Polymorphism and thermodynamic properties of chloro(cyclopentadienyl)bis(triphenylphosphine)ruthenium(II) complex

Gorbachuk, E.V., Badeeva, E.K., Zinnatullin, R.G., Pavlov, P.O., Dobrynin, A.B., Gubaidullin, A.T., Ziganshin, M.A., Gerasimov, A.V., Sinyashin, O.G., Yakhvarov, D.G.

 

A new crystalline polymorph of known chloro(cyclopentadienyl)bis(triphenylphosphine)ruthenium(II) complex [RuCl(PPh3)2(η5-C5H5)] was obtained and characterized by various analytical methods including single-crystal and powder X-ray diffraction (XRPD) and differential scanning calorimetry (DSC) in combination with thermo-gravimetric analysis (TG-DSC). The obtained crystals of new polymorph are monoclinic, space group P21/n, with a = 11.125(4), b = 19.184(6), c = 15.946(5) Å, α = 90, β = 100.174(5), γ = 90, and Z = 4. It has been found that real melting point of the complex (M.p. = 252-253 °C) can be determined only in inert atmosphere while an apparent melting is observed in the range 142-150 °C due oxygen promoted oxidative dissociation of triphenylphosphine ligand. © 2016 Elsevier B.V. All rights reserved.

 

Journal of Organometallic Chemistry, Volume 805, 1 March 2016, Pages 49-53

First example of organonickel complex bearing three cyclic substituents in the s-bonded aromatic ring: bromo[(2,2'-bipyridine)-2,4,6-tricyclohexylphenylnickel]

Il’yas F. Sakhapov, Zufar N. Gafurov, Vasily M. Babaev, Ildar Kh. Rizvanov, Alexey B. Dobrynin, Dmitry B. Krivolapov, Khasan R. Khayarov,Oleg G. Sinyashina and Dmitry G. Yakhvarov

 

The electrochemical reduction of [NiBr2(bpy)] (bpy is 2,2'-bipyridine) complex in the presence of 2,4,6-tricyclohexylphenyl bromide (TchpBr) with a sacrificial nickel anode results in the one-pot formation of an organonickel complex [NiBr(Tchp)(bpy)] bearing three cyclic substituents in the s-bonded aromatic ring. The synthesized complex was characterized by various methods including single crystal X-ray analysis.

 

Mendeleev Communications, 4756, February 12, 2016

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2019

Synthesis, structure and reactivity of acyclic and heterocyclic α-phosphino amino acids

Heinicke, J.W.Lach, J.Basvani, K.R.Ghalib, M.Fomina, O.S.Yakhvarov, D.G.

Acyclic α-phosphino amino acids can be conveniently synthesized by a one-pot three-component reaction, but are limited to N-secondary derivatives with N-alkyl, aryl or heterocyclic substituents, provided these are not too bulky or electron-withdrawing. Phosphino-bis(amino acids), stable with a P-aryl group, undergo spontaneous lactamization in the case of a P-alkyl group to five-membered heterocyclic α-P amino acids. Closely related compounds without C(O)-group, by the diagonal relationship to proline named “(phenyl)phosphaprolines”, were obtained by cyclocondensation of 2-aminoethylphosphines with glyoxylic or α-keto carboxylic acids, in this case also furnishing N-tertiary derivatives. N-Tertiary 1,3-benzazaphospholine-2-carboxylic acids are available analogously. However, the reactivity and the ability to form active nickel catalysts for ethylene oligomerization differ for the various types of α-amino phosphino acids and depends on structural aspects. Acyclic and cyclic N-aryl derivatives, in the latter case particularly those with P-tert-butyl group and sufficiently bulky N-substituents to suppress interfering amine-Ni interactions, gave the highest activities. © 2018, © 2018 Taylor & Francis Group, LLC.

Phosphorus, Sulfur and Silicon and the Related Elements, Volume 194, Issue 4-6, 27 May 2019, Pages 279-280

New 2,2'-bipyridine and 1,10-phenanthroline based nickel(II) phosphates

Gafurov, Z.N.Dobrynin, A.B.Sakhapov, I.F.Kagilev, A.A.Kantyukov, A.O.Balabaev, A.A.Toropchina, A.V.Sinyashin, O.G.Yakhvarov, D.G.

