Versatility in the coordination modes of n-chlorohenzoato ligands: synthesis, structure and magnetic properties of three types of polynuclear MnII compounds

Article abstract of DOI:10.1002/ejic.200900532

Three different types of polynuclear manganese(II) compounds with chlorobenzoato bridges were obtained from the reaction of Mn(n-ClC ₆H₄COO)₂ with 1,10-phenanthroline (phen): three trinuclear compounds [Mn₃(μ-n-ClC₆H ₄COO)₆-(phen)₂] with n = 2, 3, 4 (1-3), one one-dimensional system [Mn(μ-3-ClC₆H₄COO) ₂(phen)]_n (4) and one neutral dinuclear compound [{Mn(4-ClC₆H₄COO)(phen)}₂(μ-4-ClC ₆H₄COO)₂-(μ-H₂O)] (5). Compounds 1, 3, 4 and 5 were characterized by X-ray diffraction and show four different coordination modes for the carboxylate ligand: as a bidentate bridge in a syn-syn mode or syn-anti mode, as a monodentate bridge and as a terminal monodentate ligand. The five compounds show weak antiferromagnetic coupling; the J values are -2.9, -2.8, -2.8, -1.8 and -3.6 cm^-1 for compounds 1-5, respectively. Each type of compound may be distinguished by their characteristic EPR spectrum at 4 K. Fairly good simulations of the spectra at 4 K for the trinuclear compounds 1-3 were obtained with ground state ZFS parameters, D_5/2 and E_5/2, of 0.16 cm^-1 and 0.05 cm^-1 (1), 0.16 cm^-1 and 0.043 cm^-1 (2) and 0.16 cm^-1 and 0.053 cm^-1 (3), respectively. For the dinuclear complex 5, the best simulation of the spectrum at 4 K was obtained with ZFS parameters of the ion, D_Mn and E_Mn, of 0.187 cm^-1 and 0.061 cm^-1, respectively. Wiley-VCH Verlag GmbH & Co. KGaA.

Full text of DOI:10.1002/ejic.200900532

FULL PAPER
DOI: 10.1002/ejic.200900532
Versatility in the Coordination Modes of n-Chlorobenzoato Ligands: Synthesis,
Structure and Magnetic Properties of Three Types of Polynuclear MnII
Compounds
Verónica Gómez*[a] and Montserrat Corbella[a]
Keywords: Manganese / Carboxylate ligands / Coordination modes / Magnetic properties / EPR spectroscopy
Three different types of polynuclear manganese(II) com-
pounds with chlorobenzoato bridges were obtained from the
reaction of Mn(n-ClC6H4COO)2 with 1,10-phenanthroline
(phen): three trinuclear compounds [Mn3(µ-n-ClC6H4COO)6-
(phen)2] with n = 2, 3, 4 (1–3), one one-dimensional system
[Mn(µ-3-ClC6H4COO)2(phen)]n (4) and one neutral dinuclear
compound [{Mn(4-ClC6H4COO)(phen)}2(µ-4-ClC6H4COO)2-
(µ-H2O)] (5). Compounds 1, 3, 4 and 5 were characterized by
X-ray diffraction and show four different coordination modes
for the carboxylate ligand: as a bidentate bridge in a syn–syn
mode or syn–anti mode, as a monodentate bridge and as a
terminal monodentate ligand. The five compounds show
weak antiferromagnetic coupling; the J values are –2.9, –2.8,
–2.8, –1.8 and –3.6 cm–1 for compounds 1–5, respectively.
Each type of compound may be distinguished by their char-
acteristic EPR spectrum at 4 K. Fairly good simulations of the
spectra at 4 K for the trinuclear compounds 1–3 were ob-
tained with ground state ZFS parameters, D5/2 and E5/2, of
0.16 cm–1 and 0.05 cm–1 (1), 0.16 cm–1 and 0.043 cm–1 (2) and
0.16 cm–1 and 0.053 cm–1 (3), respectively. For the dinuclear
complex 5, the best simulation of the spectrum at 4 K was
obtained with ZFS parameters of the ion, DMn and EMn, of
0.187 cm–1 and 0.061 cm–1, respectively.
(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim,
Germany, 2009)
ylate bridges is few;[21–22,24–33] not many of them are mag-
netically characterized,[21,22,24] and there are even fewer
studied by EPR spectroscopy.[21,22] With regard to dinuclear
MnII compounds, there are not many compounds with a
[Mn2(µ-H2O)(µ-RCOO)2]2+ core reported in the litera-
ture,[34–44] and fewer whose magnetic properties have been
studied[41–44] or whose EPR spectrum have been re-
ported.[44]
Introduction
Polynuclear manganese compounds with carboxylate li-
gands are of great interest in bioinorganic chemistry[1] and
molecular magnetism.[2] In the former, several compounds
have been synthesized to mimic the active sites of various
metalloproteins, such as catalase[3] and the oxygen-evolving
complex (OEC) of photosystem II.[4] In the latter, it was
discovered that some compounds characterized by a large-
spin ground state and an appreciable magnetoanisotropy
could behave as single-molecule magnets (SMMs) at very
low temperatures.[5]
Manganese complexes containing carboxylate ligands
have been extensively studied. Carboxylate groups display a
wide variety of coordination modes such as monodentate
terminal, chelating, bidentate bridging and monodentate
bridging modes (Figure 1), which lead to several types of
compounds. There are some trinuclear compounds with a
[Mn3(µ-RCOO)6] core reported in the literature,[6–23] but
only half of them are magnetically studied,[13–22] and even
less have been characterized by EPR spectroscopy.[19–23]
The number of described 1D MnII chains with two carbox-
[a] Departament de Química Inorgànica, Universitat de Barcelona,
Martí i Franquès 1-11, 08028 Barcelona, Spain
Fax: +34-934907725
E-mail: veronica.gomez@qi.ub.es
Supporting information for this article is available on the
WWW under http://dx.doi.org/10.1002/ejic.200900532.
Figure 1. Carboxylate binding modes in metal complexes. Bridges
involved in the compounds reported here are framed.
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Here, we report the synthesis and characterization of ligands. The Mn1 ion bridges the two terminal Mn2 ions
three types of MnII compounds with different nuclearity, through three chlorobenzoato ligands. Two of them are co-
with chlorobenzoato and 1,10-phenanthroline ligands: three ordinated through both oxygen atoms (µ1,3), in a syn–syn
trinuclear compounds [Mn3(µ-n-ClC6H4COO)6(phen)2], mode, while the third carboxylate bridges through just one
where n = 2, 3, 4 (1–3), one 1D compound [Mn(µ-3- oxygen atom (µ1,1), whilst the other oxygen atom (Od) is
ClC6H4COO)2(phen)]n (4) and one neutral dinuclear com- weakly bonded to the terminal Mn2 ion. The Mn2–Od dis-
pound [{Mn(4-ClC6H4COO)(phen)}2(µ-4-ClC6H4COO)2- tance is 2.279 and 2.344 Å for compounds 1 and 3, respec-
(µ-H2O)] (5). Structural characterization of compounds 1, tively, which are comparable to those reported in the litera-
3–5 was achieved by X-ray diffraction. The magnetic behav- ture for analogous compounds (2.203–2.823 Å, av.
iour and EPR spectra of all compounds were studied.
