Abrupt spin transition in a modified-terpyridine cobalt(ii) complex with a highly-distorted [CoN6] core

Article abstract of DOI:10.1039/c8dt02367k

The cobalt(ii) complex incorporating π-conjugated substituent, [Co(Naph-C2-terpy)₂](BF₄)₂ (1; Naph-C2-terpy = 4′-(2-naphthoxy(ethoxy))-2,2′:6′,2′′-terpyridine), exhibits an abrupt spin transition (ST) behavior (cooperative factor C = 0.91) while its solvated product, 1·2MeOH, shows gradual spin crossover (SCO) behavior (C = 0.49). Single crystal X-ray structural analyses demonstrated that the octahedral coordination core [CoN₆] in 1 shows larger distortion in both high-spin and low-spin states than solvated 1·2MeOH or another two derivatives, [Co(R-terpy)₂](BF₄)₂ (R = 2-naphthyl (2), 9-anthracenyl (3)). The respective distortion parameters (Σ) are compared with those for previously reported SCO cobalt(ii) compounds. The highly-distorted [CoN₆] core in 1 (Σ = 126 in the HS state and 101.6 in the LS state) was stabilized by strong intermolecular interactions and observed an abrupt ST behaviour.

Full text of DOI:10.1039/c8dt02367k

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Abrupt spin transition in a modified-terpyridine cobalt(II) complex
with a highly-distorted [CoN ] core
6
Received 00th January 20xx,
Accepted 00th January 20xx
a
a
b
a
c
Manabu Nakaya, Ryo Ohtani, Jong Won Shin, Masaaki Nakamura, Leonard F. Lindoy and
a,d
Shinya Hayami*
DOI: 10.1039/x0xx00000x
2 4 2
The cobalt(II) complex incorporating π-conjugated substituent, [Co(Naph-C2-terpy) ](BF ) (1; Naph-C2-terpy = 4’-(2-
www.rsc.org/
naphthoxy(ethoxy))-2,2’:6’,2”-terpyridine), exhibits an abrupt spin transition (ST) behavior (cooperative factor C = 0.91)
while its solvated product, 1·2MeOH, shows gradual spin crossover (SCO) behavior (C = 0.49). Single crystal X-ray structural
analyses demonstrated that the octahedral coordination core [CoN
6
] in 1 shows larger distortion in both high-spin and
](BF (R = 2-naphthyl (2), 9-anthracenyl
low-spin states than solvated 1·2MeOH or another two derivatives, [Co(R-terpy)
2
4 2
)
(3)). The respective distortion parameters (Σ) are compared with those for previously reported SCO cobalt(II) compounds.
The highly-distorted [CoN
6
] core in 1 (Σ = 126 in the HS state and 101.6 in the LS state) was stabilized by strong
intermolecular
interactions and observed an abrupt ST behaviour.
our knowledge, mononuclear cobalt(II) compounds of only
seven ligand designs (as well as some of their derivatives) have
been shown to generate complete and abrupt or hysteretic ST
Introduction
Molecular compounds exhibiting spin state changes of their
metal centres (termed spin crossover (SCO) or spin transition
[16-22]
behaviours.
Further, detailed investigations of magneto–
structural relationships have been performed for the following
(ST) compounds) have attracted much attention because of
§
complexes : Ar’CoN(H)Ar , [Co(C14-terpy)
# [17]
[18b]
2
](BF
[Co(dpzca)
33 2
(Bn-C16H ) .
4
)
2
,
[Co(4-
the bistability in their magnetic, optical and structural
properties. They have been widely investigated for potential
application as sensors and memory devices in molecular
[19]
[20]
terpyridone)
Co(pyterpy)
2
](CF
](PF
3
SO
3
)
2
·H
2
O,
2
],
[21]
OH
[22]
[
2
6
)
2
·2CH
3
and Co(Cl
2
Gm)
3
[1-3]
For example, Brooker and co-workers reported a mononuclear
–
cobalt(II) complex incorporating the dpzca ligand, which
electronics.
Up to now, numerous SCO compounds
n
incorporating d (n = 4–7) transition metal ions have been
reported. In particular, iron(II) SCO compounds have been
6
well-studied because the 3d electron state in iron(II) yields
[
20]
showed abrupt and hysteretic ST behaviour.
