ИСТИНА

Complexes of transition metals based on pincer-type ligands are known to be effective catalysts for various processes. Among them, iridium complexes are preferred for transfer dehydrogenation and acceptorless dehydrogenation catalysis. Furthermore, some iridium complexes catalyze a number of reactions involving nitriles. In some of them the nitriles coordination to metal center activates C≡N bond to nucleophilic or electrophilic attack, but in others triple bond in a coordinated complex remains intact. In order to see the pincer-ligand influence on the reactivity of iridium pincer complexes and on the degree of C≡N bond activation we have studied the interactions of [(tBuPCP)IrH(Cl)], [( tBu POCOP)IrH(Cl)] and [( tBu POCOP)(CO 2 Et)IrH(Cl)] with a number of nitrogen bases (nitriles and iso-nitriles). Bases could coordinate on an iridium atom giving a mixture of cis- and trans-hydrido–chlorido isomers. The NMR, IR- and UV-vis-spectroscopic measurements in a wide range of temperatures (290-200 K) allowed to determine experimentally the structure of the reaction products and their thermodynamic characteristics.