2.39 Å).[6–23] The hexacoordination of the terminal Mn2 ion
is completed by 1,10-phenanthroline ligand. The
a
Mn1···Mn2 distances are 3.630 and 3.546 Å for compounds
1 and 3, respectively, which agree with those reported in the
literature (3.370–3.691 Å).[6–23]
Results and Discussion
Previously,[21] we reported the reaction between [Mn(n-
ClC6H4COO)2]·nH2O (n = 2, 3, 4) and 2,2Ј-bipyridine in
ethanol, using two different MnII/bpy ratios (3:2 or 1:1) to
obtain two different neutral compounds: trinuclear com-
plexes and 1D systems. In the present work, we carried out
the analogous reaction with 1,10-phenanthroline instead of
bpy, and used two different solvents, ethanol and acetoni-
trile. In this case, depending on the molar ratio and/or sol-
vent, three types of compounds were obtained.
With 2-ClC6H4COO, only the trinuclear complex
[Mn3(µ-2-ClC6H4COO)6(phen)2] (1) was obtained, regard-
less of the MnII/phen ratio or solvent (CH3CH2OH or
CH3CN), as reported for the reaction with bpy.[21]
With 3-ClC6H4COO, two compounds were obtained in
both solvents: the trinuclear compound [Mn3(µ-3-
ClC6H4COO)6(phen)2] (2) when the MnII/phen ratio was
3:2 and the 1D system [Mn(µ-3-ClC6H4COO)2(phen)]n (4)
when the ratio was 1:1. This behaviour is different from that
reported for the analogous reactions with bpy,[21] where, for
both MnII/bpy ratios, the trinuclear compound was ob-
tained and the 1D system appeared as a by-product after
filtration of the trinuclear complex.
With 4-ClC6H4COO, independent of the MnII/phen ra-
tio, the trinuclear compound [Mn3(µ-4-ClC6H4COO)6-
(phen)2] (3) was obtained using ethanol as solvent. The
analogous reactions with bpy lead to the formation of a 1D
compound.[21] Using acetonitrile as solvent, with both
MnII/phen ratios, the neutral dinuclear compound [{Mn(4-
ClC6H4COO)(phen)}2(µ-4-ClC6H4COO)2(µ-H2O)] (5) was
obtained. This compound had been previously reported in
the literature,[38,39] but was obtained by different procedures
and shows small structural differences.
Description of the Structures
[Mn3(µ-n-ClC6H4COO)6(phen)2] n = 2 (1), n = 4
(3·2CH2Cl2)
Figure 2. Crystal structures of trinuclear compounds 1 (top) and 3
(bottom) showing the atom labelling scheme. Hydrogen atoms are
omitted for clarity.
The structures of compounds 1 and 3 are shown in Fig-
ure 2. Selected bond lengths and angles are listed in Table 1.
These structures consist of a linear array of three MnII ions
where the central manganese ion is located on a crystallo-
The Mn1 ion shows a quite regular octahedral environ-
graphic inversion centre. In both compounds, the Mn1 ion ment, although a considerable elongation in the direction
is coordinated by six oxygen atoms of six chlorobenzoato of the µ1,1 oxygen bridge (Ob) is observed: the Mn1–Ob dis-
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Eur. J. Inorg. Chem. 2009, 4471–4482

Coordination Modes of n-Chlorobenzoato Ligands
Table 1. Selected bond lengths (Å) and angles (°) with estimated
standard deviations in parentheses for trinuclear compounds 1 and
3·2CH2Cl2.[a]
These compounds are examples of the carboxylate shift,
a term used by Lippard to describe the carboxylate move-
ment from µ1,1-O to µ1,3-O,OЈ bridging modes.[45] Analysis
of the structural parameters of this type of compounds con-
taining monodentate bridging carboxylate ligands shows
2.2242(19) that they can be arranged into three classes, from an absent
Compound 1
Compound 3·2CH2Cl2
Mn1···Mn2 3.546(4)
Mn1···Mn2
Mn1–O1
Mn1–O4
Mn1–O5
Mn2–N1
3.630(0)
2.2440(16) Mn1–O5
2.1627(17) Mn1–O3
2.1426(17) Mn1–O1
2.1684(19)
or a weak Mnt–Od interaction (class I) to a strong interac-
tion (class III). However, a further interpretation can be
2.301(2)
2.1273(19)
2.275(2)
2.266(2)
Mn2–N1
Mn2–N2
made from bridging and dangling metal-to-oxygen dis-
2.234(2)
Mn2–N2
tances (Figure 3). A symmetric bridge is indicative of a
strong µ1,1 character, while an asymmetric bridge, with a
Mnt–Ob distance larger than Mnc–Ob and a short Mnt–Od
distance, indicate a certain µ1,3 character.
Mn2–O1
Mn2–O2
Mn2–O3
Mn2–O6
C13–O1
C13–O2
2.2845(16) Mn2–O5
2.2787(17) Mn2–O6
2.0844(18) Mn2–O2
2.1029(17) Mn2–O4
2.2205(19)
2.344(2)
2.1120(19)
2.109(2)
1.289(3)
1.250(3)
1.282(3)
1.244(3)
C15–O5
C15–O6
Mn2–Mn1–Mn2a
O1–Mn1–O1a
O4–Mn1–O4a
O5–Mn1–O5a
N1–Mn2–O3
N2–Mn2–O1
O2–Mn2–O6
O2–Mn2–O1
N2–Mn2–N1
180.00(1) Mn2–Mn1–Mn2b
180.00(7) O5–Mn1–O5b
180.00(7) O1–Mn1–O1b
180.00(7) O3–Mn1–O3b
162.55(8) N1–Mn2–O2
157.23(8) N2–Mn2–O5
148.42(7) O4–Mn2–O6
179.99(1)
180.00(8)
180.00(10)
180.00(10)
160.98(8)
156.01(8)
156.41(8)
57.66(7)
57.51(7)
73.72(8)
O5–Mn2–O6
N2–Mn2–N1
Figure 3. Schematic structure of trinuclear compounds emphasiz-
ing the bridging and dangling metal-to-oxygen bonds (in bold) re-
lated to the movement from µ1,1-O to µ1,3-O,OЈ bridging modes.
73.22(9)
[a] Symmetry codes: (a) –x, –y, 1 – z, (b) –x + 1, –y, –z + 1.
Compound 1 is characterized by an asymmetric µ1,1-O
tance is ≈ 2.23 Å, while the other Mn1–O distances are bridge, with a Mn1–Ob distance (2.244 Å) smaller than the
≈ 2.15 Å. For the Mn2 ions, the acute angles Od–Mn2–Ob Mn2–Od and Mn2–Ob distances, which are quite similar
(≈ 57°) and N–Mn2–N (≈ 73°) and the difference between (2.285 and 2.279 Å, respectively). This compound therefore
the Mn2–N (≈ 2.27 Å) and Mn2–O (≈ 2.19 Å) bond lengths shows a bridge intermediate between the µ1,1 and µ1,3
lead to a distorted octahedral geometry around the ter- modes, coordinated in a syn–anti mode. However, com-
minal MnII ions.
pound 3 shows a Mn1–Ob distance very similar to Mn2–
Table 2. Selected structural parameters and carboxylate bridging mode for trinuclear MnII compounds with a [Mn3(µ1,3-RCOO)4(µ1,1
-
RCOO)2] core.
