Publications by authors named "Yuri F Oprunenko"

8 Publications

  • Page 1 of 1

DFT Investigation of the η ⇌ η-Inter-ring Haptotropic Rearrangement of the Group 8 Metals Complexes [(graphene)MCp] (M = Fe, Ru, Os).

J Phys Chem A 2021 Jan 24;125(1):366-375. Epub 2020 Dec 24.

Department of Chemistry, Universidad Técnica Federico Santa Maria, Av. Santa Maria 6400, Vitacura, 7660251 Santiago, Chile.

Metalcyclopentadienyl complexes (MCp) (M = Fe, Ru, Os) bound to the large polyaromatic hydrogenated hydrocarbon (PAH) CH used as a model for pristine graphene have been studied using a density functional theory (DFT) generalized gradient approximation (PBE functional) to reveal their structural features and dynamic behavior. The inter-ring haptotropic rearrangements (IRHRs) for these complexes were shown to occur via two transition states and one intermediate. The energy barriers of the η ⇌ η IRHRs of the (MCp) unit were found to be 30, 27, and 29 kcal/mol for M = Fe, Ru, and Os, respectively. These values are significantly lower than the values found previously for smaller PAHs. Both polar and nonpolar solvents were found not to affect significantly the energy barrier heights. Investigated transition metal complexes could be used in general as catalysts in the design of novel derivatives or materials with promising properties. Metalcyclopentadienyl complexes (MCp) of PAHs show catalytic properties mainly due to their structural details as well as their important characteristic of inter-ring haptotropic rearrangement. IRHRs take place usually by intramolecular mechanisms. During IRHRs, the ML organometallic groups (OMGs) undergo shifting along the PAH plane and could coordinate additional reagents, which is important for catalysis. Large PAHs such as graphene, fullerenes, and nanotubes possess intrinsic anticancer activity, and numerous arene complexes of Ru and Os have been proven to have anticancer properties as well. We suppose that coordinating Ru or Os to very large PAHs could synergistically increase the anticancer activity of resulting complexes.
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http://dx.doi.org/10.1021/acs.jpca.0c08251DOI Listing
January 2021

Austalides V and W, new meroterpenoids from the fungus Aspergillus ustus and their antitumor activities.

Bioorg Med Chem Lett 2019 11 4;29(22):126708. Epub 2019 Oct 4.

G.K. Skryabin Institute of Biochemistry and Physiology of Microorganisms RAS, FSBIS FRC Pushchino Scientific Centre of Biological Research, Russian Academy of Sciences, Pushchino 142290, Russian Federation.

Two new austalide meroterpenoids, named austalides V and W (1 and 2), were isolated from the fungus Aspergillus ustus VKM F-4692. Their structures were elucidated by extensive spectroscopic analysis and by comparison with related known compounds. The main structural feature of both compounds is a tetrahydrofuranyl ring (G), a structural fragment, first found in austalides. Austalides V (1) and W (2) were able to inhibit the propagation of prostate and bladder cancer cells; this biologic activity is possibly related to the inhibition of a number of key pathways regulating cell growth and migration.
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http://dx.doi.org/10.1016/j.bmcl.2019.126708DOI Listing
November 2019

Molecular Oligogermanes and Related Compounds: Structure, Optical and Semiconductor Properties.

Chem Asian J 2017 Jun 28;12(11):1240-1249. Epub 2017 Feb 28.

Department of Chemistry, Moscow State University, Leninskye Gory, 1, 3, Moscow, 119991, Russia.

The optical (UV/Vis absorbance, fluorescence in the solid state and in solution) and semiconducting properties of a number of di- and trigermanes as well as related silicon- and tin-containing germanes, 1-6 ((p-Tol) GeGeMe (1), Ph SnGe(SiMe ) (2), (C F ) GeGePh (3), (p-Tol) GeSiMe SiMe (4), (p-Tol) GeGeMe Ge(p-Tol) (5), (p-Tol) GeSiMe SiMe Ge(p-Tol) (6)) were investigated. Molecular structures of 5 and 6 were studied by X-ray diffraction analysis. All compounds displayed luminescence properties. In addition, a band gap (of about 3.3 eV) was measured for compounds 1-6 showing that those molecules display semiconductor properties.
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http://dx.doi.org/10.1002/asia.201700151DOI Listing
June 2017

Aluminum complexes based on pyridine substituted alcohols: synthesis, structure, and catalytic application in ROP.

Dalton Trans 2015 Jul 12;44(26):11963-76. Epub 2015 Jun 12.

Chemistry Department, Moscow State University, B-234 Leninskie Gory, 119991 Moscow, Russia.

A series of substituted pyridine dialcohols (2,6-bis(hydroxyalkyl)pyridines), 1-4, was used for the synthesis of various types of aluminum complexes. Aluminum methyl derivatives, 2-4a, were obtained by the reaction of AlMe3 with the corresponding ligand or transmetallation reactions of germylenes. Aluminum chloride complexes, 3-4b, were obtained by substitution of the Me group under the action of chlorinating agents. Methoxy-, 2-4c, or benzyloxy-, 2d, aluminum complexes were synthesized in transalkoxylation reaction of Me2Al(OX) (X = Me, Bn) by the corresponding ligand. All complexes obtained were thoroughly investigated by multinuclear NMR and X-ray analysis. It has been established that the structure of the ligand (number of carbon atoms) determines the nature of the complexes formed. Compounds were used as initiators of ring-opening polymerization of l-lactide and ε-caprolactone and showed moderate activity with controlled or immortal character.
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http://dx.doi.org/10.1039/c5dt01001bDOI Listing
July 2015

New oligogermane with a five coordinate germanium atom: the preparation of 1-germylgermatrane.

