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1.
The tumour-localizing abilities of various kinds of porphyrin derivatives in tumour-bearing hamsters were assessed by nitrogen-pulsed laser spectrofluorometry (N2-PLS). On examination of porphine derivatives (from haemoglobin), it was found that the dimer and acetylated and amidated compounds had a high affinity for tumour tissue; the dimer and hydroxylated compound of phorbine derivatives (from chlorophyll) also showed a high affinity. Furthermore, of the metalloporphines (gallium, zinc and indium complexes), those which contained hydrophilic groups showed a high affinity for tumour tissue; of the metallophorbines (gallium, zinc and indium complexes), those which contained hydrophobic groups showed a high affinity. A correlation was found between the side-chain structure of the porphyrins and metalloporphyrins and their affinity for tumour tissue.  相似文献   

2.
本文合成了水溶性中位-四[邻-(3-磺酸基丙氨基)苯基]卟啉和中位-四[对-(3-磺酸基丙氨基)苯基]卟啉及相应的金属(M=Fe^2+,Co^2+,Ni^2+,Cu^2+,Zn^2+)配合物。测定了以上卟啉衍生物在水中的溶解度随温度和pH值的变化关系、卟啉与金属的配合性能。  相似文献   

3.
[reaction: see text] We have synthesized a 5,15 meso-substituted methyluracyl porphyrin derivative bearing 6-methyluracyl units directly at the meso positions. The atropisomerization was regulated by steric replusion between the methyl substituents. When the atropisomers were mixed with alkylated melamine as a complementary hydrogen-bonding unit, the hydrogen-bonded assemblies were analyzed by diffusion-ordered spectroscopy (DOSY) in solution, which clarified that the alphabeta isomer formed a face-to-face dimer, whereas the alphabeta isomer took a zigzag structure.  相似文献   

4.
The chloro compound of 3-hydroxy-2-quinoxalinecarboxylic acid with nickel(II) has been prepared in ethanolic solution from which a solid compound was isolated. Spectral and magnetic measurements show that the nickel ions are in an octahedral environment. Thermogravimetry, differential thermal analysis and electrical conductivity data are reported for 3-hydroxy-2-quinoxalinecarboxylic acid and its nickel complex. The conductivity measurements indicate that electron/hole traps are emptied during heating of the complex but repopulation occurs in about 24 h at room temperature.  相似文献   

5.
Cyclopolymerization of 1,6‐heptadiyne derivatives containing the bulky substitutents was carried out by metathesis catalyst systems. The catalytic activity of molybdenum (V) chloride (MoCl5) in homopolymerization is greater than that of the MoCl5‐cocatalyst system, and copolymerization is vice versa in catalytic activity. Newly synthesized homo‐ and copolymers were soluble in common organic solvents and could afford thin film by solution‐casting onto the indium–tin oxide coated glass substrate. The NMR, Fourier transform infrared spectroscopic, and UV–visible spectra indicated that these polymers have a linear conjugated cyclic polyene structure having a bulky substitutent as a pendant group. The number‐average molecular weight of these polymers was in the range of 2.4–6.27 × 103. The copolymers exhibited a relatively higher molecular weight than that of the homopolymers. The copolymers were stable up to 380 °C. The electrical conductivities of the I2‐doped copolymer thin film by the four‐point probe method and surface plasmon resonance spectroscopy were about 500 and 600 S/cm, respectively. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 958–964, 2002  相似文献   

6.
The thermal behaviour of tetrahydroperparine (THP) and its derivatives with various acids has been investigated. The acid is liberated from the formate derivative basically in two steps, while the other aliphatic acids are released quantitatively before the thermal decomposition of the THP molecule. The thermoanalytical curves, electrical conductivity data measured in the molten phase, and infrared spectra prove that while part of the formic acid is hydrogen-bonded the other part is bound ionically in the molecule. It may be assumed that the marked biological activity of the compound can be explained by this difference in the nature of the bonds.  相似文献   

7.
Thermal studies were carried out on some products of chemical modification of poly-N-vinylcarbazole (PNVC). The effect of a substituent introduced into the carbazole ring on the thermal stability of the polymers was investigated. The kinetic parameters of the thermal degradation process were computed.
Zusammenfassung An chemisch modifizierten Produkten von Poly-N-Vinylkarbazol (PNVC) wurden thermische Untersuchungen durchgeführt, sowie der Effekt eines in den Karbazolring eingeführten Substituenten auf die thermische Stabilität des Polymers untersucht. Weiterhin wurden die kinetischen Parameter des Zersetzungsprozesses errechnet.

