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Infrared to ultraviolet upconversion luminescence in Nd^(3+) doped nano-glass-ceramic

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Journal of Rare Earths 2008年第3期26卷 428-432页

作者：陈大钦王元生余运龙刘锋黄萍 State Key Laboratory of Structural Chemistry Fujian Institute of Research on the Structure of Matter Chinese Academy of Sciences

Nd^3＋ doped transparent oxyfiuoride glass ceramic containing β-YF3 nanocrystals was prepared and the upconversion luminescence behaviors of Nd^3＋ in the precursor glass and glass ceramic were investigated. Under 796 nm laser excitation, ultraviolet upconversion emissions of Nd^3＋ ions at 354 nm （^4D3/2→^4I11/2） and 382 nm （^4D3/2→^4I11/2） were observed at room temperature. Power dependence analysis demonstrated that three-photon upconversion processes populated the ^4D3/2 excited state. In comparison with those of the precursor glass, the ultraviolet emissions were enhanced by a factor of 500 in the glass ceramic, which was attributed to the change in the ligand field of Nd^3＋ ions and the decrease in phonon energy because of the partition of Nd^3＋ ions into the β-YF3 nanocrystals after crystallization.

关键词： upconversion ultraviolet nanocrystal glass ceramic rare earths

Synthesis, Crystal structure and Spectroscopic Properties of an Octanuclear V-S-Cu Cluster {V_2S_6Cu_6}(PPh_3)_6(O)_2·2CH_2Cl_2·CH_3OH with a Metal-sulfur Dodecahedral Cage

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Chinese Journal of Structural Chemistry 2001年第6期20卷 489-493页

作者：郑发鲲郭国聪等 State Key Laboratory of Structural Chemistry Fujian Institute of Research on the Structure of Matter Chinese Academy of Sciences

A new octanuclear VSCu cluster {V2S6Cu6}(PPh3)6(O)22CH2Cl2CH3OH 1 has been prepared by extraction with CH2Cl2 of a solid mixture of (NH4)3VS4, Cu(PPh3)2Cl and NEt4Br, and its structure has been determined by single-crystal X-ray diffraction. Crystallographic data: C111H98Cl4Cu6O3P6S6V2, Mr = 2248.99, triclinic space group P , a = 13.751(6), b = 15.509(4), c = 15.642(5) ? a =114.34(2), b = 98.35(3), g = 110.43(3) , V = 2679.83 3, Z = 1, Dc = 1.538 g/cm3, F(000) = 1262, m (MoKa) = 16.9 cm-1, the final R = 0.079 and Rw = 0.083 for 5504 observed reflections with I > 2s(I). The structural determination shows that the skeleton can be described as a metal-sulfur dodecahedral cage fused by two incomplete cubane-like [VS3Cu3] subunits centrosymmetrically connected by CuS and weak CuCu bonds. The six copper and two vanadium atoms display a slightly distorted cubic array with a m4-S atom on each face of the metal cube. The selected IR, electronic and 51V NMR spectra have also been reported.

关键词： synthesis crystal structure vanadium cluster copper cluster octanuclear cluster

Synthesis and Crystal structure of a New Mononuclear Copper( Ⅱ ) Complex: [Cu(BMI)_4(SO_4)]·DMF·2H_2O

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Chinese Journal of Structural Chemistry 2006年第3期25卷 285-289页

作者：范承马成丙胡明强陈昌能刘秋田 State Key Laboratory of Structural Chemistry Fujian Institute of Research on the Structure of Matter The Chinese Academy of Sciences

A new copper（Ⅱ） complex, [Cu（BMI）4（SO4）]·DMF·2H2O （BMI = benzimidazole）, has been synthesized by the treatment of CuCN with 2-mercaptobenzimidazole in the presence of 1,10-phenanthroline, and characterized by single-crystal X-ray diffraction. It crystallizes in monoclinic, space group P21/n with a = 17.6260（4）, b = 11.1252（3）, c = 18.6573（4）A°, β= 107.9010（10）°, V = 3481.45（14）A°^3, Z = 4, C31H35CuN9O7S, Mr= 741.28, F（000） = 1540, Dc = 1.414 g/cm^3,μ = 0.746 mm^-1, the final R = 0.0649 and wR = 0.1609 for 4382 observed reflections with I 〉 2σ（I）. The Cu（Ⅱ） atom is coordinated by five unidentate ligands （one sulfate and four benzimidazole ligands） generated in situ, displaying a slightly distorted square pyramid geometry.

