Toward Rhenium-based Circularly Polarized OLEDs Using Tailored Chiral Re(CO)3 Emitters.

Chiral rhenium(I) emitters showing circularly polarized phosphorescence (CPP) are an attractive mainstay for CP organic light-emitting diodes (CP-OLEDs). However, the efficiency of such  emitters is not ideal, and they have never been explored for circularly polarized electroluminescence (CPEL) applications. Here, we have tailored robust chiral Re(I) complexes with improved CPP properties, and firstly  demonstrated CPEL from rhenium emitters.

Palladium-Catalyzed C(sp)-H Activation in A Monoterpene-Based Compound Under Mild Conditions: A Combined Experimental and Theoretical Mechanistic Study.

A rare example of the palladium-catalyzed sp C-H bond activation in a monoterpene-based compound has been observed in the reaction of PdCl with a (+)-3-carene-based ligand HL (HL=N-((1aS,3S,7bR)-1,1,3-trimethyl-7-phenyl-5-(pyridin-2-yl)-1a,2,3,7b-tetrahydro-1H-cyclopropa[f]quinolin-3-yl)acetamide), which yielded the [PdLCl] complex. In contrast to the vast majority of C(sp)-H activation reactions which require prolonged heating and mixing due to the inert character of the corresponding bond, the reaction reported herein proceeds rapidly under mild conditions. A theoretical insight into the ligand deprotonation has been performed by DFT calculations.

Outstanding Circularly Polarized TADF in Chiral Cu(I) Emitters: From Design to Application in CP-TADF OLEDs.

Low-cost molecular emitters that merge circularly polarized luminescence (CPL) and thermally activated delayed fluorescence (TADF) properties are attractive for many high-tech applications. However, the design of such emitters remains a difficult task. To address this challenge, here, we propose a simple and efficient strategy, demonstrated by the design of pseudochiral-at-metal complexes [Cu(L*)DPEPhos]PF bearing a (+)/(-)-menthol-derived 1,10-phenanthroline ligand (L*).

Efficient emission of Zn(II) and Cd(II) complexes with nopinane-annelated 4,5-diazafluorene and 4,5-diazafluoren-9-one ligands: how slight structural modification alters fluorescence mechanism.

Zinc(II) and cadmium(II) chlorido complexes with an ,-chelating nopinane-annelated 4,5-diazafluoren-9-one ligand (LO) were synthesized. While the zinc(II) complex is mononuclear and adopts a tetrahedral ZnNCl coordination geometry, its cadmium(II) analogue features a 1D polymeric structure due to the bridging coordination of chlorido ligands with Cd ions having an octahedral CdNCl coordination geometry. The photophysical properties of the oxygen-containing LO ligand and its zinc(II) and cadmium(II) complexes were studied in solution and in the solid state and matched against the properties of its oxygen-free 4,5-diazafluorene congener L and its complexes of the same metal ions.

Novel Copper(II) Complexes with Dipinodiazafluorene Ligands: Synthesis, Structure, Magnetic and Catalytic Properties.

The reactions of CuX (X = Cl, Br) with dipinodiazafluorenes yielded four new complexes [CuXL] (X = Cl (), Br (), L = (1R,3R,8R,10R)-2,2,9,9-Tetramethyl-3,4,7,8,9,10-hexahydro-1H-1,3:8,10-dimethanocyclopenta [1,2-b:5,4-b']diquinolin-12(2H)-one) and [(CuX)L]n (X = Cl (), Br (), L = (1R,3R,8R,10R,1'R,3'R,8'R,10'R)-2,2,2',2',9,9,9',9'-Octamethyl-1,1',2,2',3,3',4,4',7,7',8,8',9,9',10,10'-hexadecahydro-1,3:1',3':8,10:8',10'-tetramethano-12,12'-bi(cyclopenta [1,2-b:5,4-b']diquinolinylidene). The complexes were characterized by IR and EPR spectroscopy, HR-ESI-MS and elemental analysis. The crystal structures of compounds , and were determined by X-ray diffraction (XRD) analysis.

Variations in Essential Oils from South Siberian Conifers of the Pinaceae Family: New Data towards Identification and Quality Control.

Conifer essential oils have been used for centuries in traditional medicine, and nowadays they are of special interest for official medicine, aromatherapy and perfumery. In the present work, comprehensive information is given on the composition of essential oils prepared from the twigs of the conifer trees of the pine family (Pinaceae): Abies sibirica Ledeb., Larix sibirica Ledeb.

Electron-Precise Semiconducting ReGaGe: Extending the IrIn Structure Type to Group 7 of the Periodic Table.

