A. A. Grineva

Bio: A. A. Grineva is an academic researcher from Russian Academy of Sciences. The author has contributed to research in topics: IMes & Ligand. The author has an hindex of 5, co-authored 13 publications receiving 81 citations. Previous affiliations of A. A. Grineva include University of Toulouse.

Post-coordination backbone functionalization of an imidazol-2-ylidene and its application to synthesize heteropolymetallic complexes incorporating the ambidentate IMesCO2− ligand

Abstract: Backbone functionalization of the pre-coordinated, emblematic IMes ligand with the COOH moiety was achieved upon treatment of Cp(CO)2Mn(IMes) with n-BuLi followed by CO2 and HCl to afford Cp(CO)2Mn(IMesCOOH). The latter reacts with (1,10-phen)M(OAc)2 (M = Cu, Zn) to obtain M3Mn4 polymetallic complexes exhibiting the ambidentate IMesCO2− moiety as a key structural unit.

Oxidative Coupling of Anionic Abnormal N-Heterocyclic Carbenes: Efficient Access to Janus-Type 4,4'-Bis(2H-imidazol-2-ylidene)s.

Abstract: The oxidative coupling of anionic imidazol-4-ylidenes protected at the C2 position with [MnCp(CO)2] or BH3 led to the corresponding 4,4′-bis(2H-imidazol-2-ylidene) complexes or adducts, in which the two carbene moieties are connected through a single C−C bond. Subsequent acidic treatment of the later species led to the corresponding 4,4′-bis(imidazolium) salts in good yields. The overall procedure offers practical access to a novel class of Janus-type bis(NHC)s. Strikingly, the coplanarity of the two NHC rings within the mesityl derivative 4,4′-bis(IMes), favored by steric hindrance along with stabilizing intramolecular C−H⋅⋅⋅π aryl interactions, allows the alignment of the π-systems and, as a direct consequence, significant electron communication through the bis(carbene) scaffold.

Experimental and Theoretical Insights into the Electronic Properties of Anionic N-Heterocyclic Dicarbenes through the Rational Synthesis of Their Transition Metal Complexes.

Abstract: The lithiation of the NHC ligand backbone in Cp(CO)2Mn(IMes) followed by transmetalation on the C4 carbenic position with Cp(CO)2FeI led to the heterobimetallic complex Cp(CO)2Mn(μ-dIMes)Fe(CO)2Cp bearing the anionic ditopic imidazol-2,4-diylidene dIMes ligand. Subsequent treatment of the later with TfOH induced a selective decoordination of the [Cp(CO)2Mn] fragment to form the cationic abnormal NHC complex [Cp(CO)2Fe(aIMes)](OTf), which was further derivatized to the bis(iron) dIMes complex [Cp(CO)2Fe(μ-dIMes)Fe(CO)2Cp](OTf) by reaction with tAmOK and Cp(CO)2FeI. The effect of the metalation at the C4 or C2 position on the imidazole ring on the electronic donation properties of the associated C2 and C4 carbenic centers in the dIMes ligand was quantified through systematic experimental and theoretical studies of IMes, aIMes, and dIMes complexes. The evaluation of the catalytic activity of the series of cationic Fe(II) complexes based on IMes, aIMes, and dIMes ligands in a benchmark ketone hydrosilylation showed the superiority of the bimetallic derivative.

Coordination Polymers Formed by the Reactions between Zn(II), Co(II), and Ni(II) Cimantrenates and γ,γ'-Dipyridyl in Methanol

Abstract: Reactions between methanol adducts of Zn(II), Co(II), and Ni(II) cimantrenates and γ,γ′-dipyridyl in methanol have been found to result in the formation of 1D coordination polymers, whose structure is governed, according to X-ray diffraction data, by the nature of the transition metal.

Ab initio calculation of vibrational absorption and circular dichroism spectra using density functional force fields

Abstract: : The unpolarized absorption and circular dichroism spectra of the fundamental vibrational transitions of the chiral molecule, 4-methyl-2-oxetanone, are calculated ab initio. Harmonic force fields are obtained using Density Functional Theory (DFT), MP2, and SCF methodologies and a 5S4P2D/3S2P (TZ2P) basis set. DFT calculations use the Local Spin Density Approximation (LSDA), BLYP, and Becke3LYP (B3LYP) density functionals. Mid-IR spectra predicted using LSDA, BLYP, and B3LYP force fields are of significantly different quality, the B3LYP force field yielding spectra in clearly superior, and overall excellent, agreement with experiment. The MP2 force field yields spectra in slightly worse agreement with experiment than the B3LYP force field. The SCF force field yields spectra in poor agreement with experiment.The basis set dependence of B3LYP force fields is also explored: the 6-31G* and TZ2P basis sets give very similar results while the 3-21G basis set yields spectra in substantially worse agreements with experiment. jg

NHCs in Main Group Chemistry.

Abstract: Since the discovery of the first stable N-heterocyclic carbene (NHC) in the beginning of the 1990s, these divalent carbon species have become a common and available class of compounds, which have found numerous applications in academic and industrial research. Their important role as two-electron donor ligands, especially in transition metal chemistry and catalysis, is difficult to overestimate. In the past decade, there has been tremendous research attention given to the chemistry of low-coordinate main group element compounds. Significant progress has been achieved in stabilization and isolation of such species as Lewis acid/base adducts with highly tunable NHC ligands. This has allowed investigation of numerous novel types of compounds with unique electronic structures and opened new opportunities in the rational design of novel organic catalysts and materials. This Review gives a general overview of this research, basic synthetic approaches, key features of NHC–main group element adducts, and might be...

The key role of R–NHC coupling (R = C, H, heteroatom) and M–NHC bond cleavage in the evolution of M/NHC complexes and formation of catalytically active species

Abstract: Complexes of metals with N-heterocyclic carbene ligands (M/NHC) are typically considered the systems of choice in homogeneous catalysis due to their stable metal-ligand framework However, it becomes obvious that even metal species with a strong M-NHC bond can undergo evolution in catalytic systems, and processes of M-NHC bond cleavage are common for different metals and NHC ligands This review is focused on the main types of the M-NHC bond cleavage reactions and their impact on activity and stability of M/NHC catalytic systems For the first time, we consider these processes in terms of NHC-connected and NHC-disconnected active species derived from M/NHC precatalysts and classify them as fundamentally different types of catalysts Problems of rational catalyst design and sustainability issues are discussed in the context of the two different types of M/NHC catalysis mechanisms