卟啉-噁二唑二元体系光诱导能量及电子传递研究

以5-对氨基苯基-10,15,20-三苯基卟啉及2-苯基-5-(对氨基苯基)-1,3,4-噁二唑为原料合成了系列卟啉-噁二唑二元化合物, 其结构通过¹H NMR, ESI-MS, IR, UV-Vis确定. 对合成化合物进行光谱性能测定, 结果表明, 在卟啉与噁二唑混合体系中, 存在着卟啉激发态分子向噁二唑基态分子的分子间电子传递过程, 导致卟啉激发态的荧光猝灭; 在卟啉-噁二唑二元体系中, 315 nm激发下发生了由激发态噁二唑基团至卟啉基团的能量传递, 导致噁二唑基团荧光猝灭, 卟啉基团荧光增强. 420 nm激发下不存在分子内卟啉基团向噁二唑基团的电子回传竞争; 电化学性能测定进一步表明从噁二唑基团向卟啉基团的电子传递是可能的. 因此卟啉-噁二唑二元化合物可能作为一种模型, 模拟光合作用中电子给体至叶绿素之间的电子传递过程.     

2-(2-氨基苯基)苯并噻唑与四苯基卟啉及四苯基锌卟啉的荧光共振能量转移

采用紫外光谱和荧光光谱法研究了四氢呋喃溶液中2-(2-氨基苯基)苯并噻唑(APBT)与四苯基卟啉(TPP)、四苯基锌卟啉(ZnTPP)之间的相互作用。结果表明,APBT可作为能量供体分子分别与能量受体分子TPP或ZnTPP构成荧光共振能量转移(FRET)体系,APBT的作用将使TPP和ZnTPP的荧光增强。在此FRET体系中,APBT与TPP及ZnTPP作用的分子结合比分别为2∶1和3∶1,能量转移效率分别为0.180 3和0.137 5,能量转移临界距离分别为3.76和3.44 nm,供体-受体分子间距离分别为4.31和3.88 nm。     

meso-四[(4-苯乙烯氨基)苯基]卟啉合成及其波谱特点

以吡咯和对硝基苯甲醛为原料,经过环化、还原和缩合,合成了meso-四[(4-苯乙烯氨基)苯基]卟啉(TBAPP),通过UV-Vis、FT-IR、1H NMR及元素分析等对产物进行了表征,并对其荧光和电子顺磁共振特性进行了研究。 卟啉产物的EPR测定显示出游离基特征,表明卟啉分子的大π共轭结构对周边基团产生的自由基有稳定作用。 取代基对卟啉的紫外 可见吸收、光致发光及电子顺磁共振特性均有影响。 四席夫碱苯基卟啉TBAPP的Q带比前体四氨基卟啉（TAPP）和母体四硝苯基卟啉（TNPP）红移,而Soret谱带变化较小;TBAPP的440 nm光激发的最大荧光峰658 nm分别比TAPP蓝移5 nm和比TNPP红移9 nm;TBAPP的EPR精细结构比TAPP弱,而比TNPP强。     

ClInPc-(TPD-PVK)光电导体性能的研究

本文以氯化酞菁铟(ClInPc)为载流子发生层(CGL),四苯基联苯胺(TPD)与聚乙烯咔唑(PVK)复合为载流子传输层(CTL),形成双层结构的功能分离型有机光电导体(P/R),研究了它的静电感光性能。结果表明,ClInPc/PMMA(30%)与TPD/PVK(1:1)两者匹配时的P/R具有良好的光电导性能,其电荷接受能力V_max≈800V,光电导率△V_t(ls)>70%,暗衰小(<50V/s),残余电位低(30V/s).由真空蒸镀成膜(CGL)所研制的P/R的光电导性能更为优异。     

含酚酞基团的聚酰亚胺膜材料的合成与性能

将酚酞分别和对氯硝基苯、2-氯-5-硝基三氟甲苯经Williamson反应得到3,3-双[(4-硝基苯氧基)苯基]酚酞和3,3-双[(4-硝基-2-三氟甲基苯氧基)苯基]酚酞;在Pd/C-水合肼还原作用下分别得到3,3-双[(4-氨基苯氧基)苯基]酚酞(Ⅰ)和3,3-双[(4-氨基-2-三氟甲基苯氧基)苯基]酚酞(Ⅱ).采用上述2种二胺单体分别与1,2,3,4-环丁烷四酸二酐(CBDA)、均苯四甲酸二酐(PMDA)、3,3,4,4-二苯醚四酸二酐(ODPA)和六氟二酐(6FDA)通过两步法制备出8种含酚酞基团的聚酰亚胺(PI)薄膜,然后采用核磁(NMR)、红外光谱(FTIR)、X-射线衍射仪(XRD)、紫外-可见分光光度计(UV-Vis)、热重分析仪(TGA)、示差扫描量热仪(DSC)和溶解性测试等测试手段和方法对所得到的PI的化学结构、光学性能、热性能和和溶解性等性质进行表征.研究结果表明,这些PI主要表现出非晶结构,且具有良好的溶解性和热性能;除PMDA基PI外,其余PI均表现出良好的浅色、透明特性.     

