A molecular Popeye: Li⁺@C₆₀ and its complexes with [n]cycloparaphenylenes

Abstract

In this work, we compare for the first time the stability of [n]cycloparaphenylene ([n]CPP)-based host-guest complexes with Li+@C60 and C60 in the gas and the solution phase. Our gas-phase experiments...

[Sc©[3]CPP]+: A Viable Metal-Centered [3]Cycloparaphenylene

“…Inspired by our recently reported trisbenzene complexes of heavy alkaline earth metals and host–guest properties of CPPs, − the heavy alkaline earth metals Ca, Sr, and Ba were tried as the guest atoms to be hosted at the center of [3]­CPP. Delightfully, the [Ca©[3]­CPP] complex was found to be a symmetric D 3 h energy minimum with the [3]­CPP skeleton at the MN15/BS1 level (Figure a).…”

“…Herein, we propose that the [3]­CPP skeleton as a host may be stabilized by a guest metal atom. We were inspired by the host–guest properties of CPPs − and the recently proposed trisbenzene complexes of alkaline-earth metals M­(C 6 H 6 ) 3 (M = Ca, Sr, and Ba), where M atoms exhibited the transition-metal-like bonding behaviors of heavy alkaline-earth metals. − Note that the alkaline-earth metal-centered [3]­CPP complexes [M©[3]­CPP] can be seen as the product of dehydrogenated M­(C 6 H 6 ) 3 complexes (Figure a).…”

New Insights into Ring-In-Ring Complexes of [n]Cycloparaphenylenes including the [12]Carbon Nanobelt

“…In a recent series of collision studies aimed at the establishment of host–guest bond strengths, we successfully transferred noncovalent CPP-based host–guest complexes from solution into the gas phase. − Here we present a detailed examination of the gas-phase stabilities of ([ n + x ]­CPP⊃[ n ]­CPP) +• ( n = 5–9; x = 3–7; n + x ≤ 12) (Table ) and ([11]­CPP⊃[12]­CNB) +• ring-in-ring complexes, based on the powerful combination of electrospray ionization (ESI) with tandem mass spectrometry (MS 2 ).…”

Conformational Landscapes and Energetics of Carbon Nanohoops and their Ring-in-Ring Complexes

“…Cycloparaphenylenes (CPPs) are a class of carbon nanohoops, in which benzene rings are connected in para -position (Figure a center). − They exhibit a concave cavity, which is a suitable binding site for convex, carbonaceous partners via π–π bonding, leading to host–guest complex formation with partners such as other CPPs, fullerenes, , fullerene derivatives, , or carbon nanobelts . CPPs can also be regarded as the smallest unit of carbon nanotubes, which are promising materials due to their high thermal conductivity and tensile strength.…”

“…MS 2 has been successfully employed to establish the noncovalent nature and the relative bond strengths of different carbon nanohoop-based host–guest complexes, ,,,− and IM-MS was used to characterize CPP-based catenanes . The host–guest chemistry of carbon nanohoops is so far not well explored for cases where they act simultaneously as hosts and guests.…”