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A new compound NaIn 3 S 5 has been obtained in the CaS–In 2 S 3 /NaBr system via a reactive flux method. NaIn 3 S 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 3 S 5 structure is characterized by a three dimensional framework consisting of interconnected tripartite-octahedral [ In 3 S 8 ] ∞ 1 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 3 S 5 . Electronic structure calculation by the CASTEP code not only indicates that NaIn 3 S 5 is an indirect band gap semiconductor, but also explains why its experimental band gap is close to that of β-In 2 S 3 . [ABSTRACT FROM AUTHOR]

Abstract: In our investigation of non-centrosymmetric rare earth sulfides in the La3AgSnS7/KBr, LaAlGeS5/NaBr, HoAlGeS5/KBr, ErAlGeS5/NaBr, Er3AgGeS7/KBr and La3NaSnS7/NaBr systems, five compounds belonging to the R6B2C2Q14 family have been obtained. These compounds crystallize in the P63 space group, and the crystal data are as follows—La3AgSnS7: a =10.3780(15)Å, c =5.9900(12)Å, Z =2; La3Ge0.25GeS7: a =10.2970(15)Å, c =5.8120(12)Å, Z =2; Ho3Ge0.272(10)GeS7: a =9.6480(14)Å, c =5.7920(12)Å, Z =2; Er3Ge0.330(10)GeS7: a =9.5930(14)Å, c =5.8490(12)Å, Z =2; La3Sn0.25SnS7: a =10.2770(15)Å, c =6.0030(12)Å, Z =2. Single-crystal analysis indicated that the crystal structures consist of three types of building block: LnS n , MS4, and AgS3 (for La3AgSnS7) or MS6 units (for Ln3M x MS7, Ln=La, Ho, Er; M=Ge, Sn; 1/4≤ x ≤1/2), as any other compounds belonging to the R6B2C2Q14 family. Ln3M x MS7 (Ln=La, Ho, Er; M=Ge, Sn; 1/4≤ x ≤1/2) are deficient compounds with the B sites occupied partly by M(II), and/or M(IV). [Copyright &y& Elsevier]

Abstract: High-quality single crystals of RbInS2, CsInS2 were isolated from the halide flux as a major phase of the repeated fusion of CaS and In2S3 followed by slow cooling. RbInS2 and CsInS2 are practically isostructural with KInS2. RbInS2: C2/c, a =11.071(6)Å, b =11.068(1)Å, c =15.610(7)Å, β =100.36(3)°, V =1882(2)Å3, Z =16, d x =3.74g/cm3, R =6.38%, R w =6.42%. CsInS2: C2/c, a =11.197(3)Å, b =11.158(3)Å, c =16.358(4)Å, β =99.92(2)°, V =2013(2)Å3, Z =16, d x =4.12g/cm3, R =5.60%, R w =6.20%. The AInS2 (A=Rb, Cs) structure is characterized by double layers of vertex-sharing [In4S10] units that each consists of four [InS4] polyhedra. The charge-balancing alkali-metal cations are stuffed into the channels created by the packing of these anionic [In4S10] blocks. The optical reflectance measurements show a band gap of 3.3eV for RbInS2 and 3.4eV for CsInS2, suggesting that both are semiconductors. [Copyright &y& Elsevier]

Two new quaternary rare-earth chalcogenides, KHo2CuSe4 and KEr2CuSe4, were synthesized from the reactions of elements and binary selenides via a two-step flux technique. Single-crystal X-ray diffraction analyses indicate that both compounds crystallize in the orthorhombic KGd2CuS4 structure type with the space group Cmcm (No. 63) and Z=4. The indexed lattice constants and final R factors are as follows: KEr2CuSe4, a=4.061(1) A˚, b=13.748(4) A˚, c=14.150(3) A˚, V=790.1(3) A˚3, R=0.040, Rw=0.051; KHo2CuSe4, a=4.090(2) A˚, b=13.829(3) A˚, c=14.234(5) A˚, V=805.2(6) A˚3, R=0.046, Rw=0.052. The KLn2CuSe4 structure consists of three different building blocks: KSe6 trigonal prisms, LnSe6 octahedra and CuSe4 tetrahedra. The structure is characterized by edge-shared double octahedral Ln2Se10 units that are condensed into infinite chains along the a axis via trans-edge sharing. These double chains are further linked into a puckered layer in the a–b plane via edge-sharing and another corrugated layer in the a–c plane via corner-sharing with neighboring chains. Consequently, the structure actually forms a three-dimensional framework with additional feature from vertex-sharing CuSe4 tetrahedral chains. The K+ cations, located at the cavities defined by Se atoms, are filled in the channels along the a direction to provide appropriate Coulomb traps. Infrared spectra for both compounds show no absorption peaks between 4000 and 500 cm−1, which suggests an optical transparency in the long-wavelength infrared region. [Copyright &y& Elsevier]

Reactions of syn-2pyridinealdoxime (HL) with divalent metal salts in a mixed ethanol/acetonitrile solution resulted in two new metal complexes with different structures. The structure of the zinc complex, Zn4(L)4Cl2(μ3-OH)2 · 4CH3CN (1) features a 12-metallocrown-4 unit. The syn-2pyridinealdoxime ligand adopts a tridentate chelating and bridging coordination mode. The structure of Mn(HL)(SO4)(H2O) (2) contains a double chain along the b-axis, in which the Mn(II) cations are bridged by μ3-SO42− anions. The syn-2pyridinealdoxime ligand chelates with a Mn(II) ion using its two nitrogen atoms. These double chains are further interconnected into a 2D layer parallel to the ab-plane via hydrogen bonds between aqua ligands and the non-coordinated sulfate oxygen atoms. Results of magnetic measurements of complex 2 indicate that there is weak Curie–Weiss behavior with θ=−10(1) K indicating predominant antiferromagnetic interaction between the Mn(II) ions. Indication for magnetic low-dimensional magnetism could not be detected. [Copyright &y& Elsevier]

Three new divalent transitional metal succinates with an additional bipy (bipy=4,4′-bipyridine) ligand have been synthesized by hydrothermal reactions and structurally determined. The structure of [Cu(C4H4O4)(bipy)(H2O)2] · 2H2O (1) features a 3D open framework formed by 1D [Cu(bipy)]2+ chains along the diagonal axis of b and -c that are interconnected by Cu(C4H4O4) helixes along the c-axis. The lattice water molecules are located at the cavities of the framework. In Zn(C4H4O4)(bipy) (2), each zinc cation is octahedrally coordinated by two chelate carboxylate groups from two succinates and 2 N atoms from two bipy molecules, and the ZnO4N2 octahedra are interconnected by bridging succinate ligands into a 1D chain along the 〈0 1 1〉 direction. Such chains are further linked into a 〈0 1 1〉 layer via π–π stacking interaction between the pyridine rings. In [Co(bipy)(H2O)4] (C4H4O4) · 4H2O (3), each pair of octahedral cobalt(II) ions is bridged by a bipy ligand, resulting in a 1D [Co(bipy)(H2O)4]2+ chain, and the succinate ligands and lattice water molecules are sandwiched between two [Co(bipy)(H2O)4]2+ chains to form a 〈0 1 1〉 layer via hydrogen bonding. The layers are further interconnected into a 3D network via hydrogen bonds among carboxylate oxygen atoms, aqua ligands, and lattice water molecules. [Copyright &y& Elsevier]