modes of the carboxylate accounts for the different
6b,7
magnetic properties exhibited by its metal complexes.
Although the copper(II)
paddleꢀwheel complexes have been investigated for a long time, the first chain
compound interlinking the paddleꢀwheel structure through bisꢀmonodenate pyrazine
8
9
(
pyz) was described in 1974 and its crystalline structure reported in 2006. This chain
of formula [Cu (pyz)(O CCH exhibits a strong antiferromagnetic coupling between
2
2
3 4 n
) ]
ꢀ1
the copper(II) ions through the syn,synꢀcarboxylate bridges (J ca. ꢀ345 cm , the spin
Hamiltonian being defined as H = –J S ·S ). This example shows that the combination
1
2
of metal carboxylates and other coligands, either bridging or terminal, offers a
straightforward preparative route to build novel MOFs.
3

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Chart 1 Coordination modes exhibited by the carboxylate ligand.
Aiming at extending the magnetoꢀstructural studies on carboxylateꢀcontaining
copper(II) coordination polymers, we have chosen the 3ꢀphenylpropionate anion also
ꢀ
ꢀ
8 9 2
known as hydrocinnamic acid (C H CO hereafter noted Phpr ). This choice is based on
its conformational flexibility which would allow the formation of paddleꢀwheel and
other SBU structural motifs for the obtention of both homoꢀ and heterometallic chains.
Surprisingly, this carboxylate ligand has attracted little attention in the field of
coordination chemistry, as indicated by the small number of structural reports of its
10
metal complexes. In this work, we have explored the possibility to interlink the
ꢀphenylpropionateꢀbased SBUs of copper(II) through rigid and flexible nitrogen
donors such as pyrazine (pyz), di(4ꢀpyridyl)sulfide (dps), 2,2’ꢀbipyrimidine (bpm), and
3
1,3ꢀbis(4ꢀpyridyl)propane (bpp).
We report herein the synthesis, thermal behavior, crystal structures and variableꢀ
temperature magnetic properties of five copper(II) coordination polymers of formula
[
Cu
2
(O
2
CC
8
H
9
)
4
(pyz)]
n
(1),
[Cu
2
(O
2 8
CC H
9
)
4
(dps)]
n
(2),
4

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{
[Cu(O CC H ) (dps)(H O)]·H O} (3), {[NaCu(O CC H ) (bpm)(NO )]·H O} (4),
2 8 9 2 2 2 n 2 8 9 2 3 2 n
and [Cu (O CC H ) (OH) (bpp) ] (5).
4
2
8
9 6
2
2 n
Experimental
Materials. Copper(II) nitrate trihydrate, 3ꢀphenylpropionic acid, 2,2’ꢀbipyrimidine
bpm), 1,3ꢀbis(4ꢀpyridyl)propane and N,Nꢀdimethylformamide were purchased from
commercial sources and used as received. Di(4ꢀpyridyl)sulfide was prepared according
(
11
to a previously reported procedure. The sodium(I) salt of the 3ꢀphenylpropionic acid
of formula NaPhpr·6H O was synthesized as follows: stoichiometric amounts of sodium
2
hydroxide and the carboxylic acid solid were allowed to react in aqueous solution;
solvent removal of the resulting clear solution in a rotary evaporator afforded the
desired salt as a white solid which was filtered, washed with acetone and vacuum dried.
Preparation of Complexes. [Cu (O CC H ) (pyz)] (1). A dmf solution (3 mL) of pyz
2
2
8
9 4
n
(33 mg, 0.41 mmol) was poured into another dmf solution (4 mL) of Cu(NO
3 2 2
) ꢁ3H O
(100 mg, 0.41 mmol). A color change from the initial blue of the copper(II) solution to
green was observed which is indicative of complex formation. Then, a dmf:water (7:2
v/v) mixture (9 mL) containing NaPhprꢁ6H O (144 mg, 0.51 mmol) was slowly added.
2
The resulting solution was set aside by one day. The small amount of a blue solid,
which was not characterized, was filtered off and discarded. Several hours later, Xꢀray
suitable green square crystals of 1 were grown in the filtered solution. They were
collected, washed with cold water and dried at atmosphere for one day. Yield: 50 %.
o
M.p.: 190 C (dec). Anal. Calcd for C20
H20CuNO
4
(1): C, 59.77; H, 5.02; N, 6.48.
ꢀ1
Found: C, 57.83; H, 4.77; N, 6.25 %. IR (KBr/cm ): 3085 (νCH), 3064 (νCH), 3026
5

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(
ν
,
CH), 2954 (νCH), 2935 (νCH), 1613 (νCC/CN) 1604 (νasCOOꢀ), 1409 (νsCOOꢀ), 1320 (δδCH),
1307 (δCH), and 763 (δCꢀH outꢀofꢀplane).
[
Cu
mL of a dmf:water (10:2 v/v) mixture was added to a dmf solution (6 mL) of
Cu(NO ꢁ3H O (200 mg, 0.82 mmol). Slow diffusion of dps ligand (154 mg, 0.82
2 2 8 9 4 n 2
(O CC H ) (dps)] (2). NaPhpr·6H O (286 mg, 1.02 mmol) dissolved in 12
3
)
2
2
mmol) dissolved in 6 mL of dmf was carried out and the whole was allowed to stand at
room temperature. A small amount of a blue solid was also observed which was filtered
off and the motherꢀliquor was set aside. Green parallelepipeds suitable for Xꢀray
diffraction were grown after two days. They were collected by filtration, washed with a
o
small amount of cold water and dried in the open air. Yield: 34 %. M.p.: 200 C (dec).
Anal. Calcd for C H N Cu SO (2): C, 60.52; H, 4.82; N, 3.07; S, 3.50. Found: C,
46
44
2
2
8
ꢀ
1
6
2
7
, ,
0.34; H, 4.66; N, 2.94; S, 3.42 %. IR (KBr/cm ): 3088 (νCH) 3052 (νCH), 3021 (νCH)
958 (ν ), 2931 (ν ), 1619 (νCC/CN), 1608 (νasCOOꢀ), 1411 (νsCOOꢀ), and
CH
CH
17 (δCꢀH outꢀofꢀplane).
{[Cu(O
2
CC
8
H
9
)
2
2 2 n
(dps)(H O)]·H O} (3). Blue needles of 3 are formed in the dmf
solutions of 2 which were allowed to stand at room temperature for ten days.
o
Yield: 50 %. M.p.: 100 C (dec). Anal. Calcd for C28
H
33
N
2
CuSO
6
(3): C, 57.62; H, 4.63;
ꢀ1
N, 4.80; S, 5.48. Found: C, 58.15; H, 4.72; N, 4.79 %; S, 5.32. IR (KBr/cm ): 3344
(
(
ν
ν
OH), 3283 (νOH), 3095 (νCH), 3034 (νCH), 2967 (νCH), 2918 (νCH), 1618 (νasCOOꢀ), 1590
CC/CN , .
) 1403 (νsCOOꢀ), 1059 (δCꢀH inꢀplane), 876(δCH), and 700 (δCꢀH outꢀofꢀplane)
2 8 9 2 3 2 n
{[NaCu(O CC H ) (bpm)(NO )]·H O} (4). 4 was synthesized similarly to the
above complexes by using bpm (131 mg, 0.82 mmol) as nitrogen donor. Xꢀray suitable
blue needles of 4 were grown from the solution placed in a refrigerator at 7 ºC after
o
seven days. Yield: 40 %. Mp: 100 C (dec). Anal. Calcd for C26
26
H N
5
CuNaO
8
(4):
C, 50.12; H, 4.21; N, 11.24 %. Found: C, 50.19; H, 3.83 and N, 10.37 %.
6