柔性OLED显示用聚酰亚胺基板的合成与性能

合成了一种含吡啶结构的刚性二胺,2-(4-氨基苯基)-5-氨基吡啶(PD),将其与二氨基二苯醚(ODA)以及均苯四甲酸二酐(PMDA)共聚,调控分子链中刚性与柔性结构单元的比例,制备出一系列聚酰亚胺共聚物.结果表明:随着聚酰亚胺中含吡啶结构的刚性二胺PD含量增加,玻璃化转变温度显著提高(Tg450℃),热膨胀系数逐渐降低(CTE5×10~(-6)K~(-1),50～400℃).同时,聚酰亚胺薄膜的拉伸强度提高(1.25倍),模量显著增加(4.53倍),但仍保持较高的断裂伸长率(35%).利用广角X射线衍射(WAXD)分析聚合物聚集态结构表明,含吡啶结构刚性二胺(PD)的引入使聚酰亚胺分子链倾向于有序排列和紧密堆积,结晶度增加.因此,通过调控聚合物链中刚性二胺(PD)含量可使PI薄膜同时达到优异的尺寸稳定性、高耐热性、高强度以及较好的柔韧性,此类PI有望应用于柔性OLED显示领域.     

新型咔唑类卟啉的合成与性能

以咔唑、对氟苯甲醛和吡咯为原料制得meso-四（4-咔唑）苯基卟啉（TCPP）。以对硝基苯甲醛与吡咯为原料制得meso-四(4-硝基)苯基卟啉（TNPP）； TNPP经还原反应制得meso-四（4-氨基苯基）卟啉（TAPP）; TAPP与咔唑苯甲醛经缩合反应制得新型meso-四[对-（P-N-咔唑基亚苄基亚氨基）]苯基卟啉(TCIPP)，其结构和性能经UV-Vis, ¹H NMR, ¹³C NMR, IR,元素分析和循环伏安法（CV）表征。结果表明：TCPP在270~300 nm处有新吸收峰；TCIPP的Q带和B带相比于TCPP有明显红移。TCPP和TCIPP的E_LUMO和E_HOMO分别为-3.18 eV, -5.17 eV和-3.49 eV, -5.08 eV，两者的能级结构与纳米TiO₂的导带能级相匹配。     

卟啉化合物的研究(ⅩⅩ)——5-(p-十六烷氧基苯基)-10,15,20-三苯基卟啉和5-(p-十六羰酰氧苯基)-10,15,20-三苯基卟啉的合成及光电性质的研究

在卟啉的苯环上接上4～30个碳的长链,则其光电化学性能增强,并成为性能良好的充电导膜材料及照相感光材料。为此,本文合成了5-(p-十六烷氧基苯基)-10,15,20-三苯基卟啉(Ⅱ)和5-(p-十六羰酰氧苯基)-10,15,20-三苯基卟啉(Ⅲ),合成路线如下:     

聚酰亚胺/聚丙烯腈共混黑膜的制备及其结构与性能

采用共混的方法制备聚酰胺酸/聚丙烯腈(PAA/PAN)共混溶液.其中2种PAA溶液分别由二酐(3,3′,4,4′-联苯二酐(BPDA)与均苯四甲酸二酐(PMDA))和二胺(对苯二胺(PDA)与4,4′-二氨基二苯醚(ODA))均聚或共聚而得,N,N-二甲基乙酰胺(DMAc)为溶剂,PAN溶于DMAc中制成溶液后与PAA溶液混合,涂膜后热处理制得聚酰亚胺(PI)/PAN共混薄膜.分析了PAA和PAN在热处理过程中的变化,以及PAN的加入量对共混薄膜的结构与性能的影响.结果表明,在热处理过程中,PAA完成了亚胺化成为PI,而PAN完成了预氧化,形成了稳定的梯形结构,制备出具有良好力学性能、黑色、不透光的薄膜,但是随着PAN含量的增加,体系发生明显的相分离,薄膜力学性能有所下降,(BPDA/PDA/ODA)PI中加入10%的PAN和(PMDA/ODA)PI中加入20%的PAN时能获得具有良好力学性能的黑色、低透光率的薄膜.     

