[Synthesis and Fluorescence Properties of Rare Earth Ions Co-Doped CaMoO(4)].

In this paper, a series of CaMoO4 phosphor co-doped rare earth ions were prepared with chemistry co-precipitation method. The concentration of Pr(3+)/Tb(3+) and temperature had obvious influence on the luminescent properties. The crystal structures and spectrum characteristics of the samples were identified with X-ray powder diffraction (XRD) and fluorescence spectrophotometer (PL). According to XRD analysis, the main diffraction peaks of samples are consistent with the standard card (JCPDS 29-0351) of the diffraction peak data. This showed doped rare earth ions did not change matrix lattice structure. The emission spectrum excited by 275 nm exhibit sharp lines peaking at 488, 560, 621 and 560 nm assigned to the (3)P(0)­(3)H(4), (3)P(0)­(3)H(5)，(1)D(2)­(3)H(4) and (3)P(0)­(3)F(2) transitions of the Pr(3+) ions. The intensity of fluorescence reached the strongest when the concentration of the doping amount was 3%. The optimum calcination temperatures of CaMoO(4)∶0.03Pr(3+) and CaMoO(4)∶0.05Tb(3+) were 800 and 600 ℃. Furthermore, the intensity of excitation spectra and emission spectra are dependent on the concentration of the doping amount. The emission spectra intensities of CaMoO(4)∶Pr(3+) phosphors decrease and CaMoO(4)∶Tb(3+) phosphors firstly increase and then decrease because of concentration quenching effect with increasing Pr(3+) and Tb(3+) concentration. In addition, the luminescence properties of Pr(3+) ion in CaMoO(4)∶0.03Pr(3+), yTb(3+) system could be evidently improved with co-doping of Tb(3+) ions which was due to the efficient energy transfer process from Tb(3+) to Pr(3+) ions.

[Synthesis and fluorescence properties of SrZn(WO4)2:Tb3+, Ce3+ phosphors].

SrZn(1-x) (WO4)2:xTb3+, yCe3+ green fluorescent phosphors for near ultraviolet excitation were prepared using chemical co-precipitation. The phases of different doping ratio samples were characterized by the X-ray diffraction (XRD). The emission spectrum and excitation spectrum of samples were characterized by fluorescence spectroscopy (PL). The luminescence properties of the rare-earth Tb3+ ion doped and Ce3+ and Tb3+ ion codoped samples were discussed. XRD analysis shows that the main diffraction peaks of samples were consistent with the standard card (JCPDS 08-0490 and the JCPDS 15-0774) of the diffraction peak data. This showed that the doping rare earth ions did not change matrix lattice structure. The excitation spectrum showed that the excitation spectrum peaks at 223 nm which is assigned to the 7F-7D absorption transitions of Tb3+. The emission spectrum excited by 223 nm exhibits sharp lines peaking at 543 nm which was assigned to the 5D4-7F5 transitions of the Tb3+ ions. With Tb3+ and Ce3+ co-doping, the spectrum didn't change much. The intensity of fluorescence reached the strongest when the concentration of Tb3+:Ce3+ arrived at 0.06:0.02 which may means that there was energy transfer between the ions of Ce3+ and Tb3+.

Hexaaqua-zinc(II) dichloride bis-(hexa-methyl-enetetramine) tetra-hydrate.

The title compound, [Zn(H(2)O)(6)]Cl(2)·2C(6)H(12)N(4)·4H(2)O, has been prepared under mild hydro-thermal conditions. The Zn(II) atom, located on a centre of symmetry, is coordinated by six water mol-ecules in a distorted octa-hedral coordination geometry. The hexa-methyl-enetetra-mine mol-ecule is not coordinated to Zn(II) but links the Zn complexes via three O-H⋯N hydrogen bonds. The remaining N atom of the hexa-methyl-enetetra-mine mol-ecule is hydrogen-bonded to a solvent water mol-ecule. In the crystal structure, inter-molecular O-H⋯O, O-H⋯N and O-H⋯Cl hydrogen bonds link the components into a three-dimensional network.

Poly[[bis(µ(2)-4-amino-benzene-sul-fon-ato-κN:O)diaqua-manganese(II)] dihydrate].

The title compound, {[Mn(NH(2)C(6)H(4)SO(3))(2)(H(2)O)(2)]·2H(2)O}(n), was prepared under mild hydro-thermal conditions. The unique Mn(II) ion is located on a crystallographic inversion center and is coordinated by two -NH(2) and two -SO(3) groups from four 4-amino-benzene-sulfonate ligands and by two water mol-ecules in the axial positions, forming a slightly distorted octa-hedral coordination environment. The 4-amino-benzene-sulfonate anions behave as µ(2)-bridging ligands to produce a two-dimensional structure. In the crystal structure, inter-molecular N-H⋯O, O-H⋯O and C-H⋯O hydrogen bonds link the layers into a three-dimensional network.

Hexaaqua-copper(II) dichloride bis-(hexa-methyl-enetetra-mine) tetra-hydrate.

The title compound, [Cu(H(2)O)(6)]Cl(2)·2C(6)H(12)N(4)·4H(2)O, was prepared under mild hydro-thermal conditions. The asymmetric unit consists of one half of the [Cu(H(2)O)(6)](2+) cation, a hexa-methyl-enetetra-mine mol-ecule, two solvent water mol-ecules and a chloride ion. The formula unit is generated by crystallographic inversion symmetry. The Cu atom lies on a crystallographic inversion centre. It is in a slightly distorted octa-hedral coordination environment. In the crystal structure, inter-molecular O-H⋯O, O-H⋯N and O-H⋯Cl hydrogen bonds link the components into a three-dimensional network.

Diaqua-bis(2-carboxy-benzoato-κO)nickel(II).

In the title compound, [Ni(C(8)H(5)O(4))(2)(H(2)O)(2)], the Ni(II) atom lies on an inversion centre and exhibits a square-planar geometry incorporating two phthalate and two water O atoms. The nickel complex is stabilized by intra-molecular inter-actions involving water O atoms and H atoms of the phthalate groups. It forms one-dimensional zigzag chains along the b axis which are held together via π-π stacking inter-actions (3.647 Å) between the benzene rings of the phthalate groups. The adjacent chains are also hydrogen bonded, resulting in a three-dimensional supra-molecular network.