Photoluminescence properties of poly(thiophene-3yl-acetic acid 8-quinolinyl ester) in solution and in acid medium

The photoluminescence characteristics and quantum yields of poly(thiophene-3-yl-acetic acid 8-quinolinyl ester) have been studied. Fluorescence measurements indicate that fluorescence quantum efficiency increases with decreasing the concentration of polymer solution. The quantum yield of the polymer in the solution is higher than that of the Rhodamine B dye at lower concentration. The behaviour of photoluminescence property is studied under different acidic conditions. The fluorescence quenching is observed in the acid medium without any shift in the wavelength.     

对NFDA1和芘荧光猝灭性质的比较研究

对Bei和芘在电子给体化合物,N,N－二甲苯胺（DMA）和电子受体化合物对苯二甲酸二甲酯（DMTP）作用下的荧光猝灭进行了研究。结果表明芘与DMA和DMTP在室温下均可形成激基化合物（exciplex),而Ben仅仅与DMA形成exciplex。荧光猝灭的数据符合Stern-Volmer方程：F0／F＝1＋KSV[Q],芘的Stern-Volmer常数KSV大于Bei.Bei和芘在荧光猝灭方面的差别是由于Bei分子并不是一个典型的大共轭体系,分子的共平面性不如芘那样典型。     

Photoluminescence properties of new PPV derivatives

We investigate the emission properties of two copolymers by steady-state and time-resolved photoluminescence measurements. The copolymers are derived from poly-phenylene-vinylene (PPV) to which a non-conjugated ether group was added. The difference between the two copolymers is the group attached on the phenyl rings. Their fluorescence spectra present bathochromic and hypsochromic shift with respect to pristine PPV, well explained by their chemical properties. Additionally, we observe an enhancement of their quantum yield compared to that of PPV. Photoluminescence decays are bi-exponential for the two copolymers and their lifetime are longer than that of PPV. Finally, differences in emission properties between the two copolymers put in evidence the importance of their conformational structures in the luminescence processes.     

新型聚集荧光增强芴衍生物的光谱特性及电致发光性能研究

对新型聚集荧光增强芴衍生物的溶液状态下的光致发光和紫外-可见吸收光谱进行了表征,同时对比了其在丙酮/水混合溶液中的光致发光特性。结果表明,当水的体积比不断提高时,芴衍生物的丙酮/水混合溶液的光致发光光谱辐照度增强,这是由于该芴衍生物不溶于水,使得材料形成聚集态,导致聚集荧光增强;同时,PL光谱发生蓝移,这是因为溶液加水后形成芴衍生物的蓝色晶态聚集,这种晶态聚集会导致光致发光光谱的蓝移,并且晶态聚集越有序,发射的波长越短。另外,新型芴衍生物分子是通过在芴基团上链接四苯基苯和三苯胺官能团,具有抑制浓度猝灭及增强电荷传输能力,因此作为发光层,制得了非掺杂的有机电致发光器件。     

Fluorescence of Substituted Tetraazabacteriochlorin

The spectral, energy, and polarization characteristics of the fluorescence of substituted tetraazabacteriochlorin in solution have been obtained. On the basis of the polarization spectrum, the electronic absorption spectrum is interpreted. The quenching of the fluorescence of bacteriochlorin on substitution of methine bridges by aza bridges is noted.     

蒽、苝和1-氨基蒽醌水溶胶的制备及其荧光性能的研究

用再沉淀法分别制备了蒽、苝和1-氨基蒽醌水溶胶,研究了三者在水溶液中的荧光光谱,通过与其对应的分子荧光光谱比较,发现蒽和苝的水溶胶荧光光谱发生了红移,而1-氨基蒽醌分子从无荧光到它的水溶胶有荧光的转变,根据荧光和分子结构关系,得出3种溶胶是通过分子之间相互重叠聚集而成。同时因为他们为平面型分子,因此π电子共轭度大,使得荧光容易激发和发射,荧光光谱向长波方向移动。     

