Solvent-induced structural transformation from heptanuclear to decanuclear [Co-Ln] coordination clusters: trapping of unique counteranion and understanding of aggregation pathways

Article abstract of DOI:10.1039/d1dt01278a

Five new cobalt(ii/iii)-lanthanide(iii)-based coordination aggregates, [LnIII3CoII2CoIII2(L1)₂(O₂CCMe₃)₈(OH)₄(OMe)₂(H₂O)₄]·Ln(η¹-O₂CCMe₃

Full text of DOI:10.1039/d1dt01278a

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PAPER
Solvent-induced structural transformation from
heptanuclear to decanuclear [Co–Ln]
coordination clusters: trapping of unique
counteranion and understanding of
aggregation pathways†
Cite this: Dalton Trans., 2021, 50,
9574
a
b
b
c,d
Dipmalya Basak, Emma Regincós Martí, Mark Murrie,
Debashis Ray
Ivan Nemec
and
a
*
III
3
II
2
III
2
Five new cobalt(II/III)–lanthanide(III)-based coordination aggregates, [Ln Co Co (L1)
2 2 3 8 4
(O CCMe ) (OH)
1
2
(
OMe)
2
(H
2
O)
4
]·Ln(η -O
2
CCMe
3
)
2
(η -O
2 3 2 2 2
CCMe ) (MeOH) ·2MeOH·2H O (where Ln = Tb (1), Ho (3), and
III
II
3
III
4
III
3
II
2
III
5
H
2
L1 = N-(2-hydroxyethyl)-salicylaldimine), Tb Co Co (L1) (O CCMe ) (OH)10(H O) (4) and Ln Co Co
4 2 3 9 2
3
4 2 3
(L1) (O CCMe )10(OH)10 (Ln = Dy (5), Ho (6)) have been synthesized and characterized, including structural
analysis via single-crystal X-ray diffraction. The dysprosium analogue (2) of 1 and 3 was previously reported
by us. The heptanuclear monocationic clusters in 1 and 3 were formed by placement of seven metal ions (4
Co and 3 Ln) in a vertex shared dicubane structure from the control of two Schiff base anions and crystal-
1
2
lized in the presence of in situ generated and literature unknown counter anions Tb(η -O
2
CCMe
3 2
) (η -
−
1
2
−
O CCMe
2
3
)
2
(MeOH)
2
and Ho(η -O
2
CCMe
3
)
2
(η -O CCMe ) (MeOH) . Interesting solvent-induced cluster
2 3 2 2
structure transformation was observed on dissolving the heptanuclear aggregates in MeCN for the for-
mation of decanuclear clusters 4–6. These high nuclearity clusters consist of a vertex shared heptanuclear
dicubane part and a curved trinuclear chain linking the two cubic halves. The dicubane unit differs from that
II/III
III
Received 18th April 2021,
Accepted 6th June 2021
of the heptanuclear precursors in the presence of Co
at the shared vertex as opposed to Ln and the
absence of OMe− bridges. HRMS (+ve) analysis shed light on the pathway of formation of these heptanuc-
lear molecules, while at the same time revealing a different aggregation process for the decanuclear
clusters.
DOI: 10.1039/d1dt01278a
rsc.li/dalton
imine donor and adjacent phenol plus amino alcohol groups
Introduction
of varying types are known to provide both mononuclear and
2
Surprises in dual-mode coordination chemistry and mixed multinuclear complexes of 3d ions. The synthesis of multime-
metal ion structures of 3d–4f coordination aggregates have tallic 3d–4f coordination complexes can be achieved by utiliz-
enriched synthetic chemistry in a direct way in recent years. ing ligands bearing two different pockets appropriate to attract
3
Simple but asymmetric tridentate ONO donor ligand systems, two types of metal ions. At the same time, ligand systems
such as sal–ea, have been known to synthetic coordination without any such clearly defined pockets have been known to
1
chemists for many years. Schiff bases providing a central hold 3d and 4f ions side-by-side within the same ligand back-
bone via utilization of bridging phenoxido, alkoxido, hydro-
4
xido, carboxylato, etc. groups. The research in this area has
attracted significant devotion due to synthetic challenges,
a
Department of Chemistry, Indian Institute of Technology, Kharagpur 721 302, India.
E-mail: dray@chem.iitkgp.ac.in; Fax: (+91) 3222-82252; Tel: (+91) 3222-283324
b
unique structures and interesting magnetic properties. Most
coordination cluster molecules are synthesized by serendipi-
School of Chemistry, University of Glasgow, Glasgow, G12 8QQ, UK
c
Department of Inorganic Chemistry, Faculty of Science, Palacký University,
5
1
d
7. listopadu 12, 77147 Olomouc, Czech Republic
tous procedures and their formation is poorly understood.
Central European Institute of Technology, CEITEC BUT, Purkyňova 656/123, 61200
Recent endeavors to understand the formation of polynuclear
molecules, including metal–organic macrocycles, polyoxometa-
lates and coordination clusters, have yielded dividends in
Brno, Czech Republic
Electronic supplementary information (ESI) available: X-ray crystallographic
data, Tables S1–S5, Fig. S1–S12, and Chart S1. CCDC 2061606 and
061609–2061612 for complexes 1, 3, 4, 5 and 6. For ESI and crystallographic
data in CIF or other electronic format see DOI: 10.1039/d1dt01278a
†
6,7
certain cases through the utilization of mass spectrometry.
2
Thus, synthetic efforts can be undertaken with the anticipation
9574 | Dalton Trans., 2021, 50, 9574–9588
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of obtaining newer composition and structural types capable reported only once earlier. Recently Co
Paper
4
a
II/III
-4f aggregates have
of providing fresh insight into the formation of such coordi- attracted interest not only from a structural point of view but
1
5
nation aggregates.
also due to their interesting magnetic properties.
In our previous investigation using N-(2-hydroxyethyl)-3-
The synthetic strategies for obtaining high nuclearity
coordination clusters have attracted a lot of interest in recent methoxy-salicylaldimine, a MeCN solvent-induced transform-
8
times. The investigation of the formation of such high nucle- ation from heptanuclear to hexanuclear aggregates was investi-
4
a
arity molecules is not only fascinating from a synthetic point gated. As a continuation of that work, herein the coordi-
of view, but also helps in understanding the various factors nation potency of the ligand N-(2-hydroxyethyl)-salicylaldimine
6
c,7b,d,e
driving the aggregation process.
2
In comparison to (H L1) (Chart 1) was used, in association with in situ generated
homometallic 3d coordination cluster molecules, the literature hydroxido and methoxido bridges and bridging pivalate ions
concerning investigation into the formation of heterometallic (Chart S1†) derived from Co (µ-OH )(O CCMe ) (HO CCMe ) ,
2
2
2
3 4
2
3 4
3
d–4f clusters is extremely scarce. A very common strategy for the synthesis of mixed-valent Co-4f aggregates of two
III
II
III
employed for the synthesis of higher nuclearity aggregates is different nuclearities: heptanuclear Ln Co Co (Ln = Tb, Ho)
the utilization of flexible ligand systems with multiple bridging and decanuclear Tb Co Co and Ln Co Co (Ln = Dy, Ho).
3
2
II
2
III
III
II
III
III
3
3
4
3
2
5
groups. For example, the use of a Schiff base involving o-vanil- The Dy analogue of the heptanuclear clusters was reported
4
a
1
lin and o-aminophenol bearing adjacent ONO and OO binding earlier by us. Previously unknown counter anions Tb(η -
II
III
9
2
−
1
2
sites offered a tetranuclear Co Dy complex. When the O CCMe ) (η -O CCMe ) (CH OH) and Ho(η -O CCMe ) (η -
2
2
2
3 2
2
3 2
3
2
2
3 2
−
aminophenol backbone was replaced by amino alcohol, it
resulted in clusters with increased nuclearities.
O
2
CCMe
3
)
2
(CH
3
OH)
2
, generated in situ, were trapped by the
4
a,10
III
3
II
2
III
2
+
Using even monocationic heptanuclear aggregates Tb Co Co
and
III
II
III
2
+
smaller and simpler ligand systems like amino alcohols and Ho Co Co
during crystallization. In MeCN solution,
3
2
−
carboxylates can provide access to very high nuclearity coordi- removal of OMe bridges and coordinative trapping of the
nation clusters purely by serendipitous means, but makes it counter anion by ligand-bound mononuclear cobalt species
1
1
difficult to track their formation mostly due to numerous prob- led to the solvent induced structural transformation of the
III
II
III
able pathways of aggregation of initially formed species. heptanuclear vertex-shared-dicubane cores {Ln Co Co } to
3
2
2
III
II
III
Phenol-based Schiff bases can be useful for providing hetero- high nuclearity decanuclear {Ln Co Co } cores. The trans-
3
3=2
4=5
metallic coordination clusters having 3d 4f cores from one- formed decanuclear cores can be best described as a vertex-
m
n
III
II
III
pot reactions having mixtures of 3d and 4f metal ion salts and shared-dicubane {Ln Co Co
}
unit connected to
a
2
3=2
2=3
1
2
III
III
ligand anions. Tracking the formation of such coordination {Ln Co } curved chain. To our knowledge, the highest known
2
4
a
clusters is more feasible.
nuclearity for a Co–Ln aggregate utilizing Schiff base-type
Water and solvent molecules coordinated to metal ions are ligands is reported for a dodecanuclear Dy Co wheel. The
III
II
2
16
1
0
activated towards hydrolysis. Ligand-controlled self-assembly decanuclear aggregates discussed in this work represent the
II/III
leading to 3d–4f clusters can limit the degree of metal ion highest nuclearity for mixed valent Co
–Ln coordination
hydrolysis resulting in the formation of structurally well- clusters obtained using a Schiff base ligand, while at the same
defined hydroxide clusters. Carboxylates too are well known as time possessing a unique and previously unreported topology
time-honored ligands for the binding of lanthanide ions. Both for nuclearity ten among 3d–4f aggregates. The topology for
simple carboxylates and substituted analogues like pivalates the heptanuclear clusters has only one literature report in the
can act as hydrolysis-limiting and structure supporting co- Dy analogue from our lab. This is also only the second report
ligands. The structure and formation of 3d–4f coordination of the utilization of H L1 in the synthesis of 3d–4f molecules.
