共查询到20条相似文献,搜索用时 18 毫秒
1.
Zhang XB Guo CC Chen SH Shen GL Yu RQ 《Fresenius' Journal of Analytical Chemistry》2001,369(5):422-427
For preparing a berberine-sensitive electrode, 5,10,15,20-tetrakis[2-(2,3,4,6-tetraacetyl-beta-D-glucopyranosyl)-1-O- phenyl]porphyrin (T(o-glu)PPH2) was synthesized from the reaction of pyrrole with ortho-acetylglycosylated benzaldehyde by Lindsay's method. The electrode based on T(o-glu)PPH2 with an optimized membrane composition exhibits Nernstian response to berberine in the concentration range 2.4 x 10(-7)-5.0 x 10(-3) mol L-1, with a pH range from 3.9 to 10.2, and a fast response time of 30 s. The electrode shows fair selectivity towards berberine with respect to common co-existing species. T(o-glu)PPH2 shows better potentiometric response characteristics comparing to chloro[5,10,15,20-tetrakis[2-(2,3,4,6-tetraacetyl-beta-D- glucopyranosyl)-1-O-phenyl]-porphinato]-manganese (MnT(o-glu)PPCl) and better selectivity towards berberine than tetraphenylporphyrin (TPPH2). The effect of the composition of the electrode membrane has been studied and the experimental conditions optimized. The contents of berberine in pharmaceutical tablets were determined by direct potentiometry and the results agreed with values obtained by the pharmacopoeia method. 相似文献
2.
An amperometric artemisinin (ARN) sensor based on the supramolecular recognition of glycosylated metalloporphyrin, which is included in the Au-nanoparticles-chitosan film coated on the glass carbon electrodes, was developed. For the improvement of the selectivity of artemisinin detection, 5,10,15,20-tetrakis[2-(2,3,4,6-tetraacetyl-β-d-glucopyranosyl)-1-O-phenyl]porphyrin (T(o-glu)PPH) metal complex [FeT(o-glu)PPCl] was synthesized and employed as a ARN-sensitive and -selective material in the amperometric sensors. The proposed [FeT(o-glu)PPCl]/Au-nanoparticles modified electrodes showed excellent selectivity and sensitivity toward ARN with respect to a number of interferents and exhibited stable current response, which can be attributed to the coordination of ARN with the [FeT(o-glu)PPCl] in the electrodes. The calibration graph obtained with the proposed sensor was linear over the range of 1.8 × 10−7-1.7 × 10−9 mol l−1, with a detection limit of 1.7 × 10−9 mol l−1 for ARN. Significant advantages of the proposed procedure over the conventional reductive electrochemical methods are the selective detection and the relatively low applied potential requirement of the ARN-sensor. The prepared sensor is applied for the determination of ARN in plant samples and the results agreed with the values obtained by the pharmacopoeia method. 相似文献
3.
Synthesis of Glucoside Bonded Metal Porphyrins 总被引:1,自引:0,他引:1
Zao Ying LI* Xun Jin ZHU Li LI Yue Ning ZHANG Department of Chemistry Wuhan University Wuhan 《中国化学快报》2001,(5)
Enzyme catalyzed reaction often has high selectivity and efficiency under mild conditions. However, disadvantage of enzyme catalysts is the difficulty of recovery. Metalloporphyrin plays an important role in biological system such as redox reaction, electron transfer,oxygen transportation and charge separation etc.1,2 Metalloporphyrins as superoxide dismutase (SOD) mimics have showed the ability of catalyzing the redox reaction of some harmful radicals , such as O2·―, ·OH. Grove and co-… 相似文献
4.
