G.L. Gutsev, K.G. Belay, K.V. Bozhenko, L.G. Gutsev and B.R. Ramachandrand. A comparative study of small 3d-metal oxide (FeO)n, (CoO)n, and (NiO)n clusters. Phys. Chem. Chem. Phys., (2016) 18, 27858 —27867. doi: 10.1039/c6cp03241a.

Geometrical and electronic structures of the 3d-metal oxide clusters (FeO)n, (CoO)n, and (NiO)n are computed using density functional theory with the generalized gradient approximation in the range of 1 r n r 10. It is found that the cluster geometries are similar in the (FeO)n and (CoO)n series but noticeably different in the (NiO)n series for several values of n. All of the lowest total energy states are found to possess relatively small spin multiplicities and are either antiferromagnetic or ferromagnetic except for the states of (NiO)3, (NiO)4, (NiO)9, and (NiO)10, which are ferromagnetic. The computed polarizabilities per atom undergo a steep decrease when compared to the atomic values of the MO monomers (M = Fe, Co, and Ni). Surprisingly, the polarizability does not strongly depend on either M or n in all the considered series when n varies from 3 to 10. The binding energies per atom are the largest in the (FeO)n series, followed by the binding energies of (CoO)n and (NiO)n.

G.L. Gutsev, K.V. Bozhenko, L. G. Gutsev, A.N. Utenyshev, and S.M. Aldoshin. Transitions from Stable to Metastable States in the Cr2On and Cr2On— Series, n =1—14. J. Phys. Chem. A (2017) 121, 845–854. doi: 10.1021/acs.jpca.6b11036.

The geometrical and electronic structures of the Cr2On and Cr2On— clusters are computed using density functional theory with a generalized gradient approximation in the range of 1 ≤ n ≤ 14. Local total spin magnetic moments, polarizabilities, binding energies per atom, and energies of abstraction of O and O2 are computed for both series along with electron affinities of the neutrals and verticaldetachment energies of the anions. In the lowest total energies states of Cr2O2,Cr2O3, Cr2O4,Cr2O14,Cr2O3—,Cr2O4—, and Cr2O14—, total spin magnetic moments of the Cr atoms are quite large and antiferromagnetically coupled. In the rest of the series, atleast one of the Cr atoms has no spin-magnetic moment at all. The computed vertical electron-detachment energies of the Cr2On— are in good agreement with experimental values obtained in the 1 ≤ n ≤ 7 range. All neutral Cr2On possess electron affinities larger than the electron affinities of halogen atoms when n > 6 and are thus superhalogens. It is found that the neutrals and anions are stable with respect to the abstraction of an O atom in the whole range of n considered, whereas both neutrals and anions became unstable toward the loss of O2 for n >7. The polarizability per atom decreases sharply when n moves from one to four and then remains nearly constant for larger n values in both series. The largest members in both series, Cr2O14 and Cr2O14—, possess the geometrical structures of the Cr2(O2)7 type by analogy with monochromium Cr(O2)4.

Sergey M. Aldoshin, Konstantin V. Bozhenko and Andrey N. Utenyshev. Quantum-chemical modeling of exchange coupling in the magnetic sublattice of bifunctional compounds containing heterometallic complexes of 3d and 4d metals with oxalate and dithiooxamide ligands. Structural Chemistry (2017) 28:965-974. doi: 10.1007/s11224-016-0900-0.

To find components of the magnetic sub-lattice of bi-functional compounds with maximum ferromagnetic exchange coupling, quantum-chemical calculations of complexes [(L)₂M1^III(L)M2^II(L)₂]^5- are performed (M1^III and M2^II are tri- and divalent atoms of 3d and 4d transition metals M1^III (Cr, Mo) and M2^II (Ni, Co, Tc, Ru, Rh, Pd), L is dithiooxamide or oxalate). Calculations of the geometric structure of the complex are performed at the B3LYP/LANL2DZ level and calculations of J constants are performed at the B3LYP/TZV level. The replacement of a divalent atom of 3d metal by a divalent atom of 4d metal leads to an increase of J, whereas the replacement of a trivalent atom of 3d metal by a trivalent atom of 4d metal does not change the value of J. It is concluded that there is a correlation of J with a total change in the spin density on the M1III and M2II metals in the complexes compared to the M1³⁺ and M2²⁺ isolated cations.

Aldoshin S.M., Sanina N.A., Korchagin D.V., Shilov G.V., Mushenok F.B., Utenyshev A.N., Bozhenko K.V., Antipin I.S., Soloveva S.E. EXPERIMENTAL AND THEORETICAL STUDY OF THE INFLUENCE OF PERIPHERAL ENVIRONMENT ON MAGNETIC PROPERTIES OF TETRANUCLEAR MANGANESE SKELETON IN NEW REPRESENTATIVES OF CALIX[4]ARENE-CONTAINING [MN^II₂ MN^III₂] CLUSTERS.