This neutral
compound has no uncoordinated counter anions or lattice
solvents, and shows a transformation of crystal systems by ST
between HS and LS states. Our group has reported hysteretic
and reverse ST behaviour by the cobalt(II) complex, [Co(C14-
significant differences in properties between the diamagnetic
low-spin (LS, S = 0) and paramagnetic high-spin (HS, S = 2)
states, with both abrupt (cooperative factor C
[4-7]
hysteretic ST behaviour (C
≈ 1) and
In contrast
2 4 2
terpy) ](BF ) , together with variable temperature (VT)
> 1) being reported.
structural analyses carried out to clarify the structural changes
to iron(II) compounds, reports discussing SCO behaviour for
mononuclear cobalt(II) compounds are quite limited, reflecting
the difficulties in achieving suitable molecular design for
[18b]
accompanying the spin state changes.
Here, we focus on the distortions in octahedral [CoN
6
] cores of
[8]
selected cobalt(II) complexes as a means of investigating the
relationship between distortion and cooperativity leading to
abrupt ST behaviour. In this context it is noted that the
distortion parameters for cores in SCO iron(II/III) complexes
have been investigated previously, not only in relation to
temperature-dependent SCO, but also with respect to photo-
cobalt(II) complexes that exhibit abrupt ST behaviour, rather
[9-15]
than gradual or incomplete SCO behaviour.
To the best of
[23,24]
induced spin state changes.
For both iron(II/III) and
cobalt(II) complexes smaller distortions are observed in their
[
LS states than in the HS states (at higher temperature).
8,23-26]
However, the degree of distortion in the octahedral cores has
rarely been discussed when investigating SCO behaviour even
though intermolecular interactions producing cooperativity
would be expected to influence the distortions occurring in
cores.
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In this study, we report the thermally-induced, reversible,
complete and abrupt ST behaviour of a new cobalt(II) complex,
2 2
Table 1 Co-N distances in 1·2MeOH, 1, 2·2CH Cl and 3·2.5MeOH
1
·2MeOH @100K
2.033(2)
1·2MeOH @273K
2.105(6)
1@93K
2.001(5)
1.901(5)
2.008(5)
2.168(5)
1.962(5)
1@200K
2.114(4)
2.019(3)
2.167(3)
2.149(4)
2.032(3)
2.160(3)
2·2CHCl
3
@100K
3·2.5MeOH @100K
1.991(2)
Co-N1 (Å)
Co-N2 (Å)
Co-N3 (Å)
Co-N4 (Å)
Co-N5 (Å)
Co-N6 (Å)
2.051(4)
1.888(4)
2.062(4)
2.103(4)
1.910(4)
2.096(4)
1.888(2)
1.966(4)
1.873(2)
2.037(2)
2.117(5)
2.001(2)
2.132(2)
2.103(4)
2.133(2)
1.921(2)
1.965(4)
1.932(2)
2.123(2)
2.126(5)
2.171(5)
4’-(2-
2.133(2)
[
Co(Naph-C2-terpy)
2
](BF
4
)
2
(
1
;
Naph-C2-terpy
=
naphthoxy(ethoxy))-2,2’:6’,2”-terpyridine), incorporating π-
conjugated substituents. Solvated ·2MeOH, also showed
complete but more gradual SCO behaviour than occurs for
unsolvated . In both cases, the crystal structures of their HS
and LS states were obtained, clearly demonstrating their
structural transformation on undergoing SCO. incorporates a
highly-distorted coordination geometry for each [CoN ] core,
1, 1
1
1
6
Figure 1. Molecular structure of 1·2MeOH. Counter anions, H
atoms, and solvent molecules are omitted for clarity. Colour code:
Co; magenta, C; grey, N; blue, O; red.
giving rise to higher cooperativity. We were able to
corroborate cooperativity of the SCO behaviour and distortion
of the [CoN6]
cores by preparing a further seven derivative cobalt(II)
Molecules of 1·2MeOH are assembled via π–π interactions
complexes of types [Co(R-terpy)
anthracenyl ( )) and [Co(Naph-Cn-terpy)
), 8 ( ), 10 ( ), 12 ( )) and investigating their SCO behaviour
2
](BF
4
)
2
(R = 2-naphthyl (
2), 9-
along the a axis. Lattice MeOH molecules are incorporated by
intermolecular interactions with naphthalene substituents and
terpyridine cores. These MeOH were found to be removed by
heating up to 340 K, confirmed by thermogravimetric analysis
3
2
](BF (n = 4 (
4
)
2
4), 6
(
5
6
7
8
as well as also obtaining their crystal structures.