2
clusters also depend on the reaction and crystallization
medium. The effect of the solvent medium on the nuclearity of
4
a
such aggregates has been investigated by us previously. Such
solvent-induced transformation of cluster structure and nucle-
arity is interesting since the methodology can be utilized for
the synthesis of high nuclearity clusters not accessible via
direct reaction. The investigation of the pathway for these
transformations in solution gives a wealth of information
about the stability of intermediate species in various solvent
mediums and the different types of aggregation processes
involved. Isolation of unusual species can also be sometimes
4
a,13
accomplished during crystallization of such aggregates.
There have been only four examples of pure mononuclear
lanthanide carboxylate anions associated with alkali metal and
ammonium cations: K [Er(O CH) ]·2H O, K [Tb(O CH) ],
3
2
2
6
2
5
2
8
1
4
(NH
4
)
2
[La(O
2
CCH
3
)
6
]·0.5H
O
and
K
3
[Yb(O
2
CCH
3
)
6
2
]·4H O.
Pure monoanionic dysprosium carboxylates associated with
Chart 1 Structure of H
2
L1 and its coordination modes observed in this
large heterometallic heptanuclear cationic aggregates were work.
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calcd (%) for C84
H
164Co
4
N
2
O
44Ho
4
: C, 36.01; H, 5.90; N, 1.00.
Experimental section
Reagents and starting materials
Found (%): C, 36.00; H, 5.87; N, 1.02. Selected IR peaks: (KBr,
−1
cm , vs = very strong, br = broad, s = strong, m = medium, w =
The chemicals used were obtained from the following sources: weak): 3422 (br, ˜ν OH), 1651 (s, ˜ν CvN), 1558 (s, asym. ˜ν COO),
cobalt carbonate from SRL India; triethylamine from Merck, 1429 (s, sym. ˜ν COO). UV-vis: λmax, nm (ε, L mol− cm−1) (MeCN)
1
3 3 2
India; pivalic acid from Sigma Aldrich; Tb(NO ) ·5H O, Dy = 691 (94), 592 (193), 522 (354), 404 (2917), 312 (9022), 252
(
NO
3
)
3
·5H
2
O and Ho(NO
3
)
3
·5H
2
O from Alfa Aesar; salicylalde- (48 885).
III
II
3
III
4
hyde from Spectrochem, India and 2-hydroxyethylamine from
SD FineChem, India. All other chemicals and solvents used in Ln Co Co (L1)
Tb Co Co (L1) (O CCMe ) (OH) (H O)
(4)
and
3
4
2
3 9
10
2
III
3
II
2
III
5
4
(O
2
CCMe
3
)
10(OH)10 (Ln = Dy (5), Ho (6)). For
this work were reagent grade materials and used as received the synthesis of complexes 4–6, red block-shaped crystals of
without further purification.
Co (µ-OH )(O CCMe (HO
ing to a literature procedure.
1–3, respectively (0.01 mmol), were treated with a 2 ml portion
was prepared accord- of MeCN to partially dissolve the respective complexes. The
Cobalt carbonate (4.0 g, suspension was left to stand for half an hour and filtered. On
2
2
2
3
)
4
2
CCMe
3
)
4
1
7
3
1
4 mmol) was added to an excess of pivalic acid (20.0 g, very slow evaporation of the filtrate for a month, small red
96 mmol) in water (3 mL) at 100 °C and left to stir for 24 h, block-shaped crystals appeared which were found to be suit-
leading to its dissolution. After cooling the solution to room able for X-ray diffraction structure analysis.
III
II
III
temperature, MeCN (50 mL) was added and stirred briefly. The
solution was filtered and cooled to 5 °C, giving pink crystals
[Tb Co Co ] (4). Yield: 0.0019 g (15%). Anal. calcd (%) for
3
3
4
C
81
H
129Co
7
N
4
O
37Tb
3
: C, 36.85; H, 4.92; N, 2.12. Found (%): C,
−1
within one day. After collecting the crystals, the solution was 36.80; H, 4.89; N, 2.15. Selected IR peaks: (KBr, cm , vs = very
further cooled to −4 °C for 2 days to get a second crop. This strong, br = broad, s = strong, m = medium, w = weak): 3415
too was collected by filtration, washed with cold MeCN and (br, ˜ν OH), 1651 (s, ˜ν CvN), 1553 (s, asym. ˜ν COO), 1425 (s, sym.
˜ν COO). UV-vis: λmax, nm (ε, L mol− cm ) (MeOH) = 680 (80),
1
−1
dried in air. Yield = 65.8%.
N-(2-Hydroxyethyl)-salicylaldimine (H L1) was synthesized 583 (200), 514 (360), 410 (2810), 310 (9130), 245 (48 780).
2
1
c
III
3
II
2
III
5
following a previously reported literature procedure.
[Dy Co Co ] (5). Yield: 0.0020 g (15%). Anal. calcd (%) for
C
86
H
136Co
7
N
4
O
38Dy
3
: C, 37.78; H, 5.01; N, 2.05. Found (%): C,
Synthesis of the complexes
−1
3
7.75; H, 4.99; N, 2.03. Selected IR peaks: (KBr, cm , vs = very
strong, br = broad, s = strong, m = medium, w = weak): 3408
O (Ln = Tb (1), (br, ˜ν OH), 1650 (s, ˜ν CvN), 1554 (s, asym. ˜ν COO), 1426 (s, sym.
III
II
III
1
[
Ln Co Co (L1)
2
(O
CCMe
2
CCMe (OH)
2
(H O) ·2MeOH·2H
3
)
8
4
(OMe)
2
(H
2
O)
4
]·Ln(η -
3
2
2
2
O
2
CCMe
3
)
2
(η -O
2
3
)
2
2
2
Ho (3)). A general procedure was followed for the synthesis of ˜ν COO). UV-vis: λmax, nm (ε, L mol− cm ) (MeOH) = 682 (83),
1
−1
1
and 3. To a MeOH (2 mL) solution of H
2
L1 (0.039 g, 580 (203), 514 (366), 414 (2817), 312 (9134), 247 (48 786).
III
II
III
0
.2 mmol), a MeOH (2 mL) solution of Ln(NO
3
)
3
·5H
2
O
[Ho Co Co ] (6). Yield: 0.0020 g (15%). Anal. calcd (%) for
3 2 5
(
0.2 mmol) was added drop-wise to give a yellow solution. After C H Co Ho N O : C, 37.68; H, 5.00; N, 2.04. Found (%): C,
86 136 7 3 4 38
−1
stirring for 10 min, Co
2
(μ-OH
2
)(O
2
CCMe
3
)
4
(HO
2
CCMe
3
)
4
37.70; H, 4.97; N, 2.01. Selected IR peaks: (KBr, cm , vs = very
(0.095 g, 0.1 mmol) in MeOH (1 mL) was added and stirred for strong, br = broad, s = strong, m = medium, w = weak): 3410
another 10 min, giving a red brown solution. The resulting (br, ˜ν OH), 1650 (s, ˜ν CvN), 1553 (s, asym. ˜ν COO), 1423 (s, sym.
solution was treated with Et
N (111.2 μL, 0.4 mmol) resulting ˜ν COO). UV-vis: λmax, nm (ε, L mol− cm ) (MeOH) = 683 (78),
1
−1
3
in a dark red solution and left under magnetic stirring for a 584 (196), 516 (364), 412 (2808), 309 (9128), 244 (48 789).
period of 3 h. The precipitate was filtered off through a G4 bed
and the filtrate was kept for slow evaporation of the solvent
Physical measurements
leading to good X-ray diffraction quality crystals after about a A PerkinElmer model 240C elemental analyzer was used to
month. The synthesis of the Dy analogue (2) was described by perform elemental analyses (C, H and N). FTIR spectra were
4
a
us in a previous publication.
measured on a PerkinElmer RX1 spectrometer while a
Shimadzu UV 3100 UV/Vis/NIR spectrophotometer was used to
record the solution electronic absorption spectra. A Bruker
III
II
III
[
Tb Co Co ] (1). H
2
L1 (0.039 g, 0.2 mmol), Tb(NO
3
)
3
·5H
2
O
3
2
2
(
(
0.090 g, 0.2 mmol), Co (μ-OH )(O CCMe ) (HO CCMe )
2
2
2
3 4
2
3 4
0.095 g, 0.1 mmol), and Et
.055 (40% based on Tb). Anal. calcd (%) for collect the electrospray ionization (ESI) high resolution mass
C H Co N O Tb : C, 36.32; H, 5.95; N, 1.01. Found (%): C, spectra to understand the formation and transformation of the
3
N (111.2 μL, 0.4 mmol). Yield = Daltonics micrOTOF mass spectrometer was employed to
0
g
8
4
164
4
2
44
4
3
6.28; H, 5.92; N, 1.05. Selected IR peaks: (KBr, cm−1, vs = very coordination clusters.
strong, br = broad, s = strong, m = medium, w = weak): 3420
br, ˜ν OH), 1652 (s, ˜ν CvN), 1560 (s, asym. ˜ν COO), 1430 (s, sym.
