Ustynyuk Nikolai Aleksandrovich

Head of the laboratory for organometallic compounds, Professor, D.Sc.

Phone: 7-499-135-50-64, E-mail:

 

Scientific interests:

–        organometallic reactions induced by electron transfer;

–        molecular rearrangements of organometallic compounds;

–        chemistry of transition metal σ and π-complexes;

–        metal complex catalysis.

 

Scientific achievements:

•     Metallotropic rearrangements of a new type were found for the 18-electron fused arene (indenyl, fluorenyl, indeno[2,1-a]indenyl) transition metal complexes, which consist in inter-ring migrations of the metal-containing groups along the plane of the π-electron system. It was shown that the same inter-ring haptotropic rearrangements can be induced by electron transfer; for example, in the 19-electron iron fluorenyl complexes, they proceed considerably faster than in the 18-electron precursors.

•     A novel method for the synthesis of transition metal σ-1-alkynyl derivatives was developed based on the nucleophilic substitution of the halogen atom in 1-haloalkynes by carbonylmetallate anions.

•     A novel approach to the catalysis of electrochemical proton reduction to molecular hydrogen was proposed based on the formation and reductive activation of the C-H bonds, rather than the M-H bonds as in the earlier described approaches. The catalytic cycle involves protonation of the 18-electron catalyst (for the present time, this was shown for the η¹-(σ,π)-vinylidene, allenylidene, and η¹-σ-ethynyl complexes) at the C_β-atom of the ligand, reduction of the protonated form to the 19-electron radical followed by fast homolysis of the C_β-H bond to yield hydrogen and to regenerate the catalyst. This approach can be extended to transition metal π-complexes.

•     It was established that the oxidatively induced homolysis of the C_sp3-H bonds in transition metal cyclohexadienyl and cyclopentadiene complexes is a selective method for the synthesis of the corresponding complexes wherein the ligand hapticity has increased by one unit. The homolysis rate of the C-H_exo bond is greater than the homolysis rate of the C-H_endo bond. The application of this approach to the 17-electron platinum and palladium cyclopentadienecyclopentadienyl complexes allowed the laboratory senior researcher, the late O.V. Gusev, to prepare the first representatives of pallado- and platinocenes, i.e., the dicationic bis-cyclopentadienyl platinum and palladium complexes [(h⁵-C₅Ме₅)М(h⁵-C₅R₅)](PF₆)₂, M=Pd, R=Me, M=Pt, R=H, Me.

•     Procedures were developed for a selective modification of the ligands surroundings in the transition metal organometallic complexes via an electron transfer induced reaction, including:

–        an oxidative dehydrodimerization of manganese and rhenium phenylvinylidenes (h⁵-C₅H₅)(CO)₂M=C=CHPh into the corresponding divinylidene complexes (h⁵-C₅H₅)(CO)₂M=C=C(Ph)-C(Ph)=C=M(CO)₂(h⁵-C₅H₅) (M=Mn, Re);

–         a novel method for the synthesis of the asymmetric iron sandwich complexes by the replacement of the arene ligand in the 19-electron complex Fe(h⁵-C₅H₅)(h⁶-C₆H₆);

— the synthesis of novel dihydrofuran-2,5-diylidene complexes by oxidatively induced addition of water to the manganese and rhenium divinylidene complexes (h⁵-C₅H₅)(CO)₂M=C=C(Ph)-C(Ph)=C=M (CO)₂(h⁵-C₅H₅) (M = Mn, Re);

 

Publications: A total of 132 papers and reviews in Russian and international scientific journals.