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The shape of the spectral features in arrival time distributions (ATDs) recorded by ion mobility spectrometry (IMS) can often be interpreted in terms of the coexistence of different isomeric species. Interconversion between such species is also acknowledged to influence the shape of the ATD, even if no general quantitative description of this effect is available. We present an analytical model that allows simulating ATDs resulting from interconverting species. This model is used to reproduce experimental data obtained on a bistable system and to interpret discrepancies between measurements on different types of instruments. We show that the proposed model can be further exploited to extract kinetic and thermodynamic data from tandem-IMS measurements.

A series of arene ruthenium complexes containing o-sulfonamide azobenzene ligands were synthesized and found to exhibit uncommon coordination pattern with an exocyclic NN bond. Upon irradiation, these complexes cleanly undergo E → Z photoisomerization followed by thermal Z → E isomerization (upon resting in the dark) whose rate is dependent on the solvent, the nature of the arene group, the sulfonamide moiety, and azobenzene substitution, as revealed by structure–property studies.

The first photoswitchable bimetallic gold catalysts based on an azobenzene backbone have been synthesized and their catalytic properties have been investigated.

Chemical cross-linking of proteins permits the stabilization of noncovalent complexes through introduction of covalent bonds. A crucial challenge is to find the fastest and most efficient cross-linkers in order to minimize reaction times and to handle delicate complexes. New cross-linkers were synthesized by introducing N-hydroxyphthalimide, hydroxybenzotriazole, and 1-hydroxy-7-azabenzotriazole as leaving groups instead of the commonly used N-hydroxysuccimidyl moiety. With the use of matrix-assisted laser desorption ionization (MALDI) mass spectrometry, these new cross-linkers were then compared with the commercially available disuccinimidyl suberate (DSS) for covalent stabilization of the gluthatione-S-transferase (GST) dimer and of an antibody-antigen complex. They showed a better efficiency, generated about 30% more cross-linked complex, and reacted about 10 times faster than DSS. The reaction with the GST dimer was utilized to get information about their reaction efficiency and kinetics. Their ability to stabilize only specific protein complexes was verified by incubating them with a mixture of the proteins GST and ubiquitin. Finally, the cross-linkers were incubated with synthetic peptides to study the selectivity of the binding with various amino acid side chains. Not only lysine but also tyrosine was found to react with the newly synthesized cross-linker containing 1-hydroxy-7-azabenzotriazole as the reactive group.

Time-efficient synthetic methods of porous organic polymers are searched in order to extend the applications of these materials.

Photo-release of triphenylphosphine from a sulfonamide azobenzene ruthenium-arene complex was exploited to activate Pd II Cl 2 into Pd 0 catalyst, for the photo-initiation of Sonogashira cross-coupling. The transformation was initiated on demand -by using simple white LED strip lights -with a high temporal response and the ability to control reaction rate by changing the irradiation time. Various substrates were successfully applied to this photo-initiated cross-coupling, thus illustrating the wide functional-group tolerance of our photo-caged catalyst activator, without any need for sophisticated photochemistry apparatus.

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