两种取代酞菁锌的合成及其光物理性质的研究

文章采用熔融法合成了两种通过不同基团连接的邻苯二甲酰亚胺取代酞菁锌,四-β-(邻苯二甲酰亚胺丁氧基)酞菁锌(1)和四-β-(邻苯二甲酰亚胺甲基)酞菁锌(2).比较了两种不同的取代基连接方式对酞菁的电子吸收光谱、荧光光谱及荧光量子产率和产生单线态氧的能力的影响.结果表明:与无取代酞菁锌相比,四-β-(邻苯二甲酰亚胺丁氧基)酞菁锌(1)的电子光谱和荧光光谱的红移程度均大于四-β-(邻苯二甲酰亚胺甲基)酞菁锌(2).由于1的给电子能力比2强,两种锌酞菁的荧光量子产率(ΦF)的大小顺序为:1＞2,产生1O2的能力的大小顺序为:2＞1.     

水溶性酞菁类光敏剂的合成及其光谱性质研究

以3-硝基邻苯二甲腈与3-巯基-1-丙磺酸钠为原料，在醋酸盐存在下通过四环化合成了三种带四个3-磺基丙基磺酰基的水溶性酞菁。利用紫外-可见吸收光谱，荧光光谱等对其光谱性质进行了测量，并计算了其荧光量子产率和单线态氧量子产率。引入吸电子基团所合成的水溶性酞菁与ZnPc相比，其荧光发射光谱的形状并未改变，但其最大荧光发射波长均发生10 nm以上的红移。三种水溶性酞菁中锌酞菁的荧光量子产率最高，铜酞菁的荧光量子产率最低；它们在水溶液中的荧光呈双指数衰减，这可归结为激发态质子化或去质子化的结果。单线态氧量子产率锌酞菁最大，空心酞菁次之，铜酞菁最小。光谱分析结果表明，合成的锌酞菁和空心酞菁具有高的单线态氧量子产率和高的光稳定性，有望用作光动力治疗和光免疫治疗的光敏剂。     

两亲性金属酞菁的催化性能研究

采用耗氧法研究了4种金属酞菁配合物[α-四(对羧基苯氧基)金属酞菁(Zn,Co)、β-四(对羧基苯氧基)金属酞菁(Zn,Co)]对0.1mol.L-1亚硫酸钠的催化氧化性能,考察了配合物中心金属和取代基的位置对催化活性的影响。研究结果表明中心离子相同时,β位四取代(对羧基苯氧基)金属酞菁的催化活性优于α位;取代基位置相同时,酞菁钴的催化氧化性优于酞菁锌。且β-四(对羧基苯氧基)酞菁钴的浓度为1.00×10-4mol.L-1时,对亚硫酸钠的催化氧化性能最高。     

消自旋ESR法测量铝酞菁光敏反应中阴离子自由基的生成

用氮氧自由基消自旋ESR法探测铝酞菁原初反应过程中的阴离子自由基.结果显示在无氧条件下,当体系中存在连苯三酚或半胱胺酸这些电子施主时,可有铝酞菁阴离子自由基生成,这可能是除了单线态氧外的另一种光敏作用机制.     

酞菁锌分子激发态的超快内转移和振动弛豫

用飞秒时间分辨荧光亏蚀法研究了四特丁基酞菁（ＢｕＰｃ）、四特丁基酞菁锌（ＺｎＢｕＰｃ）和四丙氧基酞菁锌（ＺｎＰｒＰｃ）激发态的超快弛豫过程，用波长为３９８ｎｍ的超短脉冲激光激发分子，观察了Ｓ２态到Ｓ１态的内转换，其特征时间约为３０ｆｓ。在７９６ｎｍ先于３９８ｎｍ作用于样品分子时，观察到了荧光强度渐变的过程，通过分析认为这一过程反映了Ｓ１态的振动弛豫。通过对实验数据的拟合，得到了它们的振动弛豫特征时     

新型八取代酞菁谱学性质研究

对1,4,8,11,15,18,22,25-八氧代正丁基酞菁铜、1,4,8,11,15,18,22,25-八氧代丁酸甲酯基酞菁锰、1,4,8,11,15,18,22,25-八氧代正丁酸甲酯基酞菁铜、1,4,8,11,15,18,22,25-八氧代正丁酸甲酯基酞菁锌这四种新型八取代酞菁的红外光谱、紫外光谱和荧光光谱的性质...     