PPV衍生物／C60薄膜的时间分辨荧光光谱研究

用皮秒锁模Ｎｄ：ＹＡＧ激光器的倍频输出作为激发光，用同步扫描条纹相机系统对聚对苯乙炔ＰＰＶ的两种衍生物，Ｐｏｌｙ（２－ｍｅｔｈｏｘｙ－５－（４－ｂｕｔｅｎｙｌｏｘｙ）ｐｈｅｎｙｌｅｎｅ ｖｉｎｙｌｅｎｅ）（ＭＢＰＰＶ）和Ｐｏｌｙ（２－ｍｅｔｈｏｘｙ－５－（４－ｂｒｏｍｏ－ｂｕｏｘｙ）ｐｈｅｎｙｌｅｎｅ ｖｉｎｙｌｅｎｅ）ＭＢＢ－ＰＰＶ），与富勒烯Ｃ６０的组合薄膜进行时间分辨荧光测量。     

荧光猝灭光谱法测定DNA

利用荧光光谱法对5-邻氯乙酰氧基苯基-10,15,20-三苯基卟啉与脱氧核糖核酸（DNA）在不同条件下的荧光光谱特征进行了研究。实验表明,在低离子强度下,小牛胸腺DNA导致卟啉的荧光强度猝灭。在pH4.4的B-R缓冲介质中,荧光猝灭程度与小牛胸腺DNA的浓度呈线性关系,线性方程为ΔF=29.8C（μg/mL）-1.17,线性范围为0—10μg/mL,检出限为1.22μg/mL,相关系数为0.9949。对提取的植物基因组总DNA进行测试,由线性方程求得样品中的DNA含量。     

Interactions of Environmental Pollutant Aromatic Amines With Photo Excited States of Thiophene Substituted 1,3,4-Oxadiazole Derivative: Fluorescence Quenching Studies

Journal of Fluorescence - In the present work, the fluorescence quenching of novel thiophene substituted1,3,4-oxadiazole derivative 2-(4-(4-vinylphenyl)...     

Quenching of perylene fluorescence by Co2+ ions in dipalmitoylphosphatidylcholine (DPPC) vesicles

We report the fluorescence quenching of perylene by CoCl₂·6H₂O in small unilamellar DPPC vesicles via energy transfer. At the probe-to-lipid ratio of 1200 and quencher to lipid ratios of 12.51, donor-donor energy transfer between clustered perylene molecules was observed as well as energy transfer from the perylene molecules to cobalt ions bothabove andbelow the main phase transition temperature of the lipid. The fluorescence quenching of perylene by CoCl₂·6H₂O in the lipid gel state is shown to be well described by Förster long-range energy transfer when both donor-donor and donor-acceptor energy transfer are considered. In the liquid crystalline phase diffusion of the molecules is described as well as energy transfer. The interaction radiusR ₀ for energy transfer from perylene to Co²⁺ is found to be 13.4±1.1 Å in the gel phase at 303 K, in good agreement with the theoretical value forR ₀ of 13.9 Å. In the liquid crystalline phase at 323 K the lower value obtained forR ₀, 11.3±1.6 Å, is attributed to saturation of the Co²⁺ ions at the interfacial region of the bilayer. A diffusion coefficient of (1.06±0.15)×10^–6 cm² s^–1 is obtained for perylene-cobalt diffusion in the liquid crystalline phase at 323K.     

Fluorescence Probing of Cell Membranes with Azacrown Substituted Ketocyanine Dyes

