Unique behaviors of polymers having metalloporphyrin as their side chains

Several kinds of polymers having tetraphenylporphyrin (TPP) or some metallotetraphenylporphyrin (AgTPP, CuTPP, VOTPP or ZnTPP) moieties as their side chains have been prepared by the radical polymerization of the corresponding vinyl monomers. Visible spectra of these polymers show the clear hypochromism in the Soret bands of the tetraphenylporphyrin moieties as compared with those of the corresponding monomers. Polymer effects were clearly observed in the magnetic behaviors and the oxygen adsorption of paramagnetic metalloporphyrin moieties. In addition, polymer effects on photophysical and photochemical behaviors of ZnTPP were found in the amphiphilic polymers covalently tethered with small amounts of ZnTPP and hydrophobic substituents above a critical content, which form hydrophobic domains due to aggregation of the hydrophobic groups in aqueous solution.     

通过轴向配位反应实现4-乙烯基吡啶聚合物的卟啉功能化

通过轴向配位反应,将四苯基卟啉锌(ZnTPP)键合在4-乙烯基吡啶(4VP)与苯乙烯(St)共聚物P(4VP-co-St)的侧链,制得了卟啉功能化的大分子ZnTPP-P(4VP-co-St).通过FTIR与1H-NMR对其化学结构进行了表征,重点研究了时间、温度对轴配过程的影响,以及大分子轴配化合物ZnTPP-P(4VP-co-St)的谱学性能,对其光物理行为进行了较为深入的分析.研究结果表明,以共聚物P(4VP-co-St)的吡啶侧基为配体,通过轴向配位反应可顺利地制备卟啉功能化的大分子ZnTPP-P(4VP-co-St),且温度越低,键合量越大.该大分子具有类似于ZnTPP的特征电子吸收光谱与荧光发射光谱,同时也显示出轴向配位的特征.与小分子ZnTPP相比,ZnTPP-P(4VP-co-St)的吸收光谱和发射光谱都发生了明显的红移.大分子轴配化合物ZnTPP-P(4VP-co-St)的光物理行为也呈现出一定程度的高分子效应,随着大分子链中ZnTPP键合量的增大,相近的ZnTPP侧链单元之间会发生能量转移,使荧光发射强度有所减弱.     

Functionalizable polycyclic aromatics through oxidative cyclization of pendant thiophenes

We present a general strategy for obtaining large sulfur-containing polycyclic aromatics from thienyl precursors through iron(III) chloride mediated oxidative cyclizations. By placing thienyl moieties in close proximity to adjacent arenes, we have directed the oxidized intermediates into controlled cyclization pathways, effectively suppressing polymer formation. Utilizing these cyclized compounds and their thienyl precursors, we have studied cyclization/polymerization pathways of polymers such as poly(2). The unsubstituted positions alpha to the sulfur atoms within these aromatic cores allowed for efficient halogenation and further functionalization. As a demonstration, we prepared a series of arylene-ethynylene polymers with varying degrees of chromophore aromatization and used them to probe the effects of synthetically imposed rigidity on polymer photophysical behavior. The symmetries and effective conjugation pathways within the monomers play a key role in determining photophysical properties. We observed that rigid, aromatized chromophores generally led to increased excited-state lifetimes by decreasing radiative rates of fluorescence decay.     

COMPARTMENTALIZATION OF ZINQII) TETRAPHENYLPORPHYRIN IN A HYDROPHOBIC MICRODOMAIN OF AN AMPHIPHILIC POLYELECTROLYTE: A PHYSICOCHEMICAL MODEL OF BIOLOGICAL METALLOPORPHYRIN SYSTEMS