Intermetallic compounds with semiconducting properties are rare, but they give rise to advanced materials for energy conversion and saving applications. Here, we present ReGaGe, a new electron-precise narrow-gap intermetallic semiconductor. The compound crystallizes in the IrIn structure type (space group 4/, = 6.

Luminescent Zn(ii) and Cd(ii) complexes with chiral 2,2'-bipyridine ligands bearing natural monoterpene groups: synthesis, speciation in solution and photophysics.

Mononuclear zinc(ii) and cadmium(ii) complexes, ZnLCl2 (1), CdLCl2 (2), ZnL1Cl2·2H2O (3), and CdL1Cl2·2H2O (4), with chiral ligands containing a 2,2'-bipyridine moiety and natural terpene (+)-limonene (L) or (+)-3-carene (L1) moieties were synthesized. In these complexes the L and L1 ligands are shown to coordinate Zn2+ and Cd2+ ions through the 2,2'-bipyridine moiety. The acetamide group of the ligands interacts with M2+ ions by forming NM2+ and C[double bond, length as m-dash]OM2+ contacts and N-HCl hydrogen bonds with coordinated Cl- ions.

Magnetic properties of biofunctionalized iron oxide nanoparticles as magnetic resonance imaging contrast agents.

One of the future applications of magnetic nanoparticles is the development of new iron-oxide-based magnetic resonance imaging (MRI) negative contrast agents, which are intended to improve the results of diagnostics and complement existing Gd-based contrast media. Iron oxide nanoparticles designed for use as MRI contrast media are precisely examined by a variety of methods: powder X-ray diffraction (XRD), transmission electron microscopy (TEM), Raman spectroscopy, Mössbauer spectroscopy and zero-field nuclear magnetic resonance (ZF-NMR) spectroscopy. TEM and XRD measurements reveal a spherical shape of the nanoparticles with an average diameter of 5-8 nm and a cubic spinel-type crystal structure of space group -3.

Chiral -Symmetric Diimines with 4,5-Diazafluorene Units.

A synthetic approach to a new group of stable chiral -symmetric diimines with the 4,5-diazafluorene core has been developed based on condensation of dipinodiazafluorene with aromatic diamines. The chemical structures of new compounds were proven by spectroscopic methods and X-ray crystallography. All the compounds form solvates with organic solvents (chloroform, benzene, 1,4-dioxane) and water.

ReGaGe: an intermetallic compound with semiconducting properties and localized bonding.

ReGaGe2 is a new member of the family of intermetallic compounds with non-metallic properties. It displays highly localized covalent bonding patterns. Its electronic structure is governed by mixing of Re d orbitals with the s and p orbitals of Ga and Ge and features the Fermi level falling into the opened band gap, ensuring experimentally confirmed semiconducting properties.

Ln(iii) complexes (Ln = Eu, Gd, Tb, Dy) with a chiral ligand containing 1,10-phenanthroline and (-)-menthol fragments: synthesis, structure, magnetic properties and photoluminescence.

A series of lanthanide(iii) complexes based on the new chiral ligand L, which contains 1,10-phenanthroline and (-)-menthol fragments, namely [LnL(NO)] (Ln = Eu (1), Gd (2), Tb (3), Dy (4)), have been synthesized and structurally characterized. Complexes 1-4 are isostructural and crystallize in the non-centrosymmetric space group P422. The mononuclear complexes comprise a 10-coordinate Ln ion with two bidentate N,N-donor ligands (L) and three bidentate chelating nitrate groups.

CIDNP and EPR study of phototransformation of lappaconitine derivatives in solution.

Chemically induced dynamic nuclear polarization (CIDNP) and electron paramagnetic resonance (EPR) techniques have been used to study the paramagnetic species formed during the photolysis of the alkaloid lappaconitine and its synthetic analogues in solution. Lappaconitine is a photosensitive antiarrhythmic and hypertension drug, whose major photoproduct (N-acetyl anthranilic acid) is also a potent photosensitizer. Both these compounds are lipophilic and might bind efficiently to cell membranes thereby causing phototoxic damage.

De novo production of (+)-aristolochene by sporulated surface cultures of Penicillium roqueforti.

The de novo production of the fungal metabolite, (+)-aristolochene by sporulated surface cultures of Penicillium roqueforti is reported for the first time. The biosynthesis of fungal volatiles by various sporulated surface cultures was monitored by solid phase micro-extraction (SPME). When comparing malt extract agar with sabouraud dextrose agar, the highest yield of the fungal metabolite (0.