轴向嘧啶衍生物修饰硅酞菁的光谱性质、光动力抗癌活性及与白蛋白相互作用的研究

研究了一种新型轴向修饰硅酞菁,即二(2-氨基-6-三氟甲基-4-嘧啶氧基)硅酞菁(SiPcF)的光物理光化学性质、离体光动力抗癌活性以及与白蛋白的相互作用。结果表明,SiPcF的Q带最大吸收峰波长686nm,摩尔吸光系数为2.3×105 mol-1.L.cm-1,荧光发射峰694nm,荧光量子产率为0.46,光敏化产生单线态氧的量子产率为0.38,是有效的1 O2光敏剂。SiPcF与牛血清白蛋白(BSA)具有较强的相互作用,两者的结合常数为4.33×105 mol.L-1,结合位点数为1。离体细胞实验表明,SiPcF具有较高的光动力抗癌活性,对人肝癌细胞HepG2的IC50值为5×10-7 mol.L-1。     

一种新的测量单线态氧的化学发光体系

通过试验,建立了以磺化铝酞菁(Alpcs)-海萤萤光素类似物(CLA)经He-Ne激光照射产生并可检测单线态氧的化学发光体系,该体系灵敏、简便、快速、实用.     

p-HPcCo和p-HPcZn的非线性光学性质研究

采用皮秒Z-扫描技术研究了两种不同中心金属取代的酞菁配合物2,9,16,23-四-(对羧基苯氧基)酞菁钴(p-HPcCo)和2,9,16,23-四-(对羧基苯氧基)酞菁锌(p-HPcZn)的非线性光学性质,并从离域电子共轭结构理论和共振、非共振增强理论进行了分析.结果表明:吸电子能力强的金属离子Zn2+取代的p-HPcZn的吸收带相对于Co2+取代的p-HPcCo略有红移;两种样品均具有正的三阶非线性极化率,共振增强使得p-HPcZn和p-HPcCo的三阶非线性极化率在532nm条件下比1064nm条件下增强了近两个量级,中心金属离子强的吸电子能力使得p-HPcZn的三阶非线性极化率大于p-HPcCo,并在532nm激发时,χ(3)具有最大值1.76×10-10esu.     

间二羧基苯氧基取代酞菁锌与白蛋白共价结合物的合成与光谱性质

制备了四种由β-四(3,5-二羧基苯氧基)酞菁锌(记为1)和β-八(3,5-二羧基苯氧基)酞菁锌(记为2)与人血清白蛋白(HSA)或牛血清白蛋白(BSA)构成的共价结合物,结合物中酞菁与白蛋白的摩尔组成比为6～7:1.在PBS溶液中的电子吸收光谱测试表明,当酞菁1共价结合到白蛋白上后,呈现出更明显的单体特征吸收(单体特...     

Aqueous Synthesis of Water-Soluble Citrate-Modified Cadmium Selenide/Cadmium Sulfide/Zinc Sulfide Quantum Dots

Water-soluble cadmium selenide/cadmium sulfide/zinc sulfide core/shell/shell quantum dots were synthesized in aqueous solution using trisodium citrate as modifier. The crystal structure, morphology, component, and spectral properties of cadmium selenide/cadmium sulfide/zinc sulfide core/shell/shell quantum dots were characterized by X-ray power diffraction, transmission electron microscope, energy dispersive X-ray analysis, infrared spectrum, ultraviolet–visible absorption spectrum, and fluorescence spectrum. The results show that the spherical citrate-modified cadmium selenide/cadmium sulfide/zinc sulfide core/shell/shell quantum dots with diameter around 3.6 nm belong to the cubic zinc blende structure. The citrate-modified cadmium selenide/cadmium sulfide/zinc sulfide core/shell/shell quantum dots show a narrow, symmetric, and strong fluorescence emission spectrum band with narrow full width at half maximum of 53 nm, and the fluorescence quantum yield can reach up to 37.3%. The high-quality citrate-modified cadmium selenide/cadmium sulfide/zinc sulfide core/shell/shell quantum dots with good fluorescence properties have potential for application in biological fluorescence analysis.     

