Small Crown-Ether Complexes as Molecular Models for Dihydrogen Adsorption in Undercoordinated Extraframework Cations in Zeolites

2020 ◽  
Vol 124 (17) ◽  
pp. 9409-9415
Author(s):  
Toshiki Wulf ◽  
Thomas Heine
Keyword(s):  
Crown Ether ◽  
Molecular Models ◽  
Crown Ether Complexes ◽  
Extraframework Cations

scholarly journals Small Crown-Ether Complexes as Molecular Models for Dihydrogen Adsorption in Undercoordinated Extraframework Cations in Zeolites

2020 ◽  
Author(s):  
Toshiki Wulf ◽  
Thomas Heine
Keyword(s):  
Gas Phase ◽  
Crown Ethers ◽  
Hydrogen Isotope ◽  
Rational Design ◽  
Isotope Separation ◽  
Adsorbed Molecule ◽  
Molecular Models ◽  
Crown Ether Complexes ◽  
Adsorption Energies ◽  
Extraframework Cations

1:1 metal complexes of small crown-ethers are structurally similar to extraframework sites in metal-exchanged zeolites. Using <i>ab initio</i> calculations, we show that adsorbed molecular hydrogen follows the same trends in adsorption energies and vibrational frequencies at both types of metal sites. Unlike zeolites, crown-ethers can be characterized in the gas phase, which opens new possibilities for understanding the bonding of dihydrogen at undercoordinated metal sites to help guide the rational design of porous materials for hydrogen isotope separation. Because more strongly binding adsorbates affect the geometry of the hosts, the similarity of crown-ethers and zeolites with regard to the vibrational spectra of the adsorbed molecule seems to be limited to H₂.

scholarly journals Small Crown-Ether Complexes as Molecular Models for Dihydrogen Adsorption in Undercoordinated Extraframework Cations in Zeolites

2020 ◽  
Author(s):  
Toshiki Wulf ◽  
Thomas Heine
Keyword(s):  
Gas Phase ◽  
Crown Ethers ◽  
Hydrogen Isotope ◽  
Rational Design ◽  
Isotope Separation ◽  
Adsorbed Molecule ◽  
Molecular Models ◽  
Crown Ether Complexes ◽  
Adsorption Energies ◽  
Extraframework Cations

1:1 metal complexes of small crown-ethers are structurally similar to extraframework sites in metal-exchanged zeolites. Using <i>ab initio</i> calculations, we show that adsorbed molecular hydrogen follows the same trends in adsorption energies and vibrational frequencies at both types of metal sites. Unlike zeolites, crown-ethers can be characterized in the gas phase, which opens new possibilities for understanding the bonding of dihydrogen at undercoordinated metal sites to help guide the rational design of porous materials for hydrogen isotope separation. Because more strongly binding adsorbates affect the geometry of the hosts, the similarity of crown-ethers and zeolites with regard to the vibrational spectra of the adsorbed molecule seems to be limited to H₂.

Synthesis, Characterization, and Reaction of Crown Ether Complexes of Aqua(hydroxy)(aryl)iodonium Ions

2005 ◽  
Vol 44 (1) ◽  
pp. 75-78 ◽  
Author(s):  
Masahito Ochiai ◽  
Kazunori Miyamoto ◽  
Yukie Yokota ◽  
Takashi Suefuji ◽  
Motoo Shiro
Keyword(s):  
Crown Ether ◽  
Crown Ether Complexes
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