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ꢀ1
IR (KBr/cm ): 3463 (νOH), 3082 (νCH), 3032 (νCH), 2953 (νCH), 2909 (νCH), 1626
(
ν
,
asCOOꢀ), 1605 (νasCOOꢀ), 1404 (νsCOOꢀ), 1323 (νsCOOꢀ), 1580, 1565 (νCC/CN) 1385 (νNO3),
1314(νNO3), 831(νNO3), 756 (δCꢀH outꢀofꢀplane), and 692 (δCꢀH outꢀofꢀplane).
4 6 2 2 n
[Cu (Phpr) (OH) (bpp) ] (5). This compound was prepared by following an
analogous procedure to that employed for 2 but replacing dps by bpp (162 mg, 0.82
mmol). Blue squares of 5 were obtained from the mother liquor on standing at room
o
temperature after ten days. Yield: 70 %. M.p.: 140 C (dec). Anal. Calcd for
80 84 4 4
C H N Cu O14 (5): C, 63.42; H, 5.54; N, 3.70. Found: C, 63.20; H, 5.48; N, 3.62 %.
ꢀ1
IR (KBr, cm ): 3443 (νOH), 3083 (νCH), 3060 (νCH), 3025 (νCH), 2926 (νCH), 1597
(νasCOOꢀ), 1391 (νsCOOꢀ), 1322 (νsCOOꢀ), 753 (δCꢀH outꢀofꢀplane), and 700 (δCꢀH outꢀofꢀplane).
Physical Measurements. Elemental analyses (C, H, N and S) were carried out on a
PerkinꢀElmer 2400 analyzer. Thermogravimetry (TG) and differential thermal analysis
(DTA) were performed obtained simultaneously with the same modulus employing a
thermobalance (model SDT Q600, TA Instruments, USA) in the temperature range 25ꢀ
1000 °C, using alumina crucibles containing samples of approximately 3 mg under a
ꢀ1
ꢀ1
2
flow of N (100 mL min ) at a heating rate of 10 °C min . The TG/DTA equipment
was calibrated using an indium standard for temperature and an alumina calibration
weight for mass. IR spectra were recorded on a Nicolet Impact 400 spectrometer using
ꢀ1
KBr pellets in the wavenumber range of 4000ꢀ400 cm with an average of 128 scans
ꢀ1
and 4 cm of spectral resolution. Powder diffraction data were obtained in a powder Xꢀ
ray diffractometer (model Ultima IV, Rigaku, Japan) using a CuKα tube (λ = 1.5418 Å)
at a voltage of 40 kV and a current of 30 mA in the 2θ range 5ꢀ55º. Magnetic
susceptibility measurements were carried out on polycrystalline samples of 1ꢀ5 with a
Quantum Design SQUID magnetometer in the temperature range 1.9ꢀ295 K under
applied dc fields of 1 T (T ≥ 100 K) and 250 G (T < 100 K). The experimental magnetic
7

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susceptibility data were corrected for diamagnetic contributions of the constituent atoms
and the sample holder (a plastic bag), as well as for the temperatureꢀindependent
ꢀ6
3
ꢀ1
paramagnetism (TIP) of the copper(II) ion (60 x 10 cm mol ).
Computational Details. DFT calculations were performed on the two partially
optimized geometries of the centrosymmetric and nonꢀcentrosymmetric tetracopper(II)
fragments of compound 5 (see top and bottom drawings in Figure 7 and Tables S1 and
12
S2†) through the Gaussian 09 package using the B3LYP functional, the quadratic
convergence approach and a guess function generated with the fragment tool of the
1
3
same program. Tripleꢀζ and doubleꢀζ all electron basis sets proposed by Ahlrichs et al.
14,15
are employed for the metal and for the rest, respectively.
The position of the
hydrogen atoms from ꢀOH groups were optimized due to their positions cannot be
ꢀ
3
determined by Xꢀray crystallography. As it has been previously reported, the positions
of these hydrogen atoms have an important influence on the magnitude of the magnetic
coupling because they are directly linked to monoatomic bridges. However, the
optimization of the position is not problematic because the coordination of the hydroxo
group to three atoms and the possible presence of an hydrogen bond with a near
1
6
carboxylate group constrain the possible conformation of the hydroxo groups. The
magnetic coupling states were obtained from the relative energies of the several brokenꢀ
symmetry (BS) spin states from the highꢀspin state with parallel local spin moments. To
check our results seven BS spin configuration were calculated that, for the considered
different magnetic couplings, are more than the needed to evaluate the J constants. So,
i
the calculated BS spin configurations and how their energies are related to the J
i
magnetic coupling constants are shown in the Table S3†. Due to two occurrence of two
tetracopper(II) units showing different geometries in the crystal structure of 5, we have
investigated each of them separately. To stabilize the surplus of the electronic density
8