The reactivity of phosphoric acid (H3PO4) toward 2,2'-bipyridine (bpy) and 1,10-phenanthroline (phen) nickel dibromide complexes [NiBr2(bpy)2] and [NiBr2(phen)2] has been investigated. It was found that this interaction leads to new nickel phosphate complexes [Ni(HPO4)(bpy)2] and [Ni(HPO4)(phen)2]. X-ray crystal structure analysis of the obtained complexes indicates that the nickel ions have a distorted octahedral coordination and doubly bridged by two oxygen atoms of the phosphate moiety. © 2019, © 2019 Taylor & Francis Group, LLC.

Phosphorus, Sulfur and Silicon and the Related Elements, Volume 194, Issue 4-6, 27 May 2019, Pages 517-521

Hydrogenation reaction pathways in chemistry of white phosphorus

Gafurov, Z.N.Kagilev, A.A.Kantyukov, A.O.Sinyashin, O.G.Yakhvarov, D.G.

Approaches for preparation of P-H bond containing derivatives directly from white phosphorus are summarized in this microreview. Transfer hydrogenation of P 4 involving the activation and reaction of white phosphorus in the coordination sphere of transition metal complexes is a convenient and powerful route to the hydrogenated compounds. Electrochemical methods have also become popular in modern synthetic chemistry; these provide easy access to highly reactive intermediates, which can be selectively generated in situ and used for subsequent synthetic processes. These electrochemical routes provide efficient and environmentally safe methods for preparation of phosphorus derivatives bearing P-H bond. The mechanisms of the proposed processes and the nature of the intermediates formed in the overall electrochemical process are disclosed. The methods elaborated operate under the principals of "green chemistry" and can be considered as efficient alternatives to some classical pathways. © 2019 IUPAC & De Gruyter.

Pure and Applied Chemistry, Volume 91, Issue 5, 1 May 2019, Pages 797-810

Chemistry of α-Phosphanyl α-Amino Acids

Peulecke, N.Yakhvarov, D.G.Heinicke, J.W.

After a short introduction on potential applications and types of phosphanyl-substituted α-amino acids the current knowledge on syntheses of acyclic and heterocyclic α-phosphanyl α-amino acids, their structural features, properties, reactivity and usability in Ni-catalyzed ethylene oligomerizations is reviewed with the aim to encourage further studies with these new hybrid phosphane ligands and their N- and carboxy-protected as well as functionalized derivatives are still unexplored. © 2019 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

European Journal of Inorganic Chemistry, Volume 2019, Issue 11, 31 March 2019, Pages 1507-1518

Halogen-Bonding Interactions and Electrochemical Properties of Unsymmetrical Pyrazole Pincer NiII Halides: A Peculiar Behavior of the Fluoride Complex (PCN)NiF

Luconi, L.Garino, C.Cerreia Vioglio, P.Gobetto, R.Chierotti, M.R.Yakhvarov, D.Gafurov, Z.N.Morozov, V.Sakhapov, I.Rossin, A.Giambastiani, G.

Four metal halides of the (tBuPCN)NiX family [X = F (1), Cl (2), Br (3), or I (4); PCN = 1-[3-[(di-tert-butylphosphino)methyl]phenyl]-1H-pyrazole] have been prepared through a direct reaction of the corresponding anhydrous NiX2 salts and the unsymmetrical PCN pincer ligand. Structural information from single-crystal X-ray data, 19F solution nuclear magnetic resonance, and combined electrochemical results [cyclic voltammetry (CV) and in situ electron paramagnetic resonance spectro-electrochemistry] reveal that the fluoride complex 1 is different from the other halides 2-4 in terms of electro-oxidation behavior (presence of three anodic peaks instead of one in the CV profile). 1 is also different from its symmetrical analogue (tBuPCP)NiF in terms of halogen-bonding capability toward the halogen-bond donor, iodopentafluorobenzene (C6F5I, IPFB). The positive Î"S° value for the formation of the 1···IPFB adduct inferred from the van't Hoff plots is in agreement with the existence of (1·H2O) aggregates in solution, not present in 2-4. The high nucleophilicity of the fluoride ligand and the simultaneous presence of electrophilic (acidic) protons on the sidearm of the pyrazole ligand are at the origin of the observed phenomena. © 2019 American Chemical Society.

