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1.
Quenching of the fluorescence of Ad=O and its singlet-exited state (1Ad=O*) generated in chemiluminescent reaction of adamantylideneadamantane-1,2-dioxetane (AdOOAd) termolysis by C60 fullerene was detected and investigated. The “quenching efficiency-C60 concentration” plots obtained from the decrease in the fluorescence and chemiluminescence intensities obey the Stern-Volmer
law. The bimolecular rate constants (k
bim) were determined and the overlap integrals of the Ad=O fluorescence spectra with the C60 absorption spectra (∫ Ov) were calculated. Based on the nonconstant k
bim/∫Ov ratios for different singlet-exited energy donors obtained for the 1PAH*-C60 systems (PAH are polycyclic aromatic hydrocarbons) and 1Ad=O*-C60, a conclusion is drawn that quenching of 1Ad=O* by C60 fullerene is a result of inductive-resonant singlet-singlet (major contribution) and exchange-resonant singlet-triplet (minor
contribution) energy transfer.
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 5, pp. 1044–1046, May, 2007. 相似文献
2.
S. Yu. Ketkov G. A. Domrachev C. P. Mehnert J. C. Green 《Russian Chemical Bulletin》1998,47(5):868-874
The effect of methylation of ligands in bis(η6-benzene)chromium (1) on the structure of Rydberg transitions in absorption spectra has been studied. A detailed analysis
and interpretation of all Rydberg elements of the vapor-phase spectra of bis(η6-benzene)chromium (2), bis(η6-o-xylene)chromium (3), bis(η6-m-xylene)chromium (4), and bis(η6-mesitylene)chromium (5) was carried out. The vapor-phase electronic absorption spectrum of bis(η6-p-xylene)chromium (6) was measured, and the assignment of the Rydberg bands was made for the first time. The first ionization
potentials of complexes 2–5 were refined. The energy of detachment of the 3dz
2 electron and the parameters of the Rydberg excitations for molecule 6 were determined. The vibronic components of the 3dz
2→R4p
x,y
transition in the spectra of complexes 2 and 6 were assigned. The differences in the Rydberg structure of the spectra of
compounds 2–6 were analyzed in terms of the selection rules for optical transitions in the corresponding symmetry groups.
The vapor-phase spectra correspond to conformers with the symmetry groupsC
2v
andC
2 for complexes 2–4, with the symmetry groupsD
3h
andD
3 for compound 5, and with the symmetry groupD
2d
for complex 6.
Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 5, pp. 897–903, May, 1998. 相似文献
3.
Bitao Su Ke Wang Jie Bai Hongmei Mu Yongchun Tong Shixiong Min Shixiong She Ziqiang Lei 《Frontiers of Chemistry in China》2007,2(4):364-368
Fe3+-doped TiO2 composite nanoparticles with different doping amounts were successfully synthesized using sol-gel method and characterized
by X-ray diffraction (XRD), transmission electron microscopy (TEM) and ultravioletvisible spectroscopy (UV-Vis) diffuse reflectance
spectra (DRS). The photocatalytic degradation of methylene blue was used as a model reaction to evaluate the photocatalytic
activity of Fe3+/TiO2 nanoparticles under visible light irradiation. The influence of doping amount of Fe3+ (ω: 0.00%–3.00%) on photocatalytic activities of TiO2 was investigated. Results show that the size of Fe3+/TiO2 particles decreases with the increase of the amount of Fe3+ and their absorption spectra are broaden and absorption intensities are also increased. Doping Fe3+ can control the conversion of TiO2 from anatase to rutile. The doping amount of Fe3+ remarkably affects the activity of the catalyst, and the optimum efficiency occurs at about the doping amount of 0.3%. The
appropriate doping of Fe3+ can markedly increase the catalytic activity of TiO2 under visible light irradiation.
__________
Translated from Journal of Northwest Normal University (Natural Science), 2006, 42(6): 55–56 [译自: 西北师范大学学报(自然科学版)] 相似文献
4.
Alexander Konkin Frank Wendler Frank Meister Hans-Klaus Roth Albert Aganov Oliver Ambacher 《Cellulose (London, England)》2007,14(5):457-468
Degradation processes of N-methylmorpholine-N-oxide monohydrate (NMMO), cellulose and cellulose/NMMO solutions were studied by high performance liquid chromatography (HPLC)
and electron spin resonance (ESR) spectroscopy. Kinetics of radical accumulation processes under UV (λ = 248 nm) excimer laser
flash photolysis was investigated by ESR at 77 K. Beside radical products of cellulose generated and stabilized at low temperature,
radicals in NMMO and cellulose/NMMO solutions were studied for the first time in those systems and attributed to nitroxide
type radicals ∼CH2–NO•–CH2∼ and/or ∼CH2–NO•–CH3∼ at the first and methyl •CH3 and formyl •CHO radicals at the second step of the photo-induced reaction. Kinetic study of radicals revealed that formation and recombination
rates of radical reaction depend on cellulose concentration in cellulose/NMMO solutions and additional ingredients, e.g.,
Fe(II) and propyl gallate. HPLC measurements showed that the concentrations of ring degradation products, e.g., aminoethanol
and acetaldehyde, are determined by the composition of the cellulose/NMMO solution. Results based on HPLC are mainly maintained
by ESR that supports the assumption concerning a radical initiated ring-opening of NMMO. 相似文献
5.