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on the charged external ligand, solvent effects were introduced from a polarized
continuum model (PCM) with the parameters corresponding to the acetonitrile solvent
16,17
that, to some extent, simulate the effect of the surrounding in the solid sate.
More
details about the use of the brokenꢀsymmetry approach to evaluate the magnetic
18a,19,20, 21
coupling constants can be found in the literature.
Xꢀray Data Collection and Structure Refinement. Xꢀray diffraction data
collections for 1ꢀ4 were performed with an OxfordꢀDiffraction GEMINIꢀUltra
diffractometer − LabCri, Universidade Federal de Minas Gerais − using Enhance Source
MoꢀKα radiation (λ = 0.71073 Å) for (1ꢀ3) and CuꢀKα radiation (λ = 1.5418 Å) for 4.
Xꢀray diffraction data collection for 5 was performed on Bruker D8 Venture Photon 100
diffractometer − Departamento de Química, Universidade Federal do Paraná − using
graphite monochromator and MoꢀKα radiation (λ = 0.71073 Å). The values of the
temperature for the data collection were 120 (1), 270 (2), 250 (3), 293 (4), and 100 K
(
5). Data integration and scaling of the reflections for compounds 1ꢀ4 were performed
22
with the CRYSALIS suite. Final unit cell parameters were based on the fitting of all
reflections positions. Analytical absorption corrections were performed using
2
2
23
CRYSALIS suite and the space group identification was done with XPREP. Data
24
integration and reduction for compound 5 were performed using SAINT. Data were
25
corrected for absorption effects with SADABS using the multi scan technique. The
XPREP was also used in the unit cell determination. The structures of compounds 1ꢀ5
2
6
were solved by direct methods using the SUPERFLIP program. The positions of all
atoms for each compound could be unambiguously assigned on consecutive difference
2
7
2
Fourier maps. Refinements were performed using SHELXL based on F through fullꢀ
matrix leastꢀsquares routine. All nonꢀhydrogen atoms and disordered water molecules in
9

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3
1
were refined with anisotropic atomic displacement parameters. All hydrogen atoms of
ꢀ5 (except those of the disordered water molecules in 3 which neither found nor
geometrically positioned) were located in difference maps and included as fixed
28
contributions according to the riding model. The fixed parameters for the hydrogen
atoms were O−H = 0.90 Å and Uiso(H) = 1.5 Ueq(O) for the water molecules, C−H =
0
.97 Å and Uiso(H) = 1.2 Ueq(C) for the aromatic groups, C−H = 0.93 Å and Uiso(H) =
.2 Ueq(C) the methylene groups and O−H = 0.93 Å and Uiso(H) = 1.2 Ueq(O) for the
1
hydroxo ligands. A two rigid position model for all atoms, but the carboxylate group,
was used to treat the disordered Phpr groups around Cu1 atom in 2 observed during the
refinement process. The analysis of the structure of 4 indicated that components of the
oxygen atoms ADP’s along the directions of the Cu–O3 and Cu–O1 bonds are not equal
29
in magnitude. Similar results have already been reported elsewhere for complexes
3
0
with the copper(II) ion in a square pyramidal environment. In those cases, the metal
ion has more freedom along the apical direction, since there is no coordinated atom
above the basal plane, leading to ADP’s for the metal atoms bigger than those of its
ligand atoms. Finally, during the refinement of 2 and 3 some reflections were omitted
from data [1 0 1 and 0 ꢀ1 1 (2) and ꢀ4 0 14 (3)] and they were not used in the final cycle
of refinement because their intensities were significantly affected by the beam stop. The
3
1
final geometric calculations were carried out with PLATON whereas the graphical
32
33
manipulations were performed with the Mercury and ORTEP programs. A summary
of the crystal data and refinement conditions for 1ꢀ5 is given in Table 1 whereas
selected bond lengths and angles for 1ꢀ5 are grouped in Table 2. The Mercury software
was also used to calculate the Xꢀray powder diffraction patterns from both the unit cell
parameters and the atomic positions obtained from the single crystal structure analysis.
The Xꢀray diffraction patterns calculated from low temperature crystal structures (1 and
1
0

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5
) are, as expected, slightly shifted (right direction) from the experimental ones
performed at room temperature (298 K). Anyway, the experimental and calculated
powder Xꢀray diffraction (PXRD) patterns (see Figures S1ꢀS5†) regarding all five
complexes, show a great coincidence of the position of all peaks expected, each pattern
confirming that the obtained structure from the single crystal is equal to the one of the
bulk.
1
1

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Table 1. Crystallographic Data for compounds 1ꢀ5
Complexes
1
2
3
4
5
Formula
C
46
H
44
N
2
O
8
SCu
2
C
28
H
27
N
2
O
6
SCu
C
26
H
24
N
4
NaO
8
Cu
C120H126N O Cu
6
6
21
20 4
C H20NO Cu
3
0
.63 × 0.24 × 0.14
0.47 × 0.16 × 0.04
583.11
0.18 × 0.12 × 0.05
0.29 × 0.24 × 0.17
2369.50
Crystal size/ mm
0
.42 × 0.30 × 0.23
01.91
Fw
911.97
621.03
Triclinic
P
4
Crystal system
Monoclinic
Triclinic
Monoclinic
Monoclinic
Space group
P
Ia/2
P2 /n
1
C2/c
a/ Å
9.8067 (4)
23.9841(6)
13.3056 (15)
1
7.8636 (3)
.9173 (2)
10.024 (5)
10.824 (5)
b/ Å
11.9518 (5)
19.7047 (7)
83.844 (3)
5.88306 (13)
41.7264(13)
18.004 (2)
47.337 (5)
7
c/ Å
2
5.9511(6)
12.846 (5)
97.185 (5)
90.782 (5)
104.175 (5)
o
α/
90.00
90.00
9
9
9
0.00
7
9.762 (3)
9.662 (4)
106.501 (3)
90.00
96.278 (4)
90.00
β
/°
3.810 (2)
0.00
o
6
γ/
3
V / Å
2128.48 (14)
2
5645.1 (3)
8
1339.3 (10)
2
11272 (2)
4
3
662.19 (14)
Z
8
0.71073
1.423
270
1.54180
1.372
250
0.71073
1.545
293
0.71073
1.396
100
λ/Å
0.71073
1.458
ꢀ
3
ρ/ Mg m
T/K
120(2)
1
2

