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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]PF6 bearing a (+)/(−)‐menthol‐derived 1,10‐phenanthroline ligand (L*). These complexes exhibit a yellow CP‐TADF with a record‐high quantum yield (close to 100 %) and high dissymmetry factor (|glum|~1×10−2). Remarkably, the above compounds also show a negative thermal‐quenching (NTQ) of luminescence in the 300–77 K range. Exploiting the designed Cu(I) emitters, we fabricated efficient CP‐TADF OLEDs displaying mirror‐imaged CPL bands with high |gEL| factors of 1.5×10−2 and the maximum EQE of 6.15 %. Equally important, using the (+)‐[Cu(L*)DPEPhos]PF6 complex, we have discovered that an external magnetic field noticeably suppresses CP‐TADF of Cu(I) emitters. These findings are an important contribution to the CPL phenomenon and provide access to highly efficient, low‐cost and robust CP‐TADF emitters. [ABSTRACT FROM AUTHOR]

[Display omitted] The interaction of tris(6-methyl-2-pyridyl)phosphine oxide (L) with equimolar amounts of [Cu(MeCN) 4 ]PF 6 or AgClO 4 in acetonitrile produces scorpionate-like complexes [M(L)(MeCN)]X (M = Cu and Ag; X = PF 6 - and ClO 4 -). At ambient temperature, these compounds exhibit orange (λ max = 608 nm) or turquoise (λ max = 490 nm) photo-luminescence with a quantum yield up to 16% and lifetimes of microsecond order. [ABSTRACT FROM AUTHOR]

New fluorinated dibenzo-1,2,5,6-tetrathiocines 1 and 2 were synthesized by a novel condensation of 1,2-disulfenyl chlorides under the influence of elemental Cu, and structurally defined in the solid state, solution, and gas phase by single-crystal XRD, variable-temperature 19F NMR and NOESY, and DFT calculations. Crystalline 1 and 2 exhibited the C2h chair and C2 twist molecular conformations, respectively. Unlike 1 displayed only C⋯S shortened intermolecular contacts, crystal structure of 2 featured F⋯π, F⋯F, F⋯S and S⋯S contacts. In toluene solutions at 296 K, both twist and chair conformers were observed in the ∼1 : 1 and ∼7 : 1 ratios for 1 and 2, respectively. For 1, the twist ↔ chair conformer interconversion was practically temperature-independent, and for 2 revealed ΔH ∼3.5 kJ mol−1 and ΔS ∼4.4 J K−1 mol−1. With DFT, the PESs for twist–chair transformation and twist–twist racemization were analyzed and the TSs exhibiting twist–halfchair and boat conformations, respectively, were found. Several additional stationary points on the PESs, corresponding to hidden intermediates and bifurcation points and featuring twistboat and halfchair conformations were detected. In chloroform solution under sunlight, 1 underwent 1,2,5,6-tetrathiocine → 1,2,3,6-tetrathiocine isomerization whose product was characterized by XRD. [ABSTRACT FROM AUTHOR]

The title compound was synthesized by Ullmann cross‐coupling in low yield as the first representative of [n]phenylene containing hydrocarbon and fluorocarbon rings. Stille/Suzuki‐Miyaura cross‐coupling reactions, as well as substitution of fluorine in suitable starting compounds, failed to give the same product. The geometric and electronic structures of the title compound were studied by X‐ray diffraction, cyclic voltammetry and density functional theory calculations, together with Hirshfeld surface and reduced density gradient analyses. The crystal structure features head‐to‐tail π‐stacking and other fluorine‐related secondary bonding interactions. From the nucleus‐independent chemical shifts descriptor, the four‐membered ring of the title compound is antiaromatic, and the six‐membered rings are aromatic. The Janus molecule is highly polarized; and the six‐membered fluoro‐ and hydrocarbon rings are Lewis π‐acidic and π‐basic, respectively. The electrochemically‐generated radical cation of the title compound is long‐lived as characterized by electron paramagnetic resonance, whereas the radical anion is unstable in solution. The title compound reveals electrical properties of an insulator. On expanding its molecular scaffold towards partially fluorinated [n]phenylenes (n≥2), the properties presumably can be transformed into those of semiconductors. In this context, the title compound is suggested as a prototype scaffold for ambipolar materials for organic electronics and spintronics. [ABSTRACT FROM AUTHOR]

By X-ray diffraction analysis and IR spectroscopy, it was established here that vinyl carbocations C3H5+/C4H7+ with carborane counterion CHB11Cl11− form stable monosolvates C3H5+⋅C3H6/C4H7+⋅C4H8 with molecules of alkenes C3H6/C4H8. They contain molecular group =C+⋯Hδ−–Cδ+= with a new type of bond formed by the H atom of the H–C= group of the alkene with the C atom of the C+=C group of the carbocation. The short C+----Cδ+ distance, equal to 2.44 Å, is typical of that of X----X in proton disolvates (L2H+) with an quasi-symmetrical X–H+⋯X moiety (where X = O or N) of basic molecule L. The nature of the discovered bond differs from that of the classic H–bond by an distribution of electron density: the electron–excessive Hδ− atom from the (=)C–H group of the alkene is attached to the C+ atom of the carbocation, on which the positive charge is predominantly concentrated. Therefore, it can be called an inverse hydrogen bond. [ABSTRACT FROM AUTHOR]