Introduction of Niobium in the Chemistry of Octahedral Chalcogenide Clusters: Synthesis and Detailed Study of Compounds Based on Condensed and Discrete {ReNbQ} (Q = S or Se) Cores.

It is known that niobium practically does not form cluster chalcogenide compounds of the {M(μ-Q)} type, which are widespread in the chemistry of group 6 and 7 metals. This work reports the preparation of a series of polymeric and discrete niobium-containing heterometallic clusters based on the {ReNb(μ-S)} and {ReNb(μ-Se)} cores. The compounds were prepared by the high-temperature reaction between rhenium and niobium dichalcogenides in a KCN melt.

Evolution of the Electronic Structure of the -[ReSbipyCl] Octahedral Rhenium Cluster during Reduction.

Understanding the processes that occur during the redox transformations of complexes coordinated by redox-active apical ligands is important for the design of electrochemically active compounds with functional properties. In this work, a detailed analysis of the interaction energy and electronic structure was performed for cluster complexes -[ReSbipyCl] (n = 2-, 4-, 6-, 8-), which can be obtained by stepwise electrochemical reduction of a neutral cluster -[ReSbipyCl] in DMSO solution. It was shown that the formation of open-shell paramagnetic ions with S = 1, 2 and 1 is the most energetically favorable for n = 2-, 4- and 6-, respectively.

A new subclass of copper(I) hybrid emitters showing TADF with near-unity quantum yields and a strong solvatochromic effect.

We introduce here a new subclass of copper(I) hybrid emitters simultaneously containing [CuI] anions and Cu cations, separated in space by a Janus head ligand. When UV-irradiated at 298 K, these unique "Two-In-One" hybrids exhibit a short-lived green TADF with near-unity quantum yield and a strong solvatochromic effect. Moreover, they manifest a strong radioluminescence upon X-ray irradiation.

Replenishment in the Family of Rhenium Chalcobromides; Synthesis and Structure of Molecular {ReS}Br(TeBr), Dimeric [{ReS}Br(TeBr)], and Polymeric {ReS}Br Compounds Based on the {ReS} Tetrahedral Cluster Core.

We have obtained three new rhenium(IV) chalcobromides belonging to the homologous series {ReS}Br(TeBr) ( = 0, 3, 4): a molecular complex {ReS}Br(TeBr) (), a dimeric complex [{ReS}(TeBr)Br(μ-Br)] (), and a two-dimensional (2D) polymeric compound {ReS}Br (). Compound is isotypic to the already known {ReTe}(TeBr)Br, while and exhibit a new type of binding of tetrahedral clusters via μ-Br bridges. Compounds were characterized by X-ray single-crystal diffraction, X-ray powder diffraction, and thermal and elemental analyses.

The Role of Quadruple Bonding in the Electron Transport through a Dimolybdenum Tetraacetate Molecule.

A dimolybdenum tetraacetate (Mo(OCCH)) molecule is embedded between two electrodes formed by semi-infinite 1D monatomic chains of lithium, aluminum, and titanium atoms. Electron transport through the Mo(OCCH) molecule is calculated. The role of quadrupole bonding in the transport properties of the studied systems is analyzed.

Chirality and Relativistic Effects in Os(CO).

The energy and structural parameters were obtained for all forms of the carbonyl complex of osmium Os(CO) with D and D symmetries using density functional theory (DFT) methods. The calculations took into account various levels of relativistic effects, including those associated with nonconservation of spatial parity. It was shown that the ground state of Os(CO) corresponds to the D symmetry and thus may be characterized either as left-twisted (D) or right-twisted (D).

Synthesis, Structure, and Spectroscopic Study of Redox-Active Heterometallic Cluster-Based Complexes [ReMoSe(CN)].

The heterometallic cluster-based compound K[ReMoSe(CN)] was obtained by high-temperature reaction from a mixture of ReSe and MoSe in molten potassium cyanide. The redox behavior of the [ReMoSe(CN)] cluster anion was studied by cyclic voltammetry in aqueous and organic media showing two reversible one-electron-redox transitions with of -0.462 and 0.

Keggin-type polyoxometalate 1 : 1 complexes of Pb(II) and Bi(III): experimental, theoretical and luminescence studies.

Bi3+ and Pb2+ uptake by a monolacunary Keggin-type [PW11O39]7- anion leads to the formation of [PW11O39Bi]4- and [PW11O39Pb]5- complexes with a stereochemically active lone pair at the incorporated heterometal. The two complexes were isolated as (TBA)4[PW11O39Bi] (1) and (TBA)5[PW11O39Pb] (2) and characterized by 31P and 183W NMR spectroscopy, high-resolution electrospray mass-spectrometry (HR-ESI-MS) and cyclic voltammetry (CV). EXAFS and XANES data confirm the unchanged oxidation state and ψ-square pyramidal geometry of Bi3+ and Pb2+ in 1 and 2.