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Page 14 of 51
5
1
8
1
82
344
371
1387
No. parameters
235
9202
699
.03
19345
4922
1.05
41602
106707
reflns collected
22972
3535
23164
reflections with I > 2σ(I)
4082
2
1.05
1.06
Goodnessꢀofꢀfit on F
1.09
a
b
0.0374, 0.0883
0.0743, 0.2203
0.0818, 0.2323
1.08, ꢀ 0.79
0.0541, 0.1319
0.0816, 0.1519
0.44, ꢀ 0.75
0.0615, 0.1522
0.0865, 0.1654
2.31, ꢀ 0.94
R , wR [I > 2σ(I)]
0.0233, 0.0544
0.0251, 0.0554
0.27, ꢀ 0.32
a
b
0
.0536, 0.0977
.34, ꢀ 0.44
R , wR (all data)
ꢀ
3
0
Largest diffraction peak and hole/e A
a
b
2
2
2
2
1/2
2
2
o
2
2
2
2
2
o
2
R = ∑||F
o
| –|F
c
||/∑|F
o
|. wR = [∑(|F
o
| –|F
(2),
=
c
| ) /∑|F
o
| ] with w =1/[σ (F
) + (0.0159P) + 5.1699P] and P = (F
o
+ 2F
c
)/3 (1), w = 1/[σ (F
) +(0.045P) +
2
2
o
2
0
.6556P]
and
w
=
1/[σ (F
)
+
(0.1576P)
+
14.3824P]
4.4961P]
30.5795P]
2
2
o
2
(
(
3),
4),
w
1/[σ (F
)
+
(0.046P)
+
+
2
2
o
2
w
=
1/[σ (F
)
+
(0.0729P)
2
o
2
c
(5) and P = (F
+ 2F
)/3 (1ꢀ5).
1
3

Page 15 of 51
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DOI: 10.1039/C5DT03401A
Table 2. Selected interatomic bond lengths (Å) and angles (deg) for 1ꢀ5*
1
Cu1—O2
Cu1—O1
Cu1—O3
Cu1—O4
1.9596(10)
1.9616(10)
1.9644(10)
1.9718 (10)
O2—Cu1—O1
O2—Cu1—O3
O1—Cu1—O3
O2—Cu1—O4
88.67(5)
88.99 (5)
169.33 (4)
1
69.27 (4)
Cu1—N1
Cu1—Cu1
O1—C3
2.2133 (11)
2.6052 (3)
1.2649 (17)
O1—Cu1—N1
O2—Cu1—N1
94.28 (4)
i
101.81 (4)
125.82 (13)
i
O3 —C3—O1
*
Symmetry code: (i) = −x+1/2, −y+3/2, −z+2.
2
Cu1—O6
Cu1—O8
Cu1—O5
Cu1—O7
1.9624(16)
1.9521 (17)
1.9669 (19)
1.9771 (19)
O8—Cu1—O6
O5—Cu1—O7
O8—Cu1—O5
168.46 (7)
168.52 (7)
90.14 (10)
O6—Cu1—O7
90.65 (9)
Cu1—N2
2.1700(19)
2.6236 (5)
1.255 (3)
O8—Cu1—N2
O6—Cu1—N2
101.21 (7)
90.31 (7)
89.28 (9)
i
Cu1—Cu1
ii
ii
O1—C10
O4 —Cu2—O2
Cu2—O1
Cu2—O2
Cu2—O3
Cu2—O4
Cu2—N1
Cu2—Cu2
Cu1—Cu2
Cu2—Cu2
Cu1—Cu2
1.973 (2)
O1—Cu2—O2
O2—Cu2—O3
O1—Cu2—O4
O3—Cu2—O4
O1—Cu2—N1
O2—Cu2—N1
O3—Cu2—N1
O4—Cu2—N1
O1—Cu2—N1
88.92 (8)
89.38 (8)
89.28 (9)
90.20 (8)
94.52 (8)
96.97 (7)
96.88 (8)
94.20 (7)
94.52 (8)
1.9746 (17)
1.9762 (19)
1.9768 (17)
2.175 (2)
ii
2.6204 (6)
10.2571(7)
7.7388(5)
9.8067(6)
iii
iv
*
Symmetry code: (i) = −x y z x y z+1; (iii) = 1-x, 1-y, 1-z; (iv) = x, -1+y, z.
+2, − , − ; (ii) = − +2, − +1, −
1
4

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3
Cu1—O1
Cu1—N1
Cu2—O3
Cu2—O5
Cu2—N2
O1—C11
N1—C1
1.949 (3)
2.032 (4)
1.9766 (19)
2.221 (4)
2.034 (3)
1.240 (7)
1.279 (8)
O2—Cu2—N1
96.95 (7)
96.86 (8)
O3—Cu2—N2
O4—Cu2—N2
N1—Cu1—N1
94.19 (7)
ii
i
180.00 (17)
C8—S1—C3
O3—Cu2—O3
O3—Cu2—N2
O3—Cu2—O5
103.6 (2)
178.85 (17)
89.28 (12)
90.58 (8)
N2—Cu2—O5
93.69 (9)
i
N2 —Cu2—N2
172.63 (18)
*Symmetry code: (i) = −x+1, y, −z+1/2; (ii) = −x+1/2, −y−1/2, −z.
4
i
Cu1—O1
Cu1—O3
Cu1—N3
Cu1—N1
Na1—O2
Na1—O4
Na1—O6
Na1—O5
Na1—N2
Na1—N4
O3—C9
1.928 (2)
1.972 (2)
2.024 (3)
2.033 (3)
2.267 (3)
2.269 (3)
2.416 (3)
2.471 (3)
2.479 (3)
2.544 (3)
1.294 (4)
O1—Cu1—O3
92.30 (10)
172.13 (11)
93.67 (11)
172.13 (11)
80.67 (11)
78.08 (10)
88.98 (11)
140.85 (11)
144.31 (12)
140.85 (11)
66.17 (10)
O1—Cu1—N3
i
O3 —Cu1—N3
i
O3 —Cu1—N1
i
N3—Cu1—N1
i
O3 —Cu1—O3
i
O2 —Na1—O4
O4—Na1—O6
ii
ii
i
O2 —Na1—O5
O4—Na1—O6
ii
ii
N2 —Na1—N4
*
Symmetry code: (i) = −x+1, −y, −z; (ii) = x+1, y, z.
5
Cu1—N1
Cu1—O1
Cu1—O3
1.993 (3)
1.948 (3)
2.260 (2)
1.947 (3)
1.982 (3)
1.984 (3)
2.264 (3)
Cu2ꢀOH1ꢀCu1
111.03(12)
99.04 (11)
117.20 (13)
111.46(13)
116.85 (13)
98.37 (12)
98.90 (12)
i
Cu1ꢀOH1ꢀCu1
i
Cu2ꢀOH1ꢀCu1
Cu1—OH1
Cu1—OH1
Cu2—N3
Cu2—O2
Cu3ꢀOH3ꢀCu4
Cu3ꢀOH3ꢀCu5
Cu4ꢀOH3ꢀCu5
Cu4ꢀOH2ꢀCu5
i
1
5

