Building-up host-guest helicate motifs and chains: a magneto-structural study of new field-induced cobalt-based single-ion magnets
In this work, we present the synthetic pathway, a refined structural description, complete solid-state characterization and the magnetic properties of four new cobalt( ii ) compounds of formulas [Co(H 2 O) 6 ][Co 2 (H 2 mpba) 3 ]·2H 2 O·0.5dmso ( 1 ), [Co(H 2 O) 6 ][Co 2 (H 2 mpba) 3 ]·3H 2 O·0.5dps...
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Published in | Dalton transactions : an international journal of inorganic chemistry Vol. 5; no. 31; pp. 177 - 1728 |
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Main Authors | , , , , , , , , , , , , , , , , , |
Format | Journal Article |
Language | English |
Published |
Cambridge
Royal Society of Chemistry
21.08.2021
|
Subjects | |
Online Access | Get full text |
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Summary: | In this work, we present the synthetic pathway, a refined structural description, complete solid-state characterization and the magnetic properties of four new cobalt(
ii
) compounds of formulas [Co(H
2
O)
6
][Co
2
(H
2
mpba)
3
]·2H
2
O·0.5dmso (
1
), [Co(H
2
O)
6
][Co
2
(H
2
mpba)
3
]·3H
2
O·0.5dpss (
2
), [Co
2
(H
2
mpba)
2
(H
2
O)
4
]
n
·4
n
H
2
O (
3
), and [Co
2
(H
2
mpba)
2
(CH
3
OH)
2
(H
2
O)
2
]
n
·0.5
n
H
2
O·2
n
dpss (
4
) [dpss = 2,2′-dipyridyldisulfide and H
4
mpba = 1,3-phenylenebis(oxamic) acid], where
2
and
4
were obtained from [Co(dpss)Cl
2
] (
Pre-I
) as the source of cobalt(
ii
). All four compounds are air-stable and were prepared under ambient conditions.
1
and
2
were obtained from a slow diffusion method [cobalt(
ii
) : H
2
mpba
2−
molar ratio used 1 : 1] and their structures are made up of [Co
2
(H
2
mpba)
3
]
2−
anionic helicate units and [Co(H
2
O)
6
]
2+
cations, exhibiting supramolecular three-dimensional structures. Interestingly, a supramolecular honeycomb network between the helicate units interacting with each other through R
2
2
(10) type hydrogen bonds occurs in
2
hosting one co-crystallized dpss molecule. On the other hand, for the first time, linear (
3
) and zigzag (
4
) cobalt(
ii
) chains were isolated by slow evaporation of stirred solutions of mixed solvents with cobalt(
ii
) : H
2
mpba
2−
in 1 : 2 molar ratio at room temperature. Magnetic measurements of
Pre-I
revealed a quasi magnetically isolated
S
= 3/2 spin state with a significant second-order spin-orbit contribution as expected for tetrahedrally coordinated cobalt(
ii
) ions. The analysis of the variable temperature static (dc) magnetic susceptibility data through first- (
1
and
3
) and second-order spin-orbit coupling models (
2
and
4
) reveals the presence of magnetically non-interacting high-spin cobalt(
ii
) ions with easy-axis (
1
and
4
)/easy-plane magnetic anisotropies (
2
and
4
) with low rhombic distortions. Dynamic (ac) magnetic measurements for
Pre-I
and
1-4
below 8.0 K show that they are examples of field-induced Single-Ion Magnets (SIMs).
The slow diffusion method affords host-guest systems (
1
and
2
), while the stirring method results in chains (
3
and
4
) that behave as field-induced cobalt-based Single-Ion Magnets (SIMs). |
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Bibliography: | CCDC Tables S15, S16 and S19 Tables S4, S5, S9, S10 and S13 crystallographic drawings [Fig. S4-S15], ac magnetic plots [Fig. S16 Table S8 10.1039/d1dt01693h and S24 S20 and best-fit Cole-Cole parameters [Tables S23 For ESI and crystallographic data in CIF or other electronic format see DOI S22 S21 data comparison with the literature [Tables S21 Electronic supplementary information (ESI) available: Diffraction patterns [Fig. S1 S23 and 1-4 TG plots [Fig. S2 and S25 (ac measurements of 1993352 Cole-Cole plots [Fig. S26-S27 Pre-I crystallographic tables [Tables S1-S3 ( ) and S3 S22 (dc measurements of and Tables S17, S18 and S20 1 2 3 4 S24-S25 S17 S19 S18 Tables S6, S7, S11, S12 and S14 1883575 1883574 1883577 1883576 ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
ISSN: | 1477-9226 1477-9234 |
DOI: | 10.1039/d1dt01693h |