ACS Omega, Volume 4, Issue 1, 14 January 2019, Pages 1118-1129

Benzoimidazole-Pyridylamido Zirconium and Hafnium Alkyl Complexes as Homogeneous Catalysts for Tandem Carbon Dioxide Hydrosilylation to Methane

Luconi, L.Rossin, A.Tuci, G.Gafurov, Z.Lyubov, D.M.Trifonov, A.ACicchi, S.Ba, H.Pham-Huu, C.Yakhvarov, D.Giambastiani, G.

Neutral Zr IV and Hf IV alkyl/amido complexes stabilized by a tridentate N ligand that contains a “rolling” heterodentate benzoimidazole fragment have been prepared and characterized. The ultimate nature of the ligand denticity, the electronic properties of the ligand binding pocket and the metal coordination environment are controlled by the protection/deprotection of the benzoimidazole NH group. The metal precursor used [M IV (Bn) 4 or M IV (NMe 2 ) 4 ] also has an influence on the final coordination sphere of the complex; indeed, a permanent central pyridine dearomatization occurs in the presence of dimethylamido ancillary groups. DFT calculations on the real system have been used to elucidate the mechanism. Selected alkyl species from this series have been scrutinized for the tandem hydrosilylation of CO 2 to CH 4 in combination with the strong Lewis acid B(C 6 F 5 ) 3 using a variety of hydrosilanes. A positive effect of the hardness modification of the ligand donor atom set is observed in the catalytic outcomes. Indeed, κ 3 {N − ,N,N − }Zr IV (Bn) 2 catalyzes the process to methane selectively with a turnover frequency as high as 272 h −1 (at 96 % substrate conversion) almost twice as much as that claimed for the benchmark κ 3 {O − ,O,O − }Zr IV (Bn) 2 complex under similar experimental conditions. © 2019 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim

ChemCatChem, Volume 11, Issue 1, 9 January 2019, Pages 495-510

2018

Classification and synthesis of nickel pincer complexes

Gafurov, Z.N.Kagilev, A.A., Kantyukov, A.O.Balabaev, A.A.Sinyashin, O.G.Yakhvarov, D.G.

Over the past decades, the pincer ligands have attracted an increasing interest due to the unique properties of the coordination compounds they form. These monoanionic tridentate ligands are of great importance in organometallic and coordination chemistry. Their complexes with transition metals are used as homogeneous catalysts for various processes and also as functional materials with specified properties. The metal complexes formed by the pincer ligands provide an efficient alternative to the existing catalysts based on noble metals and, hence, the use of these complexes is a promising task of the modern chemical science. Therefore, nickel as the most accessible and inexpensive analog of palladium and platinum is of great practical interest. In this review, we consider the diversity of nickel complexes with pincer ligands, as well as the existing methods for their preparation and practical application. © 2018, Springer Science+Business Media, LLC, part of Springer Nature.

Russian Chemical Bulletin, Volume 67, Issue 3, 1 March 2018, Pages 385-394

Electrochemical generation and observation by magnetic resonance of superparamagnetic cobalt nanoparticles

Khusnuriyalova, A.F.,  Petr, A.,  Gubaidullin, A.T.,  Sukhov, A.V.,  Morozov, V.I.,  Büchner, B.,  Kataev, V.c,  Sinyashin, O.G.,  Yakhvarov, D.G.

The electrochemical reduction of cobalt dibromide 2,2′-bipyridine (bpy) complexes (Co/bpy molar ratio 1:1) results in the formation of cobalt nanoparticles (CoNP) formed by the disproportionation reaction of the electrochemically generated cobalt(I) mononuclear complexes. The process of the electrochemical generation of CoNP was monitored by in situ EPR-spectroelectrochemistry where the signals of the ferromagnetic resonance (FMR) have been observed for these species. According to small-angle X-ray scattering (SAXS) analysis the average diameter and the average length of the formed cylindrical CoNP is varied from 9 to 10 nm and 30–32 nm, respectively, and correlates to the g-value and the broadness of the FMR signal observed by in situ EPR-spectroelectrochemistry during electrochemical process. © 2017 Elsevier Ltd
 

Electrochimica Acta, Volume 260, 10 January 2018, Pages 324-329

Microbiological degradation of white phosphorus

Mindubaev, A.Z., Voloshina, A.D. Babynin, E.V.,Badeeva, E.K., Khayarov, K.R., Minzanova, S.T., Yakhvarov, D.G.

