Theoretical Prediction of the Host-Guest Interactions Between Novel Photoresponsive Nanorings and C-60: A Strategy for Facile Encapsulation and Release of Fullerene

摘要

A series of photoresponsive-group-containing nanorings hosts with 12 approximate to 14 angstrom in diameter is designed by introducing different number of azo groups as the structural composition units. And the host-guest interactions between fullerene C-60 and those nanoring hosts were investigated theoretically at M06-2X/6-31G(d)//M06-L/MIDI! and wB97X-D/6-31G(d) levels. Analysis on geometrical characteristics and host-guest binding energies revealed that the designed nanoring molecule (labeled as 7) which is composed by seven azo groups and seven phenyls is the most feasible host for encapsulation of C-60 guest among all candidates. Moreover, inferring from the simulated UV-vis-NIR spectroscopy, the C-60 guest could be facilely released from the cavity of the host 7 via configuration transformation between trans-form and cis-form of the host under the 563 nm photoirradiation. Additionally, the frontier orbital features, weak interaction regions, infrared, and NMR spectra of the C-60@7 host-guest complex have also been investigated theoretically. (c) 2015 Wiley Periodicals, Inc.