(
TGA) (Figure S1).
crystal (SCSC) transformation on standing its crystal at 80 ˚C
for 30 min. A single crystal of the de-solvated product was
used for SXRD measurements which were carried out at 93 K
and 200 K. Unlike ·2MeOH, crystallizes in the monoclinic
system P2 /n. The crystal packing for is shown in Figures.
(b) and 2(c), which indicates that the complex units are
1·2MeOH showed a single-crystal to single-
Results and discussion
1
Crystal structures. Complex 1·2MeOH was prepared by reaction of
4 2 2
Naph-C2-terpy with Co(BF ) ·6H O in MeOH (see experimental
1
1
section in supporting information, SI) and recrystallizing the initial
product from methanol–acetone (v/v = 1:3) to yield single crystals
of 1·2MeOH. 1·2MeOH was characterized by elemental analysis and
single crystal X-ray diffraction (SXRD) measurements. The SXRD
determination for 1·2MeOH was performed at 100 K and 273 K.
1
1
2
assembled via intermolecular π–π and CH–π interactions.
We have also synthesized cobalt(II) complexes incorporating π-
conjugated naphthyl and anthracenyl substituents rather than
1
·2MeOH crystalizes in the triclinic space group P-1. Two Naph-C2-
terpy ligands coordinate to the cobalt(II) metal centre meridionally
to yield a N donor set. The crystal structure of 1·2MeOH is
alkyl chains. [Co(R-terpy)
anthracenyl ( )) were prepared by reacting the corresponding
R-terpy ligand with Co(BF ·6H O in MeOH–CHCl , resulting in
microcrystalline precipitates. Single crystals of ·2CHCl and
·2.5MeOH were obtained by recrystallization of the initial
products from dichloromethane and methanol, respectively
see Experimental section in SI). These complexes were
2 4 2
](BF ) (R = 2-naphthyl (2), 9-
3
6
)
2
4
2
3
displayed in Figure 1. At 100 K, a Jahn–Teller distortion, as expected
for cobalt(II) ions, was observed to yield a tetragonally distorted
2
3
3
6
coordination environment for the [CoN ] core, with the cobalt(II) to
apical pyridine donors (N4 and N6) bonds being elongated relative
to those occupying the equatorial positions (Table 1). Crystal
parameters and the packing structure of 1·2MeOH are given in
Table S1 and Figures 2(a) and 2(b), with full structural data available
(
characterized by elemental analyses and SXRD measurements.
The X-ray structures and corresponding molecular assemblies
are displayed in Figures. S2 and S3. The crystal parameters for
[28]
from the CCDC.
the compounds are given in Table S2.
through CH–π interactions and π–π interactions resulting in 3-
D assembly networks. ·2.5MeOH forms 2-D assembly
networks via π–π interactions.
3
2·2CHCl assembles
3
2
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m
ST behaviour by measuring several cycles of the χ T versus T
c
-1
-1
-1
(a)
plot with scan rates of 2 K min , 1 K min and 0.5 K min ,
where each χ T plot versus T traced the result obtained for the
K min measurement (Figure S4). The cooperative factor C
for was estimated to be 0.91 using the fitting of the regular
solution model to the experimental plots (See
experimental section). This value is high enough to produce
abrupt ST behaviour. In comparison, ·2MeOH exhibited more
a
m
-1
5
1
m
χ T
[29]
1
gradual SCO behaviour than
value of 0.49.
1
which is in accord with the C
π-π interaction
2
2
1
1
0
0
.5
.0
.5
.0
.5
.0
2.0
(
a)
(b)
(b)
1
1
0
.5
.0
.5
MeOH
χ
χ
χ
χ
0.0
100
200
300
400
100
200
300
400
Temperature / K
Temperature / K
2
.0
(
c)
(c) a
1.5
c
1
0
0
.0
.5
.0
π-π interaction
χ
χ
CH-π interaction
1
00
200
300
400
Temperature / K
Figure 3. Magnetic behaviours of (a)
and (circle plots), (b) ·2CHCl , and (c)
heating (red) and cooling (blue) processes.
1
·2MeOH (triangle plots)
1
2
3
3·2.5MeOH for the
(d)
This abrupt ST behaviour observed for
investigated by a differential scanning calorimetry (DSC)
measurement by thermal treated sample of at 400 K for 1 h
to remove lattice solvent molecules. The DSC curve was
1 was further
1
−1
obtained for 100 K to 293 K with a scan rate of 5 K min .