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Cu2—O4
Cu2—O6
Cu2—OH1
Cu3—N2
Cu3—O7
Cu3—O9
1.978 (3)
1.975 (3)
1.939 (3)
1.998 (3)
1.977 (3)
2.241 (3)
Cu5ꢀOH2ꢀCu6
Cu6ꢀOH2ꢀCu4
111.03(13)
116.45 (14)
Cu3—O11
Cu3—OH3
Cu4—N5
1.974 (3)
1.940 (3)
2.006 (3)
1.945 (3)
2.178 (2)
1.985 (3)
1.972 (3)
2.002 (3)
1.921 (3)
2.201 (3)
1.959 (3)
1.987 (3)
2.002 (3)
2.269 (3)
1.974 (3)
Cu4—O10
Cu4—O12
Cu4—OH2
Cu4—OH3
Cu5—N4
Cu5—O13
Cu5—O15
Cu5—OH2
Cu5—OH3
Cu6—N6
Cu6—O14
Cu6—O16
*
Symmetry code: (i) = −x+1, −y+2, −z.
Results and Discussion
Synthesis and IR Spectroscopy
Compounds 1ꢀ5 were synthesized as illustrated in Scheme 1. All of them have been
obtained by diffusion in a testꢀshaped glass tube (1.5 cm inner diameter and 18 cm
height). A unique rupture of the original lantern structure was observed when 2 was
transformed into 3. In fact, the literature describes a lantern breakdown by addition of
2 2 2 4 3 4 2 n
the flexible nitrogen ligand in {[Cu (O CCH C H S) (bpp) ]} (bpp = 1,3ꢀbis(4ꢀ
1
6

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2
a
pyridyl)propane). In this work, the irreversible transformation of 2 into 3 was
attributed to the instability of the paddleꢀwheel unit in dmf as solvent, leading to only
one of the forms after ten days in solution at room temperature.
We have used the same solvent, room temperature and molar ratio of the reactants
for all complexes, except for 4 where the temperature of crystallization was adjusted. In
this case, it is worth noting that the temperature of the crystallization and the bpm
ligand were crucial in 4 since the solvent and the ratio of the 3ꢀphenylpropionate anion
with copper(II) ions were similar to those of the other four complexes. Recently, the
literature reported the preparation of related heterobimetallic sodium(I)/cobalt(II)ꢀ
formate coordination polymers by adjusting the solvent and ratio of the reactants via
3
4
solvothermal synthesis.
The most relevant aspect for the IR spectra of 1ꢀ5 concerns the values of
asymmetric and symmetric stretching frequencies of the carboxylate groups of the
phenylpropionate ligand (see Figure S6). The frequency difference (∆) between
ν
asym(COO) and
ν
sym(COO) stretches in the carboxylateꢀcontaining complexes in
comparison to the corresponding values in ionic species is currently taken as diagnostic
2
a,35
ꢀ
ꢀ
of the coordination mode of the carboxylate group.
The νasym(COO ) and νsym(COO )
ꢀ1
vibrations of the 3ꢀphenylpropionate for 1 and 2 occur at 1604 and 1409 cm (∆ = 195
ꢀ1
ꢀ1
ꢀ1
cm , 1) and 1608 and 1411 cm (∆ = 197 cm , 2) whereas those of the sodium salt of
ꢀ1
ꢀ1
the 3ꢀphenylproprionate are 1551 and 1350 cm (∆ = 201 cm ). These results indicate
that the carboxylate groups in 1 and 2 coordinate to the copper(II) ions in a
ꢀ1
symmetrically synꢀsyn bridging mode. ∆ for 3 is equal to 215 cm , a value which
suggests a monodentate coordination of the carboxylate for this compound. The
ꢀ
ꢀ1
ꢀ1
occurrence of two (4)/one (5) νasym(COO ) [1626 and 1605 cm (4) and 1597 cm (5)]
ꢀ
ꢀ1
ꢀ1
and two (4/5) νsym(COO ) [1404 and 1323 cm (4) and 1391 and 1322 cm (5)] point
1
7

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out the presence of two different coordination modes of the carboxylate groups in 4 and
. About the ν(CC/CN) stretching frequencies of the pyz, dps, bpm and bpp the
infrared spectra show peaks at 1623 (1), 1619 (2), 1590 (3), 1580, 1565 (4), and 1603
5
ꢀ1
cm (5). These values are consistent with their coordination to copper(II) as bridges via
2
a,11,36
ꢀ1
the pyridylꢀnitrogen atoms.
Finally, peaks at 1385 and 831 cm in the spectrum of
37
4
are due to the presence of the nitrate ion. All these spectroscopic features for 1ꢀ5
have been confirmed by their Xꢀray structures (see below).
Scheme 1. General synthetic route to 3ꢀphenylpropionateꢀcontaining copper(II)
coordination polymers using the pyz (1), dps (2 and 3), bpm (4) and bpp (5) Nꢀdonors as
spacers.
Thermal Study. Thermogravimetric curves of 1–5 are shown in Figure S7A†
.
The TG
o
curves of compounds 1 and 2 reveal that they are stable up to 155 and 196 C
respectively, in agreement with the absence of solvent molecules in their structures.
o
Two steps of weight loss in the temperature ranges 155ꢀ215 and 245ꢀ325 C occur in 1.
The first one corresponds to the release of one pyrazine molecule (obsd. 10.2%; calcd.
10.0%) whereas the second one is attributed to the decomposition of the 3ꢀ
1
8