SQUID measurements
COO). UV-vis: λmax, nm (ε, L mol cm ) (MeCN) = 692 (97), All magnetic measurements were carried out on powdered
94 (198), 521 (352), 405 (2920), 314 (9028), 255 (48 895). crystalline samples restrained in eicosane using a Quantum
(
˜
ν
−
1
−1
5
III
3
II
2
III
2
[
Ho Co Co ] (3). H L1 (0.039 g, 0.2 mmol), Design MPMS 3 SQUID magnetometer. Data were corrected for
2
Ho(NO
3
)
3
·5H
2
O
(0.090
CCMe
g,
0.2
mmol),
Co
2
(μ-OH
2
)
the diamagnetic contribution of the sample holder and eico-
sane by measurements, and for the diamagnetism of each
(O
2
CCMe
3
)
4
(HO
2
3
)
4
(0.095 g, 0.1 mmol), and Et N
3
(111.2 μL, 0.4 mmol). Yield = 0.056 g (41% based on Ho). Anal. compound.
9576 | Dalton Trans., 2021, 50, 9574–9588
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Paper
Crystal data collection and refinement
Results and discussion
Synthetic methodology
Single crystal X-ray diffraction data for 1, 3, and 4–6 were col-
lected on a Bruker SMART APEX-III CCD X-ray diffractometer
furnished with graphite-monochromated Mo Kα (λ = 0.71073 Å) 2-{(2-Hydroxyethyl)imino}methylphenol (H
2
L1) was obtained
−1
radiation by the ω scan (width of 0.3° frame ) method at through the condensation of salicylaldehyde and 2-hydroxy-
93–300 K with a scan rate of 4 s per frame. SAINT and XPREP ethylamine in a 1 : 1 molar ratio under refluxing conditions.
2
18
software were used for data processing and space group deter- The coordinative reactivity of H
mination. The structure was solved using the direct method of (NO ·5H O and Co (µ-OH )(O CCMe
SHELXS-2014 and then refined with full-matrix least squares presence of NEt and MeCN-induced structural transformation
using the SHELXL-(2014/7) program package included in have been examined to obtain products of two different types
2
L1 in MeOH toward Ln
)
) (HO CCMe in the
3 4
)
3 4
3
3
2
2
2
2
2
1
9
3
2
0
2
1
22
WINGX system Version 2014 and Olex2 Version 1.2. Data having aggregate structures as summarized in Scheme 1. The
were corrected for Lorentz and polarization effects; an empirical reaction of H
2
L1 with Ln(NO
3
)
3
·5H
2
O (Ln = Tb, Ho) and Co
2
(µ-
in
23
absorption correction was applied using SADABS.
2 2
The OH )(O CCMe (HO CCMe
)
3 4
2
3
)
4
in the presence of NEt
3
locations of the heaviest atoms (Ln and Co) were determined 1 : 0.5 : 1 : 4 molar ratio in MeOH resulted in red-brown solu-
easily. The O, N, and C atoms were subsequently determined tions, from which red block-shaped single crystals of 1 and 3
from the difference Fourier maps. These atoms are refined ani- were obtained in 40% and 41% yields, respectively (eqn (1)).
sotropically. The H atoms were incorporated at calculated posi- Single-crystal X-ray structure analysis revealed the formation of
III
3
II
2
III
2
tions and refined with fixed geometry and riding thermal para- cationic heptanuclear {Ln Co Co } cores in 1 (Tb) and 3 (Ho)
meters with respect to their carrier atoms. Some of the crystals from the coordination control of two ligand anions. Elemental
showed somewhat weak diffraction and diffuse scattering. The analysis and physical characterizations were in good agreement
electron density peak of 4.780 e at about 1.880 Å from Co3 and with the molecular formulae
.515 Å from O15 in 6 could not be modeled as any sensible
for 1 and 3, respectively, and the cationic
species and was considered as an absorption artifact. nature of the complexes. During crystallization, the previously
C
84
H
164Co
4
N
2
O
44Tb
4
and
1
84 4 2 4
C H164Co N O44Ho
1
2
Crystallographic diagrams were presented using DIAMOND soft- unreported anionic species Tb(η -O
2
CCMe
3
)
2
(η -O
CCMe (CH
parameters is summarized in Table 1. Crystallographic data were generated in situ from the reaction medium and were
including structure factors) have been deposited with the crucial for the growth of the crystals of 1 and 3 serving as
2 3 2
CCMe )
OH)
3 2
24
−
1
2
−
ware. A summary of the crystal data and relevant refinement (CH
3
OH)
2
2
and Ho(η -O CCMe
)
3 2
(η -O
2
)
3 2
(
III
II
III
Cambridge Crystallographic Data Centre as supplementary pub- counter anions to the cationic {Ln Co Co } cores.
3
2
2
2−
lications CCDC – 2061606 and 2061609–2061612.†
Coordination of imine-centered L1
to Co (µ-OH )
2 2
Table 1 Crystal data and structure refinement details for 1, 3, 4, 5 and 6
Compound
1
3
4
5
6
Formula
F.W. (g mol
Crystal system
Space group
Crystal color
Crystal size/mm
a/Å
b/Å
c/Å
α
C
84
H
164Co
4
N
2
O
44Tb
4
C
84
H
164Co
4
N
2
O
44Ho
4
C
81
H
129Co
7
N
4
O
37Tb
3
C
86
H
136Co
7
N
4
O
38Dy
3
86 7 4 3
C H136Co N O38Ho
2741.30
Monoclinic
C2/c
Red
0.16 × 0.15 × 0.13
18.1767(11)
38.392(2)
18.6387(10)
90°
−
1
)
2777.58
Monoclinic
P2/n
2801.58
Monoclinic
P2/n
2640.14
Monoclinic
P2 /n
Red
0.15 × 0.14 × 0.12
17.9546(11)
38.827(2)
18.5890(12)
90°
2734.01
Monoclinic
C2/c
1
Red
Red
Red
3
0.23 × 0.20 × 0.19
19.1693(9)
12.4008(7)
27.0683(13)
90°
0.25 × 0.23 × 0.22
19.075(3)
12.3733(18)
27.043(4)
90°
0.16 × 0.15 × 0.14
18.1864(11)
38.561(2)
18.5641(11)
90°
β
γ
V/Å
Z
D
μ/mm
107.573(3)°
90°
6134.2(5)
2
1.504
2.875
107.465(5)°
90°
6088.4(16)
2
1.526
3.172
113.214(3)°
90°
11 909.7(12)
4
1.472
2.773
108.441(3)°
90°
12 350.3(13)
4
1.470
2.774
108.166(2)°
90°
12 358.7(13)
4
1.473
2.879
3
−
3
c
/g cm
−
1
F(000)
T/K
Total reflns
R(int)
2804
298(2)
46 499
0.0459
2812
296(2)
94 615
0.0743
5292
293(2)
90 447
0.1431
5484
300(2)
47 139
0.0844
5496
296(2)
100 001
0.0513
Unique reflns
Observed reflns
Parameters
10 874
8043
678
0.0502, 0.1510
1.086
10 806
8719
675
0.0509, 0.1438
1.052
20 922
10 076
1360
0.0781, 0.2491
1.001
10 999
5523
647
0.0892, 0.3104
1.038
12 676
7747
654
0.0912, 0.2737
1.090
R
1 2
; wR 2(I > 2σ(I))
GOF (F )
Largest diff peak and hole
1.779, −2.162
1.601, −1.826
1.141, −1.698
2.088, −1.940
4.780, −2.839
−
3
(e Å
)
CCDC no.
2061606
2061609
2061610
2061611
2061612
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Scheme 1 Synthesis of 1–3 and their transformation to 4–6.
(
O
2
CCMe
3
)
4
(HO
2
CCMe
3
)
4
gave a methoxido bridged {Co
2
}
which were allowed to stand for half an hour and then filtered.
III
species, which further traps a Ln ion forming a {Co Ln} Red block-shaped crystals of 4–6 were formed after a month in
2
2 3
species. Two such {Co Ln} fragments having facial O bridging 15% yields when the filtrates were allowed to evaporate very
−
−
III
sites made from two HO and one OMe finally entrap one Ln
slowly (eqn (2) and (3)). Single-crystal X-ray structure analysis
III
II
III
center to provide the cationic cores of 1 and 3.