The equilibrium constants, K
2, have been determined for the proton-transfer reactions of 1-phenacylquinolinium ion, PHQ+, with several amines {triethylamine (TEA), N,N,N′,N′-tetramethylethylenediamine (ED), N,N,N′, N′-tetramethylpropanediamine (PD), N,N,N′,N′-tetramethylbutanediamine (BD), and 1,8-bis(dimethylamino-naphthalene (DMAN)} in acetonitrile (AN), AN-tetrahydrofuran (THF)
and AN-ethanol (EtOH) mixtures. The reaction was followed spectrophotometrically using a stopped-flow technique. The K
2 value decreased for DMAN and increased for TEA with increasing vol-% of THF in AN-THF mixtures. The changes in the K
2 value for ED, PD and BD changed in the order: ED, PD and BD from a pattern similar to TEA to a pattern similar to DMAN. The
change in the K
2 value for DMAN with increasing vol-% of THF in AN-THF mixtures was explained by the effect of polarity on the stability of
P−Q+ (the deprotonated product of PHQ+). The effect of THF on the K
2 value is consistent with that of the peak wavelength of the absorption spectrum of P−Q+. The change in the K
2 value for TEA, ED, PD and BD depended on the structures of the protonated bases, one of the products for this reaction. The
effect of EtOH on the K
2 value for DMAN was examined in ternary EtOH-THF-AN mixtures that contain different amounts of EtOH and whose relative permittivities
were adjusted to that of EtOH. The K
2 value increased with increasing vol-% of EtOH because of the stabilization of P−Q+ upon the formation of the hydrogen-bonded complex with EtOH. The absorption spectrum of P−Q+ demonstrated a blue shift as the vol-% of EtOH increased. 相似文献
6.
P. Manoj H. Mohan V. M. Manoj J. P. Mittal C. T. Aravindakumar 《Research on Chemical Intermediates》2006,32(9):817-826
Pulse radiolysis has been used to investigate the reaction of hydroxyl radical (·OH) and oxide radical anion (O·−) with 2-aminopurine (2AP), a fluorescent analogue of adenine, in aqueous medium. The second-order rate constant for the reaction
of ·OH with 2AP was determined to be 3 × 109 dm3 mol−1s−1 and for the reaction of O·− it was 7.1 × 108 dm3 mol−1s−1. The transient absorption spectrum obtained in the reaction of ·OH at pH 7 has absorption maxima at 370 and 470 nm. The spectrum undergoes a time-dependent transformation at higher time-scale.
The intermediate species was found to react with N,N,N′,N′-tetramethyl-p-phenylenediamine (TMPD). The yield of TMPD·+ was calculated in terms of G(TMPD·+) to be 3.3 × 10−7 mol J−1 at pH 7. The ·OH reactions were also carried out at pH 10 and the transient absorption spectra have λ
max at 400 and 480 nm. The transient spectra obtained in the reaction of O·− at pH ≈14 have maxima at 400 and 480 nm. The transient intermediate species at pH 7 are assigned to the formation of 2AP-4-OH· (54%), 2AP-5-OH· (7%) and 2AP-8-OH· (39%) based on the spectral evidence and TMPD·+ build-up. Both 2AP-4-OH· and 2AP-5-OH· undergo OH− elimination to form a radical cation. At higher pH (pH 10), the dehydration reaction of these OH-adducts leads to a N-centered
radical (2AP-N(9)·, 71%). Formation of 2AP-8-OH· (29%) is also proposed at this pH. In the reaction of O·− with 2AP, it is proposed that a similar nitrogen centered 2AP-N(9)· radical is formed by an electron-transfer reaction at N(9). 相似文献
7.