Abstract— Small mole fractions of zinc(II) tetraphenylporphyrin (ZnTPP) moieties were covalently incorporated into amphiphilic polysulfonates having bulky hydrophobic groups such as lauryl, cyclododecyl, and (2-naphthyi)methyl (Np) groups in their side chains. The ZnTPP moieties are "compartmentalized" in the hydrophobic domains of these amphiphilic polyelectrolytes in aqueous solution. For comparison, the ZnTPP moieties were covalently incorporated into a polysulfonate without hydrophobic groups. The ZnTPP moieties in this reference polymer are exposed to water in aqueous solution. The compartmentalized ZnTPP systems in aqueous fluid solution emitted phosphorescence and thermally activated delayed fluorescence at room temperature. This is due to an extremely long-lived triplet excited state in the compartmentalized systems at room temperature in aqueous solution, e.g. 19 ms for ZnTPP compartmentalized in Np domains, compared with 3 ms for ZnTPP in the reference polymer. These remarkable compart-mentalization effects may be attributed to a restriction of motional freedom of the ZnTPP moiety isolated in a rigid and hydrophobic microenvironment provided by the amphiphilic polyelectrolytes in aqueous solution.     

Facile Synthesis and Enhanced Nonlinear Optical Properties of Porphyrin‐Functionalized Multi‐Walled Carbon Nanotubes

Two multi‐walled carbon nanotube (MWCNT)‐based nanohybrids, MWCNT–ZnTPP and MWCNT–TPP (TPP=5‐[4‐{2‐(4‐formylphenoxy)‐ ethyloxy}phenyl]‐10,15,20‐triphenylporphyrin, ZnTPP=5‐[4‐{(4‐formylphenyl)ethynyl}phenyl]‐10,15,20‐triphenylporphinatozinc(II)), were prepared directly from pristine MWCNTs through 1,3‐dipolar cycloaddition reactions. Covalent attachment of the porphyrins to the surfaces of the MWCNTs was confirmed by Fourier transform infrared spectroscopy, ultraviolet/visible absorption, fluorescence, Raman, and X‐ray photoelectron spectroscopy, elemental analysis, transmission electron microscopy, and thermogravimetric analysis. Attachment of the porphyrin moieties to the surface of the MWCNTs significantly improves the solubility and ease of processing of these MWCNT–porphyrin composite materials. Z‐scan studies reveal that these MWCNT–porphyrin nanohybrids exhibit enhanced nonlinear optical properties under both nanosecond and picosecond laser pulses at λ=532 nm in comparison with free MWCNTs and the free porphyrin chromophores, whereas superior optical limiting performance was displayed by MWCNT–porphyrin composite materials rather than MWCNTs/ZnTPP and MWCNTs/TPP blends, which is consistent with a remarkable accumulation effect as a result of the covalent linkage between the porphyrin and the MWCNTs.     

The effect of β-CD polymers structure on the efficiency of copper(II) ion flotation

β-Cyclodextrin (β-CD) polymers were prepared by cross-linking of β-CD with phtalic and 3-nitrophtalic anhydride in anhydrous N,N-dimethylformamide (DMF) in the presence of NaH. The weight-average molecular weight (M _W) and the chemical structure of the polymers were determined using high performance size exclusion chromatography (HPSEC) with refractive index (RI) detector, and ¹H NMR spectroscopy. The molecular weight of the polymer increased with molar ratio of substrates and reaction temperature. ¹H NMR spectra revealed that the β-CD polymers contained both mono- and diesters of phtalic and 3-nitrophtalic acids. In the case of phtalic moieties about four or five diester moieties groups and for 3-nitrophtalic moieties about to or three diester moieties are linkages for β-CD molecule, respectively. Results of copper(II) flotation obtained with the use of nonylphenol polyoxyethyl glycol ether as an non-anionic surfactant and β-CD polymers as complexation collector agent, show␣that the removal of Cu²⁺ decreases with increase of molecular mass of β-CD polymers linked by phtalic or␣3-nitrophtalic anhydrides. For both derivatives with pH increase the copper(II) removal increase. The highest flotation removal, i.e. 93%, was found for β-CD polymers synthesized at 100 °C with molar ratio CD:NaH:3-nitrophtalic anhydride equal to 1:7:7.     