revealed the formation of decanuclear {Tb Co Co },
3 3 4
III
II
III
III
II
III
{
Dy Co Co } and {Ho Co Co } core-bearing clusters 4, 5
3 2 5 3 2 5
4
H2L1 þ 4Co2ðμ‐OH ÞðO2CCMe3Þ ðHO2CCMe3Þ
and 6, respectively. Dissolution of 1, 2 and 3 in MeCN led to
2
4
4
the removal of the OMe− bridges and central lanthanide ion
þ 8LnðNO3Þ ꢀ 5H2O þ 24NEt3 þ 12MeOH
3
III
III
II
CH3OH
for the disintegration of the heptanuclear {Ln3 Co2 Co2 } (Ln =
Tb, Dy, Ho) cores. Unique restructuring to higher order decan-
uclear aggregates was initiated by: (1) the entrapment of the
III
3
II
2
III
þ O2 ꢁ! 2½Ln Co Co ðL1Þ ðO2CCMe3Þ
2
2
8
1
ð1Þ
ðOHÞ ðOMeÞ ðH2OÞ ꢂ ꢀ Lnðη ‐O2CCMe3Þ
4
2
4
2
2
II/III
III
ðη ‐O2CCMe3Þ ðMeOHÞ ꢀ 2MeOH ꢀ 2H2O
2
2
bare Co
center at the vertex shared position of the Ln ion
þ 24fðNHEt3ÞðNO3Þg þ 8HO2CCMe3
by two trinuclear {Co Ln} species (formed after collapse of the
2
3
þ
3þ
heptanuclear core) forming the dicubane part and (2) trapping
þ 26H2OðLn ¼ Tb ; Ho Þ:
Separated crystals of 1 and 3 along with the previously
1
2
of the unique counter anion Ln(η -O
O CCMe ) (MeOH)
2 3 2 2
2
CCMe
3
)
2
(η -
by two mononuclear {Co L1} species
reported 2 on treatment with MeCN gave red suspensions, (generated after further dissociation of some {Co Ln} frag-
−
III
2
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ments) forming the curved chain part. Coordination driven reaction medium, scrambling of pivalate ions took place
aggregation of these two units led to the formation of 4–6 as between Co (µ-OH )(O CCMe ) (HO CCMe ) and Ln(NO ) ·
2
2
2
3 4
2
3 4
3 3
1
solid crystals. The trinuclear {Co
does not possess the bridging methoxido group compared to
that in MeOH during synthesis of 1–3, further reflected by its O CCMe ) (MeOH) which are trapped in the crystal lattice
2
Ln} species formed in MeCN 5H
2
O to yield the hitherto unknown anionic species Tb(η -
2
−
1
2
O
2
CCMe
3
)
2
(η -O
2
CCMe
3
)
2
(MeOH)
2
2 3 2
and Ho(η -O CCMe ) (η -
−
2
3 2
2
absence in the dicubane portion of 4–6. The importance of the for charge compensation in 1 and 3, respectively (Fig. 3). Two
−
III
bridging OMe in trapping the Ln ion at the shared vertex in molecules of water and methanol each are present in both the
–3 is exemplified by this transformation. Elemental analysis lattices. As the aggregates are isostructural, the discussion of
data also gave C81 and the structure is given in short mainly with respect to 1 as a
as the molecular formula for 4, 5 and 6, representative case.
The analysis of the X-ray structure revealed that in each half
1
H
7 4 3 7 4 3
129Co N O37Tb , C86H136Co N O38Dy
C
86
H
136Co
7
N
4
O
38Ho
3
respectively.
III
II
III
2−
of the vertex-shared dicubane {Ln Co Co } clusters, a L1
III
II
III
3
2
2
2
Tb Co Co ðL1Þ ðO2CCMe3Þ ðOHÞ ðOMeÞ
ðH2OÞ ꢀ Tbðη ‐O2CCMe3Þ ðη ‐O2CCMe3Þ
III
3
2
2
2
8
2
4
2
anion coordinates a Co center in its ONO site, while at the
1
II
III
4
2
2
same time bridging another Co and Ln ion through its µ3
MeCN
alcohol arm. One OMe− and two OH− µ -bridges from each
III
3
II
3
ðMeOHÞ ꢀ 2MeOH ꢀ 2H2O ꢁ! ½Tb Co
3
2
ð2Þ
ð3Þ
III
III
4
III
half were responsible for attracting the Ln in the vertex
shared position. Cover up µ1,3-bridging by six pivalate ions
derived from Co (µ-OH )(O CCMe ) (HO CCMe ) was crucial
2 2 2 3 4 2 3 4
Co ðL1Þ ðO2CCMe3Þ ðOHÞ ðH2OÞꢂ þ 5Tb
4
9
ꢁ
10
II
ꢁ
þ
þ Co þ 15Me3CCO2 þ 4OMe þ 2H
þ 8MeOH þ 9H2O
−
for stabilizing the bent dicubane structure. The OMe bridges
III
III
II
2
III
2
are important for the incorporation of the vertex shared Ln
8
Ln Co Co ðL1Þ ðO2CCMe3Þ ðOHÞ ðOMeÞ
3
2
8
2
4
2
ion and directing the ultimate structure of the cluster and will
be discussed further in subsequent sections. Fig. 2 represents
the core structure of 1 highlighting the bond distances and
intermetallic distances. A more detailed description is given in
the ESI.†
1
ðH2OÞ ꢀ Lnðη ‐O2CCMe3Þ ðη ‐O2CCMe3Þ
4
2
2
MeCN
ðMeOHÞ ꢀ 2MeOH ꢀ 2H2O þ O2 ꢁ!
2
II
2
III
III
III
4
½Ln Co Co ðL1Þ ðO2CCMe3Þ ðOHÞ ꢂ þ 20Ln
3
5
4
10
10
II
ꢁ
ꢁ
þ
þ 4Co þ 56Me3CCO2 þ 16OMe þ 4H
þ 32MeOH þ 42H2OðLn ¼ Dy ; Ho Þ:
3
þ
3þ
Crystallization of the cationic parts of the Co–Ln aggregates
was achieved through in situ generation of the unique charge-
III
1
2
compensating
(
anions
Tb (η -O
2
CCMe
3
)
2
(η -O
2 3 2
CCMe )
Description of the crystal structures
MeOH)2− and Ho (η -O CCMe ) (η -O CCMe ) (MeOH) in
III
1
2
−
2
3 2
2
3 2
2
III
3
II
2
III
2
1
[
Ln Co Co (L1) (O CCMe ) (OH) (OMe) (H O) ]·Ln(η -
1 and 3. In solution, reaction of lanthanide(III) ions with Co
2
–
2
2
3 8
4
2
2
4
2
O CCMe ) (η -O CCMe ) (MeOH) ·2MeOH·2H O (Ln = Tb (1), pivalate precursor provided these literature unknown anions
2
3 2
2
3 2
2
2
Ho (3)). Both the aggregates 1 and 3 crystallize in the monocli- suitable for crystal packing. The rareness of mononuclear car-
nic P2/n space group with Z = 2. Chosen bond distances and boxylate anions of lanthanide elements is exemplified by there
bond angles are listed in Table S1.† The perspective view of being only four known examples in association with alkali
1
4
the cationic part of the structures for 1 and 3 is shown in metal and ammonium cations and a previous report of a
4
a
Fig.
1
and consists of
a
heptanuclear {Ln Co } core similar dysprosium(III)–pivalate-based anion. In 1, the anion
3
4
III
II
2
III
+
III
Ln Co Co (L1) (O CCMe ) (OH) (OMe) (H O) . Within the consists of a Tb ion (Tb3) in O
8
coordination geometry being
3
2
2
2
3 8
4
2
2
4
Fig. 1 Molecular structures of the cationic parts of 1 (left) and 3 (right). Hydrogen atoms and solvent molecules are omitted for clarity. Color code:
grey, carbon; red, oxygen; blue, nitrogen; blue grey, terbium; teal, holmium, pink, cobalt(II); brown, cobalt(III).
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Fig. 2 Core structure of 1 with bond distances (left) and the intermetallic separation within the core (right). Carbon and hydrogen atoms are
omitted for clarity. Color code: red, oxygen; blue, nitrogen; blue grey, terbium; pink, cobalt(II); brown, cobalt(III).
1
−
2
−
coordinated by two η -Me CCO ions, two η -Me CCO ions The transformed cluster 4 crystallizes in the monoclinic P2 /n
3
2
3
2
1
and two MeOH molecules. The Tb3–O distances of 2.308(7) Å space group with Z = 4, while 5 and 6 crystallize in the monocli-
1
−
2
−
for η -Me
3
CCO
2
(O19) are shorter than those of η -Me
3
CCO
2
nic C2/c space group with Z = 4. Selected metric parameters are
(
O18, O17) at 2.369(7) and 2.387(7) Å, while the MeOH records presented in Table S1.† The molecular structures of 4–6 consist
III
II
III
the largest Tb3–O21 distance of 2.394(6) Å. From the CShM of only the charge-neutral Tb Co Co (L1)
4
(O
10(OH)10 (Ln = Dy,
the geometry around Tb3 is best defined as a distorted triangu- Ho) units with variation in the number of coordinating
2 3 9
CCMe )
3
3
4
III
II
III
3 2 5
2 4 2 3
values (CShM = 2.272 for TDD, 3.044 for BTPR, 3.759 for SAPR) (OH)10(H O) and Ln Co Co (L1) (O CCMe )
−
II
III
lar dodecahedron (Table S4† and Fig. 3). Similar observations Me
3
CCO
2
anions and Co and Co centers. The molecular
were made for Ho3 in 3.
structure of 4–6 is presented in Fig. 5. The following structural
Inter and intra-molecular hydrogen bonding interactions as description involves 4 and mainly 6, which is isostructural
structure stabilizing secondary connections play an important with 5.
role providing stability to the dicubane cores and trapping of
the unique lanthanide(III)–pivalate-based counter anions moiety {Ln Co Co } (4)/{Ln Co Co } (5, 6) with a curved
The structures of 4–6 consist of a vertex-shared dicubane
III
II
III
III
II
III
2
3
III
2
2
2
3
III
III
(Table S5† and Fig. 4). A detailed description of the hydrogen chain {Ln Co } connecting both Ln ends of the dicubane
2
bonded 1D chain structure is presented in the ESI.†
unit (Fig. 6). The overall getup of the dicubane part is similar
III
II
III
Tb Co Co (L1) (O CCMe ) (OH) (H O)
(4)
and to that observed in the case of 1–3 with the substitution of the
3
3
4
4
2
3 9
10
2
III
II
III
µ
3
-OMe− bridges by OH− ions and the Ln ion at the vertex-
III
Ln Co Co (L1)
4
(O
2
CCMe
3
)10(OH)10 (Ln = Dy (5), Ho (6)).
3
2
5
III
III
Fig. 3 Structure of the Tb and Ho –pivalate-based counteranion present in 1 (a, left) and 3 (b, left) and the distorted trigonal dodecahedral
coordination geometry around Tb3 (a, right) and Ho3 (b, right). Hydrogen atoms and solvent molecules are omitted for clarity. Color code: grey,
carbon; red, oxygen; blue grey, terbium; teal, holmium.