During the heating process (Figure 4), an endothermic peak
was observed at around 116 K, which agrees with the T1/2 for
the ST. During the cooling process, an exothermic peak was
observed around 130 K, confirming that the phase transition in
Figure 2. Molecular assembly of
ac plane. Counter anions are omitted for clarity. (b)
Intermolecular interactions involving lattice MeOH molecules.
Molecular assembly of 1: (c) view along the ac plane. (d)
1
·2MeOH: (a) view along the
Intermolecular interaction networks. Counter anions are
omitted for clarity. Color code: Co; magenta, C; grey, N; blue,
O; red. Blue-dashed lines indicate intermolecular interactions.
1
occurs reversibly.
Magnetic behaviours. The SCO behaviours of single crystals of
1,
1·2MeOH,
2·2CHCl3 and 3·2.5MeOH were investigated
employing a Superconducting Quantum Interference Device
-
1
(
SQUID) using sweep mode and scan rate of 5 K min (Figure
3). Magnetic susceptibilities are displayed by χ T versus T
m
endo
curves, where χm is the molar magnetic susceptibility and T is
3
at 5 K, 0.46 cm K mol is
-1
the temperature. The χ T value of
m
1
consistent with the presence of LS cobalt(II) in an octahedral
1
10 120 130 140 150 160 170 180 190 200
[18a]
coordination environment.
Upon heating, an abrupt ST
3
occurred at T = 124 K. The χ T value increased to 2.26 cm K
Temperature / K
Figure 4. DSC curves for . Red and blue lines correspond to
heating and cooling processes, respectively.
1
/2
m
-1
1
mol at 400 K which is in accord with the expected HS state for
cobalt(II) ion. We confirmed no scan rate dependency on the
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Figure 5. Views illustrating the terpyridine-cobalt molecule of
‡
Table 2 Distortion parameter Σ and φ of
1·2MeOH –
3·2.5MeOH, and previous compounds, at the LS and HS states
↑
Σ@LS Σ@HS
01.6 126.0
ΔΣ
φ@LS φ@HS
Δφ
Magnetic behaviour
Tc
Reference
This work (1)
Abrupt
No hysteresis
1
24.4
174.4 170.5
175.2 174.7
3.9
100 K
8
9.2
7.6
6.6
105.7
16.5
0.5
-
Gradual
Gradual
Gradual
Gradual
116 K
180 K
250 K
150 K
This work (
This work (
This work ( ·2.5MeOH)
[Co(terpy)
1
·2MeOH)
8
8
-
-
-
-
175.7
177.2
-
-
2
·2CHCl
3
)
-
3
[
14]
90
117
27
178.3 178.2
175.8 173.3
0.1
2
](BF
](BF
[Co(terpyridone) ](CF
[Co(dpzca)
4 2
)
Abrupt
Hysteresis
Abrupt
Hysteresis
Abrupt
Hysteresis
Abrupt
Hysteresis
[20b]
9
9
7
9
1.6
117.8
119.4
110.8
116.1
26.2
26.6
34.7
24.4
2.5
3.3
1.9
1.4
50 K
175 K
170 K
[Co(C14terpy)
2
4
)
2
·MeOH
SO ·H
[21]
2
O
2.8
6.1
1.7
179.2 175.9
2
3
3
)
2
[22]
178.1
180
180
2
]
[23]
178.6
190 K
2 6 2
[Co(pyterpy) ](PF ) ·2MeOH
The χmT versus T plots for
in Figures 3(b) and 3(c).
a χ T value of 0.39. χ T then gradually increases to 1.73 cm K
2
·2CHCl
3
and
3
·2.5MeOH are shown (a)
1
·2MeOH and (b) 1 in the LS (blue) and the HS (red) states.
2
3
·2CHCl is in the LS state at 100 K with
For the detailed assessment of spin state-dependent structural
distortions of [CoN6] cores, the distortion parameters Σ and φ
3
m
-
m
1
mol at 400 K; this is an expected value for a HS cobalt(II) ion. were calculated; where Σ is the sum of |90–α| for the twelve
3
·2.5MeOH was also found to be in the LS state at 100 K, but angles of cis-N-Co-N and φ is the inter-ligand angles for trans-
[25,26]
3
-1
N-Co-N.
