掺杂Tb3+的混合碱土金属钨酸盐的合成和性质

合成了掺杂Ｔｂ（３＋）的混合碱土金属钨酸盐，测定了其发射光谱和激发光谱，用粉末Ｘ射线衍射和电子衍射法表征了其晶体结构，并对钨酸钙钡单晶体进行了Ｘ射线能谱成份分析．探讨了碱土金属钨酸盐的溶混性成因以及在这些晶体中Ｔｂ（３＋）发光和能量传递机理．     

铽离子荧光探针对酶与金属离子间能量转移和结合位的研究

应用荧光光度法研究了Ｔｂ＾３＋与牛胰脱氧核糖核酸酶（ＢＰＤ），枯草杆菌α－淀粉酶（ＢＳα－Ａ）的络合发光现象，实验表明，ＢＰＤ和ＢＳα－Ａ分别在ＰＨ＝７－８和５－６范围内与Ｔｂ＾３＋络合，并发射Ｔｂ＾３＋的特征荧光，Ｔｂ＾３＋与ＢＰＤ和ＢＳα－Ａ的络合比分别为２：１和４：１。并应用Ｆｏｒｓｔｅｒ理论测定了Ｔｂ＾３＋与ＢＰＤ和ＢＳα－Ａ之间能量传递的距离Ｒ分别为１．３９ｎｍ和１．４８ｎｍ，其临界距离     

Hydrophilic Treatment of the Dyed Nylon-6 Fabric using High-density and Extensible Antenna-coupling Microwave Plasma System

High density and well surface-distributed oxygen microwave plasma with an extensible antenna-coupling design was utilized to modify a densely weaved and large-surface-area Nylon-6 fabric within a short treatment time. Plasma pretreatment and subsequent acrylic acid (AAc) or 2-hydroxyethyl methacrylate (HEMA) grafting process were studied and optimized at the stage after dyed and finished procedure. The monomer-grafted dyed Nylon-6 fabrics evolved lasting hydrophilic properties and thereafter created or improved surface properties such as water diffusion, drainage, moisture regain and water absorbency, in different degrees. The pHEMA-grafted sample exhibited minor effect in color perception, which was also much hydrophilic than the pAAc-grafted one. Based upon surface analyses and wetting assessment, the penetration of HEMA monomer into the plasma-treated fabric matrix contributed to the facilitation of wetting properties. This work accordingly ensures such plasma-induced system to incorporate with the pattern of hydrophilic properties on the analogous textiles without interrupting their finishing process.     

New silver(i) thiazole-based coordination polymers: structural and photophysical investigation

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Singlet Energy Transfer as the Main Pathway in the Sensitization of Near‐Infrared Nd3+ Luminescence by Dansyl and Lissamine Dyes

In general, sensitization of lanthanide(III ) ions by organic sensitizers is regarded to take place via the triplet state of the sensitizers. Herein, we show that in dansyl‐ and lissamine‐functionalized Nd³⁺ complexes energy transfer occurs from the singlet state of the sensitizers to the Nd³⁺ center. No sensitized emission was observed in the corresponding complexes with Er³⁺, Yb³⁺, and Gd³⁺ ions. Furthermore, the fluorescence of the sensitizers was quenched only in the Nd³⁺ complex and not in the complexes with the other ions. Only Nd³⁺ centers can accept energy from the singlet state of the dyes, because the excited states of Nd³⁺ have a high spectral overlap with the fluorescence of the dansyl and lissamine sensitizers, and because the selection rules allow a fast energy transfer, which apparently is competitive with the fluorescence.     

Preparation and characterization of silicate gel glasses containing Cr2O3

The effect of thermal treatment on the structural incorporation of Cr₂O₃ in xCr₂O₃·(100 – x)SiO₂ and 5R _n O·xCr₂O₃·(95 – x)SiO₂ (where x=0.01–1 mol.% and R=Li, Na and Ca) gel glasses was studied by optical absorption spectrophotometry, DTA-TG, XRD and electron microscopy.Samples heat treated at 60°C have green color due to the presence of Cr³⁺ in octahedral coordination. The optical transmission, and color (yellow, orange or ambar), of the samples heat treated between 200 and 700°C prove that Cr³⁺ (octahedrally coordinated) and Cr⁶⁺ (tetrahedrally coordinated) are both present. Segregation of Cr₂O₃ take place at temperatures above 800°C.In reducing conditions the gel glasses were green due to the presence of a high content of Cr³⁺ ions. Samples containing Li or Na show crystalline phases at temperatures below 850°C.     

