Azomethines of N-aminobenzazoles- a new ligand system

Azomethines of 1-aminobensimidazole (2) have been used for the first time as ligands. It is shown that their complexing properties differ from the previously studied azomethines of 2-aminobenzazoles (1) and are determined by specificity of spatial and electron structure of compounds 2. On the basis of comparison of experimental and calcOlated according to the vector scheme values of dipole momenta suppositions.U on stereochemistry of molecules 2 and mechanism of electron effect transfer in them are made. It is established that in contrast to 2-aminoderivatives of azomethines 1, coordination interaction 2 with metal salts is realized first of all according to N3-donor centre of heterofragment and not according to azomethine bond -N=C=. The result agrees with the highest value of negative charge and basicity constants pKsub(a) of N3-heteroatom. On the basis of the data of element analysis and IR spectroscopy it is shown that 2 with transition and non-transition metal salts (CdCl2, in particular) can form coordination compounds of adduct type, metal-chelate complexes and polynuclear systems of mixed metal-chelate and molecular types