It was in Saint Petersburg that in 1915, jointly with his coworker Mariya Skanawy-Grigorjewa, he conducted the experiments on reactions of CNMe with platinum complexes and obtained platinum carbene species formed via nucleophilic addition of hydrazine to Pt IIactivated methylisocyanide [Tschugajeff (Chugaev), L.; Skanawy-Grigorjewa, M.

By combining the photoswitching and localization of individual fluorophores with spectroscopy on the single molecule level, we demonstrate simultaneous multicolor imaging with low crosstalk and down to 15 nm spatial resolution using only two detection color channels. The applicability of the method to biological specimens is demonstrated on mammalian cells. The combination of far-field fluorescence nanoscopy with the recording of a single switchable molecular species at a time opens up a new class of functional imaging techniques.

A bright future: The reaction of diazomethane with acid chlorides obtained from N,N,N′,N′‐tetraalkylrhodamines affords 2‐diazo‐2,3‐dihydro‐1H‐indenespiro[1,9′]‐9H‐xanthen‐3‐ones—a novel class of caged rhodamines. These dyes allow new imaging procedures based on the step‐wise activation and detection of several fluorescent markers (see picture).

This review is focused on the analysis of current data on new methods of alkenylation of arenes and heteroarenes with alkynes by transition metal catalyzed reactions, Bronsted/Lewis acid promoted transformations, and others. The synthetic potential, scope, limitations, and mechanistic problems of the alkenylation reactions are discussed. The insertion of an alkenyl group into aromatic and heteroaromatic rings by inter- or intramolecular ways provides a synthetic route to derivatives of styrene, stilbene, chalcone, cinnamic acid, various fused carbo- and heterocycles, etc.

The design, synthesis, and evaluation of new rhodamine spiroamides are described. These molecules have applications in optical nanoscopy based on random switching of the fluorescent single molecules. The new markers may be used in (co)localization studies of various objects and their (mutual) positions and shape can be determined with a precision of a few tens of nanometers. Multicolor staining, good photoactivation, a large number of emitted photons, and selective chemical binding with amino or thiol groups were achieved due to the presence of various functional groups on the rhodamine spiroamides. Rigidized sulfonated xanthene fragment fused with six-membered rings, N,N'-bis(2,2,2-trifluoroethyl) groups, and a combination of additional double bonds and sulfonic acid groups with simple aliphatic spiroamide residue provide multicolor properties and improve performance of the rhodamine spiroamides in photoactivation and bioconjugation reactions. Having both essential parts of the photoswitchable assembly-the switching and the fluorescent (reporter) groups-combined in one chemical entity make this approach attractive for further development. A series of rhodamine spiroamides is presented along with characterizations of their most relevant properties for application as fluorescent probes in single-molecule switching and localization microscopy. Optical images with resolutions on the nanometer scale illustrate the potential of the labels in the colocalization of biological objects and the two-photon activation technique with optical sectioning.