Photochromism of metal–organic frameworks based on carbazole-dicarboxylic acid and bipyridine: sensing adjustment by controlling strut-to-strut energy transfer. Issue 23 (4th June 2020)

• Record Type: Journal Article
• Authors: Liu, Han; Fan, Yanru; Li, Xiao; Gao, Kuan; Li, Huijie; Yang, Yisen; Meng, Xiangru; Wu, Jie; Hou, Hongwei
• Is Part Of: Dalton transactions. Volume 49:Issue 23(2020)
• Page Start: 7952
• Page End: 7958
• Publication Date: 2020-06-04
• Subjects: Chemistry, Inorganic -- Periodicals; Chemistry, Physical and theoretical -- Periodicals; Chemistry, Inorganic -- Periodicals; 546.05
• DOI: 10.1039/d0dt00122h
• Languages: English
• ISSNs: 1477-9226

Abstract

Abstract : Efficient strut-to-strut energy transfer (antenna behavior) was observed in the well-ordered donor–acceptor system. Color tuning, adjustment of gamut, and regulation of sensitivity can be realized by the judicious choice of the constitutions of MOFs. Abstract : In this paper, two energy-transfer photochromic metal–organic frameworks (MOFs) {[Zn(L)0.5 (bpy)]·H2 O·DMF} n (1 ) and {[Zn(L)0.5 (bpe)]·2H2 O·DMF} n (2 ) (H4 L = 9, 9′-(1, 4-phenylenebis(methylene))bis(9 H -carbazole-3, 6-dicarboxylic acid), bpy = 4, 4′-bipyridine, bpe = 4, 4′-vinylenedipyridine) were designed and synthesized. Both 1 and 2 showed similar pillared-paddle wheel type frameworks with bpy and bpe as the chromophore, respectively, and L 4− as the antenna-type light harvester, yielding strut-to-strut energy transfer (antenna behavior) within the well-ordered structures. Among them, 1 displayed excellent energy-transfer photochromic behavior under UV light accompanied by color transformation from colorless to purple. In addition, the photochromic behavior of 1 has obvious, fast, controllable and reversible characteristics. On the other hand, 2 showed a different energy-transfer photochromic behavior in the aspects of color changing, gamut, and sensitivity. The variation has been ascribed to the substitution of chromophore bpy in 1 with bpe in 2, which influences the efficiency of energy transfer within the MOFs. Therefore, with the structural diversity and tunability of MOFs, the sensitivity, color, and gamut of energy-transfer of the photochromic MOFs can be tuned by the appropriate choice of the constitutions of MOFs. This work will provide useful guidance for developing novel energy-transfer photochromic MOF materials.