关键词： Cu(Ⅱ) complex synthesis crystal structure

Mechanisms of Fluorescence Quenching of Pr^(3+)-Doped PbWO_4 Crystal

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Journal of Rare Earths 2005年第5期23卷 641-644页

作者：熊飞兵罗遵度黄艺东 Fujian institute of research on structure of matter Chinese Academy of Sciences Fuzhou 350002 China Graduate School of Chinese Academy of Sciences Beijing 100039 China) Fujian institute of research on structure of matter Chinese Academy of Sciences Fuzhou 350002 China

Fluorescence decay curves of the ^3P0 and ^1D2 manifolds in Pr^3＋ doped PbWO4 crystal were measured at room temperature and fluorescence lifetimes of both manifolds were estimated. Combining with the radiative lifetimes of the manifolds calculated on the basis of the modified J-O theory, the main mechanisms for the fluorescence quenching of the manifolds were analyzed. The multi-phonon relaxation and the cross-relaxation energy transfer are the major reasons for the fluorescence quenching of the ^3P0 and ^1D2 manifolds, respectively. The Inokuti-Hirayama model was used to analyze the fluorescence decay curve of the ^1D2 manifold and the cross-relaxation of dlpole-dipole interaction was confirmed. Consequently, the ^3p0 manifold is more favorable as an upper laser level than the ^1D2 manifold.

关键词： fluorescence quenching Pr^3 + : PbWO4 crystal mechanism rare earths

Synthesis and structure Characterization of a Manganese(Ⅱ) Complex With Eight Coordination Geometry: [Mn(O_2CMe)_2(phen)_2]

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Chinese Journal of Structural Chemistry 2007年第7期26卷 753-756页

作者：王梅马成丙王会生陈昌能刘秋田 State Key Laboratory of Structural Chemistry Fujian Institute of Research on the Structure of Matter The Chinese Academy of Sciences

The title compound [Mn（O2CMe）2（phen）2] （phen = 1,10-phenanthroline） 1 has been synthesized and structurally determined by single-crystal X-ray diffraction. The crystal is of orthor- hombic, space group Pbcn, with a = 12.554（4）, b = 10.168（3）, c = 17.704（5）A, V= 2259.7（12）A^3 Z = 4, C28H22MnN4O4, Mr= 533.44, Dc= 1.568 g]cm^3, F（000） = 1100, Rint = 0.0242, T= 293（2） K and p = 0.631 mm^-1. The final R = 0.0687 and wR = 0.1960 for 2046 observed reflections with I 〉 20（/）. The structure of the complex consists of one Mn（II） core coordinated by two bidentate-bound CH3COO^- groups and two η^2-phen groups forming an eight-coordinate geometrical configuration.

关键词： manganese crystal structure eight-coordination photosystem Ⅱ

Synthesis,structure and Second-order Nonlinear Optical Activities of a New Tungsten(0) Compound with Pyridine-2-thiolato Ligand,[Et_4N][W(pyS)(CO)_4](pys=C_5H_4NS^-)

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Chinese Journal of Structural Chemistry 2007年第1期26卷 21-24页

作者：周张锋庄伯涛韦永勤吴克琛姚元根 State Key Laboratory of Structural Chemistry Fujian Institute of Research on the Structure of Matter The Chinese Academy of Sciences

The reaction of W（CO）6 with pyOSNa （C5H4NOSNa） and Et4NCl in MeCN affords a new tungsten（0）complex [Et4N][W（pyS）（CO）4] 1 （Mr = 536.29）. The crystal and molecular structures have been determined by X-ray single-crystal diffraction. Complex 1 crystallizes in the orthorhombic system, space group P212121 with α= 8.2429（5）, b = 9.1045（4）, c = 26.8851（14） A, β= 90.00°, V=2017.66（18） A3^, Z = 4, Dc = 1.765 g/cm^3, μ= 58.51 cm^-1, F（000） = 1048, the final R = 0.0204 and wR = 0.0400 for 4432 observed reflections with I 〉 2σ（I）. X-ray structure analysis revealed that the molecule is acentric and has large first=order hyperpolarizability （7.2 × 10^-30 esu）, so it could be an IR second=order nonlinear optical candidate material.