荧光无机/有机杂化纳米分子口袋的构建

利用能量匹配原则将无机半导体ZnO纳米粒子与有机半导体四苯基卟啉四羧酸(TCPP)分子进行组装, 在无机-有机组分之间的界面构建了杂化纳米分子口袋ZNPs-TCPP, 该纳米分子口袋对四苯基卟啉(TPP)分子具有高选择性识别功能, 同时其荧光增强了5倍以上, 并成功地将该杂化纳米分子口袋用于肺腺癌细胞(A549)的细胞成像.     

One-Pot Functionalization of Graphene with Porphyrin through Cycloaddition Reactions

Two types of graphene‐based hybrid materials, graphene‐TPP (TPP=tetraphenylporphyrin) and graphene‐PdTPP (PdTPP=palladium tetraphenylporphyrin), were prepared directly from pristine graphene through one‐pot cycloaddition reactions. The hybrid materials were characterized by thermogravimetric analysis (TGA), by TEM, by UV/Vis, FTIR, Raman, and luminescence spectroscopy, and by fluorescence/phosphorescence lifetime measurements. The presence of the covalent linkages between graphene and porphyrin was confirmed by FTIR and Raman spectroscopy and further supported by control experiments. The presence of TPP (or PdTPP) in the hybrid material was demonstrated by UV/Vis spectroscopy, with TGA results indicating that the graphene‐TPP and graphene‐PdTPP hybrid materials contained approximately 18 % TPP and 20 % PdTPP. The quenching of fluorescence (or phosphorescence) and reduced lifetimes suggest excited state energy/electron transfer between graphene and the covalently attached TPP (or PdTPP) molecules.     

Entanglement of polymer chains in ultrathin films

This investigation aimed to clarify the issue of whether polymer chains are entangled in ultrathin films spin-coated onto substrates. This was done using a fluorescence probe method to observe the behavior of two types of poly(methyl methacrylate) (PMMA), one having a carbazolyl (Cz) moiety (PMMA-Cz) and the other having an anthryl (At) moiety (PMMA-At). In both cases, the moiety fraction was 1 unit for 400 units of polymer. We prepared ultrathin films (thickness: 4-88 nm) on quartz substrates from PMMA-Cz, PMMA-At, and a mixture of the two using a spin-coating method. When the PMMA films prepared from the mixture of the two PMMAs were excited at 292 nm, which is preferentially absorbed by Cz rather than At, the Cz fluorescence was found to be quenched dramatically while the At fluorescence increased significantly. This effect is due to the proximity of the Cz to the At, which permits the transfer of excitation energy between them. The average distance between Cz and At can be calculated using the F?rster mechanism. When the ultrathin film thickness was between 12 and 88 nm, the average distance was found to be 2 nm. This is much shorter than the radii of gyration of the polymers. From this it is clear that two polymer molecules in an ultrathin film do experience entanglement, as has been hypothesized. Thus, we conclude that the difference between certain properties of ultrathin films and the properties of the same materials in bulk are not induced by a decrease in the level of polymer chain entanglement.     

Synthesis and Characterization of New Conjugated Fluorenyl‐Porphyrin Dendrimers for Optics

A new family of conjugated meso‐tetraphenylporphyrin‐based dendrimers with four ( TPP1 , TPP2 ), eight ( TPP3 , TPP4 , TPP5 ) and up to sixteen ( TPP6 ) fluorenyl groups has been synthesized and fully characterized. These tetraphenylporphyrin‐cored dendrimers present peripheral alkynyl π‐conjugated dendrons with fluorenyl termini. The meso‐aryl rings of these porphyrins are functionalized either in para‐ ( TPP1 , TPP2 , and TPP3 ) or meta‐positions ( TPP4 , TPP5 , and TPP6 ). Their detailed luminescence properties are discussed in reference to two porphyrins lacking fluorenyl dendrons ( TPP ‐ H_1,2,3 and TPP ‐ H_4,5,6 ). A strong dependence of their luminescence quantum yield and lifetime on their structures is stated, their nonlinear optical properties were also discussed.     