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III
1
2
(MeOH) −
Fig. 4 1D chain structure in 1 formed by the trapping of Tb (η -O
2
CCMe
3
)
2
(η -O
2
CCMe
3
)
2
2
and solvent molecules through hydrogen
bonded interactions.
Fig. 5 Molecular structures of 4–6. Hydrogen atoms and methyl groups on pivalate omitted for clarity. Color code: grey, carbon; red, oxygen; blue,
nitrogen; blue grey, terbium; yellow, dysprosium; teal, holmium; pink, cobalt(II); brown, cobalt(III).
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Fig. 6 Core structures of 4 (a) and 6 (b) with intermetallic separation within the cores. Carbon atoms omitted for clarity. Color code: grey, carbon;
red, oxygen; blue, nitrogen; blue grey, terbium; teal, holmium; pink, cobalt(II); brown, cobalt(III).
II
III
shared position by Co (Co3) in 4 and Co (Co3) in 5–6. In the smallest separation is at 2.933(2) Å (Co
2
⋯Co3), but the longest
presence of MeCN the structural supports of μ
3
-OMe− in 1–3 separation of 3.4478(19) Å is recorded between Ho1 and Co1
were lost leading to the collapse of the clusters with removal of and not the shared Co3 (Fig. 6b). Of the three TbO Co faces on
2
III
the shared Ln . From the molecular fragments formed by this each cubic half in 4, the separation between the doubly
disintegration of 1–3, a different route of aggregation evolved bridged Tb and Co centers is longer (Tb1⋯Co3, 3.4661(2) Å;
leading to the growth and crystallization of 4–6 as discussed in Tb2⋯Co3, 3.4729(1) Å) than the triply bridged ones
the following section. Each cubic half of the heptanuclear (Tb1⋯Co1, 3.4657(18) Å; Tb1⋯Co
2
, 3.3845(19) Å; Tb2⋯Co4,
III
II
3=2
III
III
2=3
2−
dicubane {Ln Co Co } part consists of a L1 anion co- 3.426(2) Å; Tb2⋯Co5, 3.3565(19) Å). In 6, the doubly bridged
2
ordinated to Co and extending the alcohol arm to further Ho1⋯Co3 distance at 3.4427(12) Å is intermediate between the
II
III
bridge a second Co and a Ln ion in the μ
3
-bridging mode. triply bridged Ho1⋯Co1 (3.4478(19) Å) and Ho1⋯Co
2
(3.3859
−
Three μ
attract another Co
ancillary μ1,3-pivalate bridges further support the outer Ln – the longest within the dicubane unit and much longer than
3
-OH bridges in each half were further utilized to (19) Å) separations. The Tb1⋯Tb2 separation in 4 and
II/III
ion at the vertex shared position. Four Ho1⋯Ho1 separation in 6 at 6.1781(3) Å and 6.0719(3) Å are
III
III
III
II
2
Co and Ln –Co faces, while two others show a η chelation the analogous distances in 1 and 3 pointing to less bending of
towards the Co centers. The {Ln Co } chain consists of two the dicubane in the transformed clusters mostly due to the
L1 anions coordinated to a Co ion each in their tridentate trapping of a O
ONO binding site. Two {Co L1} units trap the unique lantha- vertex. Within the {Co Ln} chain, the separation of Co from
nide–pivalate-based counter anion present in 1–3 through µ - the Ln (Tb3⋯Co6, 3.080(3) Å; Tb3⋯Co7, 3.088(2) Å in 4 and
bridging phenoxido groups along with four OH bridges. The Ho2⋯Co4, 3.039(2) Å in 6) is smaller than that from the cube
-bridging alcohol arm of L1 and two μ
OH bridges were utilized to connect the {LnCo } chain to the Ho1⋯Co4, 3.232(2) Å in 6). The distances between the Ln
II
III
III
2
2
−
III
6
3d ion in place of the O
8
4f ion at the shared
III
III
2
III
2
−
−
−
III
μ
2
2
-OH and two μ
3
-
Ln (Tb2⋯Co6, 3.277(2) Å; Tb1⋯Co7, 3.319(2) Å in 4 and
−
III
2
III
{
Ln
2 5
Co } dicubane unit at the Ln positions. The connection ions in the chain and the cubic halves (Tb3⋯Tb1, 4.7219(2) Å;
is further stabilized via two μ1,3-Me
Ln and Co ions. Interestingly the chelating coordination of were much shorter than those within the dicubane moiety (see
−
3
CCO
2
bridges between Tb3⋯Tb2, 4.7265(2) Å in 4 and Ho2⋯Ho1, 4.6444(2) Å in 6)
III
III
−
III
one Me
center in an {O
the cases of 5 and 6, monodentate coordination of two cores of 4 and 6. In 6, the Co–Ohyd–Ho (hy = hydroxido) angles
3
CCO
2
anion and a water molecule put the chain Tb
above).
9
} coordination environment in 4, whereas in
Fig. S4† presents the various bond distances within the
−
Me
3
CCO
2
anions results in {O
around the Dy and Ho ions.
8
} coordination environments within the dicubane moiety are spread over a narrow range
from 101.6(3)° (Co –O16–Ho1) to 104.7(4)° (Co3–O17–Ho1)
III
III
2
II
Within the {Co Tb} cubes in 4, the shortest intermetallic with the Co –O –Ho (alk = alkoxido) angle of 95.3(3)° (Co1–
3
alk
III
separation is observed at 2.984(2) Å (Co
2
⋯Co3) and 2.981(2) Å O2–Ho1) being smaller than the Co –Oalk–Ho angle at 101.1
–O2–Ho1). The Co–O–Co angles vary over a wide range
.4657(18) (Tb1⋯Co3) and 3.4741(18) Å (Tb2⋯Co3). For 6, the from 94.9(4)° to 105.6(4)°. Within the chain in 6, the Co4–
(Co3⋯Co5) (Fig. 6a), while the longest separations amount to (3)° (Co
2
3
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−
III
3
O18–Ho1 angle (96.2(4)°) involving the µ -OH bridge is larger Ln ion in the curved chain of 4 compared to 5 and 6 leads to
than the Co4–O18–Ho2 angle (87.5(3)°) while the Ho1–O18– subtle distortion of the octahedral geometry around the Co3
−
2
Ho2 angle at 147.5(4)° is very wide. The µ -OH bridge center (percolating through the whole structure) at the vertex-
recorded a shorter Co4–O19–Ho2 angle of 91.2(4)° compared shared position in 4 stabilizing it in the +II valence state as
to the 102.2(4)° for Co4–O4–Ho1 involving µ -alkoxido. For the opposed to the +III state in 5 and 6. The cobalt ion in its +II
2
µ
2
-phenoxido bridge the angle stands at 88.8(4)° (Co4–O3– valence state is known to accommodate much higher distor-
Ho2). Similar observations regarding bond angles were made tion of the octahedral geometry compared to the +III valence
2
5,26
3
in the case of 4. bond valence sum (BVS)
analysis for loca- state. The CShM values of Co3 in the three structures con-
lized bonds around the metal ion centers validated a formal firms this distortion (1.233 (4) > 0.992 (5) ≈ 0.946 (6))
valence state of +II for Co1, Co3 and Co4 in 4 and for Co1 and (vide infra). The preference of lower coordination number of
III
III
III
Co4 in 5 and 6 while a +III valence state could be assigned to Dy and Ho in comparison to Tb in the chain arises as a
Co , Co5, Co6, Co7, Tb1, Tb2 and Tb3 in 4 and Co , Co3, Co4, result of lanthanide contraction.
Ln1 and Ln2 in 5 and 6 (Table S2†). A uniform Octahedral coordination environment around all
To investigate the O /O coordination geometry around Co centers in 4–6 is confirmed from the CShM values. In 4, the
2
2
8
9
III
II/III
Ln and the O
tinuous shape measures (CShM) calculations were performed point to a higher distortion of the octahedral geometry com-
Tables S3 and S4†). In the case of 4, the geometry around pared to trivalent Co (0.272), Co5 (0.286), Co6 (0.305) and Co7
6
/O
5
N geometry around Co
ions in 4–6, con- higher CShM values for bivalent Co1 (4.371) and Co4 (3.854)
(
2
both the eight coordinated Tb1 and Tb2 is close to a square (0.281) (Fig. S5 and Table S3†). A similar trend is observed in
antiprism (SAPR) (CShM (Tb1) = 0.666 for SAPR, 1.834 for 5–6 with bivalent Co1 (CShM = 4.123 (5), 4.154 (6)) showing
BTPR, 2.241 for TDD; CShM (Tb2) = 0.416 for SAPR, 1.818 for comparatively higher distortion than trivalent Co2 (CShM =
BTPR, 2.289 for TDD) while that around the nine coordinated 0.329 (5), 0.338 (6)) and Co4 (CShM = 0.205 (5), 0.216 (6))
Tb3 (curved chain) is best described as a distorted muffin (Fig. S6†). The Co3 at the vertex shared position showed less
(CShM = 0.874 for MFF, 1.796 for CSAPR, 2.536 for TCTPR) as distortion (CShM = 1.233) compared to other divalent Co in 4
is evident from the lower CShM values (Fig. 7, top and while a slightly higher distortion (CShM = 0.992 (5), 0.946 (6))
Table S4†). In 6, the octa coordinated Ho1 exhibits a distorted was observed compared to other trivalent Co in 5 and 6. For a
SAPR geometry (CShM = 0.518 for SAPR, 1.663 for BTPR, 2.005 detailed discussion of various bonding parameters around the
for TDD) while the other octa coordinated Ho2 in the chain Co centers, refer to the ESI.† The crystal lattices for all the
adopts a distorted TDD geometry (CShM = 1.161 for TDD, three clusters 4–6 exhibited voids which may be accessed by
2
.000 for BTPR, 2.346 for SAPR) (Fig. 7, bottom and Table S4†). solvent molecules. These voids make up 19.6%, 21.8%
Similar observations were made in the case of Dy1 and Dy2 in and 22.6% of the volume of the unit cell in 4, 5 and 6, respect-
. The difference in coordination number and geometry of the ively. Fig. S7 and S8† show the crystal packing diagrams along
5
Fig. 7 Various geometries around Tb1, Tb2 (Distorted Square Antiprism (SAPR)) and Tb3 (Distorted Muffin (MFF)) in 4 (top) and Ho1 (Distorted
Square Antiprism (SAPR)) and Ho2 (Distorted Triangular Dodecahedron (TDD)) in 6 (bottom).