关键词： tungsten(0)-compound synthesis structure nonlinear optical property

Hydrothermal Synthesis and structure Characterization of Compound Zn(Hpydc)_2(H_2O) (pydc=pyridine-2,5-dicarboxylate)

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Chinese Journal of Structural Chemistry 2001年第6期20卷 455-458页

作者：梁玉仓江茂椿等 State Key Laboratory of Structural Chemistry Fujian Institute of Research on the Structure of Matter Chinese Academy of Sciences

The hydrothermal reaction of ZnO, H3PO4(85%), (H2NCH2CH2)2NH and H2pydc results in the formation of a discrete mononuclear zinc(II) complex Zn(Hpydc)2(H2O). It crystallizes in monoclinic space group C2/c with a = 17.9947(8), b = 7.1875(3), c = 12.5895(4) , b = 110.802(2), V = 1522.14(10) 3, Z = 4, Mr = 415.61, (C14H10N2O9Zn), Dc = 1.814g/cm3, = 16.71cm-1, F(000) = 840, R = 0.0505, wR = 0.1144. Each zinc(II) is coordinated to two nitrogen and three oxygen atoms of which two nitrogen and two oxygen atoms are from two pydc ligands, and one oxygen atom from the coordinated water molecule to form an irregular polyhedral geometry. The complex is linked further into a three-dimensional structure through the weak interactions of hydrogen bonds between the two oxygen atoms. IR spectrum of the complex is also discussed.

关键词： zinc complex hydrothermal synthesis crystal structure hydrogen bond weak interaction

A Mixed-valent Hexanuclear Cu~Ⅱ-Cu~ⅠComplex with Unusual Tridentate pbi Ligand (pbi = 2-(2-Pyridyl)-benzimidazole)

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Chinese Journal of Structural Chemistry 2006年第12期25卷 1507-1511页

作者：刘九辉吴小园张全争何翔卢灿忠 State Key Laboratory of Structural Chemistry Fujian Institute of Research on the Structure of Matter The Chinese Academy of Sciences

A mixed-valent hexanuclear complex [Cu^ⅡCu^Ⅰ2（pbi）2Br2]2 （pbi = （2-（2-pyridyl）-benzimidazole） exhibiting a dimeric unit bridged by two Br atoms was synthesized by hydrothermal reaction Interestingly, there exist intramolecular and intermolecular n^zstacking interactions as well as metalaromatic ring interactions in the title complex. The crystal belongs to the monoclinic system, space group P1, with a = 7.1061（9）, b = 12.1008（13）, c = 14.0711（17） A, α=91.742（8）,β=100.155（9）, γ=90.486（7）°, V = 1190.3（2） A^3, Z = 2, C48H32Br4CucoNt2, Mr = 1477.74, Dc= 2.061 g/cm^3, F（000） = 718, μ（MoKα） = 6.039 mm^-1, the final R = 0.0481 and wR = 0.0974 for 3426 observed reflections （I 〉 2σ（I））.

关键词： mixed-valence π-π staeking interaction metal-aromatic ring interaction

Effect of Ag on the Grain Growth and Dielectric Properties of PbTiO_3

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Chinese Journal of Structural Chemistry 2007年第9期26卷 1097-1101页

作者：黄集权洪茂椿 State Key Laboratory of Structural Chemistry Fujian Institute of Research on the Structure of Matter The Chinese Academy of Sciences

A series of Ag-PbTiO3 composites were synthesized, and the effects of silver on the morphological development of hydrothermal synthesized PbTiO3 particles and dielectric properties of PbTiO3 ceramic were investigated. Results show that the introduction of Ag benefits the crystal growth of PbTiO3. The diffusion of Ag^＋ into the perovskite accelerates the crystal growth of PbTiO3 and leads to large fine PbTiO3 crystal. Furthermore, the dielectric constant of PbTiO3-based ceramic was enhanced greatly by the percolation effect of inner Ag clusters.

关键词： Ag-PbTiO3 composite morphology dielectric constant