Journal of Molecular Structure. (2015) V.1081 pp. 217-223. ISSN: 0022-2860, DOI: 10.1016/j.molstruc.2014.10.022.

A new representative of calix[4]arene-containing tetranuclear manganese complexes like [MN^II₂MN^III₂] with 2,2’-dipyridyl bidentate ligand, which is coordinated in the equatorial plane of the complex (II) was obtained. Complex crystallized in monoclinic space group P21 / c (a = 14,9402 (7) Å, b = 32,816 (1) Å, c = 21,595 (1) Å, β = 106,888 (4)). Its magnetic properties were studied by SQUID-magnetometry. It was shown that substitution of a peripheral ligand significantly impacted on the structure of central fragment of metal complex and therefore on magnetic properties. Quantum-chemical calculations were made for given complex and for similar calix[4]arene-containing manganese complexes with pyridine ligand (I). We have found the impact of periphery on magnetic properties of tetranuclear manganese skeleton for both complexes.

Kovalchukova O.V., Aldoshin S.M., Utenyshev A.N., Bozhenko K.V. , Valeriy Tkachev. SYNTHESIS, CRYSTAL AND MOLECULAR STRUCTURE OF CATENA-(BIS(μ1- OXALIC ACID)-μ3-HYDROGEN OXALATE-DI-AQUA-SODIUM(I))

Communications in Inorganic Synthesis. 2015, Vol.3, № 2, 23-25.

Crystal and molecular structure of catene- (bis (μ-oxalic acid)-μ-oxalate-di-aqva-sodium (I)) was found by X-ray analysis. The compound crystallized in triclinic space group P-1 с (Å) 6,2378 (12); B (Å) 71115 (14); C (Å) 10,489 (2); Α (°) 94,65 (3); Β (°) 100,12 (3); Γ (°) 97,78 (3). Cation of natrium in this compound forms eight coordinated and a square antiprint. It is surrounded by two molecules of oxalic acid, one water-soluble anion and one molecule of water. Both oxalic acid and hydrogen oxalate-anion act together as polydentate bridged ligands. Centrosymmetric cations of natrium are limited by anions of hydrogen oxalate with H bond system, which is associated with oxalic acid molecules. Three-dimensional structure forms lattice and stabilizes by hydrogen bonds.

Emel’yanova N., Sanina N., Krivenko A., Manzhos R., Bozhenko K., Aldoshin S.

COMPARISON OF PURE AND HYBRID DFT FUNCTIONALS FOR GEOMETRY OPTIMIZATION AND CALCULATION OF REDOX POTENTIALS FOR IRON NITROSYL COMPLEXES WITH “L-SCN” BRIDGING LIGANDS.

Theoretical Chemistry Accounts: Theory, Computation, and Modeling. Theor. Chem. Acc. (2013) 132:1316.

The geometry and electronic structure of neutral molecules and mono-anions of iron nitrosyl complexes with “μ-SCN” bridging ligands [(μ-SC₇H₄SN)Fe(NO)₂]₂ (I) and [(μ-SC₂H₃N₄)Fe(NO)₂]₂ (II) were studied using the density functional theory: pure functionals BP86, OLYP, OPBE, TPSS, PW91 and hybrid functionals B3LYP, B1B95, B3PW91 along with 6-311++G**//6-31G*. For geometry optimization, the pure functionals are more appropriate than the hybrid functionals. For mono-anions, pure functionals favor the doublet over the quartet state by 8.0–13.9 kcal/mol, whereas hybrid functionals yield quartet spin state of these anions to be more stable. The redox potentials of complexes I and II have been computed by DFT and compared with experimental results obtained from cyclic voltammetry method. The calculated redox potentials for I and II with pure functionals (especially BP86) are close to the experimental values, whereas those obtained by using hybrid functionals significantly deviate from the experiment.

Popov I.A., Popov V.F., Bozhenko K.V., Černušák I., Boldyrev A.I., STRUCTURAL CHANGES IN THE SERIES OF BORON-CARBON MIXED CLUSTERS CXB10-X- (X = 3-10) UPON SUBSTITUTION OF BORON BY CARBON

Journal of Chemical Physics. (2013) 139, 114307.

