TY - JOUR
T1 - Fluoride Ion-Encapsulated Germoxane Cages Modified with Organosiloxane Chains as Anionic Components of Ionic Liquids
AU - Hayashi, Taiki
AU - Murase, Nanako
AU - Sato, Naoto
AU - Fujino, Koki
AU - Sugimura, Natsuhiko
AU - Wada, Hiroaki
AU - Kuroda, Kazuyuki
AU - Shimojima, Atsushi
N1 - Publisher Copyright:
© 2022 American Chemical Society. All rights reserved.
PY - 2022/6/13
Y1 - 2022/6/13
N2 - Herein, we report the preparation of a new class of inorganic-organic hybrid ionic liquids by modification of a double-four-ring (D4R)-type germoxane (Ge-O-Ge) compound, containing a fluoride ion inside and a tetraethylammonium cation outside, with organosiloxane chains. D4R-type inorganic compounds are attractive as anionic components of ionic liquids because of their ability to encapsulate a fluoride ion inside the cage and allow various functional groups to be linked at the cage corners. The crystalline D4R-type germoxanes with corner Ge-OH groups were successfully converted to clear liquids by modification with dimethylvinylsilyl groups, followed by hydrosilylation with flexible oligosiloxanes (HSi(OSiMe3)nMe3-n, n = 1-3). The resulting products showed liquid behaviors below 0 °C and were stable against thermal decomposition up to ∼200 °C. Additionally, they had high affinities for both hydrophilic and hydrophobic substances, attributable to the organosiloxane chains surrounding the ionic cage. Furthermore, the differences between the D4R-type germoxane and D4R-type siloxane were investigated using density functional theory calculations. The symmetry of the optimized structure and its electrostatic nature indicated that D4R-type germoxane is advantageous for the creation of ionic liquids.
AB - Herein, we report the preparation of a new class of inorganic-organic hybrid ionic liquids by modification of a double-four-ring (D4R)-type germoxane (Ge-O-Ge) compound, containing a fluoride ion inside and a tetraethylammonium cation outside, with organosiloxane chains. D4R-type inorganic compounds are attractive as anionic components of ionic liquids because of their ability to encapsulate a fluoride ion inside the cage and allow various functional groups to be linked at the cage corners. The crystalline D4R-type germoxanes with corner Ge-OH groups were successfully converted to clear liquids by modification with dimethylvinylsilyl groups, followed by hydrosilylation with flexible oligosiloxanes (HSi(OSiMe3)nMe3-n, n = 1-3). The resulting products showed liquid behaviors below 0 °C and were stable against thermal decomposition up to ∼200 °C. Additionally, they had high affinities for both hydrophilic and hydrophobic substances, attributable to the organosiloxane chains surrounding the ionic cage. Furthermore, the differences between the D4R-type germoxane and D4R-type siloxane were investigated using density functional theory calculations. The symmetry of the optimized structure and its electrostatic nature indicated that D4R-type germoxane is advantageous for the creation of ionic liquids.
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U2 - 10.1021/acs.organomet.2c00174
DO - 10.1021/acs.organomet.2c00174
M3 - Article
AN - SCOPUS:85131934008
SN - 0276-7333
VL - 41
SP - 1454
EP - 1463
JO - Organometallics
JF - Organometallics
IS - 11
ER -