The three dyes with similar fluorescence properties but different lipophility—azacrown- and di-methylamino-substituted ketocyanines—are proposed as probes for the studies of biomembrane structure and dynamics. Their attractive feature is an extremely strong solvatofluorochromism, covering the range from 470 to 650 nm. Two photophysical mechanisms are responsible for these features, the general polarity effect associated with substantial increase of the probe dipole moment on electronic excitation and the excited-state stabilization due to hydrogen bonding to the central carbonyl groups. On the binding of these probes with erythrocyte membranes, three components in fluorescence spectra are resolved. They are attributed to probe molecules bound in two discrete types of binding sites inside the membrane: hydrophilic polar sites, in which carbonyl groups of the probes molecules are hydrogenbonded with hydrogen donor surrounding, and hydrophobic non-polar sites. The third component present in the emission spectra was attributed to the unbound probe in the near-membrane aqueous phase. Our results suggest that such a complex response of the probes is sensitive to the dynamics of hydration of the membrane interior, and this feature can be easily studied in simple ratiometric measurements. Among three studied compounds containing two crown-, two dimethylamino-, or both crown- and diethylamino- substituents, the latter proves to be most prospective in biomembrane research. This probe was tested in monitoring the phase transition of human erythrocyte membrane.     

Yellowish-white photoluminescence from ZnO nanoparticles doped with Al and Li

ZnO nanoparticles codoped with Al and Li were chemically synthesized with a low temperature drying process. They are crystalline and can be made as small as 5 nm. Intense yellowish white photoluminescence was observed from smaller ZnO nanoparticles with a higher concentration of Al and Li. The photoluminescence peak consists of yellow and green emission bands. Both peak intensities increase with increasing the Al and Li concentrations and with decreasing the size of ZnO nanoparticles. The green and yellow emission bands were attributed to donor–acceptor-pair recombination involving Zn vacancies and lithium as the acceptor state, respectively, and the donor responsible for both emissions to oxygen vacancies. Both enhanced emissions by codoping may be explained by an increase in the number of electrons occupying the deep donor level on account of doping with Al. Although the yellowish white emission decays with time, passivation of the crystallite surface with poly(p-phenylene vinylene) suppresses the degradation. The observed high-intensity and stable yellowish white emission makes PPV-passivated ZnO nanoparticles, codoped with Al and Li, more attractive as a candidate for “white” phosphor.     

二溴羟基苯基荧光酮荧光熄灭法测定铜

研究了在pH 6 2～ 8 2磷酸二氢钾 磷酸氢二钠缓冲体系中 ,非离子表面活性剂TritonX 10 0存在下 ,铜 (Ⅱ )与二溴羟基苯基荧光酮 (DBH PF)形成 1∶2红色三元混配合物而使荧光熄灭 ,建立了荧光熄灭法测定铜的新方法。配合物的λex=5 3 0nm ,λem=5 60nm ,含量在 0～ 80 μg·L-1范围内有良好的线性关系 ,检测限为 0 2 μg·L-1。体系的灵敏度高 ,选择性好。Al(Ⅲ )、Fe(Ⅲ )、Ti(Ⅳ )的干扰 ,可用氟化钠、苦杏仁酸掩蔽。方法快速简便 ,用于人发、茶叶及水中微量铜的测定与AAS相符 ,RSD(n=5 ) <6 9% ,回收率在 98%～ 10 4 %之间。     

亮菌甲素荧光熄灭法测定微量铁

基于铁对亮菌甲素的荧光熄灭 ,建立了测定微量铁 ( )的新方法。在 p H8.81的硼砂缓冲体系中 ,最大激发波长和发射波长分别为 2 81nm和 4 6 2 nm,亮菌甲素的荧光强度与铁 ( )的加入量在 0 .0 0 5—0 .4 5 0 μg/ m L间存在线性关系 ,检出限为 0 .6 μg/ L Fe( )。方法操作简便、反应迅速、灵敏度高、选择性好 ,用于环境水样中痕量 Fe( )的测定 ,结果令人满意     

荧光熄灭法测定维生素K3针剂中甲萘醌的含量

本文利用荧光熄灭法对维生素K3针剂中甲萘醌含量的测定进行了研究，工作结果表明：荧光熄灭法测定甲萘醌较常规的VK3针剂分析方法快速、准确，相对标准偏差小于3％，回收率在96％－102％。     