Synthesis of Eu(III) and Tb(III) Complexes with Two New Amide Type Podands and Their Luminescence Properties

ＩｎｔｒｏｄｕｃｔｉｏｎＬａｎｔｈａｎｉｄｅｃｏｍｐｌｅｘｅｓｈａｖｅａｔｔｒａｃｔｅｄｍｕｃｈａｔｔｅｎｔｉｏｎｂｅｃａｕｓｅｏｆｔｈｅｉｒｉｍｐｏｒｔａｎｔａｐｐｌｉｃａｔｉｏｎｓ .1ＩｎｐａｒｔｉｃｕｌａｒＥｕ(ＩＩＩ)ａｎｄＴｂ(ＩＩＩ)ｃａｎｂｅｃｈａｒａｃｔｅｒｉｚｅｄｂｙｌｏｎｇ ｌｉｖｅｄ(ｍｓｔｉｍｅｓｃａｌｅ)ａｎｄｓｔｒｏｎｇｌｕｍｉｎｅｓｃｅｎｔｅｌｅｃｔｒｏｎｉｃａｌｌｙｅｘ ｃｉｔｅｄｓｔａｔｅｓ ,ｗｈｉｃｈｍａｋｅｓｔｈｅｍｉｍｐｏｒｔａｎｔｉｎａｎａｌｙｔｉｃａｌｃｈｅｍ…     

Crystal Structure and Luminescence of a Europium Coordination Polymer {[Eu(p-MOBA)_3·2H_2O]·0.5H_2O· 0.5(4,4′-bipy)}_∞

ＩｎｔｒｏｄｕｃｔｉｏｎＭｏｎｏｎｕｃｌｅａｒ ,ｄｉｎｕｃｌｅａｒａｎｄｐｏｌｙｍｅｒｉｃｔｙｐｅｓｏｆｃｒｙｓ ｔａｌｓｔｒｕｃｔｕｒｅｓｆｏｒｌａｎｔｈａｎｉｄｅｃｏｍｐｌｅｘｅｓｗｉｔｈｂｅｎｚｏｉｃａｃｉｄａｎｄｉｔｓｄｅｒｉｖａｔｉｖｅｓｈａｖｅｂｅｅｎｏｂｔａｉｎｅｄｂｅｃａｕｓｅｏｆｔｈｅｖａｒｉ ａｔｉｏｎｏｆｂｒｉｄｇｉｎｇｆｏｒｍｓｆｏｒｃａｒｂｏｘｙｌａｔｅｇｒｏｕｐａｎｄｃｏｏｒｄｉｎａ ｔｉｏｎａｂｉｌｉｔｙｏｆｄｉａｍｍｉｎｅｌｉｇａｎｄｓ ,ｓｕｃｈａｓ 1,10 ｐｈｅｎａ…     

Structure‐Dependent Photoinduced Electron Transfer in Fullerodendrimers with Light‐Harvesting Oligophenylenevinylene Terminals

Oligophenylenevinylene (OPV)‐terminated phenylenevinylene dendrons G1 – G4 with one, two, four, and eight “side‐arms”, respectively, were prepared and attached to C₆₀ by a 1,3‐dipolar cycloaddition of azomethine ylides generated in situ from dendritic aldehydes and N‐methylglycine. The relative electronic absorption of the OPV moiety increases progressively along the fullerodendrimer family C₆₀G1 – C₆₀G4 , reaching a 99:1 ratio for C₆₀G4 (antenna effect). UV/Vis and near‐IR luminescence and transient absorption spectroscopy was used to elucidate photoinduced energy and electron transfer in C₆₀G1 – C₆₀G4 as a function of OPV moiety size and solvent polarity (toluene, dichloromethane, benzonitrile), taking into account the fact that the free‐energy change for electron transfer is the same along the series owing to the invariability of the donor–acceptor couple. Regardless of solvent, all the fullerodendrimers exhibit ultrafast OPV→C₆₀ singlet energy transfer. In CH₂Cl₂, the OPV→C₆₀ electron transfer from the lowest fullerene singlet level (¹C₆₀*) is slightly exergonic (ΔG_CS≈0.07 eV), but is observed, to an increasing extent, only in the largest systems C₆₀G2 – C₆₀G4 with lower activation barriers for electron transfer. This effect has been related to a decrease of the reorganization energy upon enlargement of the molecular architecture. Structural factors are also at the origin of an unprecedented OPV→C₆₀ electron transfer observed for C₆₀G3 and C₆₀G4 in apolar toluene, whereas in benzonitrile, electron transfer occurs in all cases. Monitoring of the lowest fullerene triplet state by sensitized singlet oxygen luminescence and transient absorption spectroscopy shows that this level is populated through intersystem crossing and is not involved in photoinduced electron transfer.     

Luminescent properties of PP and LDPE films and rods doped with the Eu(III)‐La(III) complex

The work is devoted to luminescent properties of trivalent lanthanide complexes dispersed in thermoplastic host matrices. Polyethylene films and polypropylene‐rods, both doped with these complexes, were manufactured using an extrusion technique. Two kinds of dopants were used: Eu(III)‐thenoyltrifluoroacetone‐1,10‐phenanthroline complex (1) and Eu(III)‐La(III)‐1,10‐phenanthroline complex (2). Absorption, excitation, emission spectra and lifetime of luminescence were studied. The impact of the polymer matrix on the emission spectra was investigated. Emission spectra of the films were studied at room and helium temperatures. Time‐of‐flight secondary ion mass spectrometry (TOF‐SIMS) surface mapping showed that in the Eu(III)‐La(III) complex europium forms islands (clusters) with a dimension of 1 µm, whereas lanthanum was dispersed more uniformly in the polymer matrix. Dependence of emission intensity on the excitation was determined. Copyright © 2006 John Wiley & Sons, Ltd.