A Small Cationic Organo-Copper Cluster as Thermally Robust Highly Photo- and Electroluminescent Material.

Organic light-emitting diodes (OLEDs) are revolutionizing display applications. In this aspect, luminescent complexes of precious metals such as iridium, platinum, or ruthenium still playing a significant role. Emissive compounds of earth-abundant copper with equivalent performance are desired for practical, large-scale applications such as solid-state lighting and displays.

The Nature of P(σλ↔σλ) Dualism: 3a,6a-Diaza-1,4-diphosphapentalene as a Form of Stabilized Singlet Phosphinidene.

The current study provides a clear understanding of the chemical properties of annelated 3a,6a-diaza-1,4-diphosphapentalenes (DDPs), which are best viewed as stabilized singlet phosphinidenes. It was found that DDPs undergo reversible oligomerization in solution, which provides 1,2,3-diazaphosphole-substituted cyclotetraphosphines, isolated and characterized by X-ray crystal structure analysis. Transformation of the 10-π-electron heteropentalene system into a stabilized phosphinidene occurs when the P-N bond is lengthened, which is facilitated by weak Lewis acids and bases.

Effect of Increasing the Strength of Aluminum Matrix Nanocomposites Reinforced with Microadditions of Multiwalled Carbon Nanotubes Coated with TiC Nanoparticles.

Aluminum matrix composites reinforced with multiwalled carbon nanotubes (MWCNTs) are promising materials for applications in various high-tech industries. Control over the processes of interfacial interaction in Al/MWCNT composites is important to achieve a high level of mechanical properties. The present study describes the effects of coating MWCNTs with titanium carbide nanoparticles on the formation of mechanical properties and the evolution of the reinforcement structure in bulk aluminum matrix nanocomposites with low concentrations of MWCNTs under conditions of solid-phase consolidation of ball-milled powder mixtures.

Synthesis and ε-Caprolactone Polymerization Activity of Electron-Deficient Gallium and Aluminum Species Containing a Charged Redox-Active dpp-Bian Ligand.

The synthesis of electron-deficient gallium- and aluminum-centered species containing a redox-active dpp-Bian ligand (dpp-Bian = 1,2-bis[(2,6-diisopropylphenyl)imino]acenaphthene) is described. The reaction of digallane [(dpp-Bian)Ga-Ga(dpp-Bian)] with [PhC][PF] or AgPF resulted in polyoxidized species [(dpp-Bian)GaF] (), [(dpp-Bian)H][PF] (), and [(dpp-Bian)GaF(OPF)] (). The reaction of digallane with B(CF) led to electron-deficient gallylene [(dpp-Bian)GaB(CF)] of a dpp-Bian radical anion.

Effect of novel porphyrazine photosensitizers on normal and tumor brain cells.

Photodynamic therapy (PDT) is a clinically approved procedure for targeting tumor cells. Though several different photosensitizers have been developed, there is still much demand for novel photosensitizers with improved properties. In this study we aim to characterize the accumulation, localization and dark cytotoxicity of the novel photosensitizers developed in-house derivatives of porphyrazines (pz I-IV) in primary murine neuronal cells, as well as to identify the concentrations at which pz still effectively induces death in glioma cells yet is nontoxic to nontransformed cells.

Impact of n,γ-irradiation on organic complexes of rare earth metals.

The complexes of La, Ce, Nd, Sm, Eu, Tb and Yb with benzoxazolyl-phenolate, benzothiazolyl-phenolate, benzoxazolyl-naphtholate, benzothiazolyl-naphtholate and 4,4,4-trifluoro-1-(2-thienyl)-1,3-butanedione ligands were treated with n,γ-irradiation upon a sustained (45 h, absorbed dose of 120 krad, flux of neutrons 5·10 n/cm) and a pulse mode (3 ms, absorbed dose of 130 krad, flux of neutrons 3.6·10 n/cm). It was found that main characteristics of the compounds (shape of substance, color, IR absorption and photoluminescent spectra) have not changed.

Cerium(iii) complexes with azolyl-substituted thiophenolate ligands: synthesis, structure and red luminescence.