180. The Σ and φ values for
with the values for previously reported compounds are listed
in Table 2 and Figure 6. The solvated compound ·2MeOH
gave the distortion parameters Σ = 89.2 (LS) and 105.8 (HS),
which are both close to the values of the other the SCO
cobalt(II) complexes listed. The distortion parameters Σ at 100
A perfectly octahedral structure gives Σ = 0 and φ
even at 400 K the value was only 0.74 cm K mol , with this
compound showing incomplete gradual SCO behaviour. The
=
1
·2MeOH – ·2.5MeOH together
3
m
χ T plots for the cooling process followed the same trace as
1
found for the heating process, indicating no effect of lattice
solvents on SCO behaviour. The cooperative factors for these
derivatives estimated from the gradual SCO behaviours are
0
.37 for
than the value for
In order to investigate the influence of the length of the state of SCO compounds. On the other hand, the desolvated
appended alkyl chain on the magnetic properties of complexes compound was found to be more distorted both in the HS
of the present type, the series of complexes given by and LS states, with a Σ value for in the HS state of 126 and
01.6 in the LS state, which are both significantly higher than
those of the other SCO compounds. It is noteworthy that the
ΔΣ value for is 24.4 and is a typical ΔΣ value observed for SCO
cobalt(II) compounds. The φ for in the HS state is 170.5,
3
2·2CHCl and 0.24 for 3·2.5MeOH, which are smaller
K are 87.6 and 86.6 for
2·2CHCl and 3·2.5MeOH, respectively.
3
1.
These values are also close to the usual Σ values for the LS
1
1
1
[
2 4 2
Co(Naph-Cn-terpy) ](BF ) (n = 4 (4), 6 (5), 8 (6), 10 (7), 12 (8))
were synthesized, and the corresponding susceptibility
measurements were performed for the powder samples.
1
1
Complexes
gradual SCO behaviour over the temperature range 5 – 400 K
Figure. S5).
4 – 8 each show no cooperative effect but display
which is smaller than the values for the other compounds
listed. Nevertheless, this value corresponds to a substantial
(
6 2
distortion of the [CoN ] core in 1. [Co(dpzca) ] reported by
[20]
Discussions. We further investigated the resultant ST Brooker and co-workers shows a smaller Σ value (76.1) in
the LS state likely reflecting that the dpzca ligand contains no
–
behaviour in terms of the distortions occurring in the
complicating substituents and is more flexible than the terpy
octahedral environment of the cobalt(II) centres in the LS and
ligand. Further, this compound does not contain counter
HS states. A terpyridine-cobalt molecule of
1 shows larger
anions which might also affect its core structure.
structural changes associated with the spin state changes than
1·2MeOH (Figure 5, Figure S6).
4
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Acknowledgements
1
1
1
1
1
1
80
78
76
74
72
70
This work was supported by KAKENHI Grant-in-Aid for
Scientific Research (A) JP17H01200. M.N. is grateful to JSPS
Research Fellowships for Young Scientists (No. JP15J11333).
This work was supported by JSPS Grant-in-Aid for Young
Scientists (B) JP15K17833 and JSPS Grant-in-Aid for Scientific
Research on Innovative Areas (Dynamical Ordering
&
Integrated Functions JP16H00777, Mixed Anion JP17H05485).
This work was supported by the Cooperative Research
Program of ‘Network Joint Research Centre for Materials and
Devices’.
1
@LS
: 1
: [Co(terpy) ](BF )
2
4
2
:
:
:
1·2MeOH
2·2CHCl
3·2.5MeOH : [Co(dpzca)
2 6 2
[Co(pyterpy) ](PF ) ·2MeOH
: [Co(C14terpy)
: [Co(terpyridone)
2
](BF
4
)
2
·MeOH
1@HS
Notes and references
](CF
3
SO ·H O
3
)
2
2
3
2
2
]
#
i
#
§
=
Abbreviations: Ar′CoN(H)Ar (Ar′ = C
6
H
3
-2,6-(C
[Co(C14-terpy)
6’,2’’-terpyridine),
6
H
3
-2,6- Pr
2
)
2
, Ar
(C14-
[Co(4-
:
[
17]
C
6
H
3
-2,6-(C
4’-tetradecyloxy-2,2’
terpyridone) ](CF[ SO ·H
(1H)-pyridone), [Co(dpzca)
pyrazylcarbonyl)-2-pyrazinecarboxamide),
Figure 6. Relationship between the distortion parameters, Σ [Co(pyterpy) ](PF ·2CH OH (pyterpy
,2’:6’,2’’-terpyridine) and Co(Cl Gm)
dichloro-glyoxime dianion, Bn-C16 33 = n-hexadecyl boron).