Veleeparambil M. Manoj Usha K. Aravind Hari Mohan Charuvila T. Aravindakumar 《Research on Chemical Intermediates》2011,37(8):1113-1122
The decomposition studies of S-nitrosothiols (RSNO) are important due to their potential role in vivo in connection with the storage and transport of nitric
oxide (•NO) within the body. Reactions of hydroxyl radicals (•OH) with a number of RSNOs (S-nitroso derivatives of N-acetyl-dl-penicillamine, l-cysteinemethylester, N-acetylcysteamine, and dl-penicillamine) in aqueous medium at neutral and acidic pH have been reported in the present study. Radiation chemical technique
(steady state and pulse radiolysis) has been utilized for the determination of the reaction rate constants, the end product
analyses, and the transient intermediate species. The rate constants for the reaction of •OH with the selected RSNOs were determined using a competition kinetic method with 2′-deoxy-d-ribose as the competitor. All the rate constants were found to be of the order of diffusion controlled (1010 M−1 s−1). The degradation yield of RSNOs was found to be quantitative (i.e., G(–RSNO) ≈ G(•OH)) at neutral and acidic pH. The major products of decomposition were the respective disulfide (RSSR) and nitrite (NO2
−). A good material balance is also obtained between the degradation yield and the formation of the products (i.e., G(–RSNO) ≈ G(RSSR) + G(NO2
−)). The major transient intermediate was the thiyl radical (RS•). Its intermediacy was confirmed by making use of the electron transfer reaction of 2,2′-azinobis(3-ethylbenzothiazoline-6-sulfonate)
(ABTS2−) to RS•, which results in the formation of ABTS•− having a transient absorption spectrum with λmax at 410 nm. Based on these results, a generalized reaction mechanism is deduced for the reaction of •OH with RSNO. 相似文献
8.
E. P. Surovoi S. V. Bin N. V. Borisova 《Russian Journal of Physical Chemistry A, Focus on Chemistry》2010,84(8):1401-1405
During the irradiation of WO3 films d = 7–160 nm thick by light at λ = 320 nm (I = (1.5–7) × 1015 quantum cm−2 s−1), absorption band at λ = 850 nm appeared along with absorption band edge shift to shorter waves. The subsequent irradiation
of samples at λ = 850 nm caused the disappearance of the longwave absorption band. The intrinsic absorption edge of WO3 films was determined (λ = 320 nm). The degree of transformations of WO3 films increased under atmospheric conditions as the intensity of incident light and the time of irradiation (1–140 min) grew
and as film thickness decreased. A mechanism of photochemical transformations of WO3 films was suggested. This mechanism included the generation of electron-hole pairs, the recombination of part of nonequilibrium
charge carriers, the formation of [eVa2+e] centers, and the isolation of photolysis products. 相似文献
9.
The reactions of e−
aq, H-atoms, OH radicals and some one electron oxidants and reductants were studied with dithio-oxamide (DTO) in aqueous solutions
using pulse radiolysis technique. The transient species formed by the reaction of e−
aq with DTO at pH 6.8 has an absorption band with λ
max at 380 nm and is reducing in nature. H-atom reaction with DTO at pH 6.8 also produced the same transient species. The semi-reduced
species was found to be neutral indicating that the electron adduct gets protonated quickly. However at pH 1, the species
produced by H-atom reaction had a different spectrum with λ
max at 360 and 520 nm. Reaction of acetone ketyl radicals and CO2
− radicals with DTO at pH 6.8 gave transient spectra which were identical to that obtained by e−
aq reaction. However at pH 1, the spectrum obtained by the reaction of acetone ketyl radicals with DTO was similar to that obtained
by H-atom reaction at that pH. The transient species formed by OH radical reaction with DTO in the pH range 1–9.2 also has
two absorption maxima at 360 and 520 nm. This spectrum was identical with the spectrum obtained by H-atom reaction at pH 1.
This means that all these radicals viz. OH, H-atom and (CH3)2COH radicals react with DTO at pH 1 by H-abstraction mechanism. The transient species produced was found to be sensitive to
the presence of oxygen. One-electron oxidizing radicals such as Br2
−· and SO4
−· radicals reacted with DTO at neutral pH to give the same species as produced by OH radical reaction having absorption maxima
at 360 to 520 nm. At acidic pHs, only Br2
−· and Cl2
−· radicals were able to oxidize DTO to give the same species as produced by OH radical reaction. The semioxidized species is
a resonance stabilized species with the electron delocalized over the-N-C-S bond. This species was found to be neutral and
non-oxidizing in nature. 相似文献
10.