Electrospun Poly(acrylonitrile-co-acrylic acid) Nanofibrous Membranes for Catalase Immobilization:Effect of Porphyrin Filling on the Enzyme Activity

Porphyrin-filled nanofibrous membranes were facilely prepared by electrospinning of the mixtures of poly(acrylonitrile-co-acrylic acid)(PANCAA) and porphyrins. 5,10,15,20-Tetraphenylporphyrin(TPP) and its metal-loderivatives(ZnTPP and CuTPP) were studied as filling mediators for the immobilization of redox enzyme. Results indicate that the introduction of TPP, ZnTPP and CuTPP improves the retention activity of the immobilized catalase. Among these three porphyrins, the ZnTPP-filled PANCAA nanofibrous membra...     

Synthesis of n‐alkyl methacrylate polymers with pendant carbazole moieties and their derivatives

New methacrylate monomers with carbazole moieties as pendant groups were synthesized by multistep syntheses starting from carbazoles with biphenyl substituents in the aromatic ring. The corresponding polymers were prepared using a free‐radical polymerization. The novel polymers contain N‐alkylated carbazoles mono‐ or bi‐substituted with biphenyl groups in the aromatic ring. N‐alkyl chains in polymers vary by length and structure. All new polymers were synthesized to evaluate the structural changes in terms of their effect on the energy profile, thermal, dielectric, and photophysical properties when compared to the parent polymer poly(2‐(9H‐carbazol‐9‐yl)ethyl methacrylate). According to the obtained results, these compounds may be well suited for memory resistor devices. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2019 , 57, 70–76     

Cyclodextrins in polymer chemistry: Influence of methylated β-cyclodextrin as host on the free radical copolymerization reactivity ratios of isobornyl acrylate and butyl acrylate as guest monomers in aqueous medium

Methylated β-cyclodextrin (me-β-CD) was used to complex the hydrophobic monomers isobornyl acrylate ( 1 ) and butyl acrylate (2) yielding the water-soluble host/guest complexes isobornyl acrylate/me-β-CD ( 1a ) and butyl acrylate/me-β-CD ( 2a ). The included monomers were copolymerized in water by free-radical mechanism and the kinetics were studied. In order to evaluate these results, the corresponding uncomplexed monomers 1 and 2 were also copolymerized in organic solution. The reactivity ratios of 1a and 2a (r _1a = 0.3, r _2a = 1.7) differ significantly from the reactivity ratios of the corresponding uncomplexed acrylates 1 and 2 in organic solution (r ₁ = 1.3, r ₂ = 1.0). In addition, we found that the weight averages of the copolymers prepared by using me-β-CD are significantly higher than those of the corresponding polymers prepared from uncomplexed monomers in organic solution.     

光敏氧化还原反应——四苯基卟啉类化合物光敏还原甲基紫精

在DMSO-H₂O混合溶剂中,用TPP和它的四种金属络合物作为敏化剂,EDTA作为电子给体,经可见光照射,成功地还原了甲基紫精。反应活性顺序为ZnTPP>TPP>MgTPP》CoTPP>CuTPP。对以ZnTPP为敏化剂的反应,我们测得其量子产率为φ_418nm=0.08。我们考察了ZnTPP、MV²⁺和EDTA的浓度以及氧气对反应的影响。在一定浓度范围内,我们发现,反应速度与MV²⁺和EDTA浓度之间的关系符合于从推测的反应机理导出的动力学方程。     

New cyanopyridine‐based π‐conjugative poly(azomethine)s: Synthesis,characterization and electroluminescence studies

Four new Schiff‐base type conjugative polymers (CPs), that is, Py _1‐4 carrying a strong electron‐withdrawing cyanopyridine scaffold coupled with different electron‐donating aromatic/heteroaromatic moieties were synthesized from their respective co‐monomers by simple poly‐condensation route. They were subjected to structural, thermal, photophysical, and electrochemical characterizations and theoretical investigations in order to identify their suitability in polymer light‐emitting diode (PLED) application. All these polymers showed good film‐forming ability and exhibited favorable photophysical behaviors with an optical bandgap in the order of 2.54‐2.68 eV. Further, their electrochemical data were used to evaluate highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) levels. Finally, Py _1‐4 were successfully employed as blue‐light emitter in the construction of new ITO/PEDOT:PSS/ Py _1‐4 /Al configured light‐emitting diodes (LED), and the fabricated devices demonstrated stable blue electroluminescence behavior endorsing an effective electrons injection in the PLEDs.     