In order to obtain molecular Ce(iii) complexes which emit red light by f-d transitions the azolyl-substituted thiophenolates were used as the ligands. The thiophenolate Ce(iii) complexes were synthesized by the reaction of Ce[N(SiMe)] with respective thiophenols 2-(2'-mercaptophenyl)benzimidazole (H(NSN)), 2-(2'-mercaptophenyl)benzoxazole (H(OSN)) and 2-(2'-mercaptophenyl)benzothiazole (H(SSN)) in DME media. The structures of the benzimidazolate (Ce(NSN)(DME)) and benzothiazolate (Ce(SSN)(DME)) derivatives were determined by X-ray analysis which revealed that the cerium ion in the molecules is coordinated by one DME and three anionic thiophenolate ligands.

Reversible C=C Bond Activation by an Intramolecularly Coordinated Antimony(I) Compound.

The reaction of N,C,N-chelated stibinidene ArSb (1) (Ar=C H -2,6-(CH=NtBu) ) with selected N-alkyl/aryl-maleimides RN(C(O)CH) (R=Me, tBu, Ph) gave the addition products with bridged bicyclic [2.2.1] structure containing an antimony atom at the bridgehead position, fused with a 6-membered benzene and a 5-membered N-alkyl/aryl-pyrrolidine ring.

X-Ray excited luminescence of organo-lanthanide complexes.

A comparative study of the photoluminescence (PL) and radioluminescence (RL) of lanthanide complexes with benzimidazolylphenolate (NON), 4,4,4-trifluoro-1-(2-thienyl)-1,3-butanedionate (TTA) and 1,3-acetylacetonate (acac) ligands revealed significant differences in the total and relative intensity of emission. The PL spectra contain both bands of metal-centered and ligand centred emission while X-ray excited compounds display only the bands of Ln3+ ions, the relative intensity of which differs from that in UV excited analogues. The RL intensity of all the studied complexes is about 300 times lower than that of PL.

One-Electron Reduction of Acenaphthene-1,2-Diimine Nickel(II) Complexes.

New nickel-based complexes of 1,2-bis[(2,6-diisopropylphenyl)imino]acenaphthene (dpp-bian) with BF counterion or halide co-ligands were synthesized in THF and MeCN. The nickel(I) complexes were obtained by using two approaches: 1) electrochemical reduction of the corresponding nickel(II) precursors; and 2) a chemical comproportionation reaction. The structural features and redox properties of these complexes were investigated by using single-crystal X-ray diffraction (XRD), cyclic voltammetry (CV), and electron paramagnetic resonance (EPR) and UV/Vis spectroscopy.

Features of the Molecular Structure and Luminescence of Rare-Earth Metal Complexes with Perfluorinated (Benzothiazolyl)phenolate Ligands.

A set of Sc, Nd, Sm, Eu, Ho, Gd, Er, Yb complexes with perfluorinated 2-(benzothiazol-2-yl)phenolate ligands Ln(SON)(DME) were synthesized by the reactions of silylamides Ln[N(SiMe)] with phenol H(SON). The structure of the initial phenol, Sc, and Er complexes was established using X-ray analysis, which revealed that the obtained compounds are mononuclear, in contrast to the binuclear non-fluorinated analogues [Ln(SON)] synthesized earlier. All the obtained complexes, both in solid state and in tetrahydrofuran (THF) solutions, upon excitation by light with λ 395 or 405 nm show intense luminance of the ligands at 440-470 nm.

Tetrahedral nickel(ii) and cobalt(ii) bis-o-iminobenzosemiquinonates.

The new bis-o-iminobenzosemiquinonate nickel and cobalt complexes (imSQt-Bu)2M (M = Ni (1), Co (2)), where imSQ is a radical anion of 4,6-di-tert-butyl-N-(tert-butyl)-o-iminobenzoquinone, were synthesized and characterized in detail. The molecular structures of 1 and 2 have been established by single-crystal X-ray analysis. The metal atoms in 1 and 2 have a distorted tetrahedral environment, and the dihedral angles between the planes of two radical imSQ ligands are approximately 80° in both complexes.

Novel dioxolene nickel complexes with sterically hindered diazabutadienes. Coupling of aza-ligands coordinated to nickel.