For the first time different taxonomic groups of microorganisms are inoculated on culture medium containing white phosphorus as the single source of phosphorus. On these media microorganisms grew and have not experienced phosphorus starvation. It is the world's first example of the inclusion of white phosphorus in the biosphere cycle of elemental phosphorus. The highest concentration corresponds to 5000 times excess of MPC of white phosphorus in wastewater! Devoted to the search for the white phosphorus metabolites, and the probable way of the phosphorus metabolism. The increase of cultures resistance resulting from directed selection is demonstrated for the first time. the comparison of the sequences of ribosomal genes of the fungus, steadily metabolizing the white phosphorus, with sequences of the GenBank database, allowed us to identify this microorganism as a new strain of Aspergillus Niger, to which we have assigned the number A. Niger AM1. Inoculation of A. Niger AM1 in medium containing just two sources of phosphorus (phosphate and white phosphorus) demonstrated that P4 does not exhibit toxic properties in relation to this microorganism. the slow growth of Aspergillus in the medium with white phosphorus is not due to the toxicity of the last one for the strain, but only due its inaccessibility as a phosphorus source. © 2018 Izdatel'stvo Kalvis. All rights reserved.

Ecology and Industry of Russia, Volume 22, Issue 1, 2018, Pages 33-37

2017

Nickel and palladium N-heterocyclic carbene complexes. Synthesis and application in cross-coupling reactions

Gafurov, Z.N.,  Kantyukov, A.O.,  Kagilev, A.A.,  Balabayev, A.A.,  Sinyashin, O.G.,  Yakhvarov, D.G.

N-Heterocyclic carbenes (NHCs) are widely used as ligands in catalysis by transition metal complexes. The catalytic activity of transition metal NHC complexes is much higher than that of the transition metal complexes bearing the phosphine and nitrogen-containing ligands. They show excellent catalytic performance in different transformations of the organic compounds, especially in the carbon—carbon and carbon—element bond forming reactions. Palladium NHC complexes are very efficient catalysts for the cross-coupling reactions. On the other hand, nickel is less expensive and regarded as a promising alternative to palladium and, therefore, it attracts increasing attention from the researches. The present review is focused on the recent advances in the synthesis of N-heterocyclic carbene complexes of nickel and palladium and their application in catalysis of cross-coupling reactions of organic, organoelement and organometallic compounds with organic halides. © 2017, Springer Science+Business Media, LLC, part of Springer Nature.

Russian Chemical Bulletin, Volume 66, Issue 9, 1 September 2017, Pages 1529-1535

Electrochemical methods for synthesis of organoelement compounds and functional materials

Gafurov Z.N., Sinyashin O.G., Yakhvarov D.G.

The new efficient and environmentally safe methods for preparation of various classes of organic and organoelement compounds, including organonickel sigma-complexes and organophosphorus compounds bearing P–C bonds have been created using the electrochemical methods. The synthetic application of the elaborated techniques towards the process of formation of new carbon-carbon, carbon-metal and carbon-phosphorus bonds are discussed. The mechanisms of the proposed processes and the nature of the formed in the overall electrochemical process intermediates are disclosed. The elaborated methods operated in the principals of “green chemistry” can be considered as an efficient alternative to some classical methods for preparation of active catalysts, biologically active molecules and new polynuclear complexes displaying practically useful properties.

Pure and Applied Chemistry, Volume 89, Issue 8, July 2017, Pages 1089-1104

Study of the reactivity of organonickel sigma-complexes towards nitriles

Gafurov Z.N., Sakhapov I.F., Babaev V.M., Dobrynin, A.B., Kurmaz V.A., Metlushka K.E., Rizvanov, I.K., Shaikhutdinova G.R., Sinyashin O.G., Yakhvarov D.G.

