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Yang R.-Y.,National Pingtung University of Science and Technology | Peng Y.-M.,National Cheng Kung University | Lai H.-L.,National Pingtung University of Science and Technology | Chu C.-J.,Nanmat Technology Co. | And 3 more authors.
Optical Materials | Year: 2013

Zn2SiO4:xEu3+ phosphors were synthesized with different concentrations of Eu3+ ions (x = 0.001, 0.003, 0.005, 0.007 and 0.01) by using tetraethylorthosilicate (TEOS) solution as silicate source. The samples were sintered at 1200 C for 2 h in air using solid-state sintering. The XRD results showed the prepared Zn2SiO 4:Eu3+ phosphors have a small impurity phase of SiO 2 when the Eu3+ concentration is less than x = 0.005. However, the SEM results showed the prepared particles of Zn2- xSiO4:xEu3+ phosphor have spherical shape, and fine size powder morphologies. The PL results showed the intensity of the emission spectra of Zn2-xSiO4:xEu3+ phosphor increased first and reached a maximum value at x = 0.005, and then decrease due to concentration quenching effect. Moreover, the intensity of the emission spectra of Zn2-xSiO4:xEu3+ (x = 0.005) phosphor via TEOS solution as silicate source is stronger than that using SiO2 powder as silicate sources, which may be attributed to the uniform particle size distribution. Moreover, all the chromaticity (x, y) of Zn2-xSiO4:xEu3+ phosphors are located in the red region (0.63, 0.36) even if adopted TEOS solution as silicate source that would not influence the purity of Zn2- xSiO4:xEu3+ phosphor. © 2013 Elsevier B.V. All rights reserved. Source


Farnum G.A.,Michigan State University | Lucas J.S.,Michigan State University | Wang C.Y.,Diamond Bar High School | LaDuca R.L.,Michigan State University
Inorganica Chimica Acta | Year: 2011

Hydrothermal synthesis has afforded five d10 configuration divalent metal diphenate coordination polymers containing pyridyl-piperazine type ligands, which were structurally characterized by single-crystal X-ray diffraction. {[Cd(diphenate)(3-bpmp)(H2O)]·0.5H 2O}n (1, 3-bpmp = bis(3-pyridylmethyl)piperazine) has a double layer topology. Its perchlorate-containing analog {[Cd 3(diphenate)4(H23-bpmp)(H3-bpmp)(H 2O)2](ClO4)·7H2O} n (2) possesses a very rare 4-connected 658 dmp topology based on anionic trinuclear nodes. {[Cd(diphenate)(4-bpfp)]·H 2O}n (3, 4-bpfp = bis(4-pyridylformyl)piperazine) manifests a non-interpenetrated diamondoid lattice, while the related compound [Cd(diphenate)(4-bpmp)(H2O)]n (4, 4-bpmp = bis(4-pyridylmethyl)piperazine) has a simple (4,4) grid topology. {[Zn(diphenate)(4-bpmp)]·0.5H2O}n (5) displays a 2-fold interpenetrated diamondoid lattice. Luminescent properties of these materials are also reported. © 2010 Elsevier B.V. All rights reserved. Source


Pochodylo A.L.,Michigan State University | Wang C.Y.,Diamond Bar High School | Laduca R.L.,Michigan State University
Inorganica Chimica Acta | Year: 2011

Hydrothermal synthesis has afforded divalent cadmium coordination polymers containing isophthalate (ip) or 5-methylisophthalate (mip) dicarboxylate ligands and bis(4-pyridylformyl)piperazine (4-bpfp) or bis(4-pyridylmethyl) homopiperazine (4-bpmh) tethers. {[Cd2(ip)2(H 2O)2(4-bpfp)]·7H2O}n (1) displays a (4,4) grid topology based on {Cd2O2} dimeric clusters, along with "infinite" water molecule tapes with rare T4(0)A(1) classification. {[Cd(mip)(H2O)(4-bpfp)]·3H 2O}n (2) also exhibits (4,4) grid layers but with 2D + 2D → 3D mutual inclined interpenetration instead of parallel stacking. [Cd4(ip)4(4-bpmh)2]n (3) has tetrameric {Cd4(ip)4} cluster units linked by ip and 4-bpmh ligands into a unique self-penetrated 3,5,5,5-connected tetranodal net with (4.82)(436285)(4 46482)(4.5648) topology. {[Cd2(mip)2(H2O)2(4-bpmh)] ·2H2O}n (4) possesses a structure similar to that of 1, without the aggregated water molecule tapes. All four materials emit visible light upon ultraviolet excitation, ascribed to ligand-based electronic transitions. © 2011 Elsevier Ltd. All rights reserved. Source


Wang C.Y.,Diamond Bar High School | Wilseck Z.M.,Michigan State University | Laduca R.L.,Michigan State University
Inorganic Chemistry | Year: 2011

Divalent metal coordination polymers containing terephthalate (tere) and bis(4-pyridylformyl)piperazine (bpfp) show diverse and interesting two-dimensional (2D) interpenetrated, three-dimensional (3D) self-penetrated, or one-dimensional (1D) polyrotaxane topological features. Isostructural {[M(tere)(bpfp)(H2O)2]•4H2O}n phases (1, Zn; 2, Co) exhibit mutually inclined 2D + 2D → 3D interpenetration of gridlike layers. {[Cd4(tere)4(bpfp) 3(H2O)2]•8H2O}n (3) possesses a novel 3,4,8-connected trinodal self-penetrated network with (4.62)2(426168710 3)(4264)2 topology. [Zn 2Cl2(tere)(bpfp)2]n (4) is the first example of a 1D + 1D → 1D polyrotaxane coordination polymer, to the best of our knowledge. Metal coordination geometry plays a crucial role in dictating the overall dimensionality in this system. Thermal decomposition behavior and luminescent properties of the d10 configuration metal derivatives are also presented herein. © 2011 American Chemical Society. Source


Wang C.Y.,Diamond Bar High School | Wilseck Z.M.,Michigan State University | Supkowski R.M.,Kings College | Laduca R.L.,Michigan State University
CrystEngComm | Year: 2011

Hydrothermal reaction of divalent metal salts, phthalic acid (H 2pht), and bis(4-pyridylformyl)piperazine (bpfp) has afforded two-dimensional (2-D) and three-dimensional (3-D) dual-ligand coordination polymers. Their topologies are influenced by the coordination environment of the metal, binding mode of the pht ligands, and ligation of bpfp formyl groups. {[Co(pht)(bpfp)(H2O)2]·H2O}n (1) displays acentric (4,4) grid layers. [Cu2(pht) 2(bpfp)(H2O)2]n (2) exhibits binding of bpfp formyl oxygen atoms and a simple but previously unreported 4,4-connected binodal layer structure with (4.648)2(4 264) topology. [Cd2(pht)2(bpfp) (H2O)2]n (3) manifests a 3-D structure built from the bpfp pillaring of [Cd(pht)(H2O)]n layer motifs. A 4,5-connected binodal net with rare (4462)(4 466) tcs topology can be invoked for 3. Employment of the bpfp ligand affords topologies very different from those seen in many other divalent metal phthalate coordination polymers, including the heretofore unrecognized uninodal 6-connected 3-D self-penetrated 5106 47 topology in [Co(Hpht)2(bpy)]n (bpy = 4,4′-bipyridine). Dehydration and thermal properties of 1-3 are also discussed, along with the luminescent behavior of 3. © 2011 The Royal Society of Chemistry. Source

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