Capturing the Missing Carbon Cage Isomer of C84 via Mutual Stabilization of a Triangular Monometallic Cyanide Cluster

Runnan Guan; Muqing Chen; Jinpeng Xin; Xiao-Ming Xie; Fei Jin; Qianyan Zhang; Su-Yuan Xie; Shangfeng Yang

doi:10.1021/jacs.1c02428

Capturing the Missing Carbon Cage Isomer of C₈₄ via Mutual Stabilization of a Triangular Monometallic Cyanide Cluster

J Am Chem Soc. 2021 Jun 2;143(21):8078-8085. doi: 10.1021/jacs.1c02428. Epub 2021 May 19.

Authors

Runnan Guan¹, Muqing Chen¹, Jinpeng Xin¹, Xiao-Ming Xie², Fei Jin¹, Qianyan Zhang², Su-Yuan Xie², Shangfeng Yang¹

Affiliations

¹ Hefei National Laboratory for Physical Sciences at Microscale, CAS Key Laboratory of Materials for Energy Conversion, Anhui Laboratory of Advanced Photon Science and Technology, Department of Materials Science and Engineering, University of Science and Technology of China, Hefei 230026, China.
² State Key Lab for Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials, Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China.

PMID: 34010566
DOI: 10.1021/jacs.1c02428

Abstract

Monometallic cyanide clusterfullerenes (CYCFs) represent a unique branch of endohedral clusterfullerenes with merely one metal atom encapsulated, offering a model system for elucidating structure-property correlation, while up to now only C₈₂ and C₇₆ cages have been isolated for the pristine CYCFs. C₈₄ is one of the most abundant fullerenes and has 24 isomers obeying the isolated pentagon rule (IPR), among which 14 isomers have been already isolated, whereas the C_2v(17)-C₈₄ isomer has lower relative energy than several isolated isomers but never been found for empty and endohedral fullerenes. Herein, four novel C₈₄-based pristine CYCFs with variable encapsulated metals and isomeric cages, including MCN@C₂(13)-C₈₄ (M = Y, Dy, Tb) and DyCN@C_2v(17)-C₈₄, have been synthesized and isolated, fulfilling the first identification of the missing C_2v(17)-C₈₄ isomer, which can be interconverted from the C₂(13)-C₈₄ isomer through two steps of Stone-Wales transformation. The molecular structures of these four C₈₄-based CYCFs are determined unambiguously by single-crystal X-ray diffraction. Surprisingly, although the ionic radii of Y³⁺, Dy³⁺, and Tb³⁺ differ slightly by only 0.01 Å, such a subtle difference leads to an obvious change in the metal-cage interactions, as inferred from the distance between the metal atom and the nearest hexagon center of the C₂(13)-C₈₄ cage. On the other hand, upon altering the isomeric cage from DyCN@C₂(13)-C₈₄ to DyCN@C_2v(17)-C₈₄, the Dy-cage distance changes as well, indicating the interplay between the encapsulated DyCN cluster and the outer cage. Therefore, we demonstrate that the metal-cage interactions within CYCFs can be steered via both internal and external routes.