Yan Jingjing, MacDonald John C, Maag Alex R, Coudert François-Xavier, Burdette Shawn C
Department of Chemistry and Biochemistry, Worcester Polytechnic Institute, 100 Institute Road, Worcester, MA, 01609-2280, USA.
Department of Chemical Engineering, Worcester Polytechnic Institute, 100 Institute Road, Worcester, MA, 01609-2280, USA.
Chemistry. 2019 Jun 21;25(35):8393-8400. doi: 10.1002/chem.201901213. Epub 2019 May 17.
Photoswitchable components can modulate the properties of metal organic frameworks (MOFs); however, photolabile building blocks remain underexplored. A new strut NPDAC (2-nitro-1,4-phenylenediacetic acid) that undergoes photodecarboxylation has been prepared and incorporated into a MOF, using post-synthetic linker exchange (PSLE) from the structural analogue containing PDAC (p-phenylenediacetic acid). Irradiation of NPDAC-MOF leads to MOF decomposition and concomitant formation of amorphous material. In addition to complete linker exchange, MOFs containing a mixture of PDAC and NPDAC can be obtained through partial linker exchange. In NPDAC30-MOF, which contains approximately 30 % NPDAC, the MOF retains crystallinity after irradiation, but the MOF contains defect sites consistent with loss of decarboxylated NPDAC linkers. The defect sites can be repaired by exposure to additional PDAC or NPDAC linkers at a much faster rate than the initial exchange process. The photoremoval and replacement process may lead to a more general approach to customizable MOF structures.
光开关组件可以调节金属有机框架（MOF）的性质；然而，光不稳定的结构单元仍未得到充分探索。一种新的会发生光脱羧反应的支柱NPDAC（2-硝基-1,4-苯二甲酸）已被制备出来，并通过来自含PDAC（对苯二甲酸）的结构类似物的后合成连接体交换（PSLE）被纳入到一种MOF中。NPDAC-MOF的辐照会导致MOF分解并伴随无定形材料的形成。除了完全的连接体交换外，通过部分连接体交换还可以得到含有PDAC和NPDAC混合物的MOF。在含有约30% NPDAC的NPDAC30-MOF中，MOF在辐照后保持结晶性，但该MOF含有与脱羧的NPDAC连接体损失一致的缺陷位点。通过暴露于额外的PDAC或NPDAC连接体可以比初始交换过程快得多的速率修复这些缺陷位点。光去除和替换过程可能会导致一种更通用的可定制MOF结构的方法。