Stanislav Šabata Jiří Hetflejš Renata Rychtáriková Gabriela Kuncová Kamil Lang Pavel Kubát 《Chemical Papers》2009,63(4):438-444
Three tetracationic porphyrins differing in the position of charged nitrogen atoms on the peripheral substituents — 5,10,15,20-tetrakis(N-methylpyridinium-4-yl)porphyrin (TMPyP4), 5,10,15,20-tetrakis(N-methylpyridinium-2-yl)porphyrin (TMPyP2), 5,10,15,20-tetrakis(4-trimethylammoniophenyl) porphyrin (TMAPP), and hydrophobic 5,10,15,20-tetraphenylporphyrin (TPP), were immobilized by adsorption
and encapsulation in poly(hydroxymethylsiloxane) (PHOMS). The so prepared porphyrin-PHOMS composites were characterized by
porosimetry, scanning electron microscopy, fluorescence and diffuse reflectance UV-VIS spectroscopy. It was found that porphyrins
are immobilized in the PHOMS matrix in the free base monomer form Their irradiation produced singlet oxygen O2(1Δg) with the lifetime of 10–30 μs. 相似文献
5.
Zhi-Zhang Li Xiao-Bing Zhang Can-Cheng Guo Guo-Li Shen Ru-Qin Yu 《Analytical sciences》2002,18(4):423-426
In this paper, the synthesis of a novel ionophore, chloro[5,10,15,20-tetrakis[2-(2,3,4,6-tetraacetyl-beta-D-glucopyranosyl)-1-O-phenyl]porphinato]manganese (MnT(o-glu)PPCl), and its application as a neutral carrier for a PVC membrane electrode are described. The MnT(o-glu)PPCl-based PVC membrane electrode shows a potentiometric responses to SCN- over a concentration range of 3.4 x 10(-7) - 1.0 x 10(-1) mol L(-1) with a Nernstian slope and a response time of 20 s. The electrode exhibits an anti-Hofmeister selectivity toward SCN- with respect to common coexisting anions. As active materials, MnT(o-glu)PPCl shows better selectivity toward SCN- than chloro(tetraphenylporphinato)manganese (MnTPPCl). The effect of the electrode membrane compositions has been studied and the experimental conditions were optimized. The electrode was applied to the determination of SCN- in body fluids with satisfactory results. 相似文献
6.
The poly(o-anisidine)–sulfuric acid–glucose oxidase (POA–H2SO4–GOx) electrode has been investigated in the present work. Platinum electrode was used for the synthesis of poly (o-anisidine)–sulfuric acid (POA–H2SO4) film using galvanostatic method with 0.2 M o-anisidine, 1.0 M H2SO4 solution, 1.0 pH and 2 mA/cm2 applied current density. The synthesized film was characterized using electrochemical technique, conductivity measurement,
UV–visible spectroscopy, Fourier transform infrared spectroscopy, and scanning electron microscopy. GOX was immobilized on synthesized POA–H2SO4 film by cross-linking via glutaraldehyde in phosphate and acetate buffer. The Michaelis–Menten constant (
K\textm¢K_{\text{m}}^\prime ) was determined for the immobilized enzyme. The glucose oxidase electrode shows the maximum current response at pH 5.5 and
potential 0.6 V. The sensitivity of POA–H2SO4–GOX electrode in phosphate and acetate buffer has been recorded. The results of this study reveal that the phosphate buffer gives
fast response as compared to acetate buffer in amperometric measurements. 相似文献
7.
Dr. Yunus Zorlu Connor Brown Dr. Claudia Keil Dr. M. Menaf Ayhan Prof. Dr. Hajo Haase Dr. Richard B. Thompson Dr. Imre Lengyel Dr. Gündoğ Yücesan 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(49):11129-11134
Herein, we report the third generation of fluorescent probes (arylphosphonic acids) to target calcifications, particularly hydroxyapatite (HAP). In this study, we use highly conjugated porphyrin-based arylphosphonic acids and their diesters, namely 5,10,15,20-tetrakis[m-(diethoxyphosphoryl)phenyl]porphyrin ( m -H8TPPA-OEt8 ) and 5,10,15,20-tetrakis [m-phenylphosphonic acid]porphyrin ( m -H8TPPA ), in comparison with their positional isomers 5,10,15,20-tetrakis[p-(diisopropoxyphosphoryl)phenyl]porphyrin ( p -H8TPPA-iPr8 ) and 5,10,15,20-tetrakis [p-phenylphosphonic acid]porphyrin ( p -H8TPPA ), which have phosphonic acid units bonded to sp2 carbon atoms of the fluorescent core. The conjugation of the fluorescent core is thus extended to the (HAP) through sp2-bonded −PO3H2 units, which generates increased fluorescence upon HAP binding. The resulting fluorescent probes are highly sensitive towards the HAP in rat bone sections. The designed probes are readily taken up by cells. Due to the lower reported toxicity of ( p -H8TPPA ), these probes could find applications in monitoring bone resorption or adsorption, or imaging vascular or soft tissue calcifications for breast cancer diagnosis etc. 相似文献
8.