We report a theoretical investigation on the ten-atom boron-carbon mixed clusters C_xB_{10 — x}^— (x = 3-10), revealing a molecular wheel to monocyclic ring and linear species structural change as a function of x upon increasing the number of carbon atoms in the studied series. The unbiased searches for the global minimum structures of the clusters with x ranging from 3 to 9 were conducted using the Coalescence Kick program for different spin multiplicities. Subsequent geometry optimizations with follow-up frequency calculations at the hybrid density functional B3LYP/6-311+G(d) level of theory along with the single point coupled-cluster calculations (UCCSD(T)/aug-cc-pVTZ//B3LYP/6-311+G(d) and RCCSD(T)/aug-cc-pVTZ//B3LYP/6-311+G(d)) revealed that the C₃B₇^— and C₄B₆^— clusters possess planar distorted wheel-type structures with a single inner boron atom, similar to the recently reported CB₉^— and C₂B₈^—. Going from C₅B₅^— to C₉B^— inclusive, monocyclic and ring-like structures are observed as the most stable ones on the PES. The first linear species in the presented series is found for the C₁₀^— cluster, which is almost isoenergetic with the one possessing a monocyclic geometry. The classical 2c-2e σ bonds are responsible for the peripheral bonding in both carbon- and boron-rich clusters, whereas multicenter σ bonding (nc-2e bonds with n > 2) on the inner fragments in boron-rich clusters is found to be the effective tool to describe their chemical bonding nature. It was shown that the structural transitions in the C_xB_10-x^— series occur in part due to the preference of carbon to form localized bonds, which are found on the periphery of the clusters. Chemical bonding picture of C₁₀^— is explained on the basis of the geometrical structures of the C₁₀ and C₁₀^2— clusters and their chemical bonding analyses.

Ivanov A.S., Boldyrev A.I., Morris A.J., Pickard C.J., Bozhenko K.V.

INORGANIC DOUBLE-HELIX STRUCTURES OF UNUSUALLY SIMPLE LITHIUM-PHOSPHORUS SPECIES

Angewandte Chemie — International Edition. (2012) 51 8330. DOI: 10.1002/anie.201201843

Precision quantum-chemical calculations of some structures of lithium phosphide were made and the possible existence of double spirals structures in inorganic compounds was shown.

Ivanov A.S., Bozhenko K.V., Boldyrev A.I. ON THE SUPPRESSION MECHANISM OF THE PSEUDO-JAHN-TELLER EFFECT IN MIDDLE E6 (E = P, AS, SB) RINGS OF TRIPLE-DECKER SANDWICH COMPLEXES Inorganic Chemistry. (2012) 51 8868.

Quantum chemical calculations of the CpMoE6MoCp (E = P, As, Sb) triple-decker sandwich complexes showed that E6 fragments in the central decks of the complexes are planar. Analysis of molecular orbitals involved in vibrational coupling demonstrated that filling the unoccupied molecular orbitals involved in vibronic coupling with electron pairs of Mo atoms suppresses the PJT effect in the CpMoE6MoCp (E = P, As, Sb) sandwich, with the E6 ring becoming planar (D6h) upon complex formation. The AdNDP analysis revealed that bonding between C5H5— units and Mo atoms has a significant ionic contribution, while bonding between Mo atoms and E6 fragment becomes appreciably covalent through the δ-type M → L back-donation mechanism.

Ivanov A.S., Bozhenko K.V., Boldyrev A.I. PECULIAR TRANSFORMATIONS IN THE CXHXP4-X (X = 0-4) SERIES

Journal of Chemical Theory and Computation. (2012) 8, 135–140. dx.doi.org/10.1021/ct200727z .

ABSTRACT: In the current work, we performed a systematic study of the CxHxP4Аx (x =0А4) series using an unbiased CK global minimum and low-lying isomers search for the singlet and triplet P4АC4H4 species at the B3LYP/6-31G** level of theory. The selected lowest isomers were recalculated at the CCSD(T)/CBS//B3LYP/6-311++G** level of theory. We found that the transition from a three-dimensional tetrahedron-like structure to a planar structure occurs at x = 3, where planar isomers become much more stable than the tetrahedral structures due to significantly stronger π bonds between carbon atoms in addition to increasing strain energy at the carbon atom in the tetrahedral environment.

Popov I.A., Boldyrev A.I., Bozhenko K.V. IS GRAPHENE AROMATIC?

Nano Research. 2012 5(2) 117-123.

Using adaptive natural density partitioning analysis we prove that graphene is aromatic, but its aromaticity is different from the aromaticity in benzene, coronene, or circumcoronene. Aromaticity in graphene is local with two π-electrons delocalized over every hexagon ring.

