[en] The tetranuclear complex reported here shows luminescence features by using the electronic emission spectrum in the DMF solution at room temperature as given in Figure 3. The title complex shows high-energy emission at ca. 444 nm, which is assigned to originate predominantly from ligand-to-metal charge-transfer LMCT [NO_3"- → Ag]. Though the polynuclear d"1"0 metal complexes were discovered a long time ago, the study on photophysical and photochemical characters of polynuclear d"1"0 metal complexes has attracted much attention and developed rapidly in the last decades of last century. With the development of the computer hardware and software, theoretical studies on polynuclear d"1"0 metal systems can be more accurate and efficient. However, there are a number of difficulties to be overcome in the design of this kind of complexes with bridging and ancillary liagnds, such as bis(diphenylphosphino) methane (dppm). Dppm (Ph_2PCH_2PPh_2) is not only a very excellent bridging ligand for bonding two metal atoms to form stable eight-numbered ring [M(μ_2-dppm)_2M'] which are well known with many structural and applied studies, but also sometimes act as mono-dentate ligand. Dppm can also form a number of trinuclear complexes [M_3(μ-dppm)_3] with late transition metal ions, especially, d"1"0 metals ions. When M = Cu(I) or Ag(I), a capping ligand always accompanies the [M_3(μ-dppm)_3] core by the coordination mode of μ3-bridging.

[en] Three new diamond-like compounds with the formula of I₂−II−IV−VI₄ (I=Cu; II=Mg; IV=Si, Ge; VI=S, Se) have been synthesized via traditional high-temperature solid-state reactions and structurally characterized by single crystal X-ray diffraction analysis. All the three compounds crystallize in the space group Pmn2₁ in the wurtzite-type superstructure with a=7.563(4), b=6.448(3), c=6.179(3) Å, Z=2 for Cu₂MgSiS₄ (1); a=7.953(5), b=6.797(4), c=6.507(4) Å, Z=2 for Cu₂MgGeS₄ (2); a=7.638(4), b=6.515(4), c=6.225(3) Å, Z=2 for Cu₂MgSiSe₄ (3). All atoms in these compounds are tetrahedrally coordinated. Optical diffuse reflectance UV/Vis/NIR spectra indicate that compounds 1 and 2 have the band gaps of 3.20 and 2.36 eV, respectively. Electronic structure calculations using the CASTEP code indicate that they are all direct band gap compounds. - Graphical abstract: Three new diamond-like compounds, Cu₂MgSiS₄, Cu₂MgGeS₄, and Cu₂MgSiSe₄, have been synthesized. All the three compounds crystallize in the space group Pmn2₁ and all atoms are tetrahedrally coordinated. Highlights: • Three new diamond-like compounds Cu₂MgSiS₄, Cu₂MgGeS₄ and Cu₂MgSiSe₄ have been synthesized. • All ions are tetrahedrally coordinated. • Electronic structure calculations indicate that they are all direct band gap compounds

[en] Graphical abstract: - Highlights: • A new compound NaIn_3S_5 has been obtained in the CaS–In_2S_3/NaBr system. • NaIn_3S_5 crystallizes in a new structure type. • The experimental band gap is 2.18 eV for NaIn_3S_5. • The electronic structure of NaIn_3S_5 has been calculated. - Abstract: A new compound NaIn_3S_5 has been obtained in the CaS–In_2S_3/NaBr system via a reactive flux method. NaIn_3S_5 crystallizes in the orthorhombic space group Pbam (No. 55) with a = 12.4963(8) Å, b = 16.0811(10) Å, c = 3.8041(2) Å, and Z = 4. The NaIn_3S_5 structure is characterized by a three dimensional framework consisting of interconnected tripartite-octahedral "1_∞[In_3S_8] infinite chains, with Na"+ cations residing in the one-dimensional channels along the c direction defined by S(1), S(2), S(3) and S(4) atoms. The optical reflectance measurement shows a band gap of 2.18 eV for NaIn_3S_5. Electronic structure calculation by the CASTEP code not only indicates that NaIn_3S_5 is an indirect band gap semiconductor, but also explains why its experimental band gap is close to that of β-In_2S_3

