| Autor: |
Panteleieva OS; Department of Inorganic Chemistry, Ukrainian State University of Chemical Technology, Gagarin Ave. 8, 49005 Dnipro, Ukraine., Ponomarova VV; Inorganic Chemistry Department, National Taras Shevchenko University of Kyiv, Volodymyrska Str. 64/13, 01601 Kyiv, Ukraine., Shtemenko AV; Department of Inorganic Chemistry, Ukrainian State University of Chemical Technology, Gagarin Ave. 8, 49005 Dnipro, Ukraine., Domasevitch KV; Inorganic Chemistry Department, National Taras Shevchenko University of Kyiv, Volodymyrska Str. 64/13, 01601 Kyiv, Ukraine. |
| Jazyk: |
angličtina |
| Zdroj: |
Acta crystallographica. Section C, Structural chemistry [Acta Crystallogr C Struct Chem] 2020 Aug 01; Vol. 76 (Pt 8), pp. 753-762. Date of Electronic Publication: 2020 Jul 21. |
| DOI: |
10.1107/S205322962000950X |
| Abstrakt: |
Anion...π interactions are newly recognized weak supramolecular forces which are relevant to many types of electron-deficient aromatic substrates. Being less competitive with respect to conventional hydrogen bonding, anion...π interactions are only rarely considered as a crystal-structure-defining factor. Their significance dramatically increases for polyoxometalate (POM) species, which offer extended oxide surfaces for maintaining dense aromatic/inorganic stacks. The structures of tetrakis(caffeinium) μ 12 -silicato-tetracosa-μ 2 -oxido-dodecaoxidododecatungsten trihydrate, (C 8 H 11 N 4 O 2 ) 4 [SiW 12 O 40 ]·3H 2 O, (1), and tris(theobrominium) μ 12 -phosphato-tetracosa-μ 2 -oxido-dodecaoxidododecatungsten ethanol sesquisolvate, (C 7 H 9 N 4 O 2 ) 3 [PW 12 O 40 ]·1.5C 2 H 5 OH, (2), support the utility of anion...π interactions as a special kind of supramolecular synthon controlling the structures of ionic lattices. Both caffeinium [(HCaf) + in (1)] and theobrominium cations [(HTbr) + in (2)] reveal double stacking patterns at both axial sides of the aromatic frameworks, leading to the generation of anion...π...anion bridges. The latter provide the rare face-to-face linkage of the anions. In (1), every square face of the metal-oxide cuboctahedra accepts the interaction and the above bridges yield flat square nets, i.e. {(HCaf + ) 2 [SiW 12 O 40 ] 4- } n . Two additional cations afford single stacks only and they terminate the connectivity. Salt (2) retains a two-dimensional (2D) motif of square nets, with anion...π...anion bridges involving two of the three (HTbr) + cations. The remaining cations complete a fivefold anion...π environment of [PW 12 O 40 ] 3- , acting as terminal groups. This single anion...π interaction is influenced by the specific pairing of (HTbr) + cations by double amide-to-amide hydrogen bonding. Nevertheless, invariable 2D patterns in (1) and (2) suggest the dominant role of anion...π interactions as the structure-governing factor, which is applicable to the construction of noncovalent linkages involving Keggin-type oxometalates. |
| Databáze: |
MEDLINE |
| Externí odkaz: |
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