Galeev T.R., Boldyrev A.I., Ivanov A.S., Bozhenko K.V., Romanescu C., Li Wang L.-S. MOLECULAR WHEEL TO MONOCYCLIC RING TRANSITION IN BORON-CARBON MIXED CLUSTERS C₂B_6̄^─ AND C₃B_5̄ ^─.

PCCP: Physical Chemistry Chemical Physics. (2011) 13, 8805–8810. DOI: 10.1039/c1cp20359b

In this joint experimental and theoretical work we present a novel type of structural transition occurring in the series of CxB8-x^─ (x = 1–8) mixed clusters upon increase of the carbon content from x =2 to x = 3. The wheel to ring transition is surprising because it is rather planar-to-linear type of transition to be expected in the series since B8,B8А,B82А and CB7А are known to possess wheel-type global minimum structures while C8 is linear.

Misochko E.Y., Korchagin D.V., Bozhenko K.V., Chapyshev S.V., Aldoshin S.M. A DENSITY FUNCTIONAL THEORY STUDY OF THE ZERO-FIELD SPLITTING IN HIGH-SPIN NITRENES

Journal of Chemical Physics. (2010) v. 133, p. 4101-4110.

This work presents a detailed evaluation of the performance of density functional theory (DFT) for the prediction of zero-field splittings (ZFSs) in high-spin nitrenes. A number of well experimentally characterized triplet mononitrenes, quartet nitrenoradicals, quintet dinitrenes, and septet trinitrenes have been considered. Several DFT-based approaches for the prediction of ZFSs have been compared. It is shown that the unrestricted Kohn-Sham and the Pederson-Khanna approaches are the most successful for the estimation of the direct spin-spin (SS) interaction and the spin-orbit coupling (SOC) parts, respectively, to the final ZFS parameters. The most accurate theoretical predictions (within 10%) are achieved by using the PBE density functional in combination with the DZ, EPR-II, and TZV basis sets. For high-spin nitrenes constituted from light atoms, the contribution of the SOC part to ZFS parameters is quite small (7%-12%). By contrast, for chlorine-substituted septet trinitrenes, the contribution of the SOC part is small only to D value but, in the case of E value, it is as large as the SS part and has opposite sign. Due to this partial cancellation of two different contributions, SS and SOC, the resulting values of E in heavy molecules are almost two times smaller than those predicted by analysis of the widely used semiempirical one-center spin-spin interaction model. The decomposition of D(SS) into n-center (n=1-4) interactions shows that the major contribution to D(SS) results from the one-center spin-spin interactions. This fact indicates that the semiempirical SS interaction model accurately predicts the ZFS parameters for all types of high-spin nitrenes with total spin S=2 and 3, if their molecules are constructed from the first-row atoms.

Timokhina H.N., Ovchinnikov A.A., Bozhenko K.V. AB INITIO QUANTUM CHEMICAL CALCULATIONS OF A CLUSTER C₈H₁₂

International Journal of Quantum Chemistry. (2002) 88(4) 433–435.

Using unrestricted Hartree—Fock—Roothaan approximation and density functional theory on 6-31G* basis, ab initio calculation cluster C₈H₁₂ has been carried out. It was shown asa result of calculations thata ground state for the conformation given isa septet state. This cluster can be used for investigation of the kinematic mechanism of magnetic exchange and magnetic ordering in polyradicals.

Bozhenko K.V., Ovchinnikov A.A. NON-EMPIRICAL MOLECULAR ORBITAL STUDIES OF THE POSSIBILITY OF FERROMAGNETIC ORDERING IN ISOELECTRON-SUBSTITUTED FERROCARBON MODIFICATIONS

Computational and Theoretical Chemistry. (1995) 343, 177-182.

The vertical singlet-triplet (ST) splitting in the C₃H₆ molecule and C₂BH^-₆ and C₂NH⁺₆ ions has been investigated by means of ab initio calculations. The molecular geometry was either taken as that corresponding to the UHF/6-31G^* or UHF/6-31+G^* energy minimum of the triplet configuration (for C₃H₆, C₂BH^-₆, C₂NH⁺₆), or was extracted from the ferrocarbon crystal (for C₃H₆). Polarized split-valence basis sets (6-31G^*, 6-31+G^* and 6-311G^**) and fourth-order Moller-Plesset perturbation theory at the MP4SDTQ level of approximation provides more reliable ST splitting values, than the MP4SDQ level, the latter being the most accurate method used in our previous work. These calculations prove the presence of ferromagnetic ordering within the same quasi-graphite plane of ferrocarbon crystal. The presence of such ordering has been shown within the same quasi-graphite plane upon substitution of sp³ carbon atoms by ions B^-, N⁺ and so on.