Synthesis,Crystal Structure and Luminescence of a Novel Cadmium(Ⅱ) Coordination Polymer with 5-Connected nov Net

A novel interesting coordination polymer,[Cd（HSSA）（2-bimb）2].3H2O（1,H3SSA = 5-sulfosalicylic acid,2-bimb = 1,2-bis（imidazol-1-ylmethyl）-benzene）,has been synthesized and structurally characterized.Compound 1 crystallizes in the monoclinic system,space group P21/n with a = 10.8653（10）,b = 19.4100（17）,c = 17.4414（17） ,β = 91.944（2）°,V = 3676.2（6） 3,Z = 4,C35H38CdN8O9S,Mr = 859.19,Dc = 1.552 g/cm3,μ = 0.717 mm-1,S = 0.999,F（000） = 1760,R = 0.0531 and wR = 0.1078.The compound features a rare three-dimensional（3D） 5-connected nov topology.In addition,compound 1 exhibits strong photoluminescent emission at room temperature.

Synthesis and Crystal Structure of a Two-dimensional Cadmium Complex Based on Terephthalate and 1-Methyl-2,2'-bibenzimidazole

The title complex, [Cd（MeHbibzim）（1,4-bdc）]n （1, MelToibzim = 1-methyl-2,2＇- bibenzimidazole, 1,4-bdc = terephthalate）, was synthesized with hydrothermal reactions. The compound crystallizes in monoclinic, space group C2/c with a = 9.822（4）, b = 18.510（7）, c = 22.372（9） A, β = 98.359（6）°, C23H16CdN4O4, Mr = 524.81, V= 4024（3） A3, Z = 8, Dc. = 1.733 g/cm3, μ（MoKa） = 1.126 mm-1, F（000） = 2096, the final R = 0.0597 and wR = 0.1374 for 3906 observed reflections （1 〉 2σ（I））. X-ray diffraction analysis reveals that the Cd atom is coordinated by two nitrogen atoms from the chelating MeHbibzim and three carboxyl oxygen atoms from three terephthalate ligands, thus forming a distorted square pyramidal coordination sphere, [CdN2O3]. Every two Cd atoms are linked together via two carboxyl groups into a dinuclear unit with Cd...Cd separation of 3.806（4） A. The dinuclear building units are linked by terephthalate ligands into two-dimensional layers, which are further aggregated into a 3D framework via hydrogen bonding interactions.

Hydrothermal Synthesis and Crystal Structure of a Cadmium(Ⅱ) Polymer with One-dimensional Chain Structure:[Cd(MDPPz)(BDC)(H_2O)]_n

A metal-organic coordination compound formulated as [Cd（MDPPz）（BDC）（H2O）], 1 （MDPPz = 11-methyldipyrido[3,2-a：2′,3′-c]phenazine, BDC = 1,4-benzenedicarboxylate）has been hydrothermally synthesized and structurally characterized by elemental analysis, IR spectrum, fluorescence spectrum and single-crystal X-ray diffraction. The title compound crystallizes in the monoclinic system, space group C2/c, with a = 30.673（8）, b = 9.623（3）, c = 20.784（6） A, β = 98.646（3）°, V = 6065（3） A3, C27H17CdN4O5, Mr= 589.85, Dc = 1.292 g/cm^3, μ（MoKα） = 0.757 mm-1, F（000） = 2360, Z = 8, the fmal R = 0.0381 and wR = 0.0855 for 4191 observed reflections （I〉 2σ（Ⅰ））. 1 exhibits blue fluorescence property at room temperature.

Crystal Structures,Luminescent Properties and Hirshfeld Surface Analyses of Zn(Ⅱ)and Cd(Ⅱ)Compounds Based on 1-(2-Carboxyl-phenyl)-3-(pyridin-2-yl)pyrazole

Two compounds,[Zn2（Hcppp）2（cppp）2（H2O）2]·2 NO3·6 H2O（1） and [Cd（Hcppp）2Cl2]· 3H2O（2）（Hcppp = 1-（2-carboxyl-phenyl）-3-（pyridin-2-yl）pyrazole）,are synthesized and characterized by IR,TGA and X-ray single-crystal/powder diffraction.Compound 1 crystallizes in monoclinic system,space group P21/c with a = 9.894（2）,b = 15.856（3）,c = 20.430（4） A,β = 101.70（3）°,V = 3138.5（11） A3,Z = 2,Mr = 1457.94,Dc = 1.543 g/cm^3,F（000） = 1504,R = 0.0278 and wR = 0.0749 for 6157 observed reflections（I 〉 2σ（I））.Compound 2 crystallizes in triclinic system,space group P1 with a = 9.1424（4）,b = 11.6427（5）,c = 16.1345（7） A,α = 102.6430（10）°,β = 95.4530（10）°,γ = 104.0060（10）°,V = 1605.94（12） A3,Z = 2,Mr = 767.88,Dc = 1.588 g/cm^3,F（000） = 776,R = 0.0307 and wR = 0.0764 for 6275 observed reflections（I 〉 2σ（I））.Compound 1 exhibits a binuclear structure while compound 2 shows a mononuclear structure.In compound 1,two cppp-ligands display the μ2-kN,N′：k O and two Hcppp ligands show the μ1-kN,N′ coordination modes.However,two Hcppp ligands connect one Cd（Ⅱ） cation and exhibit the μ1-kN,N′ binding mode in compound 2.The compounds are both studied using Hirshfeld surface analyses and 2D fingerprint plots.The luminescent properties are also discussed.

