Chloro- and Trifluoromethyl Derivatives of a Pentagon-Fused C60: 1810C60Cl24, 1810C60Cl20, and 1810C60(CF3)14

Nadezhda B Tamm; Victor A Brotsman; Lev N Sidorov; Sergey I Troyanov

doi:10.1021/acs.inorgchem.1c00775

Chloro- and Trifluoromethyl Derivatives of a Pentagon-Fused C₆₀: ¹⁸¹⁰C₆₀Cl₂₄, ¹⁸¹⁰C₆₀Cl₂₀, and ¹⁸¹⁰C₆₀(CF₃)₁₄

Inorg Chem. 2021 May 17;60(10):6991-6993. doi: 10.1021/acs.inorgchem.1c00775. Epub 2021 Apr 29.

Authors

Nadezhda B Tamm¹, Victor A Brotsman¹, Lev N Sidorov¹, Sergey I Troyanov¹

Affiliation

¹ Chemistry Department, Moscow State University, Leninskie Gory, Moscow 119991, Russia.

PMID: 33913327
DOI: 10.1021/acs.inorgchem.1c00775

Abstract

The carbon cage of I_h-C₆₀, obeying the isolated-pentagon rule (IPR), can be transformed to the non-IPR D_2h-¹⁸¹⁰C₆₀ cage via two successive Stone-Wales rearrangements in the course of high-temperature chlorination of C₆₀ with SbCl₅. Two chloro derivatives, C_2v-¹⁸¹⁰C₆₀Cl₂₄ and C_2v-¹⁸¹⁰C₆₀Cl₂₀, have been isolated by high-performance liquid chromatography (HPLC). High-temperature trifluoromethylation of the chlorination products with CF₃I, followed by HPLC separation, afforded a non-IPR CF₃ derivative, C_s-¹⁸¹⁰C₆₀(CF₃)₁₄. Structural elucidation of the isolated compounds revealed that all eight sites of pentagon-pentagon fusions on the carbon cage are preferentially occupied by Cl atoms or CF₃ groups. According to density functional theory calculations, chloro and CF₃ derivatives of ¹⁸¹⁰C₆₀ are more stable than the isomeric derivatives of ¹⁸⁰⁹C₆₀ or IPR ¹⁸¹²C₆₀, possessing respectively four or no sites of pentagon fusion in their carbon cages.