[a] Abbreviations: Boc = tert-butoxycarbonyl; dme = 1,2-dimethoxyethane; BIPhMe = 2,2Ј-bis(1-methylimidazolyl)phenylmethoxymeth-
ane; dapdoH2 = 2,6-diacetylpyridine dioxime; (py)2CO = di-2-pyridyl ketone; (ph)(2-py)CO = phenyl 2-pyridyl ketone; ppei = 2-pyridinal-
1-phenylethylimine; pybim = 2-(2-pyridyl)benzimidazole; L = bis(1-methylimidazol-2-yl)methanone; dpa = 2,2Ј-dipyridylamine. [b] One
of the two crystallographically independent molecules present in the unit cell.
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V. G ómez, M. Corbella
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Ob (2.221 and 2.224 Å, respectively) and smaller than Mn2–
Od (2.344 Å). In this case, the bridge shows a significant
µ1,1 character.
Table 2 presents some structural parameters of trinuclear
compounds analogous to those reported here and the µ1,1
or µ1,3 character of the carboxylate bridge. All these com-
pounds can be arranged into four classes. Class A com-
pounds show a quite symmetric bridge (pronounced µ1,1
character) and a medium Mnt–Od interaction, although
there are two compounds with a strong Mnt–Od interaction,
the three distances being of the same order of magni-
tude.[11,14] The other three classes show asymmetric bridges.
In class B, the bridge is displaced towards Mnt, and the
Mnt–Od interaction is very weak. Class C collects com-
pounds with the bridge displaced towards Mnc, with a
rather short Mnc–Ob distance and a large Mnt–Od distance.
However, the compound [Mn3(CH3COO)6(phen)2] shows a
larger Mnt–Ob distance than the other compounds of this
group.[10] Compounds in class D, which are very scarce, dis-
play the bridge shifted also towards Mnc, but with the Mnc–
Ob distance a bit larger than those in compounds of class
C, and a short Mnt–Od distance (even shorter than Mnt–
Figure 4. Crystal structure of the 1D compound 4, showing a dinu-
clear fragment with the atom labelling scheme. Hydrogen atoms are
omitted for clarity.
Table 3. Selected bond lengths (Å) and angles (°) with estimated
standard deviations in parentheses for the 1D compound 4.[a]
Mn1···Mn1aa 4.546(1)
N1a–Mn1–O1a
O1–Mn1–N1
O3aa–Mn1–O3aaa
158.46(8)
158.46(8)
167.39(9)
Mn1–O1
Mn1–N1
Mn1–O3aa
2.0908(18)
2.298(2)
2.2004(18)
[a] Symmetry codes: (a) –x + 1, y, –z + 1/2; (aa) –x + 1, –y, –z +
Ob), showing a bridging mode with strong µ1,3 character. 1; (aaa) x, –y, z – 1/2.
Comparison of the Mn···Mn distance for the different
classes shows slightly smaller values for compounds in class
A and for some in class C, but the differences are not very
significant.
The face-to-face distance between two phen ligands of adja-
cent chains is 3.306 Å. This suggests π–π stacking interac-
tions between polymeric chains (Figure 5).
[Mn(µ-3-ClC6H4COO)2(phen)]n (4)
The structure of 4 consists of an infinite zigzag MnII
chain, as shown in Figure 4. Selected bond lengths and
angles are given in Table 3. Each manganese ion coordi-
nates four chlorobenzoato ligands and one 1,10-phenan-
throline, displaying a distorted octahedral geometry. The
manganese ions are bridged by two carboxylate ligands co-
ordinated in a syn–anti mode, with a Mn···Mn distance of
4.546 Å, which is slightly longer than that reported for the
analogous compound with 2,2Ј-bypiridine (4.515 Å)[21] but
in the range of distances reported for other 1D compounds
with a [Mn(µ1,3-RCOO)2]n core (4.515–4.852 Å).[21,22,24–33]
There are two different Mn–O distances: the shortest dis-
tances (2.091 Å) correspond to Osyn, while the largest dis-
tances (2.200 Å) correspond to Oanti. The Osyn atoms are
trans to a Nphen atom, while the Oanti atoms are trans to the
other Oanti atoms. The Mn–Osyn distance is shorter than
the Mn–Oanti distance, which is also observed in analogous
compounds with a syn–anti coordination mode of the car-
Figure 5. Interaction between neighbouring chains through the
phen ligands, view along the a axis.
[{Mn(4-ClC6H4COO)(phen)}2(µ-4-ClC6H4COO)2(µ-
H2O)] (5)
The structure of this neutral dinuclear compound is
boxylate bridge, where the Mn–Osyn distance is in the range shown in Figure 6. Selected bond lengths and angles are
2.077–2.145 Å and the Mn–Oanti distance is in the range listed in Table 4. The MnII ions are bridged by one H2O
2.183–2.238 Å.[21,22,26–33] The two Mn–N distances are molecule and two µ1,3-chlorobenzoato ligands, in a syn–anti
2.298 Å, which agree with those in the literature, which fall mode. The hexacoordination of each manganese ion is com-
in the range 2.252–2.310 Å.[21,22,26–33]
pleted by a phen ligand and a monodentate chlorobenzoato
The phenanthroline rings are parallel to each other along ligand. The molecular conformation is stabilized by hydro-
the 1D chain, with a distance of 7.221 Å between them. The gen bonds between the non-coordinated oxygen atom of the
phen ligands of neighbouring polymeric chains are ar- monodentate carboxylate group and the hydrogen atoms of
ranged in an almost parallel fashion, and the angle is 2.11°. the bridging water molecule.
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Coordination Modes of n-Chlorobenzoato Ligands
tively, close to the value of 13.125 cm3 mol–1 K, which corre-
sponds to three uncoupled MnII ions. When the tempera-
ture decreases, the χMT values fall until reaching 4.58 (1),
4.46 (2) and 4.27 cm3 mol–1 K (3) at 2 K, which are very
close to the expected value of 4.375 cm3 mol–1 K for a spin
ground state ST = 5/2 and g = 2, indicative of an antiferro-
magnetic coupling. This spin value is confirmed by the field
dependence of the magnetization at 2 K, which shows a M/
Nβ value indicative of five unpaired electrons (inset Fig-
ure 7).
Figure 6. Crystal structure of neutral dinuclear compound 5 show-
ing the atom labelling scheme. Hydrogen atoms (except those of
the water bridge) are omitted for clarity.