Bhiri F Chaabouni SE Limam F Ghrir R Marzouki N 《Applied biochemistry and biotechnology》2008,149(2):169-182
The Pol6 mutant of Penicillium occitanis fungus is of great biotechnological interest since it possesses a high capacity of cellulases and β-glucosidase production
with high cellulose degradation efficiency (Jain et al., Enzyme Microb Technol, 12:691–696, 1990; Hadj-Taieb et al., Appl Microbiol Biotechnol, 37:197–201, 1992; Ellouz Chaabouni et al., Enzyme Microb Technol, 16:538–542, 1994; Ellouz Chaabouni et al., Appl Microbiol Biotechnol, 43:267–269, 1995). In this work, two forms of β-glucosidase (β-glu 1 and β-glu 2) were purified from the culture supernatant
of the Pol6 strain by gel filtration, ion exchange chromatography, and preparative anionic native electrophoresis. These enzymes
were eluted as two distinct species from the diethylamino ethanol Sepharose CL6B and anionic native electrophoresis. However,
both behaved identically on sodium dodecyl sulfate polyacrylamide gel electrophoresis (MW, 98 kDa), shared the same amino
acid composition, carbohydrate content (8%), and kinetic properties. Moreover, they strongly cross-reacted immunologically.
They were active on cellobiose and pNPG with Km values of 1.43 and 0.37 mM, respectively. β-glu 1 and β-glu 2 were competitively inhibited by 1 mM of glucose and 0.03 mM
of δ-gluconolactone. They were also significantly inhibited by Hg2+ and Cu2 at 2 mM. The addition of purified enzymes to the poor β-glucosidase crude extract of Trichoderma reesei increased its hydrolytic efficiency on H3P04 swollen cellulose but had no effect with P. occitanis crude extract. Besides their hydrolytic activities, β-glu 1 and β-glu 2 were endowed with trans-glycosidase activity at high
concentration of glucose. 相似文献
9.
L. I. Zakharkin V. A. Ol'shevskaya R. P. Evstigneeva V. N. Luzgina L. E. Vinogradova P. V. Petrovskii 《Russian Chemical Bulletin》1998,47(2):340-342
5,10,15,20-Tetra[3-(o- andm-carboranyl)butyl]porphyrins containing carborane groups bonded to alkyl substituents of the porphyrin cycle by the C−B σ-bond
were obtained by condensation of 4-(o- andm-carboran-9-yl)pentanals with pyrrole.
Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 347–349, February, 1998. 相似文献
10.
V. I. Grishkovets A. A. Loloiko A. S. Shashkov V. Ya. Chirva 《Chemistry of Natural Compounds》1990,26(6):663-666
We have isolated from Crimean ivy berries in addition previously known triterpene glycosides — 3-O-α-L-arabinopyranosyl-28-O-[O-α-L-rhamnopyranosyl-(1
→ 4)-O-β-D-glycopyranosyl-(1 → 6)-β-D-glucopyranosyl]hederagenin, 3-O-[O-α-L-rhamnopyranosyl-(1 → 2)-α-L-arabinopyranosyl]-28-O-[O-α-L-rhamnopyranosyl-(1
→ 4)-O-β-D-glucopyranosyl-(1 → 6)-β-D-glycopyranosyl]hederagenin, the new triterpene glycosides hederoside H2-3-O-[O-β-D-glycopyranosyl-(1 → 2)-β-D-glycopyranosyl-(1 → 2)-β-D-glucopyranosyl]-28-O-[O-β-D-glucopyranosyl-(1 → 6)-β-D-glucopyranosyl]oleanolic
acid- and hederoside I-3-O-[O-β-D-glucopyranosyl-(1 → 2)-β-D-glucopyranosyl]-28-O-[O-β-D-glucopyranosyl-(1 → 6)-β-D-glucopyranosyl]hederagenin.