金属卟啉/异烟酸/二氧化钛复合光催化剂制备及其光催化性能研究

合成了四苯基卟啉(H2TPP)及铜卟啉(CuTPP)和锌卟啉(ZnTPP),获得了配合物[Zn(TPP)(DMF)]的晶体。制备了金属卟啉、异烟酸共修饰的二氧化钛复合光催化剂:金属卟啉/异烟酸/二氧化钛,红外光谱和X-射线衍射(XRD)分析结果表明金属卟啉和异烟酸负载于TiO2表面,未改变TiO2的晶型。在光催化降解水中污染物4-硝基苯酚(4-NP)时显示了好的催化效果。     

Synthesis of sulfone-containing monomers and polymers using cationic cyclopentadienyliron complexes

The synthesis of sulfone-containing monomers with pendent cationic cyclopentadienyliron (CpFe⁺) moieties has been accomplished via nucleophilic aromatic substitution of dichloroarene complexes with a number aliphatic dithiols. These complexes were further oxidized using m-CPBA to give the sulfone-based monomers. Polymerization of the sulfone-based monomers with O-containing nucleophiles produced the sulfone-based polymers. Direct nucleophilic aromatic substitution of dichloroarene complexes with dinucleophiles allowed for the formation of organoiron sulfide-based polymers. Oxidation of these polymers led to the formation of sulfone polymers with the pendent iron moieties. The organometallic monomers and polymers were found to be more soluble in polar solvents in comparison to their organic analogues.     

Syntheses and radical polymerizations of optically active (meth)acrylamides having amino acid moieties

Syntheses and radical polymerizations of several (meth)acrylamides having L -amino acid moieties were examined. The monomers were prepared by the reactions of L -amino acid ester hydrochlorides with (meth)acryloyl chloride in the presence of triethylamine in satisfactory yields. Radical polymerizations of the monomers were carried out in the presence of AIBN (1 mol %) in bulk and in several solvents to afford the corresponding polymers in satisfactory yield. The glass transition temperatures and specific rotations of the polymers depended on the substituents of the L -amino acid moieties. Nearly the same specific rotations were observed for the monomers and the model compounds of the polymer units, N-pivaloyl amino acid methyl esters. On the contrary, the specific rotations of the polymers shifted to the negative direction in ca. 30°. The interaction between the polymer side chains might affect the changes in the specific rotations from monomers to polymers. © 1997 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 35: 2619–2629, 1997     

锌卟啉轴向配合物的光谱特性及配位二聚体分子内的能量传递

通过轴向配位作用构造了ZnTPP-H₂(m-py)TPP卟啉二元体系,研究了配位二聚体的可见吸收光谱和荧光发射光谱特性,考察了二聚体分子内的能量传递过程,观察到能量从激发态ZnTPP^*流向H₂(m-py)TPP。作为对比,研究了ZnTPP-py体系的可见吸收光谱和荧光发射光谱。轴向配位的吡啶引起了ZnTPP荧光光谱明显红移,没有分子内的能量转移过程发生。用吸收光谱和荧光光谱方法计算了加合反应的平衡常数,得到了基本一致的结果。     

Molecularly imprinted stationary phase prepared by reverse micro-emulsion polymerization for selective recognition of gatifloxacin in aqueous media

A new stationary phase for selectively recognizing gatifloxacin in aqueous media based on molecularly imprinted microspheres (MIMs) has been prepared by water/oil reverse micro-emulsion polymerization. The MIMs were prepared using gatifloxacin as the template, N, N'-methylenebisacrylamide as cross-linker and acrylamide and acryloyl-β-CD (β-CD-A, synthesized by ester reaction of acrylic acid with β-CD) as combinatorial functional monomers. The surface morphology of MIMs was characterized by scanning electron microscopy. The properties of MIMs recognition for gatifloxacin in water were studied by adsorption kinetics, adsorption isotherms combined with Scatchard analysis and selective recognition experiments. The results showed that the synthesized MIMs had an excellent ability to selectively recognize gatifloxacin in aqueous media. MIMs were employed as the chromatographic stationary phase to successfully separate the template gatifloxacin from its analogues. Discovering the mechanism of the MIMs recognition revealed that the memory cavities in the surface of the MIMs and hydrophobic effects between the template and the cavities of the β-CD residues were the primary contributions to the special recognition process.     