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the c axis and representations of such voids in 4 and 6
respectively.
Due to the absence of solvent molecules in the crystal assigned to the dinuclear mixed valent Co Co
lattice only intra molecular hydrogen bonding is observed in {[Co Co L1(O
Analysis of the mass spectra of 1 and 3 in MeOH revealed a
peak at m/z = 773.1844 (Fig. S10 and S11†) which can be
II
III
species
II
III
+
2
CCMe
3 3 2 2 3 2
) (OMe)(H O) ]·2CH OH·H O + K + H}
2
−
4
–6 (Table S5 and Fig. S9†) which lends stability to these large (C H Co KNO ; calcd 773.1840). The ligand anion L1
2
7
54
2
14
−
clusters. In 6, two µ
3
-OH bridges (O15 and O16) in each cube initially coordinates to one of the cobalt centers of Co
CCMe (HO CCMe and at the same time bridges the
group (O15⋯O1, 2.723(13) Å) and O14 of η -pivalate from the second using its alkoxido arm giving rise to such dinuclear
2 2
(µ-OH )
show hydrogen bonding interaction with O1 of the phenoxido (O
2
3
)
4
2
3 4
)
2
−
−
other cube. The third µ
with the µ as well as µ
curved chain (O17⋯O18, 2.953(14) Å; O17⋯O19, 2.779(15) Å). Peaks at m/z = 1013.2030 and 1019.2080 could be further
3
-OH bridge (O17) has interaction species (Scheme 2, species a). A OMe bridge (derived from the
−
3
2
-OH bridges (O18 and O19) in the solvent) between the cobalt centers stabilizes the species.
−
The µ
3 2
and µ -OH bridges (O18 and O19) are further hydro- observed for 1 and 3, respectively, which are assignable to the
III
II
III
gen bonded to the pivalate (coordinating Ho2) O11 and O12 trinuclear fragments {[Tb Co Co L1(O
2 3 3 2 3 2
CCMe ) (HO CCMe )
+
(O18⋯O11, 3.07(2) Å; O19⋯O12, 3.02(3) Å).
(OMe)(OH) ] + H} (C H Co NO Tb; calcd, 1013.2032) and
2
35 62
2
15
III
II
III
+
{
[Ho Co Co L1(O
2
3 3 2 3 2 2
CCMe ) (HO CCMe ) (OMe)(OH) ] + H}
35 2
(C H62Co NO15Ho; calcd, 1019.2082). The initially formed
Investigation of aggregation processes and structural
transformation
II
III
III
dinuclear Co Co species traps a Ln ion using the dangling
−
groups and OH− bridges (the two coordinated H
Me CCO O
3
2
2
In order to understand the aggregation pathway leading to the molecules are prone to hydrolysis) to form such trinuclear
formation of the clusters 1 and 3, high-resolution mass spec- {Co Ln} species (Scheme 2, species b). The ultimate heptanuc-
trometry (HRMS) (+ve) was performed in MeOH (reaction mix- lear dicubane Ln Co Co core structure is generated by the
2
III
3
II
2
III
2
III
tures) to identify possible logical intermediates. Further ana- trapping of a second Ln ion at the vertex shared position by
−
lysis of HRMS (+ve) patterns of 1, 2 and 3 in MeCN revealed two {Co Ln} units via extension of the bridging capacity of OH
the formation of new intermediate species responsible for an and OMe from µ
2
−
2 3
to µ (Scheme 2, intermediate c). The brid-
altered course of aggregation for the formation of high nucle- ging OMe− is important for not only stabilizing the initial
II
III
arity clusters 4, 5 and 6. Such investigations highlighted the dinuclear Co Co species but also in trapping the vertex shared
role of the bridging OMe in directing the pathway for aggrega- Ln hence having a major directing role in the aggregation
−
III
tion and hence the ultimate structure of the clusters.
process which will be further exemplified in the following dis-
Scheme 2 Proposed pathway of aggregation for the formation of 3 in MeOH.
9584 | Dalton Trans., 2021, 50, 9574–9588
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cussions. The formation
Paper
of
anionic
mononuclear
The HRMS spectra of 1, 2 and 3 in MeCN (Fig. S12–S14†)
lanthanide carboxylate species in solution could be detected in exhibit peaks at m/z = 831.0720, 931.1343 and 937.1407 respect-
III
III
II
III
their protonated forms as {[Tb (O
2
CCMe
3
)
4
(MeOH)
2
]·H
CCMe
MeOH) ]·H O + 2H} (C H O Ho; calcd 653.2495) at m/z = {[Dy Co Co L1(O CCMe ) (OH) (H O) ]·CH CN·3H O}
2
O + ively assignable to trinuclear species {[Tb Co Co L1
+
III
+
2
(
H} (C22
H
48
O
11Tb; calcd 647.2445) and {[Ho (O
2
)
3 4
2 3 3 2 2 3 2
(O CCMe ) (OH) (H O) ]} (C24H44Co NO13Tb; calcd 831.0725),
+
III
II
III
+
2
2
22 48 11
2
3 3
2
2
3
3
III
2
III
II
6
Me
47.2440 and 653.2490 for 1 and 3, respectively. Coordination of (C26
H
CCMe
53Co
2
N
2
O
16Dy; calcd 931.1346) and {[Ho Co Co L1
−
+
3
CCO
2
, released from Co
2
(µ-OH
2
2
)(O CCMe
3 4
) (HO
2
CCMe )
3 4
(O
2
3
)
3
(OH)
2 2 3 3 2
(H O) ]·2CH CN·H O}
2 3
(C28H52Co N O14Ho;
III
following ligand binding, to Ln ions leads to the formation calcd 937.1411) (Scheme 3, species a). Such trinuclear species a
of these unique and literature unknown anions essential for arise following the collapse of the heptanuclear dicubane cat-
III
the crystallization and charge balance of monocationic ionic cluster in 1–3 due to the loss of the vertex-shared Ln ion
III
II
III
+
−
{
Ln Co Co } clusters.
along with the bridging OMe . In our previous investigation we
3
2
2
Scheme 3 Proposed aggregation pathway for the transformation of 3 into 6 in MeCN.
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had shown that the higher dielectric constant of MeCN favors lic species g. This trinuclear chain further attaches itself to the
−
4a
III
the substitution of bridging OMe with a water molecule, the proposed dicubane species
c
at the two Ln
vertices
likes of which is observed here as well. In its absence the trap- (Scheme 3, species h) by utilizing a µ
2
bridging coordination
III
ping of a Ln ion at the shared vertex position is not favorable; of the alkoxido groups at both ends, while at the same time
instead, the OH− bridge generated through hydrolysis of the extending a µ bridging mode of two OH groups along with
−
3
−
water molecule shows preference towards a 3d metal ion. Two capping µ1,3 coordination of two terminal Me
3
III
CCO
2
to give
II/III
III
II
3=2
species a moieties thus trap a Co
ion at the vertex shared rise to the final decanuclear cluster Ln Co Co
.
3
4=5
position via increase of the bridging capacity of the OH− ions
Scheme 3, intermediate b) probably leading to the formation of
Magnetic properties
c shown in Magnetic susceptibility measurements were carried out on the
(
vertex-shared dicubane cluster like species
Scheme 3. In the absence of a –OMe function on the ligand, the samples from 290 to 2 K (Fig. 8). At ambient temperature, χ T
M
3
−1
3
−1
species a cannot rearrange as observed in our previous work.