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o
phenylpropionate ligands. The remaining mass at 355 C, agrees with a mixture of CuO
o
and CuCO that slowly decomposes releasing CO and affording a residue at 700 C,
3
2
2
a
mass that would correspond to CuO (obsd. 19.5%, calcd. 19.8%). For the compound
o
2
, the first weight loss occurs abruptly in the temperature range 200ꢀ350 C and it would
correspond to the decomposition of the di(4ꢀpyridyl)sulfide and 3ꢀphenylpropionate
o
ligands (obsd. 73.6 %, calcd. 72.9 %). The residue at 355 C which is identified as
CuCO (obsd. 26.2 %, calcd. 27.1 %) undergoes a slow decomposition by releasing CO
3
2
o
at higher temperatures and it transforms into CuO at 800 C (obsd: 18.3 %, calcd. 17.5
o
%
). The TG curve for 3 shows a first weight loss in the temperature range 78ꢀ107 C
corresponding to two water molecules (obsd: 6.2 %, calcd. 6.17 %). Afterwards, the
decomposition of the organic moiety takes place in more than one step, which are
o
difficult to identify. The final residue at 800 C (ca. 18.7 %) would be CuO (13.6 %)
associated with some carbonized material. In the case of 4, the TG curve presents a
o
gentle decline up to 200 C, corresponding to the release of one water molecule (obsd
3.1 %, calcd. 2.9 %). Afterwards, the decomposition occurs in at least four steps and at
o
8
00 C the residue is consistent with CuO + ½ Na O (obsd. 17.8 %, calcd. 17.8 %). The
2
TG curve for 5 shows various steps of decomposition starting at low temperature
o
o
(
ca. 40 C) and the organic moiety is almost totally decomposed at 400 C, the
remaining solid at this temperature being practically CuCO
). It further decomposes slowly releasing CO
as CuO (obsd: 19.2 %, calcd. 20.1 %).
3
(obsd. 36.2 %, calcd. 31.3
o
%
2
and the residue at 750 C is identified
All these thermal decompositions are in agreement with the DTA behaviors (Figure
S7B†). As an illustrative example, one endothermic peak is observed in the DTA curve
of 4 at 190 °C which is due to the removal of one water molecule and the other peaks at
o
2
67 and 326 C are attributed to the decomposition process of this complex.
1
9

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Description
of
the
Structures.
[Cu
2
(O
2
CC
8
H
9
)
4
(pyz)]
n
(1)
and
[
Cu (O CC H ) (dps)] (2). The crystal structures of 1 and 2 consist of neutral
2 2 8 9 4 n
II
2
centrosymmetric paddleꢀwheel dinuclear copper(II) units, [Cu
(ꢀꢀO
2
CC
H
8 9
)
4
], which
are further connected by pyz (1) and dps (2) bridging ligands to give linear or waving
chains, respectively (Figures 1–3).
Each copper(II) ion in 1 (Cu1) and 2 (Cu1 and Cu2) is fiveꢀcoordinate in a somewhat
distorted square pyramidal surrounding. Four carboxylateꢀoxygen atoms from four 3ꢀ
phenylpropionate ligands build the basal plane at the copper atom (1/2) whereas a
nitrogen atom from the pyz (1)/dps (2) occupies the apical site. The values for the
38
trigonality parameter τ are 0.001 for Cu1 in 1 and 0.001 and 0.004 for Cu1 and Cu2 in
2
. The copper(II) ions are shifted from the mean basal plane by 0.1823(5) Å (1), and
0.1940(10) (Cu1) and 0.1965(9) Å(Cu2) (2) toward the apical position.
ii
ii
C10
C9
ii
C8
ii
C11
ii
C7
i
ii
C5
ii
C18
O1
ii
C19
ii
C17
ii
C4
ii
C20
i
O2
ii
C16
i
C2
ii
C15
ii
ii C14
C3
i
C1
Cu1
O3
ii
O1
i
i
O4
N1
ii
C12
ii
O4
C13
N1
O2
i
O3
ii
i
O2
C1
Cu1
ii
C2
ii
Cu1
iii
C1
C2
iii
O3
C12
ii
O4
ii
N1
C13
O1
iii
ii
O3
N1
iii
O4
C3
C4
ii
C1
iii
Cu1
C14
C20
iii
C2
C15
C16
O2iii
C5
C17
C6
C19
C7
iii
C11
O1
C18
C8
C10
C9
Figure 1. Perspective view of a fragment of the structure of 1 with the atom numbering
scheme. Hydrogen atoms are omitted for the sake of clarity [Symmetry codes: (i) = 1ꢀx,
1ꢀy, 2ꢀz; (ii) = 1/2ꢀx, 3/2ꢀy, 2ꢀz; (iii) = ꢀ1/2+x, 1/2+y, z].
2
0

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C73a
ii
Cu2
C71a
C75a
C42
C40
C74a
C72a
C27
O5
C38
C26
C24
ii
O7
ii
C31
S1
C25
C34
N2
O8
Cu1
C28
O6
ii
ii
C20
C29
Cu1
O6
C23
C22
C30
ii
N2
C33
C35
ii
O8
C19
O7
C31
ii
ii
C32
C38
O5
N1
C21
ii
C42
C37
C36
ii
C40
O2
O1
Cu2
O4
O3
(
a)
i
C11
i
i
C2
C10
i
O3
O1
i
i
O2
N1
O8
i
C1
i
Cu1
O7
N2
i
O4
C19
Cu2 Cu2
C28
C24
i
O4
C20
Cu1
i
O1
N1
O3
C23
C1
C5
C3
O2
O5
C10
C6
C2
C21
C25
C27
C22
S1
O6
C26
C4
C11
C7
C14
C9
C12
C15
C8
C13
C16
C18
C17
(
b)
Figure 2. Perspective views of the two centrosymmetric fragments in the structure of 2
with the atom numbering scheme. Hydrogen atoms are omitted for the sake of clarity
[
Symmetry codes: (i) = ꢀx+2, ꢀy+1, ꢀz+1; (ii) = ꢀx+2, ꢀy, ꢀz].
2
1

