Fullertubes: Cylindrical Carbon with Half-Fullerene End-Caps and Tubular Graphene Belts, Their Chemical Enrichment, Crystallography of Pristine C90- D5h(1) and C100- D5d(1) Fullertubes, and Isolation of C108, C120, C132, and C156 Cages of Unknown Structures

Ryan M Koenig; Han-Rui Tian; Tiffany L Seeler; Katelyn R Tepper; Hannah M Franklin; Zuo-Chang Chen; Su-Yuan Xie; Steven Stevenson

doi:10.1021/jacs.0c08529

Fullertubes: Cylindrical Carbon with Half-Fullerene End-Caps and Tubular Graphene Belts, Their Chemical Enrichment, Crystallography of Pristine C₉₀- D_5h(1) and C₁₀₀- D_5d(1) Fullertubes, and Isolation of C₁₀₈, C₁₂₀, C₁₃₂, and C₁₅₆ Cages of Unknown Structures

J Am Chem Soc. 2020 Sep 9;142(36):15614-15623. doi: 10.1021/jacs.0c08529. Epub 2020 Aug 31.

Authors

Ryan M Koenig¹, Han-Rui Tian², Tiffany L Seeler¹, Katelyn R Tepper¹, Hannah M Franklin¹, Zuo-Chang Chen², Su-Yuan Xie², Steven Stevenson¹

Affiliations

¹ Purdue University Fort Wayne, Department of Chemistry, Fort Wayne Indiana 46805, United States.
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: 32830484
DOI: 10.1021/jacs.0c08529

Abstract

We report a chemical separation method to isolate fullertubes: a new and soluble allotrope of carbon whose structure merges nanotube, graphene, and fullerene subunits. Fullertubes possess single-walled carbon nanotube belts resembling a rolled graphene midsection, but with half-fullerene end-caps. Unlike nanotubes, fullertubes are reproducible in structure, possess a defined molecular weight, and are soluble in pristine form. The high reactivity of amines with spheroidal fullerene cages enables their removal and allows a facile isolation of C₉₆-D_3d(3), C₉₀-D_5h(1), and C₁₀₀-D_5d(1) fullertubes. A nonchromatographic step (Stage 1) uses a selective reaction of carbon cages with aminopropanol to permit a highly enriched sample of fullertubes. Spheroidal fullerenes are reacted and removed by attaching water-soluble groups onto their cage surfaces. With this enriched (100-1000 times) fullertube mixture, Stage 2 becomes a simple HPLC collection with a single column. This two-stage separation approach permits fullertubes in scalable quantities. Characterization of purified C₁₀₀-D_5d(1) fullertubes is done with samples isolated in pristine and unfunctionalized form. Surprisingly, C₆₀ and C₁₀₀-D_5d(1) are both purplish in solution. For X-ray crystallographic analysis, we used decapyrrylcorannulene (DPC). Isomerically purified C₉₀ and C₁₀₀ fullertubes were mixed with DPC to obtain black cocrystals of 2DPC{C₉₀-D_5h(1)}·4(toluene) and 2DPC{C₁₀₀-D_5d(1)}·4(toluene), respectively. A serendipitous outcome of this chemical separation approach is the enrichment and purification of several unreported larger carbon species, e.g., C₁₂₀, C₁₃₂, and C₁₅₆. Isolation of these higher cage species represents a significant advance in the unknown experimental arena of C₁₀₀-C₂₀₀ structures. Our findings represent seminal experimental evidence for the existence of two mathematically predicted families of fullertubes: one family with an axial hexagon with the other series based on an axial pentagon ring. Fullertubes have been predicted theoretically, and herein is their experimental evidence, isolation, and initial characterization.

Publication types

Research Support, Non-U.S. Gov't
Research Support, U.S. Gov't, Non-P.H.S.