Construction of Metallacage‐Cored Supramolecular Gel by Hierarchical Self‐Assembly of Metal Coordination and Pillar[5]arene‐Based Host−Guest Recognition. Issue 24 (15th October 2018)

• Record Type: Journal Article
• Authors: Liu, Yuezhou; Shi, Bingbing; Wang, Hu; Shangguan, Liqing; Li, Zhengtao; Zhang, Mingming; Huang, Feihe
• Is Part Of: Macromolecular rapid communications. Volume 39:Issue 24(2018)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2018-10-15
• Subjects: controlled release -- metallacages -- pillararenes -- supramolecular gels; Macromolecules -- Periodicals; Polymers -- Periodicals; Chemistry -- Periodicals; 547.705
• DOI: 10.1002/marc.201800655
• Languages: English
• ISSNs: 1022-1336

Abstract

Abstract: In this work, a Pd2 L4 metallacage2 ([BF4 ] − )4 with four pillar[5]arene units is first prepared and characterized by 1D multinuclear NMR ( 1 H, 11 B, and 19 F NMR), 2D 1 H− 1 H correlation spectra, 1 H− 13 C heteronuclear single quantum coherence, and diffusion‐ordered NMR spectroscopy, and electrospray ionization time‐of‐flight mass spectrometry. By the introduction of a ditopic guest molecule3 into a chloroform solution of2 ([BF4 ] − )4, a supramolecular polymer network gel is successfully constructed based on the metal coordination interactions and host−guest recognition between the pillar[5]arene units of2 ([BF4 ] − )4 and neutral ditopic guest molecule3 . The temperature and pH responsivenesses of the supramolecular gel are studied, which are further employed for the controlled release of different cargos. As a demonstration, emodin and methylene blue are trapped in the cavities of the metallacage and in the pores of the supramolecular gel, respectively. Methylene blue is first released along with the gel–sol transition while emodin is then released by the further addition of acid to destroy the metallacage. This study explores the use of metallacage‐cored supramolecular network gels for sequential controlled release and contributes to the development of smart and adaptive materials. Abstract : A temperature and H + dual‐responsive metallacage‐cored supramolecular gel is constructed by the hierarchical self‐assembly of metal coordination and pillar[5]arene‐based host−guest recognition. Furthermore, the supramolecular gel is applied in the controlled release of different cargos.