The demand for new materials for data storage devices has increased significantly in recent years. In particular, photoswitchable systems will have an essential impact on the construction of new memory devices. In this respect, thermally stable materials are desired to be implemented as device components. Here, hybrid systems consisting of a porous host and a photochromic molecule form the foundation for such composites. In this work, we present the first hybrid materials consisting of the photoswitchable fulgide Aberchrome 670 and porous metal–organic frameworks (MOFs) of varying polarity exhibiting P-type photochromism upon light irradiation. From a fundamental point of view, this MOF embedment further enabled to trace the IR signatures of both the initial and irradiated state of Aberchrome 670 under ambient conditions, which are in correspondence with the results obtained via quantum-chemical calculations. It is precisely in these points that the interface between basic and applied research demonstrates the importance of the switch@MOF research field.

Fluorine labeling of ribonucleic acids in conjunction with 19F‐NMR spectroscopy has emerged as a powerful strategy for spectroscopic analysis of RNA structure and dynamics, and RNA– ligand interactions. Here, we present the first syntheses of 2'‐OCF3 guanosine and uridine phosphoramidites, their incorporation into oligoribonucleotides by solid‐phase synthesis and a comprehensive study of their properties. NMR spectroscopic analysis showed that the 2'‐OCF3 modification is associated with preferential C2'‐endo conformation of the U and G ribose in single‐stranded RNA. When paired to the complementary strand, slight destabilization of the duplex caused by the modification was revealed by UV melting curve analysis. Moreover, we demonstrate the power of the 2'‐OCF3 label for NMR spectroscopy by dissecting RNA pseudoknot folding and its binding to a small molecule. Furthermore, the 2'‐OCF3 modification has potential for applications in therapeutic oligonucleotides. To this end, we tested 2'‐OCF3 modified siRNAs in silencing of the BASP1 gene which indicated enhanced performance. Importantly, together with our earlier work, the present study completes the set of 2'‐OCF3 nucleoside phosphoramidites to all four standard nucleobases and hence enables applications that utilize the favorable properties of the 2'‐OCF3 group without any restrictions in placing the modification into the RNA target sequence.