= 53.4 cm mol K for 1 and 61.6 cm mol K for 3, consist-
Further scrutiny of the HRMS patterns in MeCN revealed a ent with the calculated values for uncoupled spins (53.1 cm
peak at m/z = 359.0775 in 1–3 which can be assigned to the mol K and 62.1 cm mol K, respectively) for two Co(II)
3
−
1
3
−1
III
•+
mononuclear
species
{Co L1(O
2
CCMe
3
)(H
2
O)}
centers and four Ln(III) centers (Co(II) g = 2.5, S = 3/2 and Tb(III)
(
C
14
H
22CoNO
6
; calcd 359.0774) (Scheme 3, species d). The loss g = 3/2, J = 6 for 1 and Co(II) g = 2.5, S = 3/2 and Ho(III) g = 1.25,
−
of the OMe bridge also destabilizes the trinuclear species a, a J = 8 for 3). Upon cooling the χ T value shows a marginal
M
portion of which further collapses forming the mononuclear decrease up to 90 K and then decreases more prominently to
3
−1
3
−1
species d. The spectra also indicate the presence of the lantha- have values of 25.9 cm mol K and 29.5 cm mol K for 1
nide–pivalate-based anion after loss of two MeOH in the form and 3, respectively, at 2 K. This behavior is consistent with the
III
+
of protonated species {[Tb (O
2
CCMe
3
)
4
] + 2H} (C20
H
38
O
8
Tb; thermal depopulation of the split energy levels of anisotropic
III
+
+
3+
calcd 565.1815), {[Dy (O
2
CCMe
3
)
4
] + 2H} (C20
H
38
O
8
Dy; calcd Co2 and Ln ions at lower temperatures. Spin–orbit coupling
III
+
4
II
III
5
5
70.1853) and {[Ho (O CCMe ) ] + 2H} (C H O Ho; calcd splits the T term in Co while for the Ln ions contribution
2 3 4 20 38 8
1g
71.1865) (Scheme 3, species e) at m/z = 565.1819, 570.1848 to the magnetic properties arises from 2J + 1 energy states. In
and 571.1865. Also present in the spectra are peaks at m/z = addition very weak mostly antiferromagnetic interactions
08.1114, 693.1525 and 611.1495 corresponding to heteronuc- between the metal ion centers may affect the curve at the
6
III
III
4a
lear species {[Tb Co L1
H
2
(O
68Co
2
CCMe (OH)
6
KN O16Tb; calcd 608.1118), magnetization of the complexes was studied under a dc field
3
)
3
4 2 3
(H O)]·4CH CN· lowest temperatures as observed for the Dy analogue 2. The
2
2
+
2
O + K + 3H}
(C41
H
2
III
III
{
[Dy Co L1 (O CCMe ) (OH) ]·5CH CN·2H O + K + Na + from 0 to 7 T. Both analogues do not reach saturation, with M/
2
2
2
3 4
4
3
2
2
+
3
H}
(C48
H
80Co
2
KN
7
NaO18Dy;
(OH) ]·2CH
C H Co N O Ho; calcd 611.1491) (Scheme 3, species g). shows slow magnetic relaxation in ac susceptibility studies.
calcd
693.1520)
and Nβ = 24.3 for 1 and M/Nβ = 26.6 for 3, at 2 K and 7 Tesla, con-
III
III
2
2+
{
[Ho Co L1
2
(O
2
CCMe
3
)
4
4
3
CN·3H
2
O
+
5H}
sistent with strong magnetic anisotropy. Neither complex
(
4
2
75
2 4 19
Two mononuclear species d trap the lanthanide–pivalate
anion (species e) via µ
bridging phenoxido and OH− groups bulk products from which publishable magnetic data could be
generated through hydrolysis of coordinated water) extracted. Preliminary investigations showed no slow magnetic
Scheme 3, intermediate f) to form the trinuclear heterometal- relaxation in ac susceptibility studies.
For 4–6, we were unable to synthesize magnetically pure
2
(
(
M
Fig. 8 Temperature dependence of χ T and magnetization vs. field data at 2, 4 and 6 K (inset) for 1 and 3.
9586 | Dalton Trans., 2021, 50, 9574–9588
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Paper
S. T. Ochsenbein, G. Chaboussant, H. U. Guedel,
N. Kirchner, J. v. Slageren and W. Wernsdorfer, Inorg.
Chem., 2005, 44, 4315–4325; (g) C. Boskovic, A. Sieber,
G. Chaboussant, H. U. Guedel, J. Ensling, W. Wernsdorfer,
A. Neels, G. Labat, H. Stoeckli-Evans and S. Janssen, Inorg.
Chem., 2004, 43, 5053–5068.
Conclusions
4 3 7 3
The presented syntheses of Co Ln and Co Ln type coordi-
nation aggregates highlighted the role of the parent ligand
anion, in situ generated and metal ion salt derived co-ligands
and solvent in the synthesis route, which exploits the varying
possibilities of condensation reactions. The coordination-
induced aggregation processes were explored for Co (µ-OH )
2 (a) M. Das, S. R. Chaudhuri, D. Basak, S. Dasgupta and
D. Ray, Inorg. Chim. Acta, 2019, 485, 140–154; (b) M. Das,
D. Basak, Z. Travnicek, J. Vanco and D. Ray, Chem. – Asian
J., 2019, 14, 3898–3914; (c) M. Das, G. A. Craig,
D. Escudero, M. Murrie, A. Frontera and D. Ray, New J.
Chem., 2018, 42, 14349–14364; (d) M. Das, R. Herchel,
Z. Travnicek, V. Bertolasi and D. Ray, New J. Chem., 2018,
42, 16717–16728; (e) K. Chattopadhyay, G. A. Craig,
M. J. H. Ojea, M. Pait, A. Kundu, J. Lee, M. Murrie,
A. Frontera and D. Ray, Inorg. Chem., 2017, 56, 2639–2652;
(f) K. Chattopadhyay, G. A. Craig, A. Kundu, V. Bertolasi,
M. Murrie and D. Ray, Inorg. Chem., 2016, 55, 10783–10792;
(g) M. Pait, M. Shatruk and D. Ray, Dalton Trans., 2015, 44,
11741–11754; (h) A. K. Ghosh, T. S. Mahapatra, R. Clerac,
C. Mathoniere, V. Bertolasi and D. Ray, Inorg. Chem., 2015,
54, 5136–5138; (i) M. Pait, A. Bauza, A. Frontera, E. Colacio
and D. Ray, Inorg. Chem., 2015, 54, 4709–4723; ( j) M. Pait,
E. Colacio and D. Ray, Polyhedron, 2015, 88, 90–100;
(k) S. Nayak, G. Aromi, S. J. Teat, J. R.-Arino, P. Gamez and
J. Reedijk, Dalton Trans., 2010, 39, 4986–4990;
(l) E. Pilichos, A. Escuer, M. F. Bardia and J. Mayans, Chem.
– Eur. J., 2020, 26, 13053–13062; (m) A. K. Ghosh,
M. Shatruk, V. Bertolasi, K. Pramanik and D. Ray, Inorg.
Chem., 2013, 52, 13894–13903; (n) M. Mitra, P. Raghavaiah
and R. Ghosh, New J. Chem., 2015, 39, 200–205; (o) D. Saha,
T. Maity, R. Bera and S. Koner, Polyhedron, 2013, 56, 230–
2
2
2 3 4 2 3 4
(O CCMe ) (HO CCMe ) and lanthanide nitrate salts in the
2
−
−
presence of L1 . Base-assisted in situ generation of OMe and
OH bridges from direct supports of L12− provided heptanuc-
−
III
II
2
III
2
lear 3d–4f aggregates having cationic {Ln Co Co } cores in 1
and 3 giving vertex-shared dicubane structures, where the
vertex-shared position was occupied by a Ln ion. In situ gene-
3
III
1
ration of unique lanthanide–pivalate-based anions, Ln(η -
2
−
O
2
CCMe
3
)
2
2 3 2 3 2
(η -O CCMe ) (CH OH) , was essential for the
crystallization of the cationic heptanuclear clusters. Solvent-
assisted structural disintegration and re-aggregation following
a different pathway took place when these heptanuclear clus-
ters were treated with MeCN to provide decanuclear 4–6
III
3
II
3=2
III
having neutral {Ln Co Co } cores. Dissolution of 1–3 in
4=5
−
MeCN lead to the removal of the OMe bridges and central
III
−
II/III
Ln ion, which were replaced by OH bridges and Co
ions,
respectively, in the dicubane part of the high nuclearity clus-
ters 4–6. Additionally the lanthanide–pivalate-based anion is
trapped by mononuclear {Co L1} type species to form the
curved chain connecting the two cubic halves. Analysis of
HRMS (+ve) patterns of the heptanuclear clusters in MeOH
and MeCN revealed the aggregation pathways and an altered
route of aggregation for the formation of the high nuclearity
clusters 4–6.
III
236.
Conflicts of interest
3 D. Basak, J. v. Leusen, T. Gupta, P. Kögerler, V. Bertolasi
and D. Ray, Inorg. Chem., 2020, 59(4), 2387–2405 and refer-
ences therein.
The authors declare no competing financial interests.
4
(a) D. Basak, J. v. Leusen, T. Gupta, P. Kögerler and D. Ray,
Dalton Trans., 2020, 49, 7576–7591; (b) H. Wei, C.-L. Wang,
W. Gao, J.-P. Liu and X.-M. Zhang, CrystEngComm, 2020, 22,
Acknowledgements
7
639–7647; (c) M. N. Akhtar, M. A. AlDamen, J. Khan,
M. Shahid and A. M. Kirillov, Cryst. Growth Des., 2020, 20,
545–6554; (d) Y. Wang, Z. Yuan, H. Ren, W. Xu, J. Xu,
H. Zhang, J. Sha and H. Zhang, Inorg. Chim. Acta, 2020,
11, 119786.
(a) R. E. P. Winpenny, J. Chem. Soc., Dalton Trans., 2002, 1–
10; (b) Z. Zheng, Chem. Commun., 2001, 2521–2529;
(c) R. Robson, Dalton Trans., 2008, 5113–5131;
(d) C. Papatriantafyllopoulou, E. E. Moushi, G. Christou
and A. J. Tasiopoulos, Chem. Soc. Rev., 2016, 45, 1597–1628;
(e) X. Yang, C. Chan, D. Lam, D. Schipper, J. M. Stanley,
X. Chen, R. A. Jones, B. J. Holliday, W.-K. Wong, S. Chen
and Q. Chen, Dalton Trans., 2012, 41, 11449–11453;
(f) T. C. Stamatatos, C. G. Efthymiou, C. C. Stoumpos and
S. P. Perlepes, Eur. J. Inorg. Chem., 2009, 3361–3391;
(g) J. M. Frost, F. J. Kettles, C. Wilson and M. Murrie,
Dalton Trans., 2016, 45, 18094–18097.
DB is thankful towards IIT Kharagpur for the research facilities
and his fellowship.