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The 3ꢀphenylpropionate ligand in 1 and 2 adopts the syn,synꢀ(ꢀꢀO,O’)
coordinative mode between the copper(II) ions forming a paddleꢀwheel with basal CuꢀO
distances varying in the ranges 1.9596(10) ꢀ 1.9718(10) (1) and 1.9521(17) ꢀ 1.9771(19)
Å (2) (Figure S8). These distances are smaller than the apical Cu–N ones [2.213(1) and
2.170(2)/2.175(2) Å for 1 and 2, respectively]. The copperꢀcopper separations within
i
each carboxylateꢀbridged dicopper(II) unit are 2.6052(3) Å (Cu1···Cu1 ) (1) and
ii
ii
2
.6236(5) (Cu1···Cu1 )/2.6204(6) Å (Cu2···Cu2 ) (2), as previously reported for Cu(II)
6c
paddleꢀwheel complexes.
Cu1
i
Cu1
c
[
-1 1 0]
(a)
S1
ii
O6
ii
O8
O3
N1
Cu2
O2
O1
ii
O4
O5
ii
i
O8
ii
O7
N2
O7
i
i
i
O4
O7
ii
O1
Cu2
Cu1
ii
Cu1
ii
N2
i
Cu1i
Cu2
O1
ii
O5
O4
O2
ii
i
O3
ii
O6
O8
N1
i
i
i
O5
O2
O3
b
i
O6
[0 1 1]
(b)
Figure 3. View of a fragment of the chains of 1 (a) and 2 (b) growing along the [ꢀ110]
and [110] directions, respectively.
2
2

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II
2
The paddleꢀwheel [Cu
2 8 9 4
(ꢀꢀO CC H ) ] units of 1 and 2 are connected by pyz and
dps bridges respectively leading to neutral chains that grow along the [ꢀ110] and [110]
directions (Figure 3). The values of the copperꢀcopper distance through the bisꢀ
ii
monodentate pyz (1) and dps (2) ligands are 7.2021(2) Å (Cu1···Cu1 ) and 10.2571(7)
Å (Cu1···Cu2). The chains of 1 extend into 2D networks parallel to the (001) and (002)
planes through intermolecular interactions involving a carboxylate oxygen (O2) atom
and a hydrogen atom of a propyl CH
distance of 3.272(2) Å (Figure S9†). A supramolecular 2D structure also occurs in 2
Figure S10†), the chains being interlinked by weak C H···O type and CꢀH···S type
2
group from the adjacent chain with a O2···C18
(
–
interactions [O2···C20 and S1···C11 distances are of 3.461(3) and 3.783(3) Å,
respectively] along the [011] direction.
2 8 9 2 2 2 n
{[Cu(O CC H ) (dps)(H O]·H O} (3). Unlike the paddleꢀwheel chain structure in 2,
the crystal structure of 3 is made up of di(4ꢀpyridyl)sulfideꢀbridged wavy polymeric
II
chains of neutral copper(II) units [Cu (ꢀꢀO
2
CC
8
H
9
)
2
] which grow along the
crystallographic c axis (Figure 4). The two crystallographically independent copper(II)
2 3
ions in 3 (Cu1 and Cu2) exhibit the same fiveꢀcoordinate CuN O environment. Two 3ꢀ
ii
phenylpropionateꢀoxygen atoms [O1 and O1 ; (ii) = 1/2ꢀx, y, 1ꢀz] and two nitrogenꢀ
ii
atoms (N1 and N1 ) from two dps molecules build the basal plane at Cu1, the apical
position being filled by a water molecule (O5). The bond distances in the distorted
squareꢀpyramidal geometry environment around Cu1 (τ = 0.1) are Cu1
–O1 = 1.949(3),
Cu1
–
N1 = 2.032(3) Å, and Cu1–O5 = 2.217(4) Å (Figure S11b). In the case of Cu2, two
i
oxygen atoms [O3 and O3 , (i) = 1/2ꢀx, 1/2ꢀy, 1/2ꢀz] from the 3ꢀphenylpropionate
i
ligands, two nitrogen atoms (N2 and N2 ) from two dps molecules build the basal plane
i
and one disordered oxygen atom (O6 and O6 ) of a water molecule fills the apical
2
3

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position, the whole resulting in a perfect squareꢀpyramidal geometry. This copper atom
is placed in an inversion center and due to this special position, it exhibits two
possibilities of coordination of the water molecule, which led us to fix the occupancy of
the water oxygen atom O6 as 0.5 in order to have its anisotropic displacement parameter
similar in magnitude of the other atoms in its environment (the thermal analysis for 3
supports the amount of water and indirectly this conclusion). Considering the
environment of Cu2, the pattern of two shorter equatorial distances [Cu2ꢀO3 = 1.947(3)
and Cu2
expected due to the JahnꢀTeller effect for copper(II) ion. The long Cu2
Cu2–O4= 2.751(4) Å] allows to assume that the 3ꢀphenylpropionate anions act as a
–N2 = 2.029(4) Å] compared to the axial one [Cu2–O6 = 2.64(1) Å] is as
–O4 distance
[
monodentate ligand versus Cu2 (Figure S11a).
b
c
S1
C10
C15
C16
ii
O4
a
i
C1
C9
C11 C14
ii
C19
N2
i
N1
C13
ii
O3
i
O2
C12
C5
ii
O1
O5
C18
Cu1
Cu2
Cu1
C17
O3
C19
C20
C22
C6
C7
ii
N2
O6
i
i
Cu2
N1
O1
C1
C4
O2
O4
C8
C30
C2
C3
C23
C24
C21
C27
C26
C25
Figure 4. View of a fragment of the chain of 3 showing the coordination environment
for the copper(II) atoms with the atomic numbering scheme. Hydrogen atoms have been
omitted for clarity.
2
4

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The distinct structures of 2 and 3 can be also evidenced in the intrachain
copper···copper distances. The four 3ꢀphenylpropionate groups in 2 adopt symmetric
synꢀsyn carboxylate bridging modes building paddleꢀwheel dicopper(II) units with a
Cu···Cu distance of 2.6237(5) Å, while the 3ꢀphenylpropionate anions in 3 act as
monodentate ligands and the dps molecule links the copper(II) centers, the intrachain
·
··
Cu1 Cu2 distance in 3 being 10.9632(4) Å.
The polymeric chains of 3 are interlinked along the crystallographic b axis by
hydrogen bonds involving the nonꢀcoordinated oxygen atoms of 3ꢀphenylpropionate
(O4 and O2) and the coordinated water molecules (O5 and O6). The former and latter
act as hydrogen bond acceptor and donor, respectively (Figure S12). These weak
intermolecular interactions lead to a twoꢀdimensional supramolecular structure parallel
to the (100) plane. One of the hydrogen atoms of the water molecule O6 is hydrogen
bonded to the nonꢀcoordinated oxygen (O4) from the 3ꢀphenylpropionate anion (Figure
S12). The interconnection between parallel chains along the crystallographic b axis
results in the shortest metalꢀmetal separation [Cu1
–Cu1 = Cu2–Cu2 = b axis dimension
=
5.883(1) Å] for 3 (Figure S13a). The uncoordinated disordered water molecules,
which fill the channel along the [010] direction, contribute to stabilize the whole
packing structure via hydrogen bonding (Figure S13b)
{[NaCu(O
2 8 9 2 3 2 n
CC H ) (bpm)(NO )]·H O} (4). The crystal structure of 4 consists of
heterobimetallic double chains built up by centrosymmetric tetranuclear sodium(I)ꢀ
I
2
II
2
copper(II) units, [Na
Cu
2 8 9 4
(ꢀꢀO CC H ) ], which are further connected by two 2,2’ꢀ
I
II
bipirimidine molecules acting as bisꢀbidentate ligands between the Na and Cu ions of
adjacent units (Figures 5 and 6).
2
5

