Hydrogenation of S6-C60(CF3)12

• Published in: Russian Journal of Physical Chemistry A Vol. 97; no. 9; pp. 1964 - 1977
• Main Authors: Romanova, N. A., Markov, V. Yu, Goryunkov, A. A.
• Format: Journal Article
• Language: English
• Published: Moscow Pleiades Publishing 01.09.2023; Springer Nature B.V
• Subjects: Buckminsterfullerene; Chemistry; Chemistry and Materials Science; Composition; Density functional theory; Energy of dissociation; Enthalpy; Free energy; Fullerenes; Heat of formation; High temperature; Hydrides; Hydrogen atoms; Hydrogenation; Nanomaterials; Physical Chemistry; Physical Chemistry of Nanoclusters; Protonation; Quantum chemistry; Supramolecular Structures; correlation equations; bond dissociation energy; nucleophilic hydrogenation; nanospheres; density functional theory; trifluoromethyl; linear free energy relations; nanocarbon; hydrogenation; hydrogen atom transfer; fullerene
• ISSN: 0036-0244; 1531-863X
• DOI: 10.1134/S0036024423090200

The first results of the hydrogenation of S 6 -symmetric trifluoromethylfullerene C 60 (CF 3 ) 12 in two types of reactions were reported: (1) high-temperature radical hydrogenation with 9,10-dihydroanthracene and (2) nucleophilic hydrogenation with sodium tetraborohydride under mild conditions. The high-temperature radical hydrogenation of S 6 -C 60 (CF 3 ) 12 is accompanied by partial elimination of CF 3 groups and leads to the formation of a complex mixture of products of a composition C 60 (CF 3 ) 8–12 H 18–22 . During the hydrogenation of NaBH 4 under mild conditions, selective formation of the hydride C 60 (CF 3 ) 12 H 12 was recorded by mass spectroscopy. A kinetic analysis of the sequential nucleophilic hydrogenation of S 6 -C 60 (CF 3 ) 12 was performed, using quantum-chemical modeling at the level of density functional theory, under the assumption of linear correlation between the activation energy and the enthalpy of elementary steps of the same type. The isomeric composition was predicted for the series of anionic intermediates C 60 (CF 3 ) 12 H and their protonation products C 60 (CF 3 ) 12 H 2 n , where n = 1–6. The hydrogenation of S 6 -C 60 (CF 3 ) 12 should lead to the formation of the thermodynamically and kinetically most stable product ortho - S 6 -C 60 (CF 3 ) 12 H 12 , in which all hydrogen atoms are located in neighboring positions near the CF 3 groups, forming together with them a near-equatorial belt of 24 addends while retaining the triphenylene fragments at two opposite poles. The average bond dissociation energy BDE(C–H) in ortho - S 6 -C 60 (CF 3 ) 12 H 12 is 298 kJ mol –1 , which is approximately 20 kJ mol –1 higher than the BDE(C–H) of known fullerene hydrides C 60 H 18 and C 60 H 36 (PBE0/def2-SVP).