Dalton Trans 2014 May;43(18):6605-9

Department of Chemistry, Moscow State University, Leninskye Gory 1, Moscow 119991, Russia.

The first example of an oligogermane, N(CH2CH2O)3Ge-Ge(SiMe3)3 (1), containing a hypercoordinate germanium atom was prepared and characterized by various methods (NMR, UV/vis, and X-ray analysis). The electronic structure of compound 1 was investigated via DFT calculations.
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http://dx.doi.org/10.1039/c3dt53523aDOI Listing
May 2014

DFT study of intramolecular interring η6,η6-haptotropic rearrangements in tricarbonylchromium complexes of 2-aminobiphenyl and 4-aminobiphenyl.

Dalton Trans 2013 Aug;42(29):10487-94

Department of Chemistry, University of Wisconsin-La Crosse, 1725 State Street, La Crosse, WI 54601, USA.

DFT studies have been carried out to investigate the role of nitrogen participation in the interring haptotropic rearrangements of [(η(6)-C6H5)(C6H4-4-NH2)]Cr(CO)3 and [(η(6)-C6H5)(C6H4-2-NH2)]Cr(CO)3. For the para-substituted case, where intramolecular coordination of nitrogen to chromium is not possible, DFT modeling predicts an activation barrier of 32.5 kcal mol(-1), which is in very close agreement with the experimentally determined value of 32.57 kcal mol(-1). In the case of the ortho-substituted isomers, modeling of a mechanism that does not invoke stabilization via nitrogen coordination yields a predicted energy barrier of 32.7 kcal mol(-1), while a mechanism that does invoke nitrogen participation and accounts for interconversion of rotational isomers gives a predicted value of 30.2 kcal mol(-1). This is consistent with the experimentally determined value of 31.22 kcal mol(-1). These data provide evidence that intramolecular stabilization via nitrogen coordination to chromium is responsible for the ortho substituted isomer undergoing haptotropic rearrangement with a rate nearly five times greater than that observed for the para isomer. For the mechanism that invokes ortho-amino group participation, transition state analysis in the frame of Bader theory shows that each transition state along the proposed mechanistic pathway has a bond critical point between nitrogen and chromium.
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http://dx.doi.org/10.1039/c3dt50655jDOI Listing
August 2013

Palladium complexes with stabilized germylene and stannylene ligands.

Dalton Trans 2013 Jun 11;42(22):7901-12. Epub 2013 Feb 11.

B-234 Leninskie Gory, Chemistry Department, Moscow State University, 119991 Moscow, Russia.

The syntheses of novel Pd complexes with germylene and stannylene ligands are reported. [MeN(CH2CH2NC6F5)2Sn]4Pd (2) and [MeN(CH2CPh2O)(CH2CH2O)Ge]4Pd (8) were obtained by different methods including ligand substitution in (Ph3P)4Pd or by the reaction of the free corresponding germylene or stannylene with (Ph3P)2PdCl2 or Pd(OAc)2. Crystal structures of complexes 2, 8 were determined by single crystal X-ray diffraction analysis. The catalytic activity of complexes 2, 8 was examined in the Suzuki-Miyaura and Heck cross-coupling.
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http://dx.doi.org/10.1039/c3dt32867hDOI Listing
June 2013

Lariat ethers with fluoroaryl side-arms: a study of CFmetal cation interaction in the complexes of N-(o-fluoroaryl)azacrown ethers.

Dalton Trans 2009 Feb 4(5):843-50. Epub 2008 Dec 4.

Chemistry Department of the M. V. Lomonosov Moscow State University, 119992 Moscow.

New lariat ethers, N-(o-fluorophenyl)aza-15-crown-5 (F-A15C5) and N,N'-bis(o-fluorophenyl)diaza-18-crown-6 (F(2)-A(2)18C6), were prepared by the N-arylation of the corresponding azacrown ethers. The interaction of the ligands with metal cations was studied in solution by (1)H and (19)F NMR (in acetone-d(6)) and UV spectroscopy (MeOH) confirming the formation of complexes of F(2)-A(2)18C6 with K(+), Na(+), Ag(+), Ba(2+), Pb(2+) and of F-A15C5 with Na(+) and giving evidence of CFmetal cation interaction. Cation binding constants (beta, evaluated by UV titration method), demonstrate that F-A15C5 and F(2)-A(2)18C6 form more stable complexes than their fluorine-free analogs. The effect depends on the nature of the metal cation and is at a maximum for hard, singly charged cations (up to 3 logbeta units for K(+) complex of F(2)-A(2)18C6). The X-ray structures of complexes [Pb(F(2)-A(2)18C6)(H(2)O)](ClO(4))(2) () and [Ba(F(2)-A(2)18C6)(ClO(4))(2)] () reveal short Pb-F (2.805 A) and Ba-F (2.965 A) contacts. Complex is centrosymmetric (C(i)), while complex has C(2) symmetry with one-side coordination of o-fluorophenyl groups to Pb(2+). This "one-side" coordination mode of Pb(2+) is indicative of a partial localization of the Pb(2+) lone pair.
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http://dx.doi.org/10.1039/b807199cDOI Listing
February 2009
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