The reactivity of organonickel sigma-complexes of type [NiBr(Ar)(bpy)], where Ar = 2,6-dimethylphenyl (Xyl), 2,4,6-trimethylphenyl (Mes), 2,4,6-triisopropylphenyl (Tipp), 2,4,6-tricyclohexylphenyl (Tchp), bpy = 2,2´-bipyridine, towards nitriles (acetonitrile, propionitrile, chloroacetonitrile, benzonitrile) has been investigated. This reaction leads to imines by formation of new carbon—carbon bond between aromatic fragment and nitrile group C≡N. © 2017, Springer Science+Business Media, LLC.

 

Russian Chemical Bulletin, Volume 66, Issue 2, 1 February 2017, Pages 254-259

Tracking of the formation of binuclear nickel complexes of [Ni2(µ-O2PR1R2)2(bpy)4]Br2 type by ESI and MALDI mass spectrometry

Khusnuriyalova A.F., Babaev V.M., Rizvanov I.K., Metlushka K.E., Alfonsov V.A., Sinyashin O.G., Yakhvarov, D.G.

The formation of binuclear nickel complexes of type [Ni2(µ-O2PR1R2)2(bpy)4]Br2, where R1 = H, R2 = phenyl (Ph), 2,4,6-trimethylphenyl (Mes), 2,4,6-triisopropylphenyl (Tipp) or R1R2 = [sbnd]OCH2CH(Et)NHCH(Ph)[sbnd]; bpy = 2,2′-bipyridine, in solution and their fragmentation behavior have been investigated by ESI and MALDI mass spectrometry. It was found that binuclear cationic fragments [Ni2(µ-O2PR1R2)2(bpy)2Br]+ are characteristic ions displaying the formation of binuclear nickel(II) complexes in solution. © 2017 Elsevier Ltd

Polyhedron, Volume 127, 2017, Pages 302-306

2016

 

The synthesis of novel N-heterocyclic α-diphenylphosphinoglycines

 Fomina, O.S.Heinicke, J.W.Sinyashin, O.G.Yakhvarov, D.G. 

The one-pot reaction of glyoxylic acid hydrate with diphenyl phosphine and a heretocyclic primary amine in methanol results in formation of first examples of N-hererocyclic α-diphenylphosphinoglycines bearing imidazo[4,5-d]-pyrimidine-6-yl, 4,6-dimethylpyrimidin-2-yl, pyridine-2-yl and pyridine-3-yl substituents.

Phosphorus, Sulfur and Silicon and the Related Elements, Volume 191, Issue 11-12, 1 December 2016, Pages 1478-1479

Thermal stability of primary and secondary phosphine oxides formed as a reaction of phosphine oxide with ketones

Gorbachuk, E.V.Badeeva, E.K.Katsyuba, S.A.Pavlov, P.O., Khayarov, K.R.Sinyashin, O.G.Yakhvarov, D.G.

We present the study of reactivity of electrochemically generated in situ from white phosphorus P4 phosphine oxide H3PO toward various ketones (acetone, methylethylketone, methyl-n-propylketone). This interaction was found to give a selective formation of mono- and bis-(α-oxyalkyl)phosphine oxides RRʹC(OH)P(O)H2 (1) and (RRʹC(OH))2P(O)H (2) where R = Me; Rʹ = Me, Et, n-Pr. Thermal properties of the formed primary and secondary phosphine oxides have been studied and quantum chemical calculations of thermodynamic stability of these compounds were performed.

Phosphorus, Sulfur and Silicon and the Related Elements, Volume 191, Issue 11-12, 1 December 2016, Pages 1480-1481

Aziridine-Functionalized Multiwalled Carbon Nanotubes: Robust and Versatile Catalysts for the Oxygen Reduction Reaction and Knoevenagel Condensation

Tuci, G.Luconi, L.Rossin, A.Berretti, E.Ba, H.Innocenti, M.Yakhvarov, D.Caporali, S.Pham-Huu, C.Giambastiani, G. 

This paper describes the exohedral N-decoration of multiwalled carbon nanotubes (MWCNTs) with NH-aziridine groups via [2 + 1] cycloaddition of a tert-butyl-oxycarbonyl nitrene followed by controlled thermal decomposition of the cyclization product. The chemical grafting with N-containing groups deeply modifies the properties of the starting MWCNTs, generating new surface microenvironments with specific base (Brønsted) and electronic properties. Both of these features translate into a highly versatile single-phase heterogeneous catalyst (MW@NAz) with remarkable chemical and electrochemical performance. Its surface base character promotes the Knoevenagel condensation with activity superior to that of related state of the art N-doped and N-decorated carbon nanomaterials; the N-induced electronic surface redistribution drives the generation of high-energy surface "C" sites suitable for O2 activation and its subsequent electrochemical reduction (ORR).