A square-planar bis-o-semiquinonato nickel complex interacts with N,N'-disubstituted 1,4-diazabutadienes-1,3 forming six-coordinate compounds. The X-ray structural study indicates complex geometry to be close to the octahedral. Magnetic properties are determined by metal-ligand ferromagnetic exchange interactions which are promoted by complex geometry.

The first water-soluble polynuclear metallamacrocyclic Sr(ii)-Cu(ii) complex based on simple glycinehydroximate ligands.

Recently, aminohydroximate ligands have found wide applications in the fascinating class of polynuclear metallamacrocyclic compounds named 15-MC-5 metallacrowns. The enhanced interest in water-soluble aminohydroximate Ln(iii)-Cu(ii) complexes is largely due to their rich coordination chemistry, diverse properties and ease of synthesis. We examined glycinehydroxamic acid as a simple ligand for the preparation of the first water-soluble polynuclear metallamacrocyclic Sr(ii)-Cu(ii) compound.

Catechol thioethers with physiologically active fragments: Electrochemistry, antioxidant and cryoprotective activities.

A number of asymmetrical thioethers based on 3,5-di-tert-butylcatechol containing sulfur atom bonding with physiologically active groups in the sixth position of aromatic ring have been synthesized and the electrochemical properties, antioxidant, cryoprotective activities of new thioethers have been evaluated. Cyclic voltammetry was used to estimate the oxidation potentials of thioethers in acetonitrile. The electrooxidation of compounds at the first stage leads to the formation of o-benzoquinones.

Correction: Amido Ca(ii) complexes supported by Schiff base ligands for catalytic cross-dehydrogenative coupling of amines with silanes.

Correction for 'Amido Ca(ii) complexes supported by Schiff base ligands for catalytic cross-dehydrogenative coupling of amines with silanes' by Natalia V. Forosenko et al., Dalton Trans.

Thermally Stable Ln(II) and Ca(II) Bis(benzhydryl) Complexes: Excellent Precatalysts for Intermolecular Hydrophosphination of C-C Multiple Bonds.

A series of Ln(II) and Ca(II) bis(alkyl) complexes with bulky benzhydryl ligands, [( p- tBu-CH)CH]M(L ) (M = Sm, L = DME, n = 2 (1); M = Sm, Yb, Ca, L = TMEDA, n = 1 (2, 3, 4), were synthesized by the salt-metathesis reaction of MI(THF) ( n = 0-2) and [( p- tBu-CH)CH]Na. In complex 1, the benzhydryl ligands are bound to the metal center in η-coordination mode. Unlike complex 1, in isomorphous complexes 3 and 4, due to the coordination unsaturation of the metal center, the both benzhydryl ligands coordinate to the metal in η-fashion.

Rydberg state mediated multiphoton ionization of (η-CH)(η-CH)Cr: DFT-supported experimental insights into the molecular and electronic structures of excited sandwich complexes.

The resonance-enhanced multiphoton ionization (REMPI) of a mixed sandwich complex has been achieved for the first time when exciting (η7-C7H7)(η5-C5H5)Cr via the Rydberg 4pz state. The REMPI spectrum is indicative of unexpectedly small changes of the sandwich geometry on excitation. Time-dependent DFT calculations reveal fine effects of the ligand nature on the molecular and electronic structure variations accompanying electronic excitation.

Gallium "Shears" for C=N and C=O Bonds of Isocyanates.

Digallane [L Ga-GaL ] (1, L =dpp-bian=1,2-[(2,6-iPr C H )NC] C H ) reacts with RN=C=O (R=Ph or Tos) by [2+4] cycloaddition of the isocyanate C=N bonds across both of its C=C-N-Ga fragments to afford [L (O=C-NR)Ga-Ga(RN-C=O)L ] (R=Ph, 3; R=Tos, 4). The reactions with both isocyanates result in new C-C and N-Ga single bonds. In the case of allyl isocyanate, the [2+4] cycloaddition across one C=C-N-Ga fragment of 1 is accompanied by insertion of a second allyl isocyanate molecule into the Ga-N bond of the same fragment to afford compound [L Ga-Ga(AllN- C=O) L ] (5) (All=allyl).

