Specific Intermolecular Interactions by the Localized π‐Electrons in C₇₀‐fullerene

Abstract

We report the specific intermolecular interactions on C 70fullerene. A newly developed silica-monolithic capillary column, which was modified with C 70 -fullerene via a particular thermal reactive molecule, perfluorophenyl azide, provided a selective retention behavior toward polycyclic aromatic hydrocarbons in liquid chromatography. Especially, a hemispherical molecule, i. e., corannulene, was significantly retained on this C 70 -fullerene column. Results of the computer simulation of the molecules suggested that the specific interaction might be caused by the deflection of the p-electrons-density in C 70 -fullerene. Furthermore, the absorption spectrometry also indicated that the absorption spectra of C 70 -fullerene with/without corannulene were dramatically changed by the specific interaction, whereas no spectrum differences were observed with C 60 -fullerene.

Development of a C₇₀-Fullerene Bonded Silica-Monolithic Capillary and Its Retention Characteristics in Liquid Chromatography

“…The results also supported that the immobilized C60 or C70 contributed the retention by hydrophobic interaction. These fundamental results were corresponded to our previous studies [34,38].…”

“…Although the reaction time by the microwave was significantly shorter than that of the oil bath, the yield was much higher [39]. In both reactions, similar FT-IR spectrum, mass spectrum, and the results of elemental analysis were identified as well as our previous study [38].…”

“…Yan et al suggested that perfluorophenyl azide (PFPA) is effectively worked for the immobilization of the carbon materials [27][28][29][30][31] and we also reported the immobilization of C 60 -fullerene (C60) on the surface of a silica monolith [32][33][34]. Additionally, we recently reported similar silica-monolithic capillary modified with C 70 -fullerene (C70), which has aspheric structure and greater π electrons compared to C60 [35][36][37], for the separation medium in LC [38]. In these our studies, the fullerene bonded monoliths provided the specific retention behavior, in brief, the C70 bonded monolith provided the higher selectivity for hemispherical molecule, corannulene (Crn) by the induced dipole interaction between C70 and Crn.…”

“…As well as the previous studies [34,38], a C70 bonded silica-monolithic capillary was prepared. To modify C70 via PFPA, a C70 conjugated molecule with PFPA and NHS was synthesized as follows (Scheme 1-a).…”

Separation of halogenated benzenes enabled by investigation of halogen–π interactions with carbon materials

“…39,40 In our previous studies, we developed novel separation media immobilized with carbon materials. [41][42][43] These media exhibited strong p interactions because of their many p electrons. Characteristics of weak interactions from aromatic rings were claried by evaluating their retention behaviors with HPLC measurements.…”