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O7
O6
O5
ii
N4
ii
N2
Na1
N4
N2
O2
i
O4
N1
Cu1
N3
i
C19
C10
i
O3
O1
O3
i
i
O1
i
C10
Cu1
C19
i
N3
i
N1
O4
i
O2
i
i
i
N4
Na1
N2
Figure 5. Perspective view of the centrosymmetric tetranuclear unit in 4 with the atom
numbering scheme. Thermal ellipsoids are shown at the 50% probability level.
Hydrogen atoms were omitted for clarity.
Each Cu(II) ion in 4 is fiveꢀcoordinate with three carboxylateꢀoxygen atoms (O1, O3
i
and O3 ) of the 3ꢀphenylpropionate groups and two nitrogen atoms (N1 and N3) of the
bpm molecule in a slightly distorted square pyramidal environment (τ = 0.0008). The
i
basal plane is formed by the N1, N2, O1 and O3 [symmetry code: (i) = 1–x, –y,–z]
atoms and the apical position is occupied by the symmetry related O3 atom (Figure 5).
2
6

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i
The basal Cu1
N1 = 2.033(3), and Cu1
and 2 and those from the literature. The apical Cu1
–
O and Cu1
–N distances [Cu1–O1 = 1.928(2), Cu1–O3 = 1.972(2), Cu1–
–
N3 = 2.024(3) Å] are in agreement with the values found in 1
39
–
O3 distance of 2.276(3) Å is
significantly longer than the equatorial ones. The angle subtended at the Cu1 atom by
the bpm ligand is 80.67(1)º. The remaining oxygen atoms of the carboxylate ligands
i
ii
[
O2 and O4 ; (i) = 1–x, –y,–z] and two nitrogen atoms of the bpm molecule [N2 and
ii
N4 (ii) = ꢀx, ꢀy, ꢀz] build the equatorial plane at the Na1 atom [leastꢀsquare plane r.m.s.
deviation = 0.0914(16) Å]. The sodium atom is shifted by 0.3590(36) Å from this mean
plane. The sixꢀcoordination around Na1 is completed by the O5 and O6 oxygen atoms
from a chelating nitrate anion leading to a cisꢀNaO
Figure S14). The Na1 O and Na1
O6 = 2.418(4); Na1 O5 = 2.471(4); Na1
4
N
2
distorted octahedral environment
i
(
–
–
N bond lengths [Na1
–
O4 = 2.271(3); Na1
–O2 =
ii
ii
2
.267(3); Na1
–
–
–
N2 = 2.479(4) and Na1
–
N4 =
2.545(4) Å; symmetry codes: (i) = 1ꢀx, ꢀy, ꢀz and (ii) = ꢀx, ꢀy, ꢀz] are in agreement with
36,40
those ones previously found other Na(I) complexes.
The bridging bpm ligand is
planar (r.m.s deviation of fitted atoms = 0.012 Å) and its bond distances and angles are
as expected.
10.024(2)
Na1
Cu1
Na1
Cu1
Na1
6.009(3)
Na1
Cu1
Cu1
6.935(3)
Cu1
Cu1
Cu1
Na1
Cu1
Na1
b
Na1
Na1
a
c
3.305(2)
7.139(2)
Figure 6. Projection view onto the plane (014) of a fragment of the double chain in 4
which grows parallel to the crystallographic a axis. Hydrogen atoms were omitted for
clarity.
2
7

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Each pair of 3ꢀphenylpropionate bridging ligands within the tetranuclear
I
2
II
2
[
Na
Cu
2 8 9 4
(ꢀꢀO CC H ) ] units, act in an asymmetric syn,syn,antiꢀ(ꢀꢀO,O’) coordination
II
I
mode toward the two Cu and one Na ions, with one short and one long CuꢀO distance
I
II
I
2
II
2
(
Figure 5). The Na and Cu ions from adjacent [Na
Cu
(ꢀꢀO
2
8 9 4
CC H ) ] units are
II
2
I
2
further bridged by two bisꢀbidentate bpm molecules affording Cu Na cages that
alternate regularly along the double sodium(I)ꢀcopper(II) chains (Figure S15). This
metallacyclic cage has a cavity with a diameter of 7.139(4) and 6.935(3) Å, considering
the distances between directly opposed copper and sodium atoms, respectively. It is
II
I
2 2
interesting to note that in the Cu Na motif the four 3ꢀphenylpropionate bridging
ligands are oriented with their phenyl rings toward the ring center, working as a cage
gate. The opposing rings are separated by ca. 13 Å and the two pairs of phenyl rings are
slightly shifted “upward” and “downward” (see Figure S15).
It is interesting to note that within the Cu
2
O
2
motif each bridging oxygen (O3
i
II
and O3 ) simultaneously occupies an apical site at one Cu ion and the basal position of
II
the other Cu ion (see Figure 5], the apical Cu1ꢀO3 distance [2.276(4) Å] being longer
i
than the basal Cu1ꢀO3 bond length [1.972(3)]. This is a typical structural aspect for
II
2a
parallelꢀplanar dinuclear Cu complexes with two oxo(carboxylate) bridges. Thus, the
Phpr ligands act as monoatomic bridges through of the oxygen atom (O3) linking
individual cages and leading to a 1D polymer which grow parallel to the
crystallographic a axis (Figure 6). The copperꢀcopper separation through the double
oxo(carboxylate) bridge and the value of the angle at the oxo(carboxylate) atom are
3.305(2) Å and 101.93(9)º, respectively. The values of the intrachain copperꢀsodium
iii
distances are 3.663(1) (Cu1···Na1) and 6.009(3) Å [Cu1···Na1 ; symmetry code: (iii)
=
ꢀ1+x, y, z].
2
8