Crown ether-like octanuclear molybdenum() clusters for cation binding and gas adsorption
Octanuclear polyoxomolybdenum-based porous materials, Na 8 [Mo 8 O 8 (μ 2 -O) 8 (μ 2 -OH) 8 (3-apz) 4 ] 2 ·26H 2 O ( 1 , 3-Hapz = 3-aminopyrazole), K 8 [Mo 8 O 8 (μ 2 -O) 8 (μ 2 -OH) 8 (3-apz) 4 ] 2 ·7H 2 O ( 2 ) and (NH 4 ) 4 [Mo 8 O 8 (μ 2 -O) 8 (μ 2 -OH) 4 (3-apz) 8 ]·20.5H 2 O ( 3 ), have been s...
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| Published in | Dalton transactions : an international journal of inorganic chemistry Vol. 53; no. 21; pp. 898 - 8987 |
|---|---|
| Main Authors | , , , , |
| Format | Journal Article |
| Language | English |
| Published |
England
Royal Society of Chemistry
28.05.2024
|
| Subjects | |
| Online Access | Get full text |
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| Summary: | Octanuclear polyoxomolybdenum-based porous materials, Na
8
[Mo
8
O
8
(μ
2
-O)
8
(μ
2
-OH)
8
(3-apz)
4
]
2
·26H
2
O (
1
, 3-Hapz = 3-aminopyrazole), K
8
[Mo
8
O
8
(μ
2
-O)
8
(μ
2
-OH)
8
(3-apz)
4
]
2
·7H
2
O (
2
) and (NH
4
)
4
[Mo
8
O
8
(μ
2
-O)
8
(μ
2
-OH)
4
(3-apz)
8
]·20.5H
2
O (
3
), have been successfully synthesized by a hydrothermal method and fully characterized. X-ray structural analyses show that microporous materials
1-3
contain round pores formed by octanuclear molybdenum-oxygen groups connected sequentially with pore sizes of 4.0, 4.0, and 4.8 Å, respectively. Both
1
and
2
are composed of two {Mo
8
} rings, which are connected by strong intramolecular hydrogen bonds between bridging hydroxy groups and oxygen atoms to form dimeric structures. The central pores in
1
and
2
are occupied by Na
+
and K
+
, respectively, while they are empty in
3
. This reflects the structural expansion and contraction effects induced by different cations. Through intermolecular stacking,
1-3
also exhibit channels with sizes of 14.0 × 6.4, 4.6 × 2.6, and 5.4 × 5.4 Å, respectively, which were used for the studies of gas adsorption. The results show that
1-3
can selectively adsorb CO
2
and O
2
, including the empty hole in
3
, while they show little or no affinity for gases H
2
, N
2
, and CH
4
. Moreover, an additional polyoxomolybdenum-based species (Mo
8
O
26
)
n
·4
n
(3-H
2
apz) (
4
) has been obtained with protonated 3-aminopyrazole in the absence of a reducing agent, which can serve as an intermediate for the polyoxomolybdenum-based porous products.
Octanuclear molybdenum(
v
) clusters with porous structures have been constructed using 3-aminopyrazole. Interestingly, the central porous structures in
1
and
2
are occupied by sodium and potassium cations, respectively, while it is empty for
3
. |
|---|---|
| Bibliography: | https://doi.org/10.1039/d4dt00825a at 110 K, detailed adsorption data for O H for CO and CH at different pressures, crystallographic details, selected bond distances and angles, hydrogen bonds, bond valence calculations for molybdenum atoms. CCDC , N 2340878 For ESI and crystallographic data in CIF or other electronic format see DOI 2 4 1-3 Electronic supplementary information (ESI) available: Powder XRD patterns, IR and solid UV-vis spectra, TG curves, solid EPR spectra of 2341220-2341222 ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 14 content type line 23 |
| ISSN: | 1477-9226 1477-9234 1477-9234 |
| DOI: | 10.1039/d4dt00825a |