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The retention behavior of fullerenes and fullertubes on a PYE column in reversed-phase chromatography was investigated to clarify the influence of their shapes on the separation process. The impact of anisotropy was further elucidated using a pair potential interaction model, together with experimental data and ab initio calculations, to evaluate its contribution to various parameters characterizing the interaction models. The findings indicate that the shape of fullerenes plays a more significant role than anticipated in the retention mechanisms, highlighting the necessity of considering the shape of fullerenes and fullertubes to accurately predict their retention times. Furthermore, a phenomenological pair potential was devised to demonstrate the feasibility of precisely predicting the retention times of fullerenes and fullertubes through first-principles calculations, regardless of their shape. The existence of such a model paves the way for the development of a method to identify isomers of fullerenes from minute amounts of sample. 

We report the seminal experimental isolation and DFT characterization of pristine [5,5] C130-D5h(1) fullertubes. This achievement represents the largest soluble carbon molecule obtained in pristine form. The [5,5] C130 species is the highest aspect ratio fullertube purified to date and now surpasses the recent gigantic [5,5] C120-D5d(1). In contrast to C90, C100, and C120 fullertubes, the longer C130-D5h has more nanotubular carbons (70) than end-cap fullerenyl atoms (60). Starting from 39,393 possible C130 isolated pentagon rule (IPR) structures and after analyzing polarizability, retention time, and UV-vis spectra, these three layers of data remarkably predict a single candidate isomer and fullertube, [5,5] C130-D5h(1). This structural assignment is augmented by atomic resolution STEM data showing distinctive and tubular “pill-like” structures with diameters and aspect ratios consistent with [5,5] C130-D5h(1) fullertubes. The high selectivity of the aminopropanol reaction with spheroidal fullerenes permits a facile separation and removal of fullertubes from soot extracts. Experimental analyses (HPLC retention time, UV-vis, and STEM) were synergistically used (with polarizability and DFT property calculations) to down select and confirm the C130 fullertube structure. Achieving the isolation of a new [5,5] C130-D5h fullertube opens the door to application development and fundamental studies of electron confinement, fluorescence, and metallic character for a fullertube series of molecules with systematic tubular elongation. This [5,5] fullertube family also invites comparative studies with single-walled carbon nanotubes (SWCNTs), nanohorns (SWCNHs), and fullerenes.