Synthesis and spectroscopic analysis of tetraphenylporphyrinatoantimony(V) complexes linked to boron-dipyrrin chromophore on axial ligands

Tetraphenylporphyrinatoantimony(V) complexes, linked to boron-dipyrrin chromophores on axial ligands, were synthesized. The fluorescence spectra of 1a, 1b and 1c (3-[4-(N,N′-difluorobornyl-5-dipyrrinyl)phenyl]propoxo(methoxo)antimony(V) tetraphenylporphyrin bromide (1a); 6-[4-(N,N′-difluorobornyl-5-dipyrrinyl)phenyl]hexyloxo(methoxo)antimony(V) tetraphenylporphyrin bromide (1b); bis{3-[4-(N,N′-difluorobornyl-5-dipyrrinyl)phenyl]propoxo}antimony(V) tetraphenylporphyrin bromide (1c)) were analyzed under the excitations of N,N′-difluorobornyl-5-dipyrrinylphenyl (Bdpy) and tetraphenylporphyrinatoantimony(V) (Sb(TPP)) chromophores. Under the irradiation of Bdpy chromophore, the excitation energy was transferred from Bdpy chromophore to the Sb(TPP) moiety at 0.13–0.40 of the quantum yields, even in a polar solvent. On the other hand, the emission of Sb(TPP) chromophores was quenched by Bdpy chromophores at rate constants of 10⁸–10⁹ s⁻¹, independent of on the solvent polarity. Under the excitation of the Bdpy chromophore of 1d (3-[4-(N,N′-difluorobornyl-5-dipyrrinyl)phenyl]propoxo(phenyloxo)antimony(V) tetraphenylporphyrin bromide) involving both the Bdpy and the phenoxy chromophores on the axial ligands, the excited singlet state of the Sb(TPP) chromophore generated by the energy transfer from the Bdpy chromophore was quenched by the phenoxy ligand via non-radiative processes involving electron transfer. However, rapid back electron-transfer may occur because no absorption of the anion radical of Sb(TPP) was observed by nanosecond laser photolysis.     

Imaging by sensitized oxygenations of photochromic anthracene films: examination of effects that improve performance and reversibility

The aliphatic anthracene compound 1 and the oligomeric anthracene 2 were synthesized. Thin films of 1 and 2 mixed with the sensitizers tetraphenylporphyrin (TPP) and methylene blue (MB) were irradiated with visible light in air. Upon formation of singlet oxygen, the anthracene units were converted quantitatively to the corresponding endoperoxides. Heating of the irradiated samples afforded the parent anthracenes with high yields. Here, we demonstrate that the kinetics and reversibility of this reaction strongly depend on the microenvironment of the anthracene groups in the two compounds. The photooxidation of thin films of 1 is accompanied by interesting changes in the morphology of the film and allows the first application of 1 as a nondestructive negative-tone photoresist for lithography and as an oxidizing ink. The morphology of 2 remained unchanged after photooxidation as a result of the stabilizing oligomer backbone. This stabilizing effect significantly improves the photochromic performance of 2. The reversibility of the photooxidation is very high (>90 %) for oligomeric films of 2 after several cycles of irradiation and heating. Decomposition of the anthracene and a loss of the activity of the sensitizer diminish slightly the performance of the monomeric species.     

Effect of zeolite properties on ground-state and triplet-triplet absorption, prompt and oxygen induced delayed fluorescence of tetraphenylporphyrin at gas/solid interface

The ground-state and transient absorption, prompt and delayed fluorescence of tetraphenylporphyrin (TPP) adsorbed onto the external surface of different zeolites was monitored using diffuse-reflectance steady-state and laser flash photolysis. The delayed fluorescence (DF) of TPP detected in the presence of O2 is attributed to the energy transfer from 3TPP to 3O2 to form 1O2 and subsequent energy transfer from 1O2 to some other 3TPP within the organised molecular ensembles on the zeolite surface. The spectroscopic and kinetic parameters, namely the yield of DF (2-20% relative to prompt fluorescence), depend on the zeolite properties: the observed differences were correlated with the acid-base properties of the two zeolite series studied in this work (KA, NaA, CaA) and (NaA, NaX, NaY).     

Preparation and characterization of 5,10,15,20‐tetraphenylporphyrin Langmuir films for gas chemsensor applications

In this work is reported the preparation and characterization of 5,10,15,20‐tetraphenylporphyrin (H₂TPP) films at the water‐air interfaces. The surface pressure‐area isotherms (π‐A) and UV‐Vis spectroscopy were used to investigate the effect of the spreading methods and parameters on the porphyrin monolayer formation. Also, Langmuir‐Blodgett (LB) and Langmuir‐Schaefer (LS) films were deposited onto glass substrates in order to study the conformation changes in porphyrin molecular packing. Quartz crystal microbalance (QCM) was utilized as the active solid substrate for the development of the NO₂ gas sensor based on the H₂TPP molecular films. The results of π‐A curves have clearly shown the significant contribution of the preparation methods and processing parameters on the conformation of porphyrin molecular films. The UV‐Vis spectroscopy results using polarized absorption dichroism have indicated different molecular packing for porphyrin films deposited by LB and LS methods, with relative tilted angles of 50° ± 5° and 35° ± 5°, respectively. Moreover, the QCM response has given strong evidence that H₂TPP porphyrin molecular films have performed as NO₂ chemsensor. Copyright © 2011 John Wiley & Sons, Ltd.     