. .
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8.
A set of physical constants of gallium(ortho-)phosphate GaPO4 has been determined in recent years. These constants allow to calculate precisely the properties of the most important applications of GaPO4 such as BAW and SAW devices.  相似文献   

9.
10.
2-Vinyl-5,10,15,20-tetraphenylporphyrinatozinc(II) reacts with nitrile imines, generated in situ from ethyl hydrazono-α-bromoglyoxylates, affording the corresponding pyrazolines in good to excellent yields. Treatment of pyrazoline derivatives with DDQ affords the corresponding pyrazole derivatives with moderate to excellent yields. When the hydrolysis of ester group in the pyrazoline derivatives was considered, it was observed the concomitant oxidation of the heterocyclic unit, which allowed directly obtaining porphyrin-pyrazole derivatives with a carboxylic group, in very good yields.The photophysical properties of the pyrazoline and pyrazole porphyrin derivatives show that the influence of the heterocyclic substituents is limited by the tendency of these molecules to aggregate. All other properties and especially the triplet kinetics remain unaffected. The adducts with low tendency to aggregate showed very high singlet oxygen yield, which makes these compounds interesting for their use as photosensitizers for PDT.  相似文献   

11.
The thermal stabilities of 33 polynitroaromatic compounds and their derivatives were determined using non-isothermal differential thermal analysis (DTA). For twelve of these, the thermal stabilities of their mixtures with 1,3,5-trinitrobenzene was also determined. The results obtained are discussed from a molecular structural point of view.The results obtained from DTA measurements are compared with the published data which were derived from the results of the application of the manometric method to the study of the thermal reactivity of polynitroaromatic compounds. The differences which exist between the conclusions reached on basis of DTA application, on the one hand, and those obtained on the basis of the application of the manometric method, on the other hand, are discussed.Using the published relationship for the calculation of the temperature limit (Tmax) for the use of polynitroaromatic compounds as secondary thermostable explosives, Tmax values are calculated for the compounds being measured. A relationship is derived between Tmax and TD the initial exothermal decomposition temperature obtained from the DTA of the studied compounds.  相似文献   

12.
The electronic absorption spectra of 5-(o-substituted phenylazo)-6-amino-2-thiouracils and 6-(o-substituted phenylazo)-5-aminouracils containing different substituents are studied at different pH's. The dissociation constants are evaluated and discussed. Phenomenon of tautomerism is more supported by (1)H NMR and (13)C NMR spectra. The electrical conductivity of some ligands and their Co(II), Ni(II) and Cu(II) complexes in the temperature range 293-150K favoured their semiconducting properties where the metal ion forms a bridge to facilitate the flow of the current. The biological activity of some ligands and their complexes are tested against a number of Gram-positive and Gram-negative bacteria. The results showed that some of the compounds have a well considerable activity against some of the organisms.  相似文献   

13.
Novel functional hyperbranched poly(aryl ether ketone)s(HPAEKs) bonded with nonlinear optical chromophores(meso-tetrakis(4-hydroxyphenyl) porphyrin, THPP and its metal derivatives) were synthesized and characterized by 1H-NMR and UV-Vis absorption spectra. The incorporation of chromophores into HPAEKs endowed HPAEKs novel NLO and OL properties. Indeed, dendritic architecture allowed for maximum dispersion of the chromophores, avoided aggregation, more optical limiting property was obtained. Simultaneously, they retained the excellent properties of the materials, particularly in thermal stability. Their optical properties were evaluated by nonlinear optical analyses and optical limiting. The results showed that these polymers possessed good optical limiting(OL) property and large nonlinear optical(NLO) susceptibilities(ca. 10 12esu). All polymers containing chromophores presented excellent thermal stability(DT5 524.17 °C).  相似文献   