Table 4. Selected bond lengths (Å) and angles (°) with estimated
standard deviations in parentheses for the neutral dinuclear com-
pound 5.[a]
Mn1···Mn1a
Mn1–O34a
Mn1–O10
Mn1–O33
Mn1–O35
Mn1–N11
Mn1–N22
C8–O9
3.484(7)
C8–O10
C32–O34
C32–O33
O35–H35
O35–Mn1–N22
O34a–Mn1–N11
O10–Mn1–O33
Mn1–O35–Mn1a
1.262(3)
1.260(2)
1.263(2)
0.92(3)
162.09(5)
160.72(6)
174.51(6)
101.94(8)
2.1422(14)
2.1617(15)
2.1824(14)
2.2428(14)
2.2952(17)
2.2622(17)
1.252(3)
Figure 7. χMT vs. T and M vs. H (inset) plots for [Mn3(µ-n-
ClC6H4COO)6(phen)2] (n = 2, 3, 4) 1 (ᮀ), 2 (᭹), 3 (᭛). The solid
line is the best fit to the experimental data.
On the basis of the structure of these compounds and
Kambe’s vector coupling scheme (Scheme 1),[46] the spin
Hamiltonian considered would be H = –J(S1·S2 + S2·S3) –
J13(S1·S3), where it is assumed that J12 = J13 = J. However,
because of the large distance between the terminal manga-
nese ions in the linear complex, Mn1···Mn3, their magnetic
interaction is negligible (J13 = 0)[19,21] and only the
Mn1···Mn2 and Mn2···Mn3 interactions (J) are considered.
The expression for the magnetic susceptibility of three lin-
ear MnII ions is obtained from the Van Vleck formula.[47]
The best fit of experimental data corresponds to J =
–2.9 cm–1, g = 2.02, and R = 2.18ϫ10–4 for compound 1,
J = –2.8 cm–1, g = 2.03 and R = 1.04ϫ10–4 for compound
2 and J = –2.8 cm–1, g = 2.04 and R = 2.48ϫ10–4 for com-
pound 3. These J values agree with those from –5.6 to
–2.1 cm–1 reported in the literature for other linear MnII
trinuclear compounds.[15–22]
[a] Symmetry codes: (a) –x + 3/2, y, –z + 1.
The Mn···Mn distance is 3.484 Å, the shortest distance
found for this type of compound (3.502–3.786 Å).[34–44] The
Mn–Ow–Mn angle (101.84°) is also one of the smallest val-
ues reported in the literature (101.70–114.97°). However,
the Mn–Ow distance of 2.243 Å agrees with those in the
literature that fall in the range 2.111–2.315 Å. The distances
between the manganese ions and the oxygen atoms of the
carboxylate bridges are quite different: the Mn1–O34 dis-
tance is shorter than Mn1–O33 (2.142 and 2.182 Å, respec-
tively), probably because of the trans effect. With regard to
the monodentate carboxylate, the C8–O9 distance is similar
to the C8–O10 distance, which indicates a significant delo-
calization of the double bond as a result of the hydrogen
bond between the non-coordinated oxygen atom and the
bridging water molecule (H35–O9 distance of 1.643 Å).
Magnetic Measurements
Scheme 1. Kambe’s vector coupling scheme.[46]
Magnetic susceptibility data were recorded for all com-
pounds (1–5), from room temperature to 2 K. χMT vs. T
Selected structural parameters and J values of com-
and M vs. H plots for trinuclear compounds 1–3 are shown pounds 1 and 3 as well as those of some other analogous
in Figure 7. The three compounds show analogous mag- MnII compounds reported are listed in Table 5. For trinu-
netic behaviour. At 300 K, the χMT values are 13.20, 13.51 clear complexes, the µ1,3-carboxylate bridges are coordi-
and 13.85 cm3 mol–1 K for compounds 1, 2 and 3, respec- nated in a syn–syn mode and the oxo bridge is formed by a
Eur. J. Inorg. Chem. 2009, 4471–4482
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V. G ómez, M. Corbella
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Table 5. Selected structural and magnetic data for MnII compounds with a [Mn3(µ1,3-RCOO)4(µ1,1-RCOO)2] core.
[b]
Mn···Mn
/ Å
Mn–Ob
/ Å
Mn–Od
/ Å
(Mn–Od) –
(Mn–Ob) / Å / °
Mn–Ob–Mn
J[c]
Compound[a]
Class
Ref.
/ cm–1
[15]
[17]
[19]
[22]
[20]
[13]
[18]
[13]
[Mn3(bpy)2(FcCOO)6]
[Mn3((CH3)2CHCOO)6(dpa)2]·2CH3CN
[Mn3(bpy)2(CH3COO)6]
[Mn3(bpy)2(ClCH2COO)6]
[Mn3(CH3COO)6(pybim)2]
[Mn3{(CH3)2CHCOO}6(phen)2]
[Mn3(CH3COO)6(dapdoH2)2]
[Mn3(bpy)2{(CH3)2CHCOO}6]
[Mn3(4-ClC6H4COO)6(phen)2] (3·2CH2Cl2)
[Mn3(C6H5COO)6{(ph)(2-py)CO}2]
[Mn3(2-ClC6H4COO)6(phen)2] (1)
[Mn3(BIPhMe)2(CH3COO)6][d]
C
C
B
B
B
B
B
A
A
A
D
–
3.429
3.611
3.614
3.624
3.558
3.531
3.603
3.489
3.546
3.603
3.630
3.597
2.241
2.194
2.179
2.184
2.184
2.185
2.177
2.175
2.223
2.251
2.265
2.230
2.358
2.376
2.605
2.611
2.823
2.439
2.402
2.471
2.344
2.249
2.279
2.419
0.117
0.182
0.426
0.427
0.639
0.254
0.225
0.296
0.121
–0.002
0.014
0.109
99.82
–4.8
–3.7
–4.4
–3.8
–3.6
–3.2
–3.2
–3.7
–2.8
–2.7
–2.9
–5.6
110.82
112.12
112.12
109.07
107.85
111.7
106.67
105.82
106.31
106.58
109.8
this work
[14]
this work
[16]
[a] Abbreviations: BIPhMe = 2,2Ј-bis(1-methylimidazolyl)phenylmethoxymethane; Fc = ferrocene; dpa = 2,2Ј-dipyridylamine; pybim =
2-(2-pyridyl)benximidazole; dapdoH2 = 2,6-diacetylpyridine dioxime; (py)2CO = di-2-pyridyl ketone; (ph)(2-py)CO = phenyl 2-pyridyl
ketone. [b] Average value for Mnc–Ob and Mnt–Ob distances. [c] Magnetic exchange coupling parameter based on the Hamiltonian H = –
J(S1·S2 + S2·S3). [d] Structural data are average values for all three isomers of [Mn3(BIPhMe)2(CH3COO)6] as magnetic data are available
for a bulk sample possibly containing all three isomers.