Abbreviaꢀons: [Co(terpy) ](BF (terpy 2,2’:6’,2’’-
](ClO (terpyR8 = 4’’-Octoxy-2,2’ :
6
H
2
-2,4,6-Me
3
)
2
),
2
](BF
4 2
)
[
18b]
terpy
=
:
70
80
90
100 110 120 130
2
3
3
)
2
2
O (4-terpyridone = 2,6-bis(2-pyridyl)-
(Hdpzca N-(2-
19]
Σ / degree
4
2
]
=
[
20]
2
6
)
2
3
=
4’-(4’’’-pyridyl)-
(Cl Gm =
[
21]
2
2
3
(Bn-C16
H
33
)
2
2
and φ, for
1·2MeOH and 3·2.5MeOH, as well as for the
[
22]
H
previously reported compounds listed in their LS (blue) and the
HS (red) states.
‡
2
4
)
2
=
[
12]
terpyridine), [Co(terpyR8)
2
4 2
)
[
13]
These results indicate that the removal of the lattice methanol 6’,2’’-terpyridine).
solvents from
distortion of the [CoN
1
·2MeOH leads to an increase in the structural
] cores and, at the same time, increasing
6
1
2
O. Kahn and C. J. Martinez, Science, 1998, 279, 44.
Spin Crossover in Transition Metal Compounds I-III; ed. P.
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the cooperativity for SCO behaviour. On removing the lattice
methanol molecules, the Co–Co centres become closer by
about ~0.9 Å (from 8.923 Å to 8.045 Å), in accord with stronger
intermolecular interaction being present in
Stronger intermolecular interaction might be expected to help
stabilize the highly-distorted [CoN ] cores as well as to increase
1 than in 1·2MeOH.
3
4
6
the cooperativity to produce the resultant observed abrupt ST
behaviour.
5
6
7
M. A. Halcrow, Polyhedron, 2007, 26, 3523-3576.
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Conclusions
,
The present results are in keeping with the highly distorted
203-240. (b) S. Brooker and J. A. Kitchen, Dalton Trans.,
2009, 7331.
core of [CoN ] in [Co(Naph-C2-terpy) ](BF ) (1) resulting in
6
2
4 2
8
9
R. G. Miller, S. Narayanaswamy, J. L. Tallon and S. Brooker,
New J. Chem., 2014, 38, 1932-1941.
enhanced intermolecular interaction leading to abrupt ST
behaviour. We have demonstrated that a single-crystal-to-
single-crystal transformation occurs on removal of the lattice
(a) M. Nakaya, R. Ohtani, K. Sugimoto, M. Nakamura, L. F.
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53, 10009-10011.
solvent from
. The crystal structures of
in both their HS and LS states and showed that he presence of
the lattice solvents in ·2MeOH results in a reduction of the
distortion of the [CoN ] core. This influences the observed SCO
1·2MeOH to form the above de-solvated product
1
1
and ·2MeOH were determined
1
1
1
6
behaviour due to the presence of lower cooperativity and, in 11 V. V. Novikov, I. V. Ananyev, A. A. Pavlov, M.V. Fedin, K. A.
turn, is reflected by ·2MeOH displaying gradual SCO
Lyssenko and Y. Z. Voloshin, Phys. Chem. Lett., 2014, , 496-
00.
1
5
5
behaviour – contrasting with the abrupt SCO found for
1.
1
2 C. A. Kilner and M. A. Halcrow, Dalton Trans., 2010, 39
9
,
Overall, the present study gives new insights for the better
understanding of the magneto-structural correlations in SCO
compounds.
009012.
1
3 P. Nielsen, H. Toftlund, A. D. Bond, J. F. Boas, J. R. Pilbrow, G.
R. Hanson, C. Noble, M. J. Riley, S. M. Neville, B. Moubaraki
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Chem., 2001, 40, 9-10.
1
1
Conflicts of interest
5 A. Galet, A. B. Gaspar, M. C. Munoz and J. A. Real, Inorg.
Chem., 2006, 45, 4413-4422.
There are no conflicts to declare.
This journal is © The Royal Society of Chemistry 20xx
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DOI: 10.1039/C8DT02367K
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DOI: 10.1039/C8DT02367K
2 2 2
The cobalt(II) complex [Co(Naph-C2-terpy) ](BF ) ·2MeOH (1·2MeOH) showed single crystal to
single crystal transition, resulted in its desolvated product of 1. Complex 1 incorporating a highly
distorted [CoN6] core was found to exhibit abrupt spin transition behavior, unlike 1·2MeOH, which
showed gradual spin crossover behavior.