14.
锌卟啉的合成及与咪唑类客体反应的光谱性质   总被引:1,自引:0,他引:1  
将一对手性丙氨酸,通过烷氧基侧链与卟啉环相连,合成了一对手性卟啉5-对(L-丙氨酰氧乙氧基)苯基-10,15,20-三苯基卟啉和5-对(D-丙氨酰氧乙氧基)苯基-10,15,20-三苯基卟啉及其各自对应的锌卟啉.通过元素分析、紫外-可见光谱、1 H核磁共振和红外光谱等方法对合成的自由卟啉及锌卟啉配合物进行了结构确定.此外,采用荧光光谱滴定实验研究了金属锌卟啉与咪唑类客体进行配位反应的光谱性质,结果表明,咪唑类客体与手性锌卟啉相互作用时均具有荧光猝灭效应,金属卟啉的手性结构对该性质未造成影响.  相似文献   

15.
The ferro-paramagnetic phase transition in dilute Cr-Ni base alloys is investigated through a qualitative study of their thermal conductivity as a function of temperature in the near vicinity of the transition. A single apparatus was used to measure the thermal and electrical conductivities and the specific heat of three thin rod samples having Cr concentrations of 0.12, 0.51 and 1.13 at.%.A voltage-temperature (V-) realign was applied to measure the ratio between the thermal and electrical conductivities. The thermal conductivity data were then evaluated by using the electrical resistivity results obtained from the measured current-voltage (I–V) characteristic curves. A model describing the effect of Cr concentration on the I–V curve is proposed and tested. The effect of Cr concentration on specific heat is also presented.
Zusammenfassung Der ferro-paramagnetische Phasenübergang von gestreckten Cr-Ni Ausgangslegierungen wurde mittels einer quantitativen Untersuchung ihrer Wärmeleitfähigkeit als eine Funktion der Temperatur in nächster Nähe des Phasenüberganges untersucht. Mit Hilfe einer einzigen Apparatur wurden Wärme- und elektrische Leitfähigkeit sowie die spezifische Wärme von drei Probenstäben mit einem Cr-Gehalt von 0.12, 0.51 bzw. 1.13% bestimmt.Für die Ermittlung des Verhältnisses zwischen Wärme- und elektrischer Leitfähigkeit wurde eine Spannungs-Temperatur (V-) Beziehung angewendet. Aus dem elektrischen Widerstand, erhalten aus den gemessenen Strom-Spannungskurven (I-V), kann dann die Wärmeleitfähigkeit ermittelt werden. Es wurde ein Modell entwickelt und getestet, um den Einfluß der Cr-Konzentration auf die (I-V)- Kurven wiederzugeben. Die Wirkung der CrKonzentration auf die spezifische Wärme wird ebenfalls beschrieben.
  相似文献   

16.
The ferro-paramagnetic phase transition in dilute Cr-Ni base alloys was investigated through a qualitative study of their thermal conductivity as a function of temperature in the near vicinity of the transition. A single apparatus [I] was used for measurements of the thermal and electrical conductivities and specific heats of three thin rod samples having Cr concentrations of 0.12, 0.51 and 1.13 at%.A voltagevs. temperature (V vs 0) relation was applied [2] to measure the ratio between the thermal and electrical conductivities. The thermal conductivity data were then evaluated by using the electrical resistivity results obtained from the measured currentvs. voltage (I vs. V) characteristic curves. A model describing the effect of Cr concentration on the (I vs. V) curve wasproposed and tested. The effect of Cr concentration on specific heat is presented.
Zusammenfassung Die ferromagnetische Phasenumwandlung von Cr-Ni Legierungen wurde über die Temperaturabhängigkeit der Wärmeleitfähigkeit dieser Proben in der Nähe der Phasenumwandlung untersucht. Mit einem einzigen Instrument [1] konnten für die drei Stäbchenproben mit einem Cr-Gehalt von 0,12, 0,51 und 1,13% die elektrische als auch die Wärmeleitfähigkeit bestimmt werden. Zur Bestimmung des Verhältnisses von Wärme- und elektrischer Leitfähigkeit wurde eine Spannungs-Temperatur-Beziehung [2] angewendet. Unter Hinzunahme des aus den charakteristischen Stromstärke-Spannungsdiagrammen (I-U) ermittelten specizifischen elektrischen Widerstandes konnten dann die Leitfähigkeitangaben ermittelt werden. Es wurde ein Modell zur Interpretation des Effektes der Cr-Konzentration auf die I-U Diagramme entwickelt und getestet. Außerdem wurde der Effekt der Cr-Konzentration auf die specifische Wärme dargestellt.