ACS Applied Materials and Interfaces, Volume 8, Issue 44, 9 November 2016, Pages 30099-30106

Novel Azo-Dyes-Modified Isatin Derivatives: Synthesis, UV/VIS Spectroscopic, and Electrochemical Study

 Musin, L.I.Abdullin, I.T.Vandyukov, A.E.Yakhvarov, D.G.Zinnatullin, R.G.Mironov, V.F.Bogdanov, A.V.  

A high-yield and simple synthesis of certain aminomethylisatins bearing dye fragments via the Mannich reaction of isatin with amino-containing azobenzenes was reported. It was found that the absence of electron-donating groups in azo-dye molecule prevents aminomethylation of isatin. The effect of the incorporation of an isatin moiety with an azobenzene dye in one molecule on its absorption and electrochemical behavior was studied using UV spectroscopy and cyclic voltammetry.

Helvetica Chimica Acta, Volume 99, Issue 8, 1 August 2016, Pages 597-600

First example of organonickel complex bearing three cyclic substituents in the σ-bonded aromatic ring: bromo[(2,2'-bipyridine)-2,4,6-tricyclohexylphenylnickel]

Il’yas F. Sakhapov, Zufar N. Gafurov, Vasily M. Babaev, Ildar Kh. Rizvanov, Alexey B. Dobrynin, Dmitry B. Krivolapov, Khasan R. Khayarov, Oleg G. Sinyashina and Dmitry G. Yakhvarov

 

The electrochemical reduction of [NiBr2(bpy)] (bpy is 2,2'-bipyridine) complex in the presence of 2,4,6-tricyclohexylphenyl bromide (TchpBr) with a sacrificial nickel anode results in the one-pot formation of an organonickel complex [NiBr(Tchp)(bpy)] bearing three cyclic substituents in the σ-bonded aromatic ring. The synthesized complex was characterized by various methods including single crystal X-ray analysis.

 

Mendeleev Communications, 2016, February 12, 4756

Polymorphism and thermodynamic properties of chloro(cyclopentadienyl)bis(triphenylphosphine)ruthenium(II) complex

Gorbachuk, E.V., Badeeva, E.K., Zinnatullin, R.G., Pavlov, P.O., Dobrynin, A.B., Gubaidullin, A.T., Ziganshin, M.A., Gerasimov, A.V., Sinyashin, O.G., Yakhvarov, D.G.

 

A new crystalline polymorph of known chloro(cyclopentadienyl)bis(triphenylphosphine)ruthenium(II) complex [RuCl(PPh3)2(η5-C5H5)] was obtained and characterized by various analytical methods including single-crystal and powder X-ray diffraction (XRPD) and differential scanning calorimetry (DSC) in combination with thermo-gravimetric analysis (TG-DSC). The obtained crystals of new polymorph are monoclinic, space group P21/n, with a = 11.125(4), b = 19.184(6), c = 15.946(5) Å, α = 90, β = 100.174(5), γ = 90, and Z = 4. It has been found that real melting point of the complex (M.p. = 252-253 °C) can be determined only in inert atmosphere while an apparent melting is observed in the range 142-150 °C due oxygen promoted oxidative dissociation of triphenylphosphine ligand. © 2016 Elsevier B.V. All rights reserved.

 

Journal of Organometallic Chemistry, Volume 805, 1 March 2016, Pages 49-53

2015

 

Electrochemical Properties and Reactivity of Organonickel SigmaComplex [NiBr(Mes)(bpy)] (Mes = 2,4,6Trimethylphenyl, bpy = 2,2'Bipyridine)

Sakhapov, I.F., Gafurov, Z.N., Babaev, V.M., Kurmaz, V.A., Mukhametbareev, R.R., Rizvanov, I.K., Sinyashin, O.G., Yakhvarov, D.G. 

