A series of ruthenium(II) bis(2,2'-bipyridyl) complexes containing N-phenyl-substituted diazafluorenes (Ru-C1, Ru-C6, Ru-C7 and Ru-F) was synthesized and their potential antibacterial activity against methicillin resistant Staphylococcus aureus (MRSA) was investigated. The Ru-C7 complex showed significant improvement in both minimum inhibitory concentration (MIC, 6.25 μg mL(-1)) and minimum bactericidal concentration (MBC, 25 μg mL(-1)) towards MRSA when compared with those of methicillin (positive control) (MIC = 25 μg mL(-1) and MBC = 100 μg mL(-1)). The Ru-C7 complex possessed much stronger antibacterial effects than the Ru-C6 complex (MIC, 25 μg mL(-1), MBC, >100 μg mL(-1)). Both Ru-C6 and Ru-C7 complexes were also demonstrated to be biologically safe when tested on normal human skin keratinocytes.

The large non‐radiative recombination is the main factor that limits state‐of‐the‐art organic solar cells (OSCs). In this work, two novel structurally similar oligomers (named 5BDTBDD and 5BDDBDT) with D‐A‐D‐A‐D and A‐D‐A‐D‐A configuration are synthesized for high‐performance ternary OSCs with low energy loss. As third components, these PM6 analogue oligomers effectively suppress the non‐radiative recombination in OSCs. Although the highest occupied molecular orbital (HOMO) levels of 5BDTBDD and 5BDDBDT are higher than that of PM6, the oligomers enabled ultra‐high electroluminescence quantum efficiency (EQEEL) of 0.05% and improved VOC, indicating suppressing non‐radiative recombination overweighs the common belief of deeper HOMO requirement in third component selection. Moreover, the different compatibility of 5BDTBDD and 5BDDBDT with PM6 and BTP‐BO4Cl fine‐tunes the active layer morphology with synergistic effects. The ternary devices based on PM6:5BDTBDD:BTPBO4Cl and PM6:5BDDBDT:BTP‐BO4Cl achieve a significantly improved PCEs of 17.54% and 17.32%, representing the state‐of‐the art OSCs processed by green solvent of o‐xylene. The strategy using novel oligomer as third component also has very wide composition tolerance in ternary OSCs. This is the first work that demonstrates novel structurally compatible D‐A type oligomers are effective third components, and provides new understanding of synergetic energy loss mechanisms towards high performance OSCs.

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Since the first synthesis of red-phosphorescent metal complexes for use in highly efficient organic light-emitting diodes (OLEDs), [1] the scope and diversity of studies on metalorganic phosphors in color tuning have continued to expand at an exponential rate. [2,3] While great success has been achieved in green-light phosphors, the design and synthesis of efficient red emitters is intrinsically more difficult, in accordance with the energy-gap law.[4] Many red organic dyes currently in use do not show a good compromise between device efficiency and color purity because of the nature of red-light emitters.[4] Typically, efficient and bright dopants are not red enough, and red-enough dopants are not efficient and bright. Optimization of the OLED efficiency/color purity trade-offs is therefore a key consideration for the realization of highly efficient phosphors of good color purity for pure red OLEDs.Recent research endeavors in the field of OLED devices have focused on solution-processable phosphorescent dendrimers and polymers owing to their advantages as low-cost, largearea displays and lighting sources.[5] In this regard, however, only a limited number of examples of phosphorescent dendrimers have been developed, [6] and their solution-processed OLEDs show a maximum external quantum efficiency (h ext ) of 5.7 % for red light.[6c] In such cases, the first-generation molecules are not very effective in relieving molecular interactions among the emissive cores, [6e] although higher-generation dendrimers can usually reduce the carrier mobility substantially. [7] Despite this situation, the apparently poorer performance of the OLEDs fabricated by spin-coating than that of their vacuum-deposited counterparts suggests the need for more efforts in developing highly amorphous Ir III complexes with new dendritic frameworks. Generally, a large hole-injection (HI) barrier for organic materials often limits the device efficiency. Since most of the hole-transporting (HT) materials reported are derived from aromatic amines, [8] the incorporation of arylamine units into the dendritic wedges should improve the HI/HT properties and the morphological stability of the Ir III phosphors. In light of this, pure red-emitting bifunctional Ir III complexes with triphenylamine dendrons (Ir-G1 and Ir-G2) have been synthesized and compared with Ir-G0. The new dendrimers were isolated as highly amorphous (T g % 145-220 8C) and thermally stable (decomposition starts above 417 8C) solids. The T g value increases gradually with dendron size.The Ir III dendrimers show two major absorption bands in their UV/Vis spectra (Figure 1). The intense bands below 380 nm are assigned to the spin-allowed intraligand 1 p-p* transitions. The weaker, lower-energy features in the visible region are due to the 1 MLCT and 3 MLCT (metal-ligand charge transfer) excitations induced by the strong spin-orbital coupling between the singlet and triplet manifolds. Upon light irradiation at 420 nm, all Ir complexes show deep-red photo-

A new approach has been illustrated for the development of stable, efficient, and environmentally "friendly" white phosphorescent materials. Under mild conditions, a new one-dimensional coordination polymer has been prepared from benzo-18-crown-6 with CuI in the presence of KI, which is capable of emitting direct white light in the solid state.

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A series of rigid-rod alkynylferrocenyl precursors with oligothiophene (from thiophene to terthiophene) linkage units in the backbone, [(η 5 -C 5 H 5 )Fe(η, have been prepared in moderate to good yields. The ferrocenylacetylene complexes 4a-4c can be used to form a range of stable platinum() alkynyl and bis(alkynylAll these new compounds have been fully characterized by analytical and spectroscopic methods and the molecular structures of the bithienyl-linked complexes [(η2b, 4b, 5b and 6b have been established by X-ray crystallography. Structural analysis of 6b confirms its rigid-rod structural motif, featuring coplanar bithienyl rings and a trans arrangement of the two bithiophene groups. An iron-iron throughspace distance of ca. 32 Å is observed in 6b. Although there is no significant metallocene-metallocene interaction through the alkynyl-platinum-oligothiophene bridge, a slight negative shift of the ferrocene-ferrocenium redox potential in the platinum-containing species indicates some degree of electron delocalization into the platinum segment, in line with the results from theoretical studies. Oxidation of the thiophene units is facilitated by the presence of the platinum centre and increased conjugation in the chain. Results and discussion SynthesisScheme 1 summarizes the reaction steps leading to the new ferrocenyl compounds in this study. 2-Bromo-5-(2-ferrocenylethynyl)-DALTON

Novel 2,3-bis(1H-pyrrol-2-yl)quinoxaline-functionalized Schiff bases were prepared and characterized as new fluorescent sensors for mercury(II) ion. The X-ray crystal structures of compounds 4, 5, 4a and 5a were determined. The binding properties of 4 and 5 for cations were examined by UV-vis and fluorescence spectroscopy. The UV-vis and fluorescence data indicate that a 1 : 1 stoichiometric complex is formed between compound 4 (or 5) and mercury(II) ion, and the association constant is (3.81 +/- 0.7) x 10(5) M(-1) for 4 and (3.43 +/- 0.53) x 10(5) M(-1) for 5. The recognition mechanism between compound 4 (or 5) and metal ion was discussed based on their chemical construction and the fluorescence quenching effect when they interact with each other. Competition experiments revealed that compound 4 (or 5) has a highly selective response to mercury(II) ion in aqueous solution.