, Cr-Ni, . , 0,12; 0,51 1,13 . '- . , , - . , - . .
  相似文献   

17.
In this study results of thermal degradation of aliphatic hyperbranched polyesters, AHBP, and their derivatives, determined by non-isothermal thermogravimetric analysis in inert atmosphere (N2) are presented. The thermal stability of linear polyester PHPA (polyhydroxypivalic acid), additionally synthesized from hydroxypivalic acid, was also studied. AHBP samples, from second to tenth pseudo-generation, were synthesized starting from 2,2-bis(hydroxymethyl)propionic acid and di-trimethylolpropane. Modification of some selected AHBP samples was accomplished with the propionyl and benzoyl chloride, as well as with stearic acid. Thermal degradation of AHBP samples starts in the region between 250 °C and 275 °C and it ends around 430 °C. The thermal stability of AHBP samples increases with the number of end groups in the macromolecule, as well as with the modification of end groups with stearic acid and propionyl chloride. An AHBP sample of the fourth pseudo-generation, where all -OH end groups are modified with benzoyl chloride, shows lower thermal stability than the corresponding unmodified sample. The thermal stability of the linear polyester PHPA is lower than the thermal stability of the AHBP samples of the similar molar mass. The activation energies of thermal degradation for all synthesized AHBP samples were also calculated.  相似文献   

18.
The thermal properties of a dye molecule (guest) inside the cavity of a host amylose helix were studied by TGA, DSC, and Thermal Desorption MS. The results show that the degradation temperature of dye shifts to a higher temperature by approximately 20°C.  相似文献   

19.
Aggregation of two porphyrin derivatives with carboxylic groups, 4-oxo-4-((4-(10,15,20-triphenyl-21H,23H-porphin-5-yl)phenyl)amino)butanoic acid (MAC) and 4,4',4',4'-[21H,23H-porphine-5,10,15,20-tetrayltetrakis(4,1-phenyleneimino)]tetrakis(4-oxo-butanoic acid) (TA4C), and their affinity to bovine serum albumin were investigated via absorption spectrometry, (1)H NMR and fluorescence spectrometry. MAC and its complexes with beta-cyclodextrin could form aggregates in an aqueous solution while TA4C was self-associated loosely. From the absorbance profiles of MAC in the titration of bovine serum albumin, hypochromicity was observed without any shift of the maximum absorbance wavelength. In both absorption spectra of TA4C in aqueous solutions and in solid state, three Q bands appeared in the visible region. In the measurements of absorption and fluorescence spectra upon titration of BSA, some spectral changes of TA4C were observed. The whole procedure of titration could be divided into three successive stages. The three-banded profiles of TA4C might be explained according to a loose dimer model.  相似文献   

20.
Absorption, fluorescence emission, fluorescence excitation spectra and fluorescence decay kinetics of carborane derivatives of 5,10,15,20-tetra(p-aminophenyl)porphyrin have been investigated. Carborane derivatives are prepared by acylation of the amino groups of 5,10,15,20-tetra(p-aminophenyl)porphyrin by 9-carboranyl acetyl chloride. From the analysis of the absorption and fluorescence spectra, it is concluded that covalent linking of carborane molecules to the tetraphenylporphyrin molecule significantly changes the self-conjugated pi-system of the porphyrin macrocycle: positions of maxima of absorption and fluorescence spectra shift to the red region by 3-8 nm; the halfwidths of these bands are broadened by 2.5-5.0 nm; the relative intensity of the bands I-IV also changes. The fluorescence decay kinetics of the carborane derivatives are biexponential. According to the experimental data and model simulation, it is concluded that the intramolecular electron transfer proceeds from the porphyrin excited part of the molecule to carboranyls with a rate constant of 415 ps(-1) and efficiency of 0.16-0.8. Recombination of separated charges occurs within 1.4 ns.  相似文献   

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