Details of their13C NMR spectra are given.
M. V. Frunze Simferopol' State University. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 779–783, November–December,
1990. 相似文献
11.
5,10,15,20-tetrakis(phenoxy acetic acid) porphyrin (PAAP) was covalently linked to Merrifield chloromethylated resin. Characterization
of PAAP and the modified polymeric matrix were performed by 1H NMR, FTIR and elemental analysis. The sorbent was used for the separation and enrichment of the d-electron metals (Mn(II), Co(II), Ni(II), Cu(II) and Zn(II)) at pH 6–8 and of the f-electron metals U(VI) and Th(IV) at pH 4–5. The metals ions were preconcentrated with a concentration factor range of 115–215
and then determined by flame atomic absorption spectrometry or visible spectrophotometry using Arsenazo(III). The retained
metals were eluted with 2.0 mol L−1 HNO3 in the case of the d-electron metals and 0.1/0.25 mol L−1 HCl in the case of the f-electron metals. The procedure was validated by analyzing the NIST standard reference material 2709 (San Joaquin Soil).
Correspondence: Melek Merdivan, Chemistry Department, Faculty of Arts and Sciences, Dokuz Eylul University, 35160 Buca, Izmir,
Turkey 相似文献
12.
Yong Hou Jiarong Zhou Xiaoping Liu Linliang Yu Chunlin Ni 《Transition Metal Chemistry》2008,33(4):411-416
Two new salts, [oClBzTPP]2+[Ni(mnt)2]2−(1) and [oClBzTPP]+[Ni(mnt)2]−(2) ([oClBzTPP]+ = 1-(2′-chlorobenzyl)triphenylphosphonium and mnt2− = maleonitriledithiolate) have been prepared and characterized by elemental analyses, UV, IR, MS spectra, single crystal
X-ray diffraction, and magnetic susceptibility. The Ni ions of the Ni(mnt)2 anions for 1 and 2 exhibit the square-planar coordination geometry. The Ni(III) ions of 2 form a 1D zigzag alternating magnetic chain within a Ni(mnt)2− column through Ni···S, S···S, or Ni···Ni interactions. The C–H···N, C–H···S, C–H···π hydrogen bonds or π···π stacking interactions
play important roles in the molecular stabilizing and stacking of 1 and 2. Magnetic susceptibility measurements in the temperature range 1.8−300 K show that 2 exhibits diamagnetic behavior. 相似文献
13.
