Preparation, characterization, and application of multistimuli-responsive microspheres with fluorescence-labeled magnetic cores and thermoresponsive shells

Novel functional microspheres with multistimuli-responsive properties have been prepared and characterized. The as-prepared microspheres respond to an external magnetic field, environmental temperature, and ultraviolet radiation. The in vitro drug-loading efficiency and drug-release behavior of these microspheres demonstrated that they could be used as drug carriers for drug controlled release. The results of in vivo distribution investigations of these microspheres showed that they exhibit a high magnetic-targeting effect, which holds promise for applications in various fields such as magnetic drug targeting and tissue labeling, among others.     

A facile synthesis of solid-emissive fluorescent dyes: dialkylbenzo[b]naphtho[2,1-d]furan-6-one-type fluorophores with strong blue and green fluorescence emission properties

A new type of organic fluorophores, dialkylbenzo[b]naphtho[2,1-d]furan-6-one-type fluorophores, exhibiting strong blue and green emission in the solid state has been easily synthesized by an one-step reaction. The X-ray crystal structure demonstrated that the structural form with a chair-shape with the sterical hindered dialkyl substituents and the 9-dibutylamino group prevents the fluorophores from forming short intermolecular contacts and produces intense solid-state fluorescence emission.     

Theoretical study of the excited singlet and triplet states of alloxan

The possibility of excited‐state protomeric shifts in the biologically important molecule, alloxan, is investigated. We have focused on the S₁ and T₁ excited states of alloxan and its hydroxy tautomers. Modifications brought in by excitation on the relative stabilities, activation barriers, and optimized geometries, computed at the MNDO, AM1, and PM3 levels of approximation, have been discussed for both excited electronic states. The absorption and fluorescence spectra for the three tautomers are also discussed. Results show significant changes in the geometries on excitation, although the changes are similar for the singlet and triplet excited states. Though the relative stability orders do not change, the 2‐hydroxy tautomer is stabilized, while the 4‐hydroxy tautomer gets destabilized on excitation. The excited states are (n,π*) states, involving the promotion of a nonbonding oxygen lone pair from the CO? CO? CO moiety, which explains why the oxygens of this group become less basic and the 4‐hydroxy tautomer gets destabilized on excitation. However, the activation barriers do not reduce significantly on excitation, and this precludes the possibility of ground‐ or excited‐state proton transfer in the gas phase. © 2001 John Wiley & Sons, Inc. Int J Quantum Chem, 2001     

Determination of dipole moment in the ground and excited state by experimental and theoretical methods of N-nonyl acridine orange

The absorption and fluorescence spectra of N-nonyl acridine orange are determined at room temperature (298 K) in cyclohexane, benzene, carbon tetrachloride, chloroform, chlorobenzene and dichloromethane. The ground state of dipole moment was obtained by impedance measurements using Guggenheim-Debeye's method. The experimental excited state dipole moment of N-nonyl acridine orange was determined using Bakhshiev's and Kawski-Chamma-Viallet's formulae and solvent polarity parameter proposed by Reichardt. These experimental results were completed with theoretical results using quantum chemical methods. The experimental (muexp=10.76 D) and theoretical (mucal=9.9 D) dipole moments in the ground and excited state (muexp*=14.56 D) were compared.     

手性胺醇稀土配合物的合成、荧光性质及其催化芳香酮的不对称氢化反应

合成了三种新的含C₂-对称轴的手性胺醇(PhOHCHCH₂)₂NCH₂C₆H₄R (R＝OCH₃, L₁; R＝CH₃, L₂; R＝Cl, L₃), 将其与无水氯化稀土LnCl₃•4THF (Ln＝La, Sm, Gd)反应生成了九个新的胺醇类稀土配合物LLnCl•2THF (L＝L₁, L₂, L₃; Ln＝La, Sm, Gd). 用元素分析、热重分析、红外和紫外光谱等手段对它们进行了表征. 荧光光谱显示一些配合物具有荧光性能. 原位催化芳香酮的不对称氢化反应表明: L₁/SmCl₃•4THF体系催化苯乙酮不对称氢化反应的转化率达71%, 相应的对映体过量值达32%.     

Recent progress in two-photon small molecule fluorescent probes for enzymes

This review aims to provide a summary of the progress in TP small molecule fluorescent probes for enzymes in recent years and displays the main fluorescent mechanisms that have been applied to design probes.     

四苯基卟啉在改性磷酸锆层间的插入及荧光增强

近年来,出于节约一次性能源的考虑,人们已经加大对太阳能等天然资源的利用,致力于模拟天然光合作用的研究[1￣3],而光合作用中的捕光复合物又称为光子天线。光子天线中往往存在一种或几种猝灭剂,猝灭剂吸收光子后产生激发态的能量可以在不同分子或者同一分子的不同生色团之间转移,转移出能量的一方为能量给体,另一方为能量受体。     

A new Fluorimetric Reagent for Highly Selective and Sensitive Determination of Terbium Ion

 In this work, a new ligand, 2,9-bis[N,N-bis(carboxymethyl)-aminomethyl]-1,10-phenanthroline (BBCAP), was synthesized and used to establish a novel fluorimetric method for the determination of trace amounts of terbium in a binary system. Its luminescence mechanism was studied. The excitation and emission wavelengths are 284 nm and 547 nm, respectively. Other rare-earth metal ions in 100-fold excess caused no interference. The fluorescence intensity was a linear function of the concentration of terbium in the range of 5.0 × 10⁻¹⁰–1.0 × 10⁻⁶ mol/L. The detection limit was 2.0 × 10⁻¹¹ mol/L (n = 12). The standard addition method was used to determine the terbium in a synthetic rare-earth sample with satisfactory results. This method represents a direct, rapid, selective and sensitive analytical procedure with a widely linear range. Received November 29, 2001 Revision February 9, 2002     

同步辐射白光全反射XRF在痕量元素检测的初步应用研究

叙述了同步辐射白光全反射Ｘ射线荧光分析的实验装置，给出了几种标准物质ＴＸＲＦ实验的检出限，并对实验结果进行了讨论。     

铕（Ⅲ）—β—二酮—4,5—二氮芴—9—酮三元配合物的合成

铕（Ⅲ）┐β┐二酮┐４，５┐二氮芴┐９┐酮三元配合物的合成成义祥徐端钧＊徐元植（浙江大学化学系杭州３１００２７）关键词铕，β－二酮，二氮芴酮，三元配合物，合成，荧光光谱１９９７－０３－３１收稿，１９９７－０７－１５修回噻吩甲酰三氟丙酮（ＴＴＡ）和苯甲...