µ1,1-carboxylate ligand, where the Mn–Ob distance is in the
range between 2.175 and 2.265 Å and the Mn–Ob–Mn an-
gle between 99.82 and 112.2°. As was reported for CuII
compounds,[48] the magnetic interaction is very sensitive to
the M–Ob–M angle and is more antiferromagnetic for
larger angles. Therefore, in this type of compounds, the
antiferromagnetic interaction may depend on the Mn–Ob–
Mn angle. However, there are other factors, such as the µ1,1
or µ1,3 character of the monatomic bridge, which may pro-
vide different pathways for the magnetic interaction. For
compounds in class A, the interaction through the µ1,1
bridge should be the most important pathway for the mag-
netic interaction, although some small contribution from
the µ1,3 pathway may exist. For compounds of classes B and
C, the most important pathway for the magnetic interaction
Figure 8. Trend observed between the J value and the difference
between Mnt–Od and Mn–Ob distances (∆) in trinuclear com-
is the µ1,1 bridge. On the other hand, for compounds of
class D, both pathways, µ1,1 and µ1,3, may contribute to the
pounds. ꢀ corresponds to compounds that are not considered (see
magnetic coupling.
text).
By taking into account this classification, although there
are few compounds in class C (two) and D (only one), a substituents. The last exception is [Mn3(CH3COO)6-
slight trend may be observed with respect to the |J| value: (pybim)2], which displays a Mn–Od distance (2.823 Å) that
|J|C Ͼ |J|B Ͼ |J|A Ͼ |J|D. Compounds with the additional is much larger than those in the other compounds. In spite
µ1,3 pathway show a weaker antiferromagnetic coupling of these exceptions, a linear correlation between ∆ and J is
than compounds in which the interaction is mediated only observed: the larger the difference (∆), the more antiferro-
through the µ1,1 bridge. Therefore, the extra µ1,3 pathway magnetic the compound. However, there may be some other
decreases the antiferromagnetic interaction. The difference factors contributing to the magnetic coupling in these com-
between the Mnt–Od and Mnc/t–Ob distances (∆) could ex- pounds.
press the µ1,1 character (high values of ∆) or the µ1,1 + µ1,3
character (low values of ∆) of the bridge. A certain corre- 4.50 cm3 mol–1 K at 300 K, close to the typical value for one
lation between ∆ and J can be observed (Figure 8).
MnII ion (4.375 cm3 mol–1 K), to 0.19 cm3 mol–1 K at 2 K,
For the 1D compound 4, χMT values decrease from
However, there are three compounds that do not obey showing an antiferromagnetic interaction between the man-
this tendency. One of them is [Mn3(BIPhMe)2(CH3COO)6]; ganese ions in the chain (Figure 9). The magnetic suscep-
in this case, the magnetic data corresponds to a bulk sample tibility data were analyzed by the analytical expression de-
that may possibly contain the three different isomers found rived by Fisher[49] for an infinite chain of classical spins
for this compound. In the case of [Mn3(bpy)2(FcCOO)6], based on the Hamiltonian H = –JΣSi·Si+1, for local spin
the deviation may be due to the ferrocene group in the car- values of S = 5/2. The best fit is obtained with J =
boxylate bridge, which is not comparable with the other –1.8 cm–1, g = 2.07 and R = 6.57ϫ10–5.
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Eur. J. Inorg. Chem. 2009, 4471–4482

Coordination Modes of n-Chlorobenzoato Ligands
bridges are coordinated in a syn–syn mode. Moreover, the
difference between the two Mn–O distances in this com-
pound is larger than for the other compounds. Both factors
could explain the larger |J| value reported for this chain.[50]
The dinuclear compound 5 shows a χMT value of
8.70 cm3 mol–1 K at 300 K, which is very close to the ex-
pected
value
for
two
uncoupled
MnII
ions
(8.75 cm3 mol–1 K) (Figure 9). On decreasing the tempera-
ture, the χMT values fall until 0.24 cm3 mol–1 K, indicative
of an antiferromagnetic coupling. The experimental data
were fitted by using the spin Hamiltonian H = –J S1·S2 and
the corresponding susceptibility expression for two MnII
ions,[47] obtaining the best fit with J = –3.6 cm–1, g = 2.05
and R = 3.52ϫ10–5. This J value agrees with those reported
in the literature, from –5.8 to –2.0 cm–1 (Table 7).[41–44] All
magnetically studied compounds show that the carboxylate
bridging ligands are coordinated in a syn–syn mode. How-
ever, compound 5 displays a syn–anti coordination mode,
with Mn–Osyn distances shorter than Mn–Oanti distances,
and it shows the shortest Mn···Mn distance and the small-
est Mn–Ob–Mn angle.
Figure 9. χMT vs. T plot for [Mn(µ-3-ClC6H4COO)2(phen)]n (4, ᭢)
and [{Mn(4-ClC6H4COO)(phen)}2(µ-4-ClC6H4COO)2(µ-H2O)] (5,
᭛). The solid line is the best fit to the experimental data.
To the best of our knowledge, there are only three 1D
compounds with a similar core that have been structurally
and magnetically characterized.[21,22,24] As can be seen in
Table 6, the analogous compound with a bpy ligand,
The five compounds reported here (1–5) show an antifer-
[Mn(bpy)(3-ClC6H4COO)2]n,[21] shows similar structural romagnetic behaviour; the |J| values decrease from the neu-
parameters and J value to those of 4, which is indicative tral dinuclear compound to the 1D system, |J|di Ͼ |J|tri
Ͼ
of the minor effect of the basicity of the terminal ligands. |J|1D, the magnetic coupling constant for the 1D system (4)
However, changing the bridging ligands from chloro- being appreciably smaller. In this compound, the magnetic
benzoato to chloroacetato as in [Mn(ClCH2COO)2- interaction is through two µ1,3-carboxylate bridging ligands,
[22]
(phen)]n
leads to a modification of the Mn–O distances while in the dinuclear and trinuclear complexes there is an
and hence the J value. In these compounds, the carboxylate additional monatomic bridge: an oxygen atom from a µ1,1
-
bridging ligands are coordinated in a syn–anti mode, with a carboxylate ligand for the trinuclear compounds (1 and 3)
Mn–Osyn distance shorter than the Mn–Oanti distance. The or from a µ-H2O ligand for the dinuclear compound (5)
difference between these distances is smaller for the chloro- (Scheme 2). On the other hand, the µ1,3-carboxylate bridg-
acetato compound than for the chlorobenzoato com- ing ligand can be coordinated in a syn–syn mode, as in 1
pounds, and its magnetic interaction is weaker than for and 3, or in a syn–anti mode, as in 4 and 5. It is well known
compound 4 and the analogous compound with bpy.[21]
A
that the magnetic interaction through the µ1,3-carboxylate
larger antiferromagnetic coupling was reported for bridging ligand is usually weak and antiferromagnetic, and
[Mn(FcC6H4COO)2(phen)]n,[24] in which the carboxylate depends on the coordination mode of the carboxylate li-
Table 6. Selected structural and magnetic data for MnII 1D systems [Mn(µ-RCOO)2(nn)]n.
Compound[a]
Mn–Osyn / Å
Mn–Osyn/anti / Å
J[b] / cm–1
Ref.