Mine Sulak Ak Hasalettin Deligöz 《Journal of inclusion phenomena and macrocyclic chemistry》2007,59(1-2):115-123
Four new azocalix[4]arenes {5,11,17,23-tetrakis[(2-hydroxy-5-tert-butylphenylazo)]-25,26,27,28-tetrahydroxycalix[4]arene (1), 5,11,17,23-tetrakis[(2-hydroxy-5-nitro phenylazo)]-25,26,27,28-tetrahydroxycalix[4]arene (2), 5,11,17,23-tetrakis[(2-amino-5-carboxylphenylazo)]-25,26,27,28-tetrahydroxycalix[4]arene (3) and 5,11,17,23-tetrakis[(1-amino-2-hydroxy-4-sulfonicacidnapthylazo)]-25,26,27,28-tetrahydroxycalix[4]arene (4)} have been synthesized from p-tert-butylphenol, p-nitrophenol, p-aminobenzoic acid and 1-amino-2-hydroxy-4-sulphonic acid by diazo coupling reaction with p-aminocalix[4]arene. The resulting ligands (1–4) were treated with three transition metal salts (e.g., CuCl2·2H2O, NiCl2·6H2O or CoCl2·6H2O). Cu(II), Ni(II) and Co(II) complexes of the azocalix[4]arene derivatives were obtained and characterized by UV-vis, IR,
1H-NMR spectroscopic techniques and elemental analysis. All the complexes have a metal:ligand ratio of 2:1. The Cu(II) and
Ni(II) complexes of azocalix[4]arenes are square-planar, while the Co(II) complexes of azocalix[4]arenes are octahedral with
water molecules as axial ligands. The solvent extraction of various transition metal cations from the aqueous phase to the
organic phase was carried out by using azocalix[4]arenes (1–4). It was found that, azocalix[4]arenes 1, 2 and 3 examined selectivity for transition metal cations such as Ag+, Hg+ and Hg2+. In addition, the thermal stability of metal:azocalix[4]arene complexes were also reported.
Dedicated to Prof. Dr. Mustafa Yılmaz on the occasion of his 50th birthday 相似文献
14.
Weijun Kong Zulun Li Xiaohe Xiao Yanling Zhao Ping Zhang 《Journal of Thermal Analysis and Calorimetry》2010,102(1):331-336
In this study, the microcalorimetric method was applied to investigate the activity of berberine on Shigella dysenteriae (S. dysenteriae). Heat flow power (HFP)–time curves of the growth metabolism of S. dysenteriae affected by berberine were determined using the thermal activity monitor (TAM) air isothermal microcalorimeter, ampoule mode,
at 37 °C. By analyzing these curves and some quantitative parameters using multivariate analytical methods, similarity analysis
(SA) and principal component analysis (PCA), the antibacterial activity of berberine on S. dysenteriae could be accurately evaluated from the change of the two main parameters, the maximum heat flow power P
m2 and total heat output Q
t: berberine at low concentration (25 μg mL−1) began to inhibit the growth of S. dysenteriae, high concentrations (50–200 μg mL−1) of berberine had strong antibacterial activity on S. dysenteriae, when the concentration of berberine was higher (250–300 μg mL−1), this antibacterial activity was stronger. All these illustrated that the antibacterial activity of berberine on S. dysenteriae was enhanced with the increase of the concentration of this compound. Berberine can be used as potential novel antibacterial
agent for treating multidrug-resistant Shigella. This work provided a useful idea of the combination of microcalorimetry and multivariate analysis for studying the activity
of other compounds or drugs on organisms. 相似文献
15.
The relative enthalpies, ΔHo (0) and ΔHo (298.15), of stationary points (four minimum and three transition structures) on the •O3H potential energy surface were calculated with the aid of the G3MP2B3 as well as the CCSD(T)–CBS (W1U) procedures from which
we earlier found mean absolute deviations (MAD) of 3.9 kJ mol−1 and 2.3 kJ mol−1, respectively, between experimental and calculated standard enthalpies of the formation of a set of 32 free radicals. For
CCSD(T)-CBS (W1U) the well depth from O3 + H• to trans-•O3H, ΔHowell(298.15) = −339.1 kJ mol−1, as well as the reaction enthalpy of the overall reaction O3 + H•→O2 + •OH, ΔrHo(298.15) = −333.7 kJ mol−1, and the barrier of bond dissociation of trans-•O3H → O2 + •OH, ΔHo(298.15) = 22.3 kJ mol−1, affirm the stable short-lived intermediate •O3H. In addition, for radicals cis-•O3H and trans-•O3H, the thermodynamic functions heat capacity Cop(T), entropy So (T), and thermal energy content Ho(T) − Ho(0) are tabulated in the range of 100 − 3000 K. The much debated calculated standard enthalpy of the formation of the trans-•O3H resulted to be ΔfHo(298.15) = 31.1 kJ mol −1 and 32.9 kJ mol −1, at the G3MP2B3 and CCSD(T)-CBS (W1U) levels of theory, respectively. In addition, MR-ACPF-CBS calculations were applied
to consider possible multiconfiguration effects and yield ΔfHo(298.15) = 21.2 kJ mol −1. The discrepancy between calculated values and the experimental value of −4.2 ± 21 kJ mol−1 is still unresolved.