6
5
References
5
1
(a) A. Shyamal and D. Kumar, J. Less-Common Met., 1980,
1, 113–117; (b) O. Stetsiuk, N. Plyuta, N. Avarvari,
7
E. Goreshnik, V. Kokozay, S. Petrusenko and A. Ozarowski,
Cryst. Growth Des., 2020, 20, 1491–1502; (c) L. E. H. Paul,
I. C. Foehn, A. Schwarzer, E. Brendler and U. Böhme, Inorg.
Chim. Acta, 2014, 423, 268–280; (d) S. Majumder,
J. P. Naskar, A. Bhattacharya, R. Ganguly, P. Saha and
S. Chowdhury, J. Coord. Chem., 2015, 68, 599–615;
(
e) H. Hoepfl, M. Sanchez, V. Barba, N. Farfan, S. Rojas and
R. Santillan, Inorg. Chem., 1998, 37, 1679–1692;
f) A. Sieber, C. Boskovic, R. Bircher, O. Waldmann,
(
This journal is © The Royal Society of Chemistry 2021
Dalton Trans., 2021, 50, 9574–9588 | 9587

View Article Online
Paper
Dalton Transactions
6
(a) H.-L. Zheng, X.-L. Chen, T. Li, Z. Yin, Y. Zhang,
M. Kurmoo and M.-H. Zeng, Chem. – Eur. J., 2018, 24,
906–7912; (b) H. X. Na, P. Y. Yang, Z. Yin, Y. H. Wang,
L. X. Chang, R. Si, M. Kurmoo and M. H. Zeng, Chem. –
Eur. J., 2016, 22, 18404–18411; (c) Y.-Q. Hu, M.-H. Zeng,
K. Zhang, S. Hu, F.-F. Zhou and M. Kurmoo, J. Am. Chem.
Soc., 2013, 135, 7901–7908.
2015, 54, 7600–7606; (b) F. Ortu, D. Reta, Y.-S. Ding,
C. A. P. Goodwin, M. P. Gregson, E. J. L. McInnes,
R. E. P. Winpenny, Y.-Z. Zheng, S. T. Liddle, D. P. Mills and
N. F. Chilton, Dalton Trans., 2019, 48, 8541–8545;
(c) W. Huang, F.-X. Shen, S.-Q. Wu, L. Liu, D. Wu, Z. Zheng,
J. Xu, M. Zhang, X.-C. Huang, J. Jiang, F. Pan, Y. Li, K. Zhu
and O. Sato, Inorg. Chem., 2016, 55, 5476–5484;
(d) W. Wernsdorfer, N. A. Alcalde, D. N. Hendrickson and
G. Christou, Nature, 2002, 416, 406–409.
7
7
(a) H. N. Miras, E. F. Wilson and L. Cronin, Chem.
Commun., 2009, 1297–1311; (b) X. L. Chen, H. B. Xu,
X. X. Shi, Y. Zhang, T. Yang, M. Kurmoo and M. H. Zeng, 13 (a) S. Paul, R. Clérac, N. G. R. Hearns and D. Ray, Cryst.
Inorg. Chem., 2017, 56, 14069–14076; (c) T. Zhang,
L.-P. Zhou, X.-Q. Guo, L.-X. Cai and Q.-F. Sun, Nat.
Commun., 2017, 8, 15898; (d) G. J. T. Cooper, G. N. Newton,
P. Kögerler, D.-L. Long, L. Engelhardt, M. Luban and
L. Cronin, Angew. Chem., Int. Ed., 2007, 46, 1340–1344;
Growth Des., 2009, 9, 4032–4040; (b) R. Lee, A. I. Kamiyama,
H. Motoyoshi and T. Konno, CrystEngComm, 2012, 14,
1936–1938; (c) D. Liu, H.-X. Li, Z.-G. Ren, Y. Chen, Y. Zhang
and J.-P. Lang, Cryst. Growth Des., 2009, 9, 4562–4566;
(d) H.-P. Xiao, J. Zhou, X.-L. Wang, H.-H. Zou, R.-Q. Zhao
and H. Xiao, Dalton Trans., 2014, 43, 12306–12312.
(
e) G. N. Newton, G. J. T. Cooper, P. Kögerler, D.-L. Long
and L. Cronin, J. Am. Chem. Soc., 2008, 130, 790–791.
(a) M. Du, X.-H. Bu, Y.-M. Guo and J. Ribas, Chem. – Eur. J.,
14 J.-S. Lu and R. Wang, in The rare earth elements:
Fundamentals and applications, ed. D. A. Atwood, Wiley,
2012, Carboxylate, pp. 229.
8
2
004, 10, 1345–1354; (b) A. K. Gupta and A. Orthaber, Cryst.
Growth Des., 2020, 20, 4232–4237; (c) X.-M. Luo, N.-F. Li, 15 (a) H. Ke, L. Zhao, Y. Guo and J. Tang, Dalton Trans., 2012,
Q.-F. Lin, J.-P. Cao, P. Yuan and Y. Xu, Inorg. Chem. Front.,
020, 7, 2072–2079; (d) X.-F. Ma, H.-L. Wang, Z.-H. Zhu,
B. Li, K.-Q. Mo, H.-H. Zou and F.-P. Liang, Dalton Trans.,
019, 48, 11338–11344; (e) M. Chen, M. Zhang, X. Wang,
Y. Bi, B. Chen and Z. Zheng, Inorg. Chem., 2019, 58, 6276–
41, 9760–9765; (b) L. Zhao, J. Wu, S. Xue and J. Tang,
Chem. – Asian J., 2012, 7, 2419–2423; (c) M. C. Majee,
S. M. T. Abtab, D. Mondal, M. Maity, M. Weselski,
M. Witwicki, A. Bieńko, M. Antkowiak, G. Kamieniarz and
M. Chaudhury, Dalton Trans., 2018, 47, 3425–3439.
2
2
6
282; (f) Z. Chen, Y. Shen, L. Li, H. Zou, X. Fu, Z. Liu, 16 L. F. Zou, L. Zhao, Y. N. Guo, G. M. Yu, Y. Guo, J. K. Tang
K. Wang and F. Liang, Dalton Trans., 2017, 46, 15032– and Y. H. Li, Chem. Commun., 2011, 47, 8659–8661.
5039; (g) Y. Zhou, X.-Y. Zheng, J. Cai, Z.-F. Hong, 17 G. Aromi, A. S. Batsanov, P. Christian, M. Helliwell,
1
Z.-H. Yan, X.-J. Kong, Y.-P. Ren, L.-S. Long and L.-S. Zheng,
A. Parkin, S. Parsons, A. A. Smith, G. A. Timco and
Inorg. Chem., 2017, 56, 2037–2041.
R. E. P. Winpenny, Chem. – Eur. J., 2003, 9, 5142–5161.
9
K. C. Mondal, A. Sundt, Y. Lan, G. E. Kostakis, 18 Saint, Smart and XPREP, Siemens Analytical X-ray
O. Waldmann, L. Ungur, L. F. Chibotaru, C. E. Anson and
A. K. Powell, Angew. Chem., Int. Ed., 2012, 51, 7550–7554.
0 (a) P.-P. Yang, X.-L. Wang, L.-C. Li and D.-Z. Liao, Dalton
Instruments Inc., Madison, WI, 1995.
19 G. M. Sheldrick, SHELXS-2014, University of Göttingen,
Göttingen, Germany, 2014.
1
Trans., 2011, 40, 4155–4161; (b) R. Modak, Y. Sikdar, 20 G. M. Sheldrick, Acta Crystallogr., Sect. C: Struct. Chem.,
G. Cosquer, S. Chatterjee, M. Yamashita and S. Goswami,
2015, 71, 3–8.
Inorg. Chem., 2016, 55, 691–699.
21 L. J. Farrugia, J. Appl. Crystallogr., 2012, 45, 849–854.
1
1 (a) H.-J. Lun, M.-H. Du, D.-H. Wang, X.-J. Kong, L.-S. Long 22 O. V. Dolomanov, L. J. Bourhis, R. J. Gildea,
and L.-S. Zheng, Inorg. Chem., 2020, 59, 7900–7904;
b) Q. Lin, J. Li, Y. Dong, G. Zhou, Y. Song and Y. Xu, Dalton
J. A. K. Howard and H. Puschmann, J. Appl. Crystallogr.,
2009, 42, 339–341.
(
Trans., 2017, 46, 9745–9749; (c) X.-Y. Zheng, S.-Q. Wang, 23 G. M. Sheldrick, SADABS Software for Empirical Absorption
W. Tang, G.-L. Zhuang, X.-J. Kong, Y.-P. Ren, L.-S. Long and
L.-S. Zheng, Chem. Commun., 2015, 51, 10687–10690;
Correction, University of Göttingen, Institute fur
Anorganische Chemieder Universitat, Göttingen, Germany,
1999–2003.
(d) J.-B. Peng, Q.-C. Zhang, X.-J. Kong, Y.-Z. Zheng,
Y.-P. Ren, L.-S. Long, R.-B. Huang, L.-S. Zheng and 24 DIAMOND, Visual Crystal Structure Information System,
Z. Zheng, J. Am. Chem. Soc., 2012, 134, 3314–3317. version 3.1, Crystal Impact, Bonn, Germany, 2004.
2 (a) K. S. Pedersen, J. Dreiser, H. Weihe, R. Sibille, 25 I. D. Brown and D. Altermatt, Acta Crystallogr., Sect. B:
H. V. Johannesen, M. A. Sørensen, B. E. Nielsen, M. Sigrist, Struct. Sci., 1985, 41, 244–247.
H. Mutka, S. Rols, J. Bendix and S. Piligkos, Inorg. Chem., 26 I. D. Brown, Chem. Rev., 2009, 109, 6858–6919.
1
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