Aqueous Synthesis of Water-Soluble L-Cysteine-Modified Cadmium Sulfide Doped with Silver Ion/Zinc Sulfide Nanocrystals

The water-soluble silver ion-doped cadmium sulfide nanocrystals were synthesized by a co-precipitation technique in aqueous solution using L-cysteine as surface modifier, and then L-cysteine-modified cadmium sulfide doped with silver ion/zinc sulfide core/shell nanocrystals were prepared by zinc sulfide epitaxial coated on surface of silver ion-doped cadmium sulfide nanocrystals. The crystal structure, morphology, and spectral properties of cadmium sulfide doped with silver ion/zinc sulfide nanocrystals were characterized by X-ray power diffraction, transmission electron microscope, infrared spectrum, and photoluminescence spectrum. The results show that the photoluminescence quantum yield of cadmium sulfide doped with silver ion/zinc sulfide nanocrystals is improved greatly after doped with silver ion and coated with zinc sulfide shell. The cysteine modified on the surface of cadmium sulfide doped with silver ion/zinc sulfide nanocrystals renders the nanocrystals water-soluble and biocompatible.     

Effect of different catalysts and growth temperature on the photoluminescence properties of zinc silicate nanostructures grown via vapor-liquid-solid method

We explore the photoluminescence properties of zinc silicate (Zn₂SiO₄) nanostructures synthesized by vapor-liquid-solid (VLS) mode of growth using three different catalysts (Sn, Ag, and Mn). Different catalysts significantly influence the growth rate which in turn has an impact on the structure and hence the photoluminescence of the prepared zinc silicate nanostructures. Zn₂SiO₄ has a wide bandgap of about 5.5 eV and in its pure form, it does not emit in visible region due to its inner shell electronic transitions between the 3d⁵ energy levels. However, the incorporation of different catalysts (Sn, Ag and Mn) at different growth temperatures into the Zn₂SiO₄ crystal growth kinetics provides wide visible spectral range of photoluminescence (PL) emissions. PL analysis shows broad multi-band spectrum in the visible region and distinct colors (red, yellow, green, blue, cyan and violet) are obtained depending on the crystalline structure of the prepared nanostructures. The allowed transitions due to the effect of different catalysts on zinc silicate lattice offer a huge cross-section of absorption that generates strong photoluminescence. The correlation between the structural and optical properties of the synthesized nanostructures is discussed in detail. The synthesized photoluminescent nanostructures have potential applications in solid-state lighting and display devices.     

Interaction between the end groups and the main chain of conjugated polymers by time-resolved EPR and fluorescence spectroscopy

ABSTRACT

Interaction between a zinc porphyrin (ZnPor) as the end-group and poly(9,9-di-n-octylfluorene-2,7-vinylene) (PFV) as the main chain in a porphyrin end-modified fluorescent conjugated polymer, ZnPFV, was studied by time-resolved electron paramagnetic resonance (EPR) and fluorescence spectroscopy. While fluorescence from the PFV part of ZnPFV showed a spectral profile almost identical to that of a PFV oligomer without end-modification, the emission spectrum of the ZnPor part exhibited a much broader profile compared to that of the reference zinc porphyrin monomer. Based on the analysis of lifetimes and quantum yields, it was found that radiative rate constant of the ZnPor part was enhanced by nearly three times. The observed unusual enhancement in the radiative rate constant was rationalised in terms of a partial π-conjugation between the end group and the main chain, as a result of co-planarisation in fluid solution. On the other hand, the time-resolved EPR spectrum of ZnPFV at 100?K basically showed a similar spectral pattern to that of the reference zinc porphyrin, but with significant differences in zero-field spitting parameters and initial population ratios. The π-system of the excited triplet state is deduced to deviate from D_4h symmetry in the end zinc porphyrin groups. The obtained results show that interaction of the porphyrin end group with the main chain of the polymer significantly influences the excited singlet state properties of the porphyrin, while its triplet state properties were affected to a lesser extent.     

含喹啉基团的杯芳烃衍生物的合成及其Zn2+和Cu2+配合物光谱性质的研究

杯[4]芳烃下缘引入荧光基团,合成了一种具有荧光特性的新型杯[4]芳烃衍生物(25,27-二2-甲基喹啉杯[4]芳烃,简称MQBC)。通过红外光谱、元素分析、核磁共振氢谱、质谱等波谱分析确定其结构。研究了MQBC的紫外光谱和荧光光谱,并对其Zn2 和Cu2 配合物的荧光性质进行了分析。MQBC与Zn2 和Cu2 作用主要源于其杯式腔体下缘的氧原子提供孤对电子参与配位,紫外光谱实验发现MQBC与Zn2 作用后,226 nm处的吸收强度减弱,315 nm处吸收强度增强,同时测定了结合常数(K=2 064 L.mol-1)与结合比(n=1),MQBC有用于对微量Zn2 检测的前景。荧光光谱实验发现MQBC存在分子内光诱导电子转移过程(PET),导致其荧光较弱;当其与Zn2 和Cu2 生成配合物后,光诱导电子转移受阻,荧光增强。文章初步探讨了光诱导电子受阻作用机理,研究了Zn2 和Cu2 浓度对荧光强度的影响。     