Note added in proof: Yu-Ran Luo and J. Alistair Kerr, based on the discussion in reference 12, recently presented an experimental
value of ΔfHo(298.15) = 29.7 ± 8.4 kJ mol−1 in the 85th edition of the CRC Handbook of Chemistry and Physics (in progress). 相似文献
16.
M. R. Tarasevich P. V. Mazin N. A. Kapustina 《Russian Journal of Electrochemistry》2011,47(8):923-932
Cathodic oxygen reduction on the XC-72R carbon black modified by the products of pyrolysis of cobalt 5,10,15,20-tetrakis(4-methoxyphenyl)porphyrin
(CoTMPP) (XC-72M) was studied in acidic and neutral electrolytes. Formation of new active centers on XC-72M is confirmed by
voltammetric curves (specific charge density grows as compared to the XC-72R carbon black by 2–2.5 times) using the methods
of rotating disk electrode (a shift in half-wave potential E
1/2 by 600 mV) and rotating ring-disk electrode (the fraction of the direct reaction increases to 70%). Herewith, the $\frac{{\partial E_{1/2} }}
{{\partial pH}}$\frac{{\partial E_{1/2} }}
{{\partial pH}} value in the range of pH 0.3–8.5 is −60 mV. It is shown that proton necessarily participates in the slow stage of the first
electron transfer for the further occurrence of the direct reaction to water. At a transition from acidic solutions to neutral
ones, the polarization curves converge for XC-72M and XC-72R, which is due to a decrease in the concentration of proton in
the solution and variation of the mechanism of the oxygen reduction slow stage. 相似文献
17.
Wen-J. Mei Yu-Z. Ma Jie Liu Jin-C. Chen Kang-C. Zheng Liang-N. Ji Jun-H. Yao 《Transition Metal Chemistry》2006,31(3):277-285
A series of ruthenium(II) complexes with electron-donor or electron-acceptor groups in intercalative ligands, [Ru(phen)2(o-MOP)]2+ (1), [Ru(phen)2(o-MP)]2+ (2), [Ru(phen)2(o-CP)]2+ (3) and [Ru(phen)2(o-NP)]2+ (4), have been synthesized and characterized by elementary analysis, ES-MS, 1H NMR, electronic absorption and emission spectra. The binding properties of these complexes to CT-DNA have been investigated
by spectroscopy and viscosity experiments. The results showed that these complexes bind to DNA in intercalation mode and their
intrinsic binding constants (Kb) are 1.1, 0.35, 0.53 and 1.7 × 105 M−1, respectively. The subtle but detectable differences occurred in the DNA-binding properties of these complexes are mainly
ascribed to the electron-withdrawing abilities of substituents (–OCH3 < –CH3 < –Cl < –NO2) on the intercalative ligands as well as the intramolecular H-bond (for substituent –OCH3) which increase the planarity area of the intercalative ligand to some extent. The density functional theory (DFT) calculations
were also performed and used to further discuss the trend in the DNA-binding affinities of these complexes. 相似文献
18.
