A cationic water-soluble pillar[7]arene: Synthesis and its fluorescent host−guest complex in water. Issue 28 (12th July 2017) - Zhang, Zhihua
Graphical abstract: Highlights: First cationic pillar[7]arene. Host−guest complexation induced fluorescent enhancement. Size-selective host−guest complex. Abstract: The first cationic water-soluble pillar[7]arene CWP7 was prepared. 1 H NMR, 13 C NMR, and MALDI-TOF-MS were performed to provide converging evidences of the structure of obtained CWP7. Host–guest complexation between this novel pillar[7]arene-based host and sodium pyren-1-olate guest G was fully investigated in aqueous solution. Increased fluorescence intensity was observed during the inclusion complexation. Driven by the cooperativity of electrostatic interactions, π-stacking interactions and hydrophilic/hydrophobic interactions, the guest penetrated into the cavity of CWP7 to form a pseudorotaxane-type inclusion complex with relatively high binding affinity.