The reaction of 6,7-dicyanodipyridoquinoxaline (DICNQ) with AgNO3 in a 1:1 molar ratio by solution method gave a new complex [Ag(DICNQ)2]NO3 1. Single-crystal X-ray diffraction analysis reveals that the complex crystallizes in the space group Ibca of orthorhombic system with eight formula units in a cell. Crystal data for 1: a = 15.7055(17), b = 18.411(2), c = 20.680(2)A, V = 5979.7(11)A3, Z = 8, C32Hl2AgN13O3, Mr = 734.42, Dc = 1.632 g/cm3, μ= 0.734 mm-1, F(000) = 2928, S = 1.023 and T= 293(2) K. The final R = 0.0659 and wR = 0.1927 for 2118 observed reflections with I 〉 2σ(I), and R = 0.0801 and wR = 0.2196 for all data. The complex builds up a packing structure by π-π stacking interactions and shows a luminescent feature.
Five new quaternary isostructural rare-earth sulfides, Al0.57Gd3(Si0.27Al0.73)S7 (1), Al0.55Dy3(Si0.34Al0.66)S7 (2), Al0.50Y3(Si0.50Al0.50)S7 (3), Al0.44Gd3(Si0.70Al0.30)S7 (4) and In0.33Sm3SiS7 (5), have been synthesized by facile solid-state reactions. They crystallize in the 3-D ALn3EQ7 structure type in the hexagonal chiral space group P63. The structures feature a 3-D host framework constructed by Ln-S bicapped trigonal prisms, in which the octahedral and tetrahedral interspaces are occupied by A and E atoms, respectively. The investigation of optical and magnetic properties of 4 indicates that it is a semiconductor and behaves antiferromagnetic-like interaction.
GUO ShengPing, GUO GuoCong & HUANG JinShun State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002, China
The reaction of CdCl2 with 6,7-dicyanodipyridoquinoxaline (DICNQ) by solvothermal reaction gives rise to a coordination polymer [CdCl2(DICNQ)]n 1. Single-crystal X-ray diffraction analysis reveals that the compound in space group Pbcn creates 1-D chloro-bridging chains. Crystal data for 1: a = 6.756(1), b = 35.371(6), c = 7.027(1)A , V = 1679.1(5) A^3, Z = 4.00, C16H6CdCl2N6, Mr = 465.57, Dc = 1.842 g/cm^3, μ = 1.630 mm-1, F(000) = 904, S = 1.005 and T = 293(2) K. The final R = 0.0376 and wR = 0.1029 for 1291 observed reflections with I 〉 2σ(I), and R = 0.0499 and wR = 0.1125 for all data. The 1-D chloro-bridging chains are parallel-stacked in the a and b directions, and further stabilized through π-stacking interactions, hydrogen-bonding interactions and C≡N···π interactions to generate a 3-D structure. Compound 1 displays intense bluish-green photoluminescence from the intraligand charge-transfer of the DICNQ ligand and the Cl--to-DICNQ charge-transfer mechanism which is probed by the density of states (DOS) calculations.
A new quaternary sulfide, Al0.36Sm3Ge0.98S7 1, has been prepared by a facile solidstate reaction, and its crystal structure was determined by single-crystal X-ray diffraction analysis. It crystallizes in the hexagonal space group P63 with a = 9.964(1), c = 5.768(2)A, V = 495.9(1)A^3 and Z = 2. In the crystal structure of 1, Al^3+ and Ge^4+ occupy the octahedral and tetrahedral interspaces of the 3-D main-framework constructed by SmS8 bicapped trigonal prisms, respectively. The investigation of optical and magnetic properties of 1 indicates that its optical band gap is 2.18 eV and it shows antiferromagnetic-like interaction.
Covellite CuS hexagonal nanoplatelets were prepared by a simple hydrothermal process at mild temperature, using sodium dodecyl benzene sulfonate (SDBS) as an assisting reagent. The products were characterized by X-ray powder diffraction (XRD), transmission electron microscopy (TEM) and UV-vis absorption spectroscopy. An energy-dispersive X-ray spectrometer (EDS) was used to analyze the elementary compositions of the intermediate products. A possible formation mechanism of hexagonal nanoplatelets is discussed, using TEM observations.