Yu. B. Ivanova N. Zh. Mamardashvili A. V. Glazunov A. S. Semeikin 《Russian Journal of General Chemistry》2014,84(7):1404-1410
2,3,7,8,12,13,17,18-Octaethyl-5,10,15,20-tetrakis(4-methoxyphenyl)porphyrin has been synthesized, and its acid-base and complexing properties in the systems 1,8-diazabicyclo[5.4.0]undec-7-ene-acetonitrile, acetonitrile-Zn(OAc)2, and 1,8-diazabicyclo[5.4.0]undec-7-ene-acetonitrile-Zn(OAc)2 have been studied by spectrophotometry. Titration of 2,3,7,8,12,13,17,18-octaethyl-5,10,15,20-tetrakis(4-methoxyphenyl)porphyrin with 1,8-diazabicyclo[5.4.0]undec-7-ene is accompanied by successive deprotonation of the pyrrole nitrogen atoms with formation of the corresponding mono- and dianion. The overall acid dissociation constant of the title compound has been determined. The complexation of neutral and doubly deprotonated 2,3,7,8,12,13,17,18-octaethyl-5,10,15,20-tetrakis(4-methoxyphenyl)porphyrin with Zn(OAc)2 has been studied, and kinetic parameters for the formation of the zinc complex according to the molecular and ionic mechanisms have been determined. Extra coordination of 1,8-diazabicyclo[5.4.0]undec-7-ene by the zinc complex of 2,3,7,8,12,13,17,18-octaethyl-5,10,15,20-tetrakis(4-methoxyphenyl)porphyrin. 相似文献
19.
Z. H. Zhang Z. C. Tan Y. S. Li L. X. Sun 《Journal of Thermal Analysis and Calorimetry》2006,85(3):551-557
The molar heat capacities of the room temperature
ionic liquid 1-butyl-3-methylimidazolium tetrafluoroborate (BMIBF4)
were measured by an adiabatic calorimeter in temperature range from 80 to
390 K. The dependence of the molar heat capacity on temperature is given as
a function of the reduced temperature X
by polynomial equations, C
P,m
(J K–1 mol–1)=
195.55+47.230 X–3.1533 X
2+4.0733 X
3+3.9126 X
4 [X=(T–125.5)/45.5] for the solid phase (80~171
K), and C
P,m (J
K–1 mol–1)=
378.62+43.929 X+16.456 X
2–4.6684 X
3–5.5876 X
4 [X=(T–285.5)/104.5] for the liquid phase (181~390
K), respectively. According to the polynomial equations and thermodynamic
relationship, the values of thermodynamic function of the BMIBF4
relative to 298.15 K were calculated in temperature range from 80 to 390 K
with an interval of 5 K. The glass translation of BMIBF4
was observed at 176.24 K. Using oxygen-bomb combustion calorimeter, the molar
enthalpy of combustion of BMIBF4 was determined to
be Δc
H
m
o=
– 5335±17 kJ mol–1. The standard
molar enthalpy of formation of BMIBF4 was evaluated
to be Δf
H
m
o=
–1221.8±4.0 kJ mol–1 at T=298.150±0.001 K. 相似文献
20.
Conventional electrochemical studies on the ferrocinium–ferrocene (Fc+–Fc) redox system in 80 mass-% propylene carbonate (PC) + 20 mass-% p-xylene (PX) medium are reported, leading to a calculation of the proton medium effect. The dissociation constant of ferrocinium
picrate in this medium was determined by conductivity measurements. The value of EFe+ /FeoE_{\mathrm{Fe^{+} /Fe}}^{\mathrm{o}} against the Hg/HgCl2(s) reference electrode in 80 mass-% PC + 20 mass-% PX was determined potentiometrically in conjunction with conductivity
data, and found to be 0.133±0.001 V versus the SHE at 25 °C. The EFe+ /FeoE_{\mathrm{Fe^{+} /Fe}}^{\mathrm{o}} value has also been calculated using cyclic voltammetric data obtained in 80 mass-% PC + 20 mass-% PX at a micro platinum
working electrode against the Ag/AgCl (nonaq.) reference electrode, and found to be comparable with the value obtained by
potentiometry. The proton medium effect for transfer from water to the present mixed solvent medium was calculated using the
value of EFe+/FeoE_{\mathrm{Fe^{+}/Fe}}^{\mathrm{o}} versus SHE at 25 °C and found to be 4.5. Based on values of proton medium effect reported in the literature, it is inferred
that the present mixed solvent medium is slightly more basic than pure PC. 相似文献