 

Electrochemical properties and reactivity of electrochemically activated forms of organonickelsigmacomplex [NiBr(Mes)(bpy)] (where Mes = 2,4,6trimethylphenyl, bpy = 2,2'bipyridine) were studied.The activation of the organonickel sigmacomplex was found to proceed under both electrochemical reduction and oxidation conditions to give coordinatively unsaturated forms of the complex: radical[Ni(Mes)(bpy)]• and cationic complex [Ni(Mes)(bpy)]+, respectively. It was shown experimentally that theactive forms of organonickel complex [NiBr(Mes)(bpy)] can react with organic substrates (cyclohexene,octene1, tetrahydrofuran) and convert nitriles (acetonitrile, acetonitriled3, chloroacetonitrile) into corresponding imines containing 2,4,6trimethylphenyl fragment.)

 

Russian Journal of Electrochemistry, Volume 51, Issue 11, 1 November 2015, Pages 1061-1068

Electrochemical properties and catalytic activity in the ethylene polymerization processes of nickel complexes with 2,2′-bipyridine in the presence of ortho-phosphinophenol derivatives

Fomina, O.S., Kislitsyn, Y.A., Babaev, V.M., Rizvanov, I.K., Sinyashin, O.G., Heinicke, J.W., Yakhvarov, D.G. 

 

Electrochemical properties of the [NiBr2(bpy)2] complex, where bpy = 2,2′-bipyridyl, have been studied in the presence of derivatives of ortho-phosphine phenol: 2-diphenyl phosphanyl-4-methyl phenol CH3C6H3(PPh2)OH (1), 2-diphenyl phosphanyl-4-methylphenyldiphenyl phosphinate CH3C6H3(PPh2)OP(O)Ph2 (2), and 2-diphenylphosphoryl-4-methyl phenol CH3C6H3(P(O)Ph2)OH (3). It is found that interaction of products of electrochemical reduction of complex [NiBr2(bpy)2] with 1 and 2 results in formation of active catalysts of the process of homogeneous oligomerization/polymerization of ethylene.

 

Russian Journal of Electrochemistry, Volume 51, Issue 11, 1 November 2015, Pages 1069-1078

Pyrazole-Based PCN Pincer Complexes of Palladium(II): Mono- and Dinuclear Hydroxide Complexes and Ligand Rollover C-H Activation

Bailey, W.D., Luconi, L., Rossin, A., Yakhvarov, D., Flowers, S.E., Kaminsky, W., Kemp, R.A. , Giambastiani, G., Goldberg, K.I.

 

Palladium complexes of the novel unsymmetrical phosphine pyrazole-containing pincer ligands PCNH (PCNH = 1-[3-[(di-tert-butylphosphino)methyl]phenyl]-1H-pyrazole) and PCNMe (PCNMe = 1-[3-[(di-tert-butylphosphino)methyl]phenyl]-5-methyl-1H-pyrazole) have been prepared and characterized through single-crystal X-ray diffraction and multinuclear 1H, 13C{1H}, and31P{1H} NMR spectroscopy. In preparations of the monomeric hydroxide species (PCNH)Pd(OH), an unexpected N detachment followed by C-H activation on the heterocycle 5-position took place resulting in conversion of the monoanionic {P,C-,N} framework into a dianionic {P,C-,C-} ligand set. The dinuclear hydroxide-bridged species (PCNH)Pd(μ-OH)Pd(PCC) was the final product obtained under ambient conditions. The "rollover" activation was followed via 31P{1H} NMR spectroscopy, and dinuclear cationic μ-OH and monomeric PdII hydroxide intermediates were identified. DFT computational analysis of the process (M06//6-31G∗, THF) showed that the energy barriers for the pyrazolyl rollover and for C-H activation through a σ-bond metathesis reaction are low enough to be overcome under ambient-temperature conditions, in line with the experimental findings. In contrast to the PCNH system, no "rollover" reactivity was observed in the PCNMe system, and the terminal hydroxide complex (PCNMe)Pd(OH) could be readily isolated and fully characterized. (Chemical Equation Presented).

 

Organometallics, Volume 34, Issue 16, 24 August 2015, Pages 3998-4010

Quantum chemical calculations of 31P NMR chemical shifts: Scopes and limitations

Latypov, S.K. , Polyancev, F.M., Yakhvarov, D.G., Sinyashin, O.G.