含荧光生色基团烯类单体及其聚合物的光化学行为

近年来关于电荷转移现象的研究因理论及应用方面的重要性而备受瞩目。缺电子性丙烯酰类单体可以和给电子性化合物形成激态电葆转移复合物进而引发光聚合。我们合成了一系列同一分子中既含有给电子性荧光生色团又含缺电子性双键的烯类单体,发现这类单体在相同生色团浓度下的荧光强度均无穷氏人相应的聚合物的荧光强度。我们将这咎现象称为荧光结构自猝灭效应（ＳＳＱＥ）,以区别于众所周知的浓度自猝灭现象。对于电子状态与之相反的     

Synthesis of porphyrin‐end‐functionalized polycyclohexane with well‐controlled and defined polymer chain structure

Tetraphenylporphyrin‐end‐functionalized polycyclohexane (H₂TPP‐PCHE) and its metal complexes (MTPP‐PCHE) were synthesized as the first successful example of porphyrin‐end‐functionalized transparent and stable polymers with a well‐controlled and defined polymer chain structure. Chloromethyl‐end‐functionalized poly(1,3‐cyclohexadiene) (CM‐PCHD) was synthesized as prerequisite prepolymer by the postpolymerization reaction of poly(1,3‐cyclohexadienyl)lithium and chloro(chloromethyl)dimethylsilane. CM‐end‐functionalized PCHE (CM‐PCHE) was prepared by the complete hydrogenation of CM‐PCHD with p‐toluenesulfonyl hydrazide. H₂TPP was incorporated onto the polymer chain end by the addition of 5‐(4‐hydroxyphenyl)‐10,15,20‐triphenylporphyrin to CM‐PCHE. The complexation of H₂TPP‐PCHE and Zn(OAc)₂ (or PtCl₂) yielded a zinc (or platinum) complex of H₂TPP‐PCHE. H₂TPP‐PCHE and MTPP‐PCHE were readily soluble in common organic solvents, and PCHE did not inhibit the optical properties of the H₂TPP, ZnTPP, and PtTPP end groups. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011     

一类基于苝酰亚胺和亚苯基亚乙炔基交替共轭聚合物的合成与表征

以1,7"bay"位置溴化苝酰亚胺为电子受体、低聚亚苯基亚乙炔基(OPE)为电子给体,通过Sonagashira反应制备了一系列不同OPE含量的具有p-n结构主链全共轭交替聚合物,并对其光物理和电化学性质进行了表征.紫外-可见吸收光谱表明,聚合物具有较宽的光吸收范围(350~900 nm),有利于提高体系的光吸收效率;荧光光谱实验发现,对苝酰亚胺单元进行选择性激发,产生由分子内电荷分离所导致的荧光猝灭现象,为该材料应用于光伏器件提供了理论和实验依据.     

β-CYCLODEXTRIN REGULATED STEREOREGULARITY AND MOLECULAR WEIGHT IN INCLUSION POLYMERIZATION OF ACRYLONITRILE

Polyacrylonitrile (PAN) polymers were prepared by inclusion polymerization of the monomer using various molar equivalents of β-cyclodextrin (β-CD). Stereoregular (isotactic, atactic and syndiotactic) distributions of the prepared PAN polymers were determined from terminal model Bernoullian statistics using ¹³C-NMR data. With an increase in acrylonitrile (AN): β-CD ratios, the proportion of isotactic polymers increased. Also, T_g increased along with degradation temperature at higher AN: β-CD ratios. However, molecular weight of the polymers prepared was lower at an AN: β-CD ratio of 10:1, but was found to be larger than the control at an AN: β-CD ratio of 20:1.