Two iodoargentate hybrids templated by viologen or viologen-like cations, i.e. [MV（Ag2I4）]n （1） and [MBYP（AgI2）]n （2）, （MV^2＋ = methyl viologen, MBYP^＋ = 1-methyl-2,2＇- bipyridine） have been synthesized in polar organic solvents. （Ag2I4）n^2- and （AgI2）n^2- chains in both compounds were constructed from edge-sharing of normal and distorted AgI4 tetrahedra, and a 2-D supramolecular layer based on C–H…I hydrogen bond was observed in 1. The band gaps of 1.54 and 2.67 eV indicated their semiconductor nature. Their band gap difference was led by different hydrogen bond donors in MV^2＋ and MBYP^＋, which result in more diffused p-π＊ antibonding orbitals in MV^2＋.
Due to the high affinity between dithiocarbamate （DTC） and Hg2＋, a fluorescent probe based on squaraine chromophore with DTC side arm for Hg2＋ via coordination induced deaggregation signaling has been designed and synthesized. Squaraine has a high tendency to aggregate in aqueous solution, and such self-aggregation usually results in a dramatic absorption spectral broadening with fluorescence emission quenching. The combination of the DTC side arm of the probe with Hg2＋ induces steric hindrance, leading to the deaggregation of the dye complex, companying with a fluorescence emission restoration. In EtOH-H2O （20：80, v/v） solution, this ＂turn on＂ fluorescent probe has high selectivity and sensitivity toward Hg2＋ over other metal ions, and the limit of detection for Hg2＋ was estimated as 2.19 × 10^-8 mol/L by 3σ/k.
Shuang-Yong LinHui-Jun ZhuWen-Jian XuGui-Mei WangNan-Yan Fu
A new bismuth（III） iodide inorganic/organic hybrid containing larger heterocyclic conjugated organic ligand, [（dppz）2Bi2I6]·2DMF （1） （dppz = dipyrido[3,2-a：2＇,3＇-c]phenazine）, has been synthesized by solution process and structurally determined by X-ray diffraction method. 1 crystallizes in triclinic, space group Pī with Mr= 1844.08, α = 9.215（5）, b = 11.488（6）, c = 12.424（9） ？, α = 106.66（2）, β = 90.84（2）, γ = 92.34（2）°, V = 1258.5（13） ？3, Z = 1, Dc = 2.433 g/cm3, F（000） = 830, μ（MoKα） = 10.702 mm–1, the final R = 0.0834 and wR = 0.1947 for 2749 observed reflections with I 〉 2σ（I）. 1 consists of a dimeric structure [（dppz）2Bi2I6], in which two [（dppz）BiI3] fragments are bridged by a pair of iodine atoms. Hydrogen bonds and π···π stacking interactions contribute to the structural extension and stabilization. Experimental band gap of about 2.13 eV indicates its semiconductor nature. The optical absorption spectrum and electronic structure were also discussed.
Density functional theory （DFT） calculations are employed to investigate the structural and electronic properties of MoS6^- and MoS6 clusters. Generalized Koopmans＇ theorem is applied to predict the vertical detachment energies and simulate the photoelectron spectra （PES）. Intriguingly, the terminal S2-, polysulfide S2^2- and S3^2- ligands simultaneously emerge in the lowest-energy structure of MoS6. Molecular orbital analyses are performed to analyze the chemical bonding in MoS6^-/0 clusters and elucidate their structural and electronic properties.