[Mn(3-ClC6H4COO)2(phen)]n (4)
[Mn(bpy)(3-ClC6H4COO)2]n
[Mn(ClCH2COO)2(phen)]n
[Mn(FcC6H4COO)2(phen)]n
2.091
2.104
2.134
2.090c
2.200anti
2.196anti
2.183anti
–1.8
–1.7
–0.9
–6.5
this work
[21]
[22]
[24]
[c]
2.210syn
[a] Abbreviations: Fc = ferrocene. [b] Magnetic exchange coupling parameter based on the Hamiltonian H = –JΣSi·Si+1. [c] Average
values.
Table 7. Selected structural and magnetic data for MnII dinuclear compounds with a [Mn2(µ-RCOO)2(µ-H2O)]2+ core.
Compound[a]
Mn···Mn / Å Mn–Osyn / Å Mn–Osyn/anti / Å Mn–Ob / Å
Mn–Ob–Mn / ° J[b] / cm–1 Ref.
[c]
[41]
[Mn2(F5C2COO)4(H2O)3L2]
[Mn2(CH3COO)4(H2O)(tmeda)2]
[Mn2(H2O)(Me2bpy)2(piv)4]
[Mn2(CH3COO)4(H2O)2(im)4]
[Mn2(CH3COO)5(H2O)(py)4]–
[Mn2(4-ClC6H4COO)4(H2O)(phen)2] (5)
3.739
3.621
3.595
3.777
3.618
3.484
2.115[c]
2.136[c]
2.109[c]
2.206
2.152syn
2.127syn
2.163syn
2.183syn
2.140syn
2.252[c]
2.210[c]
2.192[c]
2.227
114.6
–3.3
–5.8
–5.5
–2.5
–2.0
–3.6
[c]
[c]
[42]
[42]
[43]
[44]
110.04
110.16
114.4
108.3
101.94
[c]
2.144[c]
2.142
2.182[c]
2.243
2.182anti
this work
[a] Abbreviations: L = 2-ethyl-4,4Ј,5,5Ј-tetramethyl-3-oxo-4,5-dihidro-1H-imidazolyl-1-oxyl; tmeda = N,N,NЈ,NЈ-tetramethylethylenedi-
amine; piv = pivalate; Me2bpy = 4,4Ј-dimethyl-2,2Ј-bipyridine; im = imidazole; py = pyridine. [b] Magnetic exchange coupling parameter
based on the Hamiltonian H = –JS1·S2. [c] Average values.
Eur. J. Inorg. Chem. 2009, 4471–4482
© 2009 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
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V. G ómez, M. Corbella
FULL PAPER
gand: the syn–syn mode induces larger |J| values than the the ground state is ST = 5/2 with S13 = 5, and the first
syn–anti mode.[50] The presence of a monatomic bridge in excited state (ST = 3/2 with S13 = 4) is at –3J/2 above the
the dinuclear and trinuclear complexes reduces the ground state. Therefore, when J ≈ –2.8 cm–1, at 4 K only the
Mn···Mn distance and increases the |J| value, displaying a ground state may be populated. A spin state ST = 5/2 can
major antiferromagnetic coupling. Therefore, both factors exhibit zero-field splitting (ZFS), which causes three doubly
can influence the magnetic exchange interaction.
degenerate spin states, Ms = Ϯ1/2, Ϯ3/2 and Ϯ5/2 (Kra-
mer’s degeneracy). If the ZFS effect is negligible, a narrow
signal may arise around g = 2; however, when the ZFS is
considerable, the signal should be broad at room tempera-
ture and split into several features at low temperature, as
found for compounds 1–3 and for analogous compounds
reported in the literature.[19–22]
Scheme 2. Bridges found in 1D, trinuclear and dinuclear com-
pounds reported in this study, respectively.
It is interesting to compare the two compounds with the
same µ1,3-carboxylate ligand, 4-ClC6H4COO, and one oxy-
gen-bridging ligand (3 and 5). This monatomic ligand must
be the most important pathway for the antiferromagnetic
interaction. As was indicated, this interaction is very sensi-
tive to the M–Ob–M angle, and is more antiferromagnetic
for larger angle values. Compound 3 presents a larger angle
than compound 5 (105.82 and 101.94°, respectively) and
µ1,3-carboxylate ligands in a syn–syn mode, compared to a
syn–anti mode in compound 5. A greater antiferromagnetic
behaviour should therefore be expected for 3 than for 5.
However, the experimental results show a larger |J| value
for 5 than for 3. In the trinuclear complex, one of the car-
boxylate ligands coordinated in a syn–syn mode is coplanar
to the Mn–Ob–Mn group and could exert a countercomple-
mentary effect, so would decrease the antiferromagnetic
contribution through the oxo bridge.[48] Therefore, the |J|
value is less than that expected, and this effect could explain
the greatest antiferromagnetic behaviour found for com-
pound 5.
Figure 10. Variable-temperature X-band EPR spectra of a pow-
dered sample of trinuclear compound 3.
The spectra at 4 K were simulated, with the easyspin
software,[51] by considering an isolated spin state S = 5/2
with axial (D) and rhombic (E) zero-field splitting. The ZFS
parameters obtained from these simulations therefore corre-
spond to the ground state, D5/2 and E5/2 and depend on the
ZFS parameters of the interacting ions, DMn and EMn, and
EPR Spectra
The EPR spectra of compounds 1–5 were recorded on dipolar and anisotropic interactions between the ions. By
powdered samples at different temperatures. At room tem- using this approach, quite good simulations were obtained
perature, all of them show a band centred at g ≈ 2; however, with D5/2 = 0.16 cm–1 and E5/2 = 0.05 cm–1 (linewidth of
at 4 K, the spectrum of each compound is noticeably dif- 600 G) for compound 1, D5/2 = 0.16 cm–1 and E5/2
ferent and allows identification of each type of complex.
=
0.043 cm–1 (linewidth of 450 G) for compound 2 and D5/2
The shape of the spectra of the trinuclear compounds 1– = 0.16 cm–1 and E5/2 = 0.053 cm–1 (linewidth of 800 G) for
3 is very sensitive to temperature. A very broad band compound 3 (Figure 11). These simulations reproduce the
centred at g ≈ 2 is observed at 295 K, with a peak-to-peak bands at low field quite well. However, compounds 1 and 3
linewidth (∆Hpp) of 930 G for 1, 890 G for 2 and 860 G for show other features around g Ͻ 2 that are not possible to
3. A broadening of this band is observed by decreasing the reproduce with similar ZFS values to compound 2. Never-
temperature until 100 K, where the ∆Hpp is 960 G for 1, theless, D and E values obtained for these compounds are
995 G for 2 and 950 G for 3. This band remains the most comparable to those reported elsewhere.[22]
intense feature until very low temperatures. However, at
The EPR spectrum of the 1D system 4 shows a single
4 K, the spectrum becomes quite complicated: the most in- band centred at g ≈ 2 that widens on decreasing the tem-
tense signal is found at low field (g ≈ 4), with a less intense perature (Supporting Information, Figure S1). The peak-to-
signal at g ≈ 2 and some others at high field. Figure 10 peak linewidth changes from 98 G at 77 K to 147 G at 4 K.
shows the effect of temperature on the EPR spectrum of The same behaviour was observed for analogous com-
compound 3; a similar behaviour is observed for the other pounds reported in the literature.[21,22] This broadening on
two trinuclear complexes (1 and 2). This spectrum is char- lowering the temperature may be explained by considering
acteristic of this type of compound.[19–23] As was indicated, the main factors that influence the linewidth for an iso-
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Eur. J. Inorg. Chem. 2009, 4471–4482

Coordination Modes of n-Chlorobenzoato Ligands
teraction J = –3.6 cm–1 and the zero-field splitting param-
eters of the single ion DMn and EMn. A fairly good simula-
tion was obtained with DMn = 0.187 cm–1 and EMn
0.061 cm–1 and g = 2 (Figure 12).
