Molecular emitters that combine circularly polarized luminescence (CPL) and high radiative rate constants of the triplet exciton decay are highly attractive for electroluminescent devices (OLEDs) or next-generation photonic applications, such as spintronics, quantum computing, cryptography, or sensors. However, the design of such emitters is a major challenge because the criteria for enhancing these two properties are mutually exclusive. In this contribution, we show that enantiomerically pure {Cu­(CbzR)­[( S/R )-BINAP]} [R = H (1), 3,6-tBu (2)] are efficient thermally activated delayed fluorescence (TADF) emitters with high radiative rate constants of k TADF up to 3.1 × 105 s–1 from 1/3LLCT states according to our temperature-dependent time-resolved luminescence studies. The efficiency of the TADF process and emission wavelengths are highly sensitive to environmental hydrogen bonding of the ligands, which can be disrupted by grinding of the crystalline materials. The origin of this pronounced mechano-stimulus photophysical behavior is a thermal equilibrium between the 1/3LLCT states and a 3LC state of the BINAP ligand, which depends on the relative energetic order of the excited states and is prone to inter-ligand C–H···π interactions. The copper­(I) complexes are also efficient CPL emitters displaying exceptional dissymmetry values g lum of up to ±0.6 × 10–2 in THF solution and ±2.1 × 10–2 in the solid state. Importantly for application in electroluminescence devices, the C–H···π interactions can also be disrupted by employing sterically bulky matrices. Accordingly, we have investigated various matrix materials for successful implementation of the chiral copper­(I) TADF emitters in proof-of-concept CP-OLEDs.

The high element abundance and d10 electron configuration make ZnII‐based compounds attractive candidates for the development of novel photoactive molecules. Although a large library of purely fluorescent compounds exists, emission involving triplet excited states is a rare phenomenon for zinc complexes. We have investigated the photophysical and ‐chemical properties of a series of dimeric and monomeric ZnII halide complexes bearing a cyclic (alkyl)(amino)carbene (cAAC) as chromophore unit. Specifically, [(cAAC)XZn(μ‐X)2ZnX(cAAC)] (X=Cl (1), Br (2), I (3)) and [ZnX2(cAAC)(NCMe)] (X=Br (4), I (5)) were isolated and fully characterized, showing intense visible light photoluminescence under UV irradiation at 297 K and fast photo‐induced transformation. At 77 K, the compounds exhibit improved stability allowing to record ultra‐long lifetimes in the millisecond regime. DFT/MRCI calculations confirm that the emission stems from 3XCT/LEcAAC states and indicate the phototransformation to be related to asymmetric distortion of the complexes by cAAC ligand rotation. This study enhances our understanding of the excited state properties for future development and application of new classes of ZnII phosphorescent complexes.

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(2016). Highly water-soluble cyclopentadienyl and indenyl molybdenum(II) complexes -second generation of molybdenum-based cytotoxic agents. European Journal of Inorganic Chemistry, 2016Chemistry, (4), 519-529. doi:10.1002 This article may be used for non-commercial purposes in accordance With Wiley-VCH Terms and Conditions for self-archiving". Ondřej Mrózek, [a] Lucie Šebestová, [b] Jaromír Vinklárek,* [a] Martina Řezáčová, [c] Aleš Eisner, [b] Zdeňka Růžičková, [a] and Jan Honzíček [d] Abstract [BF4]2 were determined by the X-ray crystallography. All synthesized compounds exhibit increased activity against human leukemia cell lines MOLT-4 and HL-60. They are about one order of magnitude more active than cisplatin. This study has proven that modification of the outer coordination sphere of molybdenum complexes has a strong impact on their activity and may be successfully used for a design of novel highly cytotoxic active species.

Synthesis, reactivity and properties of unusually stable propene complexes of molybdenum and tungsten are reported.