Activation of small molecules with iridium pincer complexes

SNIC 2018/6-9


SNAC Small

Principal Investigator:

Roman Gritcenko


Lunds universitet

Start Date:


End Date:


Primary Classification:

10404: Inorganic Chemistry



Transition metal complexes play an important role in various types of catalytic processes such as activation of small molecules and selective functionalization of unreactive bonds. In this context, development of new efficient catalytic systems is an important goal of modern chemistry. In order to achieve that, our group is focused on comprehensive mechanistic and structural studies of these chemical processes catalyzed by transition metal complexes. Such approach requires extensive use of various analytical techniques and molecular modeling. Current project is focused on comparing reactivity of reactive species in Ir-catalyzed hydrogenation. Two species are generally present in the solution: L–IrH2 and L–IrH4. The tetrahydride is usually significantly more stable, but the dihydride species is supposed to be more reactive, due to a lower oxidation state of iridium. The answer to the question which species are more reactive is not given in the published literature. In the meantime, often these reactions require quite elevated temperatures, which may be attributed not to the high barrier of the main reaction, but to the conversion of the L–IrH4 to the L–IrH2. Current experimental results require additional insights from the quantum-chemical calculations, in order to give answers to the following questions: – Which species is more reactive? – Can we influence stability of iridium hydrides by modifying ligand’s electronic properties? – Can we influence the stability of iridium hydrides by changing the electronic configuration upon excitation with visible light? Corresponding DFT and WFT calculations will be performed in ORCA software, which has unique and efficient approximations that save a lot of time and computational resources or even make such calculations possible at all.