Dicopper(I) Paddle-Wheel Complexes with Thermally Activated Delayed Fluorescence Adjusted by Ancillary Ligands.

A suite of paddle-wheel shaped [Cu(PymPPh)(L)](PF) complexes showing efficient thermally activated delayed fluorescence (TADF) has been synthesized. In these complexes, Cu(I) ions are ,-bridged by three diphenyl(2-pyrimidyl)phosphine (PymPPh, L) ligands in a "head-to-tail" fashion, and one or both metals are also capped by the ancillary ligand (L = MeOH, MeCO, MeCN, PhCN). At ambient temperature, the solid complexes emit TADF with the quantum yield of up to 85% and the lifetimes of from 9.

Effect of spin-phonon interactions on Urbach tails in flexible [M(bdc)(dabco)].

The optical properties of metal-organic frameworks [M(bdc)(dabco)] (M = Co, Ni, Cu, Zn) in the wavelength region of 300-1000 nm were studied, and the electronic band-to-band transitions were determined and characterized by the Kubelka-Munk approach and DFT calculations. Urbach edges for band-to-band transitions were determined. The effect of spin-phonon interactions on the width of Urbach edges in paramagnetic [M(bdc)(dabco)] is discussed.

Soluble Molecular Rhenium Cluster Complexes Exhibiting Multistage Terminal Ligands Reduction.

Substitution of terminal halide ligands of octahedral rhenium cluster complexes [ReQX] in a melt of 4,4'-bipyridine (bpy) led to us obtaining four new compounds with the general formula -[ReQ(bpy)X] (Q = S or Se; X = Cl or Br) in high yield. In contrast to most of the known molecular rhenium cluster complexes with heteroaromatic terminal ligands, compounds - are soluble in organic solvents. This made it possible to carry out a detailed characterization of the new compounds both in solids and in solutions.

Tailoring Heterometallic Cluster Functional Building Blocks: Synthesis, Separation, Structural and DFT Studies of [Re Mo Se (CN) ].

Influence of the metal core composition and geometry on the structure, spectroscopic properties and redox potentials was investigated for the first time for heterometallic (Re/Mo) octahedral clusters. The discrete anionic clusters [Re Mo Se (CN) ] (x=2, 3; n=4, 5) were obtained as individual salts. Their isomeric composition and bond-length distribution were inspected using a combination of single-crystal X-ray structure analysis, NMR, EXAFS, and DFT calculations.

Luminescent twelve-nuclear rhenium clusters.

The first luminescent twelve-nuclear rhenium cluster complexes were obtained. Three new clusters, namely, [ReCS(μ-Cl)Cl], [ReCS(μ-Br)Cl] and [ReCS(μ-Br)Br], were synthesized using the non-isovalent substitution of μ-O ligands within the {ReCS(μ-O)} cluster core by halide anions. The geometry of the new clusters was investigated by X-ray structural analysis, and the electronic structures were evaluated by the use of DFT calculations.

On the catalytic transfer hydrogenation of nitroarenes by a cubane-type MoS cluster hydride: disentangling the nature of the reaction mechanism.

Cubane-type MoS cluster hydrides decorated with phosphine ligands are active catalysts for the transfer hydrogenation of nitroarenes to aniline derivatives in the presence of formic acid (HCOOH) and triethylamine (EtN). The process is highly selective and most of the cluster species involved in the catalytic cycle have been identified through reaction monitoring. Formation of a dihydrogen cluster intermediate has also been postulated based on previous kinetic and theoretical studies.

Understanding structural flexibility of the paddle-wheel Zn-SBU motif in MOFs: influence of pillar ligands.

Structural parameters and energies of secondary building units (SBUs) in Zn2(C8H4O4)2·C6H12N2 have been examined with DFT and CCSD(T) methods. The SBU structure exhibits flexibility due to close energies of formation of its D4h, D4, and D2d forms. The potential energy surfaces (PESs) calculated for these systems testify that the presence of pillar ligands with negatively charged nitrogens (NCH or DABCO) can lead to almost barrier-free transitions between structural SBU forms.

Synthesis, Crystal Structure, and Liquid Exfoliation of Layered Lanthanide Sulfides KLnCuS (Ln = La, Ce, Pr, Nd, Sm).

Among the great amount of known lanthanide nanoparticles, reports devoted to chalcogenide ones are deficient. The properties of such nanoparticles remain almost unknown due to the lack of simple and proper synthetic methods avoiding hydrolysis and allowing preparation of oxygen-free lanthanide nanoparticles. A liquid exfoliation method was used to select the optimum strategy for the preparation of quaternary lanthanide sulfide nanoparticles.