[en] A large nonlinear optical (NLO) coefficient and a wide band gap are two crucial but contradictory parameters that are difficult to achieve simultaneously in a single infrared (IR) NLO compound. A salt-inclusion chalcogenide (SIC), Li[LiCs${}_2$Cl][Ga${}_3$S${}_6$] (1), was prepared that presents a nanosized tunnel framework constructed from monotype chalcogenide tetrahedra. Highly oriented covalent GaS${}_4$ tetrahedra in the host lead to a moderate second harmonic generation response (0.7 AgGaS${}_2$), and ionic guests effectively broaden the band gap to the widest value (4.18 eV) among all IR NLO chalcogenides, thereby achieving a remarkable balance between NLO efficiency and band gap. (© 2019 Wiley‐VCH Verlag GmbH and Co. KGaA, Weinheim)

[en] The first indiumsilicate oxysulfide Ba_2In_2Si_3O_1_0S (1) was obtained by an alkali polychalcogenide flux method through a high-temperature solid-state reaction. It crystallizes in the non-centrosymmetric space group Pca2_1 (No. 29), with a = 23.060(6), b = 5.2954(6), c = 8.779(2) Aa, and Z = 4. Its three-dimensional (3D) framework is constructed from one-dimensional (1D) infinite _∞"1[In_2O_7S_2_/_2] double octahedral chains bridged by corner-sharing Si tetrahedral trimers [Si_3O_1_0]"8"-, yielding a 3D framework with the channels filled with Ba"2"+ cations along the b direction. It is unprecedented in that the two distorted indium octahedra in 1 face-share to form a [In_2O_7S_2] dimer in indium oxides and oxide chalcogenides. (Copyright copyright 2016 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

[en] We evaluated the individual atom contributions to the second harmonic generation (SHG) coefficients of LiCs₂PO₄ (LCPO) by introducing the partial response functionals on the basis of first principles calculations. The SHG response of LCPO is dominated by the metal-cation-centered groups CsO₆ and LiO₄, not by the nonmetal-cation-centered groups PO₄ expected from the existing models and theories. The SHG coefficients of LCPO are determined mainly by the occupied orbitals O 2p and Cs 5p as well as by the unoccupied orbitals Cs 5d and Li 2p. For the SHG response of a material, the polarizable atomic orbitals of the occupied and the unoccupied states are both important. (copyright 2018 Wiley-VCH Verlag GmbH and Co. KGaA, Weinheim)

[en] Three new ternary rare-earth zirconium chalcogenides, Ce_2ZrSe_5 (1), Pr_2ZrSe_5 (2) and Nd_2ZrSe_5 (3), have been synthesized by a facile solid-state route with boron as the reducing reagent. They crystallize in the space group Pnma of the orthorhombic system, belonging to the U_3Se_5 structure type. Their 3-D structures are constructed by parallel polyanionic {[ZrSe_5]"6"–}_n chains and LnSe_8 bicapped trigonal prisms. The magnetic susceptibilities' data indicate their antiferromagnetic-like behavior without magnetic order down to 2 K. The structural relationships among several similar structures are discussed, together with the lanthanide contraction in the Ln_2ZrSe_5 system. - Highlights: • Single-crystals of ternary selenides Ln_2ZrSe_5 (Ln = Ce–Nd) were synthesized. • Magnetic susceptibility data were studied. • Comparison between Ln_2ZrSe_5 and related compounds' crystal structures. • Lanthanide contraction among Ln_2ZrSe_5 (Ln = La–Nd, Sm, Gd and Tb).

[en] Highlights: • An acentric ferroelectric MOF has been successfully synthesized. • The structure of 1 is composed of a 2D inorganic Pb–O–Pb layer and two μ₆-TDC^2- anions pillars.. • 1 is the first example of ferroelectric H₂TDC-based MOF. - Abstract: Self-assembly reaction of Pb(NO₃)₂ with thiophene-2, 5-dicarboxylic acid (H₂TDC) led to an acentric three-dimensional (3D) metal-organic framework under solvothermal conditions, namely, Pb(TDC) (1). The 3D framework of 1 is a pillared-layer structure with the I²O¹ type which is composed of a 2D inorganic Pb–O–Pb substructural layer and two independent μ₆-TDC^2- anions pillars. This 3D framework shows a six-connected pcu topological net according to the topological analysis. Compound 1 crystallizes in an acentric space group and displays potential ferroelectric property which could be due to the swing of the thiophene rings. The remnant polarization (P_r), coercive field (E_c) and saturation spontaneous polarization (P_s) of 1 are ca. 0.034 μC cm⁻², 15.7 kV cm⁻¹ and 0.0997 μC cm⁻², respectively. Among the H₂TDC-based MOFs, the present compound is the first example which shows ferroelectric property. In addition, 1 also exhibits photoluminescent property which can be attributed to ligand-to-metal charge transfer.

