TY - JOUR
T1 - Isotope Effects on Hydrogen Bonding and CH/CD-π Interaction
AU - Kanao, Eisuke
AU - Kubo, Takuya
AU - Naito, Toyohiro
AU - Matsumoto, Takatoshi
AU - Sano, Tomoharu
AU - Yan, Mingdi
AU - Otsuka, Koji
N1 - Funding Information:
This research was partly supported by the Grant-in Aid for Scientific Research (No. 25620111 and 15K13756) from the Japan Society for the Promotion of Science and an Environment Research and Technology Development Fund (5-1552) from the Ministry of the Environment, Japan, and the National Science Foundation (CHE-1112436 to M.Y.).
Publisher Copyright:
© Copyright 2018 American Chemical Society.
PY - 2018/7/5
Y1 - 2018/7/5
N2 - We study the isotope effect by liquid chromatography (LC) with a variety of separation media under reversed and normal phase conditions using the protiated and/or deuterated compounds as the solutes. Results of reversed phase LC (RPLC) suggested that the protiated compounds were more hydrophobic than that of deuterated compounds due to the isotope effect based on the hydrogen bonding between hydrogen atoms of isotopologues and hydroxy groups in the mobile phase. The importance of the hydrogen bonding was also supported by the separation of isotopologues with a silica stationary phase on normal phase LC (NPLC), where the deuterated compounds showed stronger hydrogen bonding to hydroxy groups on silanol. Additionally, we investigated the difference of the strength between CH-π and CD-π interactions. Comparison of free energies of isotopologues by RPLC suggested that the CH-π interaction was slightly stronger than CD-π interaction. Finally, we demonstrated the separation of a few isotopologues on NPLC using a column coated with C70-fullerene, which is capable of strong π-based interactions, by effective CH/CD-π interactions.
AB - We study the isotope effect by liquid chromatography (LC) with a variety of separation media under reversed and normal phase conditions using the protiated and/or deuterated compounds as the solutes. Results of reversed phase LC (RPLC) suggested that the protiated compounds were more hydrophobic than that of deuterated compounds due to the isotope effect based on the hydrogen bonding between hydrogen atoms of isotopologues and hydroxy groups in the mobile phase. The importance of the hydrogen bonding was also supported by the separation of isotopologues with a silica stationary phase on normal phase LC (NPLC), where the deuterated compounds showed stronger hydrogen bonding to hydroxy groups on silanol. Additionally, we investigated the difference of the strength between CH-π and CD-π interactions. Comparison of free energies of isotopologues by RPLC suggested that the CH-π interaction was slightly stronger than CD-π interaction. Finally, we demonstrated the separation of a few isotopologues on NPLC using a column coated with C70-fullerene, which is capable of strong π-based interactions, by effective CH/CD-π interactions.
UR - http://www.scopus.com/inward/record.url?scp=85048240275&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85048240275&partnerID=8YFLogxK
U2 - 10.1021/acs.jpcc.8b04144
DO - 10.1021/acs.jpcc.8b04144
M3 - Article
AN - SCOPUS:85048240275
SN - 1932-7447
VL - 122
SP - 15026
EP - 15032
JO - Journal of Physical Chemistry C
JF - Journal of Physical Chemistry C
IS - 26
ER -