Facile electrosyntheses of high tensile strength alkyl‐bridged dicarbazole polymer films and its fluorescence spectra

Homogeneous and high‐quality free‐standing poly(1,6‐bis(carbazolyl) hexane) (P2Cz‐H) and poly(1,12‐bis(carbazolyl)dodecane) (P2Cz‐D) films were electrochemically synthesized in CH₂Cl₂ + 0.1 M tetrabutylammonium tetrafluoroborate solution. The electrochemical and physical properties indicated that the quality of P2Cz‐D film with tensile strength of 165 kg cm⁻² was better than that of P2Cz‐H due to the flexible monomer 1,12‐bis(carbazolyl)dodecane (2Cz‐D) has a longer carbon chain than that of monomer 1,6‐bis(carbazolyl)hexane (2Cz‐H). On the other hand, both the dicarbazole monomers showed better polymer‐film‐forming capabilities than the single carbazole monomer, partly because of the special design of the polymer backbone constituted of stiff bicarbazyl chromophores linked by flexible long carbon segments. The structures of both dicarbazole polymers were investigated by UV–visible, infrared spectroscopy and scanning electron microscopy. Fluorescence spectral studies revealed that the two dedoped polymer films in solid state had strong emissions at ca. 411 and 415 nm. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 5232–5241, 2008     

Spectroscopic and optical characterization of porphyrin chromophores incorporated into ultrathin polyimide films

Polyamic acid (PAA) containing free-base porphyrin and zinc(II) porphyrin chromophores was synthesized by copolymerization of diphenylether-type tetracarboxylic dianhydride and diamines. The monolayer of the alkylamine salts of PAA (PAASs) at the air/water interface was deposited on solid substrates by the Langmuir-Blodgett (LB) technique. The PAAS LB films thus obtained were converted to polyimide (PI) LB films by chemical treatment. The fluorescence of porphyrin moieties in the PI LB film was observed, because of the weak electron-accepting properties of the diphenylether unit. Therefore, the photophysically important processes, such as photoinduced electron transfer, excitation energy transfer, and excitation energy migration could be investigated in relation to the layered nanostructures of the ultrathin PI films. The fluorescence spectrum suggested that the aggregation of porphyrin moieties in the PI LB films was effectively prevented by the use of polymeric films. The surface plasmon (SP) measurement showed that the thickness of the monolayers was 0.9-1.0 nm for PAAS films and 0.32-0.40 nm on average for PI LB films. The absorption dichroism of the Soret band of porphyrin indicated that porphyrin moieties in the PAAS and PI LB films are oriented in parallel with the substrate. These results showed that the orientation and the spatial distribution of porphyrin units can be efficiently regulated in the PI LB films in a nanometer dimension.     

Electrocatalytic Reduction of Oxygen at Glassy Carbon Electrodes Coated with Diazonium‐derived Porphyrin/Metalloporphyrin Films

In this study, the influence of the film structure was investigated on the electrocatalytic oxygen reduction at GC electrodes covered with porphyrin and metalloporphyrin rings via the diazonium modification method. For that purpose, primarily, tetraphenylporphyrin (TPP) films on GC electrode surfaces were prepared by electroreduction of in situ generated diazonium salts of 5‐(4‐aminophenyl)‐10,15,20‐triphenylporphyrin (APP) and 5,10,15,20‐tetrakis(4‐aminophenyl)porphyrin (TAPP) molecules. Next, the formation of metalloporphyrin films on the modified surfaces was accomplished through the complexation reactions of surface porphyrin rings with metal ions in the salt solutions containing Mn(II), Fe(III) and Co(II) ions. The resulting porphyrin and metalloporphyrin layers were identified with XPS and ICP‐MS. The electrochemical barrier properties of the films on GC surfaces were examined by cyclic voltammetry in K₃Fe(CN)₆ aqueous solution. The electrocatalytic abilities of the resulting films were also investigated for the oxygen electrochemical reduction by employing cyclic voltammetry in PBS solutions saturated with oxygen. The results showed that the oxygen reduction potentials on modified GC electrodes were shifted to less negative potentials compared to that of bare GC electrode. Also, it was obtained that the oxygen reduction reaction was more effective on the GC electrodes modified with TPP rings by using TAPP molecules than those prepared by using APP molecules.