From a 2,1-Benzazaarsole to Elusive 1-Arsanaphthalenes in One Step.

The 2,1-benzazaarsole (1) showed a diene-like reactivity towards selected alkynes RC≡CR (R=CO Me, C F N) thus forming 1-arsa-1,4-dihydro-iminonaphthalenes 2 a and 3 a as hardly isolable intermediates, that underwent facile CH→NH proton migration leading to before elusive substituted 1-arsanaphthalenes 2 b and 3 b that could be completely structurally characterized.

Deprotonation of Benzoxazolium Salt: Trapping of a Radical-Cation Intermediate.

The deprotonation of N-2,6-diisopropylphenyl-substituted benzoxazolium tetrafluoroborate 1 with NaH results in the formation of electron-rich diaminodioxaethylene 2. The radical cation salt 2·BF is found to be an intermediate product in the redox reaction leading from 1 to 2.

Synthesis, structure and long-lived NIR luminescence of lanthanide ate complexes with perfluorinated 2-mercaptobenzothiazole.

To obtain new efficient lanthanide-based NIR luminophores perfluorinated 2-mercaptobenzothiazole was used as a ligand. The ate-complexes [(Ln(mbtF)4)-(Na(DME)3)+] of Nd (1), Sm (2), Tb (3), Er (4), Yb (5) and [(Y(mbtF)4)-(Li(DME)3)+] (6) were synthesized in high yields by the reactions of the respective silylamide compounds Ln[N(SiMe3)2]3 and M[N(SiMe3)2] (M = Li, Na) with 4,5,6,7-tetrafluoro-1,3-benzothiazol-2(3H)-thione (HmbtF) in DME media. The complexes 1-3 and 6 were structurally characterized by X-ray diffraction analysis.

One-Electron Reduction of 2-Mono(2,6-diisopropylphenylimino)acenaphthene-1-one (dpp-mian).

The electrochemical characteristics of 2-mono(2,6-diisopropylphenylimino)acenaphthene-1-one (dpp-mian) have been investigated. One-electron reduction of dpp-mian involves the iminoketone fragment, which is revealed by the EPR spectrum obtained after the electrolysis of the dpp-mian solution in tetrahydrofuran (THF). The reduction of dpp-mian with one equivalent of metallic potassium leads to a similar EPR spectrum.

Ca , Yb and Sm Bis(Amido) Complexes Coordinated by NHC Ligands: Efficient Catalysts for Highly Regio- and Chemoselective Consecutive Hydrophosphinations with PH.

The first example of intermolecular hydrophosphination of styrene, 2-vinylpyridine and phenylacetylene with PH catalyzed by bis-(amido) complexes [(Me Si) N] M(NHC) (M=Ca, Yb, Sm) coordinated by NHC ligands is described. The reactions of styrene with PH proceed under mild conditions in quantitative yields to afford only anti-Markovnikov product and allow for the chemoselective synthesis of primary, secondary and tertiary phosphines. Addition of phenylacetylene to PH regardless the initial molar substrates ratio results in the exclusive formation of a tertiary tris-(Z-styryl)-phosphine.

Ca(ii), Yb(ii) and Tm(iii) complexes with tri- and tetra-anions of 1,2-bis[(2,6-diisopropylphenyl)imino]acenaphthene.

Reduction of [(dpp-bian)2-M2+(thf)4] (M = Ca, 1; Yb, 6; dpp-bian = 1,2-bis[(2,6-diisopropylphenyl)imino]acenaphthene) by alkali metals results in heterometallic, [(dpp-bian)3-M2+K+(thf)2]2 (M = Ca, 2; Yb, 7), [(dpp-bian)4-Ca2+A2+(thf)4]2 (A = Na, 3; Li, 4; K, 5), [(dpp-bian)4-Yb2+K2+(thf)4]2 (8) and [(dpp-bian)24-Yb32+K2+(thf)8] (9). The reduction of [(dpp-bian)TmBr(thf)n] (in situ) affords [(dpp-bian)4-Tm3+Na+(thf)]2 (10).