[en] A novel open-framework cadmium selenite bromide, [Cd₁₀(SeO₃)₈Br₄]·HBr·H₂O (1), has been obtained by a solid-state reaction at 450 °C, and the structure has been determined by single-crystal X-ray diffraction analysis. Compound 1 crystallizes in Pbcm of the orthorhombic system: a=10.882(3), b=16.275(5), c=18.728(6) Å, V=3317(2) ų, R1/wR2=0.0411/0.0659. Compound 1 is characteristic of a novel 3-D open-framework structure, composing _∞²[CdSeO₃] layers and the pillars of edge-shared CdO₃Br₂ square pyramids. The lattice water molecules and the HBr molecules locate in the voids of the framework. Optical absorption spectrum of 1 reveals the presence of an optical gap of 1.65 eV. Solid-state photoluminescent study indicates that compound 1 exhibits strong violet emission. TG–DSC measurement shows that compound 1 is thermally stable up to 200 °C. - Graphical abstract: A metal selenite halide has been synthesized and features a 3-D open-framework structure, composing edge-shared CdO₈ decahedra and pillars of edge-sharing pentahedra. UV–vis, TG–DSC and luminescent measurements are also reported. Highlights: • This paper reports a novel cadmium selenite bromide obtained by an intermediate-temperature solid-state reaction. • The title compound is characteristic of a novel 3-D open-framework structure, composing _∞²[CdSeO₃] layers and the pillars of edge-shared CdO₃Br₂ square pyramids. • The title compound is thermally stable up to 200 °C. • The title compound has an optical gap of 1.65 eV and exhibits strong violet emission

[en] Different composition, thickness and structure of CoNi thin films supported on glassy carbon were prepared by electrochemical codeposition. Potential step method was applied to prepare CoNi thin films with different composition which was controlled by varying the concentration ratio of Co²⁺/Ni²⁺ (x:y) in the deposition solution, thus this type of CoNi thin film was defined as CoNi(x:y). Nevertheless, CoNi thin films with different thickness and structure (denoted as CoNi(n)) were synthesized in a fixed Co²⁺/Ni²⁺ solution under cyclic voltammetric conditions by varying the cyclic numbers (n) within a defined potential range. AES and EDS analysis revealed that the atomic ratio of Co/Ni in the film (including both outer and inner layer) was in good accordance with the initial Co²⁺/Ni²⁺ ratio. XRD investigation indicated that the CoNi(20:0) and CoNi(15:5) thin films were hexagonal closed-packed (hcp) structure, however, the CoNi(10:10), CoNi(5:15) and CoNi(0:20) thin films were face centered cubic (fcc) structure. SEM studies demonstrated that the CoNi(x:y) thin films were uniformly composed of irregular nanoparticles. In the case of CoNi(n), with n increasing, the structure of nanoparticles inside the CoNi thin films underwent a transition from imperfectly spherical particles to multiform particles, and finally to irregular polyhedral particles, accompany with an increase of average size. In situ FTIR reflection spectroscopic studies demonstrated that the mainly chemisorbed CO species (COad) on CoNi(x:y) surfaces were transferred from linearly bonded CO (CO_L) to bridge bonded CO (CO_B) as a function of the content of Ni and the crystal phase structure of CoNi thin films. CoNi(x:y) and CoNi(n) thin films all exhibited anomalous IR properties, corresponding respectively to abnormal IR effects (AIREs), Fano-like IR effects and surface-enhanced IR absorption effects. AIREs characterized mostly with inversion of IR band was found on CoNi(x:y), CoNi(4), CoNi(8) thin films which were dominated by irregular or imperfectly spherical particles. Fano-like IR bands with positive-going peak on the lower wavenumbers side were observed in cases of CO adsorbed on CoNi thin films composed mainly of multiform nanoparticles, typically on CoNi(25) thin film. IR features were finally changed into surface-enhanced IR absorption as CO adsorbed on the CoNi(50) thin film, i.e., the CoNi thin film was dominated by smooth irregular polyhedral particles