Self-assembly of novel [3]- and [2]rotaxanes based on donor-acceptor and hydrogen-bonding interactions. Intensified inter-ring repulsion interaction and shuttling behavior.
Three novel hetero[3]rotaxanes, which comprise one neutral tetraamide cyclophane, one tetracationic cyclophane, and one linear component, have been assembled by utilizing hydrogen-bonding and donor-acceptor interactions, through three neutral [2]rotaxanes as intermediates. Three tetracationic [2]rotaxanes are also prepared for property comparison. For all three linear components, diamide subunits, the hydrogen-bonding templating moieties, are introduced at the center of the molecules, while the electron-rich hydrogquinone subunits, the donor-acceptor interaction templates, are incorporated between the diamides and the triphenylmethyl stoppers. Compared with the reported [3]rotaxanes, the novel hetero[3]rotaxanes exhibit remarkably intensified spatial interaction between the two ring components, which had been proved by (1)H NMR and UV study. For the first time, inter-ring NOEs are observed for interlocked [3]rotaxanes.
Chen
Lin
L
School of Chemistry and Chemical Engineering, Shanghai Jiaotong University, 800 Dongchuan Lu, Shanghai 200240, China.
Zhao
Xin
X
Chen
Yan
Y
Zhao
Cheng-Xue
CX
Jiang
Xi-Kui
XK
Li
Zhan-Ting
ZT