Optical Characteristics of Spiropyran@MOF Composites as a Function of the Metal–Organic Framework Linker Substitution

In functional materials, the understanding of interactions between individual components is essential for further development. One example such materials are guest@host systems, with a metal–organic framework (?MOF) as host matrix. These porous compounds consist metal nodes and organic linker molecules therefore inorganic–organic hybrid materials. Combining MOFs photoswitchable dyes spiropyrans (SPs) resulted in new fascinating properties. To obtain technologically relevant properties, knowledge adjusting screws to modulate, example, optical response obligatory push material’s design. Within this work, we systematically studied properties nitro-substituted SP inside an MIL-68(In) series function substitution. particular, 1,3,3-trimethylindolino-6?-nitrobenzopyrylospiran (?SP-Nitro) was non-covalently attached into pores terephthalate molecule being functionalized either Br-, NH2-, or NO2-group. Three different systems were obtained, exhibiting both photochromic solvatochromic response. The observed characteristics found strongly depend on substitution pattern molecule. Based resulting structural dielectric substituted terephthalic acid calculated at B3LYP MP2 levels, UV/vis reflectance spectra directly correlated out-of-plane rotation carboxyl group vicinity respective substituent.