Mixed-metal clusters with a {ReMoSe} core: from a polymeric solid to soluble species with multiple redox transitions.

Cluster compounds based on a new {ReMoSe} core were obtained and studied. The polymeric solid K[ReMoSe(CN)(CN)] (1) containing 24 cluster valence electrons (CVE) was isolated as a result of high-temperature reaction. Water-soluble salts K[ReMoSe(CN)]·11HO (2) and Cs[ReMoSe(CN)]·HO (3) were prepared from compound 1.

Bright green-to-yellow emitting Cu(i) complexes based on bis(2-pyridyl)phosphine oxides: synthesis, structure and effective thermally activated-delayed fluorescence.

A family of brightly luminescent dinuclear complexes of [Cu(μ-X)(N^N)] type (X = I or SCN) has been synthesized in 76-90% yields by the reaction of bis(2-pyridyl)phosphine oxides (N^N) with the corresponding Cu(i) salts. The X-ray diffraction study reveals that the CuI core of the [Cu(μ-I)(N^N)] complexes has either a butterfly- or rhomboid-shaped structure, while the eighth-membered [Cu()Cu] ring in the [Cu(SCN)(N^N)] complexes is nearly planar. In the solid state, these compounds exhibit a strong green-to-yellow emission (λ = 536-592 nm) with high PLQYs (up to 63%) and short lifetimes (1.

Metal-metal bond excitation in colloidal solution of NbS.

For the first time the comparison of the theoretical and experimental data have shown that UV-vis absorption in the region of 600nm in colloidal solution of NbS can be described by the d-d electronic transitions to the antibonding molecular orbital. It is proved that the process leads to excitation of metal-metal bond.

Solid-state reaction as a mechanism of 1T ↔ 2H transformation in MoS2 monolayers.

Monolayers of molybdenum disulfide MoS2 are considered to be prospective materials for nanoelectronics and various catalytic processes. Since in certain conditions they undergo 1T ↔ 2H phase transitions, studying these phase changes is an urgent task. We present a DFT research of these transitions to show that they can proceed as a solid-state reaction.

Evolution of chemical bonding and electron density rearrangements during D(3h) → D(3d) reaction in monolayered TiS2: a QTAIM and ELF study.

Monolayered titanium disulfide TiS2, a prospective nanoelectronic material, was previously shown to be subject to an exothermic solid-state D3h -D3d reaction that proceeds via a newly discovered transition state. Here, we study the reaction in detail using topological methods of quantum chemistry (quantum theory of atoms in molecules and electron localization function analysis) and show how electron density and chemical bonding between the atoms change in the course of the reaction. The reaction is shown to undergo a series of topological catastrophes, associated with elementary chemical events such as break and formation of bonds (including the unexpected formation of S-S bonding between sulfur layers), and rearrangement of electron density of outer valence and core shells.

Dithiolene dimetallic molybdenum(V) complexes displaying intraligand charge transfer (ILCT) emission.

Bifunctional dithiolene ligands have been coordinated to the Mo(V)(O)(μ-S2)Mo(V)(O) unit to afford [Mo2O2(μ-S)2(BPyDTS2)2](2-) (1(2-)) (BPyDTS2 (2-bis-(2-pyridyl)methylene-1,3-dithiolene) dianions. Reaction of the 1(2-) molybdenum dimer with pentacarbonylchlorothenium(i) affords a tetrametallic complex of formula [Mo2O2(μ-S)2(BPyDTS2)2{Re(CO)3Cl}2](2-) (2(2-)). The monomeric (CH3)2Sn(BPyDTS2) (3) tin complex has also been prepared for comparative purposes.

Nucleus-independent chemical shifts and aromaticity in hexanuclear cluster complexes [Mo6X8]n- (X = S, Se, and Te; n = 0 and 4) of Chevrel phases.

Molecular diamagnetism and multicentered X-Mo-Mo and Mo-Mo-Mo interactions in hexanuclear cluster complexes [Mo(6)X(8)](n-) (X = S, Se, and Te; n = 0 and 4) are studied using calculations of nuclear independent chemical shifts (NICS) and the methods "atoms in molecules" and electron localization function. It is shown that [Mo(6)X(8)](4-) complexes are characterized by large negative NICSs related to the aromaticity of Mo-Mo bondings and to diatropic currents in Mo(6) metallic core of the cuboctahedral clusters. The calculated currents can participate in the mechanism of nucleation of the vortex lattice of macroscopic Abrikosov's electronic whirls responsible for the magnetic high-field stability of the superconducting currents in type II superconductors.