=
Conclusions
The three chlorobenzoato ligands (ortho, meta and para)
behave differently when forming polynuclear MnII com-
pounds. Depending on the MnII/phen ratio or solvent, three
types of complexes were obtained. For 2-ClC6H4COO, in-
dependent of the ratio or solvent, only the trinuclear com-
plex 1 was obtained. With 3-ClC6H4COO, independent of
the solvent, two compounds were obtained: the trinuclear
complex 2 and the 1D system 4. For 4-ClC6H4COO, inde-
pendent of the MnII/phen ratio, trinuclear 3 and the neutral
dinuclear compound 5 were obtained when ethanol and
acetonitrile were used, respectively.
The five compounds were magnetically characterized, all
displaying weak antiferromagnetic coupling. The exchange
coupling depends on the number of bridges involved and
the carboxylate bridge conformation. The dinuclear and tri-
nuclear compounds, with three bridging ligands, present |J|
values of the same order and larger than that of the 1D
compound, which has only two bridging ligands. In the tri-
nuclear complexes, the countercomplementary effect of the
µ1,3-carboxylate bridges reduces the antiferromagnetic in-
teraction. It is possible to distinguish the different com-
pounds from their EPR spectrum at 4 K.
Figure 11. X-band EPR spectra of powdered samples of trinuclear
compounds 1–3 at 4 K. The dashed line is the best simulation
achieved.
tropic Heisenberg 1D system.[52] When the superexchange
interactions along the chain are the predominant effect, a
narrowing of the signal is observed, while when the dipolar
interactions are more important, a broadening of the signal
is observed, as in compound 4. Moreover, for MnII 1D sys-
tems, there are additional broadening mechanisms, such as
the hyperfine coupling and the single-ion ZFS effects.
Neutral dinuclear compound 5 also displays some
changes in the shape of the EPR spectrum at different tem-
peratures (Supporting Information, Figure S2). The most
important signal, centred at g ≈ 2, shows a ∆Hpp of 260 G
at 77 K, which increases until reaching 360 G at 4 K. This
compound shows an antiferromagnetic coupling, the
ground state is therefore S = 0, and at 4 K it should be
Experimental Section
General Remarks: C, H, N and Cl analyses were carried out by
the Servei de Microanàlisi of the Consell Superior dЈInvestigacions
Científiques (CSIC). Infrared spectra were recorded on KBr pellets
in the range 4000–400 cm–1 with a Thermo Nicolet Avatar 330
FTIR spectrometer. X-ray diffraction measurements and resolution
were carried out at the Unidade de Raios X (Universidade de San-
tiago de Compostela). Magnetic susceptibility measurements (2–
300 K) and magnetization measurements at 2 K, (0–50000 G) were
carried out in a Quantum Design MPMP SQUID Magnetometer
at the Unitat de Mesures Magnètiques (Universitat de Barcelona).
Two different magnetic fields were used for the susceptibility mea-
surements, 300 G (2–5 K) and 3000 G (2–300 K), with superimpos-
able graphs. Pascal’s constants were used to estimate the diamag-
netic corrections for the compound. The fit was performed by mini-
mising the function R = Σ[(χMT)exp – (χMT)calcd]2/Σ[(χMT)exp]2. So-
lid-state EPR spectra were recorded with X-band (9.4 GHz) fre-
quency from room temperature to 4 K by using a Bruker ESP-300E
spectrometer, at the Unitat de Mesures Magnètiques (Universitat
de Barcelona). The computational package easyspin[51] was used to
simulate the EPR spectra of the trinuclear and dinuclear com-
pounds. For the trinuclear complexes, the simulation was per-
formed by considering an isolated ground state, S = 5/2, with zero-
field splitting (D and E). The simulation of the EPR spectrum of
the dinuclear complex was performed by considering all the spin
states and including the magnetic interaction between the MnII ions
(J) and the zero-field splitting parameters for each manganese ion
(DMn and EMn) in the calculations.
EPR-silent. However, as the
J
value is small
(–3.6 cm–1), the lowest excited states may also be populated.
For the simulation of the experimental EPR spectrum at
4 K with the easyspin software,[51] a dinuclear system of two
S = 5/2 ions was considered, with a magnetic exchange in-
Figure 12. X-band EPR spectra of powdered sample of neutral di-
nuclear compound 5. The dashed line is the best simulation
achieved.
Eur. J. Inorg. Chem. 2009, 4471–4482
© 2009 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.eurjic.org
4479

V. G ómez, M. Corbella
FULL PAPER
Synthesis: All manipulations were carried out at room temperature
under aerobic conditions. Reagents and solvents were obtained
from commercial sources and used without further purification.
ClC6H4COO)2]·nH2O instead. A yellow solid was formed, isolated
by filtration and dried in air. Yield: 0.55 g (75%).
C66H40Cl6Mn3N4O12·H2O (1476.59 gmol–1): calcd. C 53.68, H
[Mn(n-ClC6H4COO)2]·nH2O (n = 2, 3, 4) was synthesized by the 2.87, Cl 14.41, N 3.79; found C 53.5, H 2.8, Cl 14.4, N 3.8. Yellow
reaction of MnCO3 and n-ClC6H4COOH in boiling water. After
several hours, the solution was filtered and concentrated under re-
duced pressure to give a pale pink precipitate of the desired prod-
uct. Yields were calculated from the stoichiometric reaction.
needlelike crystals, suitable for X-ray diffraction, were obtained
when a solution of [Mn(4-ClC6H4COO)2]·nH2O in CH3CH2OH
was layered with 1,10-phenanthroline dissolved in CH2Cl2 in a 1:1
ratio. Selected IR data (KBr pellet): ν = 1604 (vs), 1557 (vs), 1538
˜
(s), 1516 (m), 1406 (vs), 1091 (m), 1013 (m), 854 (m), 843 (m), 774
Synthesis of Compounds
(s), 729 (m), 687 (w), 534 (m) cm–1.
[Mn3(µ-2-ClC6H4COO)6(phen)2] (1): [Mn(2-ClC6H4COO)2]·nH2O
(0.60 g, 1.50 mmol) and 1,10-phenanthroline (0.20 g, 1.00 mmol),
both dissolved in absolute ethanol, were mixed (total volume
≈ 75 mL) and stirred for 15 min. The yellow solid formed was iso-
lated by filtration and dried in air. Yield: 0.59 g (81%).