Effect of mechanical anisotropy on material removal rate and surface quality during polishing CdZnTe wafers

The mechanical characters of CdZnTe crystal were investigated by nanoscratch tests, and the effects of mechanical anisotropy on the material removal rate and surface quality were studied by polishing tests. There is a peak of frictional coefficient at the early stage of scratch, and increasing the vertical force will result in the increase of peak value correspondingly. The fluctuation phenomenon of frictional coefficient is generated at high vertical force. The lateral forces show the apparent twofold and threefold symmetries on （110） and （111） planes, respectively. To obtain high surface quality, low polishing pressure and hard direction （〈 T10 〉 directions on （110） plane and 〈 112 〉 directions on （111） plane） should be selected, and to achieve high material removal rate, high polishing pressure and soft direction （〈001〉 directions on （110） plane and 〈 121 〉 directions on （111） plane） should be selected.

Construction and Photoluminescence Properties of Zn(Ⅱ)/Cd(Ⅱ) Complexes with 4-Amino-3,5-propyl-1,2,4-triazole Ligand

Reaction of ZnCI2 and 4-amino-3,5-propyl-1,2,4-triazole （dpatrz） or CdC12, NaN3 and dpatrz, in aqueous solution at room temperature yields two neutral clusters： a dinuclear complex [Zn2（dpatrz）2Ch] （I） and a linear trinuclear complex, [Cd3（dpatrz）4（N3）2Cl4] （II）. Both complexes have been characterized by X-ray single-crystal diffraction, powder XRD, IR, elemental analysis, TG and fluorescence analysis. Complex I crystallizes in orthorhombic, space group Pbca with a = 11.865（2）, b = 14.464（3）, c = 15.985（3） A, V= 2743.4（9） A3, Z = 4, C16H32NsCI4Zn2, Mr = 609.4, Dc = 1.475 g.cm3, p = 2.16 mm-1, F（000） = 1248, GOOF = 1.091, the final R = 0.0295 and wR = 0.0665 for 1999 observed reflections （I 〉 2a（/））. Complex Ⅱcrystallizes in monoclinic, space group P2/c with a = 11.408（2）, b = 15.211（3）, c = 18.152（6） A, fl = 123.75（2）°, V = 2619.1（1） A3, Z = 2, C32H64N22ClaCd3, Mr = 1236.05, Dc = 1.567 g.cm3, p = 1.46 mm-1, F（000） = 1244, GOOF = 1.042, the final R = 0.0444 and wR = 0.0913 for 3466 observed reflections （I 〉 2a（/））. The analysis of X-ray revealed that both structures lie about the inversion centers： complex I adopts two pl,2-triazole bridges linking two Zn（II） ions and II forms a linear trinuclear structure with four μ1,2-triazoles and two/μIA-N3 bridging modes. There are different coordinated geometries for three Cd（II） ions in Ⅱ： one is coordinated with an octahedral environment, and the other two are distorted tetragonal pyramids （r = 0.34）. The hydrogen bonds of C-H...C1 and N-H...C1 lead to the discretes into a 3D supramolecular network in both compounds. The thermal stabilities and photoluminescence behaviors of them were also studied.

Growth and optical properties of Cr^(3+)-doped CdWO_4 single crystals

A high-quality Cr 3＋：CdWO4 single crystal at a size of approximatelyΦ25×80 mm is grown using the Bridgman method with CdO,WO3,and Cr2O3 as raw materials and their molar ratio of 100：100：0.5.The temperature gradient of solid-liquid interface at growth is approximately 50？C/cm and the growth rate is 0.05 mm/h.The X-ray diffraction（XRD）,absorption,excitation,and emission spectra of different parts of the as-grown and O2-annealed crystals are investigated.Two strong broad optical absorption bands of about 472 and 708 nm are observed,and they are associated with the transitions 4 A2→ 4 T1 and 4 A2→ 4 T2.The weak 4 T2→ 2 E transition（the R-line）at 632 nm is also observed.The crystal-field parameter Dq and the Racah parameters B and C are estimated to be 1 412.4,776.8,and 3 427.6 cm？ 1,respectively,according to the absorption spectra and crystal-splitting theory.A broadband fluorescence at about 1 000 nm due to 4 T2→ 4 A2 transition is produced by exciting the samples at 675 nm.After being annealed in an O2 atmosphere,the crystals become more transparent,while the effective light absorption of Cr 3＋ ions is evidently enhanced and the emission intensity is also strengthened due to the reduction of oxygen vacancies in the CdWO4 crystal after annealing.

Intensifying process of polarization effect within pixellated CdZnTe detectors for X-ray imaging

The intensifying process of polarization effect at room temperature in a pixellated Cadmium zinc telluride （CdZnTe） monolithic detector is studied. The process is attributed to the increase in build up space charges in the CdZnTe crystal, which causes an expansion of the space charge region under the irradiated area. The simulations of electric potential distributions indicate that the distorted electric potential due to the high X-ray flux is significantly changed and even deteriorated due to increasing space charges within the irradiated volume. An agreement between the space charge distribution and electric potential is discussed.