Perowskit‐Nanokristalle CsPbX3‐Nanokristalle (X=Cl, Br, I) wurden hergestellt, die gleichförmig rote, grüne und blaue Photolumineszenz‐Quantenausbeuten ergeben. S. Baitalik, N. Pradhan et al. erläutern die Chemie in ihrer Zuschrift auf S. 5608.

A series of heteroleptic tridentate ruthenium(II) complexes of composition [(H(2)pbbzim)Ru(tpy-X)](PF(6))(2) (1-7), where H(2)pbbzim = 2,6-bis(benzimidazole-2-yl)pyridine and tpy-X = 4'-substituted terpyridine ligands with X = H, p-methyl phenyl (PhCH(3)), p-bromomethylphenyl (PhCH(2)Br), p-dibromomethylphenyl (PhCHBr(2)), p-cyanomethylphenyl (PhCH(2)CN), p-triphenylphosphonium methylphenyl bromide (PhCH(2)PPh(3)Br), and 4'-phenylformyl (PhCHO) groups, has been synthesized and characterized by using standard analytical and spectroscopic techniques. These compounds were designed to increase the excited-state lifetime of ruthenium(II) bisterpyridine-type complexes. The X-ray crystal structure of a representative compound 2, which crystallized with monoclinic space group P2(1)/c, has been determined. The absorption spectra, redox behavior, and luminescence properties of the ruthenium(II) complexes have been thoroughly investigated. All of the complexes display moderately strong luminescence at room temperature with lifetimes in the range of 10-58 ns. Correlations have been obtained for the Hammett sigma(p) parameter with their MLCT emission energies, lifetimes, redox potentials, proton NMR chemical shifts, etc. The anion binding properties of all the complexes as well as the parent ligand H(2)pbbzim have been studied in acetonitrile using absorption, emission, and (1)H NMR spectral studies, and it has been observed that the metalloreceptors act as sensors for F(-), AcO(-), and to some extent H(2)PO(4)(-). At a relatively lower concentration of anions, a 1:1 H-bonded adduct is formed; however, in the presence of an excess of anions, stepwise deprotonation of the two benzimidazole N-H fragments occurs, an event which is signaled by the development of vivid colors visible with the naked eye. The receptor-anion binding constants have been evaluated. Cyclic voltammetric (CV) measurements carried out in acetonitrile-dimethylformamide (9:1) provided evidence in favor of anion (F(-), AcO(-)) concentration dependent electrochemical responses, enabling 1 - 7 to act as suitable electrochemical sensors for F(-) and AcO(-) ions.

Doping Mn­(II) in inorganic Ruddlesden–Popper phase Cs2PbCl2I2 perovskite nanoplatelets is reported. The host nanostructures were prepared with a calculative protocol taking the exact required composition of Cs­(I) and Pb­(II) and injecting the preformed mixed oleylammonium chlorides and iodides at optimized reaction temperature. Reactions were optimized with various halides and their mixtures, but the stable phase of the Cs2PbX4 system was obtained only for the chloride–iodide mixed-halide system. Introduction of Mn­(II) along with Pb­(II), resulted in successful light-emitting doped nanocrystals. Measuring the photoluminescence and the decay lifetimes at room and liquid nitrogen temperatures, the variations in the excitonic, self-trapped, and Mn dopant emission properties were compared with those of the chalcogenide and perovskite nanocrystals.

In this paper we have utilized a heteroditopic polypyridyl− imidazole system 4′-[4-(4,5-dipyridin-2-yl-1H-imidazol-2-yl)-phenyl]-[2,2′;6′,2″]terpyridine (tpy-Hbzim-dipy), wherein the terpyridine moiety has been utilized as the cation binding site and the imidazole motif as the anion binding site. This system is an efficient deep-blue emitter in chloroform with Commission Internationale de L'Eclairage (CIE) coordinates of 0.14 and 0.06. On the basis of the response profiles in terms of absorption or emission intensity and wavelength toward selected anions and cations, we developed a molecular system which can mimic sequential Boolean logic functions capable of integrating into a "Writing−Reading−Erasing−Reading" combinational circuit. In this work, we also examined the effect of selective anions and cations on the optical properties of the receptor by means of computational (DFT and TD-DFT) studies.

A mixed-ligand monometallic ruthenium(ii) complex of composition [(bipy)2Ru(tpy-Hbzim-dipy)](ClO4)2 (), where tpy-Hbzim-dipy = 4'-[4-(4,5-di-pyridin-2-yl-1H-imidazol-2-yl)-phenyl]-[2,2';6',2'']terpyridine and bipy = 2,2'-bipyridine has been synthesized and characterized using standard analytical and spectroscopic techniques including X-ray crystallography. The complex displays very intense, ligand centered absorption bands in the UV and moderately intense MLCT bands in the visible region. On excitation at the MLCT bands, the complex exhibits strong luminescence at room temperature with lifetimes in the range of 116-257 ns, depending upon the nature of the solvents. The complex is found to undergo one reversible oxidation in the positive potential window (0 to +1.8 V) and two successive quasi-reversible reductions in the negative potential window (0 to -2.0 V). Both anion and cation binding properties of the receptor were thoroughly investigated in acetonitrile solution using (1)H NMR, absorption, steady state and time-resolved emission spectral studies and by cyclic voltammetry. The anion sensing studies revealed that the receptor acts as a "turn on" luminescence sensor for H2PO4(-) and HSO4(-) ions, and as a "turn off" sensor for F(-) and AcO(-) ions. It is evident that in the presence of excess F(-) and AcO(-) ions, deprotonation of the imidazole N-H fragment of the receptor occurs, an event which is signaled by the change of color from orange yellow to red visible to the naked eye. On the other hand, the probable mode of interaction of the receptors with H2PO4(-) and HSO4(-) ions is through hydrogen bonding interaction. The cation-sensing properties showed that the receptor was found to exhibit a colorimetric sensing ability that was highly selective for Fe(2+), as evidenced by the distinct color change from yellow orange to deep red-violet to the naked eye over the other cations studied (Mn(2+), Fe(3+), Co(2+), Ni(2+), Cu(2+), Zn(2+), Cd(2+), and Hg(2+)).