Spectral and photochemical characteristics of the photosensitizers chlorin <Emphasis Type="Italic">e</Emphasis><Subscript>6</Subscript> and photolon in the presence of melanin

The effect of DOPA melanin on the spectral and kinetic properties of the photosensitizers chlorin e ₆ and Photolon in buffer solutions with different pH (8.5, 7.0, and 6.0) is studied. The data obtained indicate that no complex formation between molecules of DOPA melanin and either photosensitizer in the ground or excited states occurs (at least, at melanin concentrations ≤0.1 mg/ml). The presence of melanin in the samples has no effect on the spectral-luminescent or kinetic characteristics of either chlorin e ₆ or Photolon. At a small concentration of DOPA melanin (≤0.02 mg/ml), the quantum yield of generation of singlet oxygen by the photosensitizers does not change; however, the generation efficiency of singlet oxygen decreases due to the shielding action of melanin.     

Generation of singlet oxygen by indotricarbocyanine dyes in low-polarity media

We present the results of a study of the spectral luminescence properties of three groups of indotricarbocyanine dyes, each of which is formed from compounds with the same cation and different anions. In high-polarity solvents, in the absorption and emission spectra of the dyes we see one type of center; in low-polarity solvents, due to the presence of different ionic forms of the dyes (free ions, contact ion pairs), we observe either one type or two types of centers. By analysis of the luminescence of molecular oxygen in the 1.27 μm spectral region, we determined the efficiency of photosensitization of ¹O₂ formation by dyes in deuterated solvents. We have shown that in low-polarity solvents, the yield for singlet oxygen generation is higher for indotricarbocyanine dyes which are found in the contact ion pair state and which also contain a heavy atom (I) in the anion. We have observed that an increase in the fraction of contact ion pairs in solution as the dye concentration increases or when an additional salt is introduced leads to an increase in the quantum yield for generation of singlet oxygen. In polar deuterated acetonitrile, the counterion has no effect on the efficiency of photosensitization of oxygen by the dyes. Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 75, No. 5, pp. 684–693, September–October, 2008.     

Biophysical Properties of Phenyl Succinic Acid Derivatised Hyaluronic Acid

Modification of hyaluronic acid (HA) with aryl succinic anhydrides results in new biomedical properties of HA as compared to non-modified HA, such as more efficient skin penetration, stronger binding to the skin, and the ability to blend with hydrophobic materials. In the present study, hyaluronic acid has been derivatised with the anhydride form of phenyl succinic acid (PheSA). The fluorescence of PheSA was efficiently quenched by the HA matrix. HA also acted as a singlet oxygen scavenger. Fluorescence lifetime(s) of PheSA in solution and when attached to the HA matrix has been monitored with ps resolved streak camera technology. Structural and fluorescence properties changes induced on HA-PheSA due to the presence of singlet oxygen were monitored using static light scattering (SLS), steady state fluorescence and ps time resolved fluorescence studies. SLS studies provided insight into the depolymerisation kinetics of PheSA derivatised HA matrix in the presence of singlet oxygen. Time resolved fluorescence studies grave insight into the dynamics of the reaction mechanisms induced on HA-PheSA by singlet oxygen. These studies provided insight into the medical relevance of PheSA derivatised HA: its capacity of scavenging singlet oxygen and of quenching PheSA fluorescence. These studies revealed that HA-PheSA is a strong quencher of electronic excited state PheSA and acts as a scavenger of singlet oxygen, thus medical applications of this derivatised form of HA may protect tissues and organs, such as skin, against reactive oxygen species damage.     

近红外微弱光信号检测镜头的研制

运用ZEMAX设计了一款大孔径、小畸变微弱光信号检测镜头,与高灵敏近红外CCD图像传感器匹配,实现了对微弱单态氧¹O₂信号的实时、快速、高准确度的检测.检测镜头相对孔径1:0.86,半像高为6.3 mm,光谱范围为1 250~1 290 nm,放大倍率为1X,畸变小于0.1%.运用AutoCAD设计光学系统的机械结构,采用双高斯对称式结构以降低成本,手动聚焦、直插式滤片切换机构方便实验的调节,检测镜头研制成功并在实验中采集到较好的微弱单态氧¹O₂信号.