C66H40Cl6Mn3N4O12 (1458.57 gmol–1): calcd. C 54.35, H 2.76, Cl
14.58, N 3.84; found C 54.3, H 2.7, Cl 14.7, N 3.8. Yellow needle-
like crystals, suitable for X-ray diffraction, were obtained by dis-
solving [Mn(2-ClC6H4COO)2]·nH2O in CH3CN and layering with
1,10-phenanthroline in CH2Cl2 in a 1:1 ratio. Selected IR data
[Mn(µ-3-ClC6H4COO)2(phen)]n (4): 1,10-phenanthroline (0.30 g,
1.50 mmol) in absolute ethanol was added to a solution of [Mn(3-
ClC6H4COO)2]·nH2O (0.60 g, 1.50 mmol) in the same solvent. The
resulting mixture (≈100 mL) was stirred for 15 min to give a pale
yellow solid that was filtered and dried in air. Yellow crystals suit-
able for X-ray diffraction were obtained after several days by slow
evaporation of the mother liquor in the refrigerator. Yield: 0.61 g
(74%). C26H16Cl2MnN2O4 (546.26 gmol–1): calcd. C 57.17, H 2.95,
Cl 12.98, N 5.13; found C 57.0, H 2.9, Cl 13.2, N 5.1. Selected IR
data (KBr pellet): ν = 1653 (vs), 1606 (s), 1562 (s), 1512 (w), 1422
˜
(KBr pellet): ν = 1607 (vs), 1549 (m), 1514 (w), 1436 (w), 1420 (m),
˜
(m), 1386 (vs), 1143 (w), 1068 (w), 862 (w), 849 (m), 761 (s), 730
1406 (s), 1387 (vs), 1051 (m), 862 (w), 843 (m), 762 (s), 727 (m),
(s) cm–1.
648 (w), 464 (w) cm–1.
[{Mn(4-ClC6H4COO)(phen)}2(µ-4-ClC6H4COO)2(µ-H2O)]
(5):
[Mn3(µ-3-ClC6H4COO)6(phen)2] (2): The same procedure was fol-
lowed as for compound 1, in this case with [Mn(3-ClC6H4COO)2]
·nH2O. A yellow solid was formed, filtered and dried in air. Yield:
0.66 g (89%). C66H40Cl6Mn3N4O12·0.5H2O (1467.58 gmol–1):
calcd. C 54.01, H 2.82, Cl 14.49, N 3.82; found C 54.1, H 2.9, Cl
1,10-phenanthroline (0.12 g, 0.63 mmol) in acetonitrile was added
to a suspension of [Mn(4-ClC6H4COO)2]·nH2O (0.25 g, 0.63 mmol)
in the same solvent. The resultant mixture (total volume ≈50 mL)
was stirred for about 15 min, and a yellow solid formed that was
filtered and dried in air. Yellow crystals suitable for X-ray diffrac-
tion were obtained by slow evaporation of the mother liquor in the
refrigerator after several days. Yield: 0.66 g (89%).
C52H34Cl4Mn2N4O9 (1110.53 gmol–1): calcd. C 56.24, H 3.09, Cl
12.77, N 5.05; found C 56.3, H 3.0, Cl 13.1, N 5.1. Selected IR
14.4, N 3.7. Selected IR data (KBr pellet): ν = 1606 (vs), 1560 (vs),
˜
1539 (m), 1516 (m), 1422 (m), 1392 (s), 867 (w), 846 (w), 763 (m),
748 (w), 731 (m), 675 (w), 657 (w), 639 (w), 439 (w) cm–1.
[Mn3(µ-4-ClC6H4COO)6(phen)2] (3): The same procedure for the
preparation and crystallization of 1 was followed, by using [Mn(4-
data (KBr pellet): ν = 1606 (vs), 1591 (s), 1556 (s), 1515 (m), 1423
˜
Table 8. Crystallographic data for compounds 1, 3·2CH2Cl2, 4 and 5.
1
3·2CH2Cl2
4
5
Chemical formula
Formula weight
Crystal colour, habit
T / K
λ (Mo-Kα) / Å
Crystal system
Space group
Crystal size / mm
a / Å
b / Å
c / Å
α / º
β / º
C66H40Cl6Mn3N4O12
1458.54
yellow, prism
100(2)
C68H44Cl10Mn3N4O12
1628.39
colourless, prism
100(2)
C26H16Cl2MnN2O4
546.25
needle, yellow
100(2)
0.7107
monoclinic
C2/c
0.25ϫ0.05ϫ0.02
26.6151(11)
11.8583(5)
7.2206(3)
90
94.008(3)
90
2273.32(16)
4
1.596
C52H34Cl4Mn2N4O9
1110.51
yellow, prism
100(2)
0.7107
monoclinic
I2/a
0.21ϫ0.08ϫ0.07
15.4589(17)
15.610(2)
20.154(3)
90
101.578(5)
90
4764.4(12)
4
1.545
0.7107
0.7107
triclinic
triclinic
¯
¯
P1
P1
0.24ϫ0.06ϫ0.04
11.2545(3)
11.3480(3)
13.1717(4)
68.8470(10)
72.5150(10)
75.8420(10)
1478.76(7)
1
0.15ϫ0.09ϫ0.07
11.1636(4)
13.0051(5)
13.2017(5)
72.328(2)
66.058(2)
89.276(2)
1655.59
γ / º
V / Å3
Z
1
ρcalcd. / g cm–3
µ / mm–1
F(000)
1.638
0.97
737
1.633
1.034
821
0.854
1108
0.818
2256
θ range / º
Index ranges
1.7–26.4
1.66–26.41
–12 Յ h Յ 13
–15 Յ k Յ 16
0 Յ l Յ 16
6797/9/449
1.043
1.53–26.42
–33 Յ h Յ 33
0 Յ k Յ 14
0 Յ l Յ 9
4144/0/160
0.920
1.66–26.38
–19 Յ h Յ 18
0 Յ k Յ 19
0 Յ l Յ 25
4881/0/325
1.055
–13 Յ h Յ 14
–12 Յ k Յ 14
0 Յ l Յ 16
Data/restraints/parameters 6059/0/412
Goodness-of-fit on F2
0.991
0.0377, 0.0754
0.062, 0.0836
[b]
R1[a], wR2[b] [IϾ2σ(I)]
0.0457, 0.1077
0.0562, 0.1147
0.0457, 0.0867
0.1011, 0.0978
0.0360, 0.0823
0.0481, 0.0869
R1[a], wR2 (all data)
2
2 2
2
[a] R1 = ∑||Fo| – |Fc||/∑|Fo|. [b] wR2 = {∑[w(Fo – Fc ) ]/∑[w(Fo2)2]}1/2, w = 1/[σ2(Fo2) + (aP)2 + bP], where P = [max(Fo2,0) + 2Fc ]/3.
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Eur. J. Inorg. Chem. 2009, 4471–4482

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This work was supported by the Ministerio de Ciencia y Tecnología
of Spain through the project CTQ2006-01759/BQU and the Com-
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V. G ómez, M. Corbella
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Received: June 14, 2009
Published Online: September 2, 2009
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