 

The aim of this work is to convince practitioners of 31P NMR methods to regard simple GIAO quantum chemical calculations as a safe tool in structural analysis of organophosphorus compounds. A comparative analysis of calculated GIAO versus experimental 31P NMR chemical shifts (CSs) for a wide range of phosphorus containing model compounds was carried out. A variety of combinations (at the HF, DFT (B3LYP and PBE1PBE), and MP2 levels using 6-31G(d), 6-31+G(d), 6-31G(2d), 6-31G(d,p), 6-31+G(d,p), 6-311G(d), 6-311G(2d,2p), 6-311++G(d,p), 6-311++G(2d,2p), and 6-311++G(3df,3pd) basis sets) were tested. On the whole, it is shown that, in contrast to what is claimed in the literature, high level of theory is not needed to obtain rather accurate predictions of 31P CSs by the GIAO method. The PBE1PBE/6-31G(d)//PBE1PBE/6-31G(d) level can be recommended for express estimation of 31P CSs. The PBE1PBE/6-31G(2d)//PBE1PBE/6-31G(d) combination can be recommended for routine applications. The PBE1PBE/6-311G(2d,2p)//PBE1PBE/6-31+G(d) level can be proposed to obtain better results at a reasonable cost. Scaling by linear regression parameters significantly improves results. The results obtained using these combinations were demonstrated in 31P CS calculations for a variety of medium (large) size organic compounds of practical interest. Care has to be taken for compounds that may be involved in exchange between different structural forms (self-associates, associates with solvent, tautomers, and conformers). For phosphorus located near the atoms of third period elements ((CH3)3PS and P(SCH3)3) the impact of relativistic effects may be notable.

 

 

Physical Chemistry Chemical Physics, Volume 17, Issue 10, 14 March 2015, Pages 6976-6987

Synthesis, crystal structures and luminescent properties of the copper(I) pyrazolonate complexes

Bochkarev, L.N., Bariniva, Y.P., Ilicheva, A.I., Ketkov, S.Y., Baranov, E.V., Ilichev, V.A., Yakhvarov, D.G.

 

New copper(I) complexes with pyrazolonate ligands [Cu(Pri-PMP)(DPEphos)] (1) and [Cu(But-PMP)(DPEphos)] (2) (Pri-PMP = 1-phenyl-3-methyl-4-isobutyryl-5-pyrazolonato, But-PMP = 1-phenyl-3-methyl-(2,2-dimethylpropan-1-oyl)-5-pyrazolonato; DPEphos = bis[2-(diphenylphosphino)-pheny]ether) were synthesized and structurally characterized. An unusual η1 coordination of pyrazolonate ligand to the copper atom was found in complex 2. Photo- and electroluminescent properties of the synthesized compounds were investigated. In crystalline form compounds 1 and 2 revealed dual emission consisting of the bands at 445-450 and 485-488 nm which were assigned to transitions from the S1 and T1 states. DFT and TD DFT calculations as well as electrochemical studies correlate with the photophysical data. Synthesized copper(I) complexes generated electroluminescence of yellowish-orange (1) and yellow (2) colors with the maximum luminance of 286 and 39 cd/m2, respectively.

 

Inorganica Chimica Acta, Volume 425, 30 January 2015, Pages 189-19

First neutral dinuclear cobalt complex formed by bridging [μ-O2P(H)R]- ligands: Synthesis, X-ray crystal structure and quantum-chemical study

Yakhvarov, D.G., Trofimova, E.A., Dobrynin, A.B., Gerasimova, T.P., Katsyuba, S.A., Sinyashin, O.G.

 

The reaction of cobalt dibromide hexahydrate with 2,2′-bipyridine (bpy) and 9-anthrylphosphinic acid AntP(O)(OH)H (Ant = 9-anthryl) leads to the first example of a neutral dinuclear cobalt(ii) complex {Co2Br2[μ-O2P(H)Ant]2(bpy)2} formed by two bridging [μ-O2P(H)Ant]- ligands. The complex has been characterized by X-ray diffraction analysis and quantum-chemical calculations.

 

 

Mendeleev Communications, Volume 25, Issue 1, January/February 2015, Pages 27-28

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