How Does a Container Affect Acidity of its Content: Charge-Depletion Bonding Inside Fullerenes

0489832 - ÚOCHB 2019 RIV DE eng J - Článek v odborném periodiku
Jaroš, Adam - Badri, Z. - Bora, P. L. - Bonab, E. F. - Marek, R. - Straka, Michal - Foroutan-Nejad, C.
How Does a Container Affect Acidity of its Content: Charge-Depletion Bonding Inside Fullerenes.
Chemistry - A European Journal. Roč. 24, č. 17 (2018), s. 4245-4249. ISSN 0947-6539. E-ISSN 1521-3765
Grant CEP: GA ČR(CZ) GA17-07091S
Institucionální podpora: RVO:61388963
Klíčová slova: ab initio calculations * acidity * chemical bond theory * fullerenes
Obor OECD: Physical chemistry
Impakt faktor: 5.160, rok: 2018

A recent study (Sci. Adv. 2017, 3, e1602833) has shown that FHOH2 hydrogen bond in a HFH2O pair substantially shortens, and the H-F bond elongates upon encapsulation of the cluster in C-70 fullerene. This has been attributed to compression of the HFH2O pair inside the cavity of C-70. Herein, we present theoretical evidence that the effect is not caused by a mere compression of the H2OHF pair, but it is related to a strong lone-pair- (LP-) bonding with the fullerene cage. To support this argument, a systematic electronic structure study of selected small molecules (HF, H2O, and NH3) and their pairs enclosed in fullerene cages (C-60, C-70, and C-90) has been performed. Bonding analysis revealed unique LP-(cage) interactions with a charge-depletion character in the bonding region, unlike usual LP- bonds. The LP-(cage) interactions were found to be responsible for elongation of the H-F bond. Thus, the HF appears to be more acidic inside the cage. The shortening of the FHOH2 contact in (HFH2O)@C-70 originates from an increased acidity of the HF inside the fullerenes. Such trends were also observed in other studied systems.
Trvalý link: http://hdl.handle.net/11104/0284165