Interaction of Thyroxine with 7 Hydroxycoumarin: A Fluorescence Quenching Study

The interaction between thyroxine hormone and 7 hydroxycoumarin (7HC) was investigated using fluorescence quenching method. The experimental results showed that thyroxine could quench the fluorescence of 7HC by forming the 7HC–thyroxine complex with static quenching. The apparent binding constants (K) between 7HC and thyroxine were determined to be 1.51 × 10⁴ (297 K) and 9.06 × 10³ (310 K). The binding sites (n) 0.98 ± 0.1. The thermodynamic parameters showed that the interaction between 7HC and thyroxine was driven mainly by hydrogen bonding interactions and van der Waals force. Calibration for thyroxine, based on quenching titration data, was linear in the concentration range 2.0 × 10⁻⁸ to 3.0 × 10⁻⁷ mol/l. The relative standard deviation was 2.58% for 2.0 × 10⁻⁷ mol/l thyroxine (n = 4) and the 3σ limit of detection was 3.42 × 10⁻⁸ mol/l in cationic surfactant CTAB medium.     

5′-硝基-水杨基荧光酮-溴化十六烷基 三甲胺荧光猝灭法测定微量锆

本文基于Ｚｒ（Ⅳ）－５′－硝基－水杨基荧光酮（５′－Ｎ－ＳＡＦ）－溴化十六烷基三甲铵（ＣＴＭＡＢ）体系的荧光猝灭效应,提出一种测定微量锆的新荧光分析方法。在０．８～１．２ｍｏｌ／Ｌ的Ｈ２ＳＯ４介质中,在ＣＴＭＡＢ存在下,锆与５－Ｎ－ＳＡＦ生成组成比为１∶４的橙红色络合物。该体系存在两个激发峰,其激发波长分别为λｅｘ１＝４７５ｎｍ,λｅｘ２＝５０５ｎｍ,发射波长λｅｍ＝５２５ｎｍ。锆（Ⅳ）浓度在２．０～８０μｇ／Ｌ呈良好线性关系,检出限为２．０μｇ／Ｌ。本法灵敏度高,选择性好,用于铝合金中微量锆的测定,获得满意结果。     

二苯乙烯类侧链的苯乙烯衍生物单体的合成及其荧光性能研究

用三苯基4-乙烯基苄基氯化季膦盐和三种芳醛的Wittig反应合成了具有二苯乙烯类侧链的三种苯乙烯衍生物：4-乙烯基二苯乙烯(VS), 4’-N,N-二甲氨1基-4-乙烯基二苯乙烯(DMAVS)和4-(2-(9-蒽基))-乙烯基苯乙烯(AVS)。这三种物质都具有良好的光致发光性能,随取代基的不同,光致发光光谱的最大发射位置从375到530 nm,强度也随着共轭程度的加大和推电子基团的引入而大幅度增强。     

Perylene-containing polysiloxane: An effective candidate for corrosion protection of iron surface

A new modified polysiloxane, perylene-containing polysiloxane (PCP), was successfully synthesized by amine-terminated polysiloxane (ATP) and 3,4,9,10-perylene tetracarboxylic dianhydride. The synthesized compound was characterized by Fourier transform infrared spectroscopy (FT-IR) and ¹H nuclear magnetic resonance (¹H NMR). The thermal analysis of the PCP indicates that the modified polysiloxane has outstanding thermal stability. The PCP also possesses good fluorescence property. Due to the appearance of lone-pair electrons and π bond in PCP, it could be self-assembled on iron surface and thus used in the corrosion protection area. The PCP films were characterized by EIS (electrochemical impedance spectroscopy) and SEM (scanning electron microscopy). These results indicate that the films modified by PCP could protect the iron from corrosion efficiently.     

依诺沙星的荧光熄灭法测定

基于依诺沙星对十二烷基苯磺酸钠的荧光具有猝灭的特性,建立了一种测定依诺沙星的新方法。在pH2.00的磷酸缓冲溶液中,十二烷基苯磺酸钠的激发波长为283nm,发射波长为326nm,依诺沙星的浓度在0—8.1μg/mL范围内与其荧光强度呈良好的线性关系,检出限为0.016μg/mL,方法的相对标准偏差为1.17%。本法灵敏度高、选择性好,用于制剂中依诺沙星的含量测定,结果令人满意。