Vol 44, No 4 (2018)

Structural features and reactivity of the N,N-disubstituted cyanamide ligands in the complexes of late 3d metals are discussed. The results obtained by author’s research group within the recent four years are analyzed in comparison. The reactivity of the cyanamide and nitrile ligands in the presence of the 3d-metal salts is comparatively examined. The reaction behavior of substituted cyanamides in the presence of 3d-metals is compared with that of coordinated cyanamides in the complexes of transition metals of the 4d and 5d series (platinum, palladium).

The results of theoretical studies of the reactions of cycloaddition to the metal-activated substrates with the isocyamide ligands performed by the author and coworkers within the recent five years are generalized and examined. The reaction mechanisms, main factors, and driving forces affecting the kinetic and thermodynamic parameters of the processes are considered.

The key regularities of redox isomerism of six-coordinate bis-semiquinonato cobalt complexes in the crystalline phase are considered. The factors determining the temperature of transition between the redox isomers of various cobalt complexes (mononuclear and binuclear complexes, coordination polymers) were described. The transition parameters were shown to depend not only on the electronic and spatial structure of the ligands in a particular complex, but also on the crystal structure of the complex and intermolecular interactions in the lattice.

A survey of the studies dealing with the development of new porphyrazine type tetrapyrrole dyes promising for the application in photonics and biophotonics is presented. An original synthetic approach to the template assembly of the porphyrazine macrocycle at room temperature in high yield has been proposed. A porphyrazine macrocycle containing eight nitrile groups at the periphery has been prepared for the first time. The replacement of four nitrile groups in the macrocycle by aryl groups has been found to generate a unique porphyrazine structure demonstrating a fluorescent molecular rotor behavior, i.e., a strong dependence of fluorescence parameters (quantum yields and lifetimes) on the viscosity of the medium. Some aspects of possible applications of the obtained compounds in biophotonics are described. Good prospects for the use of these compounds as efficient agents for tumor diagnosis, sensitizers for photodynamic therapy, and probes for intracellular viscosity are outlined.