以硼酸和碳酸盐为原料,用高温固相法制备了可被(近)紫外光(369、254 nm)有效激发的Tb3+单掺杂Li Ba1-xBO3∶xTb3+(物质的量分数x=0.02、0.03、0.04、0.05、0.06、0.07)及Bi3+和Tb3+共掺杂LiBa0.95-yBO3∶0.05Tb3+,y Bi3+(物质的量分数y=0.02、0.03、0.04、0.05、0.06、0.07)的2个系列荧光粉,产物的结构和形貌分别用粉末X射线衍射(PXRD)和扫描电子显微镜进行表征。PXRD测定结果表明2个系列的产物均为纯相LiBaBO3。通过对第一系列产物荧光光谱的测定,筛选出发光强度最好的产物,据此确定铽离子的最佳掺杂量;在此基础上制备出铋离子掺杂量不同的第二系列荧光粉。荧光光谱测定的实验结果表明,Tb3+/Bi3+共掺杂的荧光粉的发光强度好于Tb3+单掺杂的荧光粉,这说明Bi3+对Tb3+有敏化作用;而且随着Bi3+掺杂量的增加,产物的荧光强度表现出先增加后减小的趋势,当Bi3+的掺杂量y=0.03时,产物的荧光强度达到最大。Bi3+和Tb3+之间存在偶极-四极相互作用而进行能量传递。系列荧光粉的CIE坐标显示其发光颜色在一定程度上呈现出由绿色光到白光的渐变趋势。 相似文献
11.
Rate constants for reactions of 2-pyridinol with one electron reductants, such ase
aq
−
and H atoms and one-electron oxidants, viz. OH, N3, Br
2
−
, C1
2
−
and O− have been determined at different pH values using the pulse radiolysis technique. From the corrected absorption spectra of
the product transient species, the extinction coefficients of these species at their respective absorption maxima have been
determined. The kinetics of decay of these transients have been investigated. ThepK
a values of transients formed bye
aq
−
and OH radical reactions have been estimated to be 7.6 and 3.5 respectively. Rate constants for electron transfer from semireduced
2-pyridinol to different electron acceptors have been determined. 相似文献
12.
Nature of the transient species formed during pulse radiolysis of thioacetamide in aqueous solutions
K. Kishore P. Dwibedy G. R. Dey D. B. Naik P. N. Moorthy 《Research on Chemical Intermediates》1998,24(1):35-45
Thioacetamide (TA) is an organic compound having thioamide group similar to that in thiourea derivatives. Its reactions with
eaq−, H-atom and OH radicals were studied using the pulse radiolysis technique at various pHs and the kinetic and spectral characteristics
of the transient species were determined. The initial adduct formed by the reaction of TA with OH radicals at pH 7 does not
absorb light in the 300–600 nm region but reacts with the parent compound to give a transient species with an absorption maximum
around 400 nm. At pH 0, the reaction of OH radicals with TA directly gives a similar transient species with absorption maximum
at 400 nm. Transient species formed by H-atom reaction with TA and pH 0 has no absorption in the 300–600 nm region but at
higher acidity a new transient species is formed which has absorption maximum at 400 nm. This transient absorption observed
in the case of both OH and H atom reaction with TA is ascribed to the formation of a resonance stabilized radical similar
to that obtained in the case of thiourea derivatives. The species produced by electron reaction viz. electron adduct was found to be a strong reductant and could reduce MV2+ with a high rate constant. H2S was produced as a stable product in the reaction of eaq− and its G-value was determined to be about 0.8. 相似文献
13.
I. A. Badmaeva N. V. Surovtsev V. K. Malinovskii L. L. Sveshnikova 《Journal of Structural Chemistry》2010,51(2):244-250
The UV induced photopolymerization of Langmuir-Blodgett films of lead salt of 2-docosynoic acid (CH3(CH2)18C=CCOOH) is studied using IR and Raman spectroscopy. It is found that the films are a highly ordered system with trans-configuration of alkyl chains and a bridged complex generated between the carboxyl group and the lead ion. Based on a change
in the absorption band intensity in the IR spectra corresponding to the triple bond vibration, the degree of polymerization
depending on the irradiation time is determined. In the Raman spectra, a peak at ∼1635 cm−1 appears during polymerization, which corresponds to the C=C double bond. The formation of conjugated double bonds in these
systems is observed for the first time. During polymerization, methylene chains of molecules retain trans-configuration; the structural ordering of molecules in the film is observed. 相似文献
14.
L. A. Syrtsova N. A. Sanina N. I. Shkondina E. S. Chudinova N. S. Emel’yanova A. I. Kotel’nikov S. M. Aldoshin 《Russian Chemical Bulletin》2009,58(1):64-70
The reaction of hemoglobin (Hb), oxyhemoglobin (HbO2), and methemoglobin (metHb) with the tetranitrosyl iron complex of the fu2-S type [Fe2(SC4H3N2)2(NO)4] (1) was studied. The reaction results in the nitrosylation of the free SH group of 93-β-cysteine in these forms of hemoglobin.
The change in the Hb, HbO2, and metHb concentrations was monitored by spectrophotometry, recording the difference absorption spectra of the experimental
systems with these forms of hemoglobin and the buffer containing complex 1 in the same concentration. The absorption spectra
were processed to obtain the components using the MATHCAD method. The nitrosothiol concentration was determined by the Saville
reaction. In a protic medium containing 3.3% DMSO, complex 1 spontaneously generates NO due to hydrolysis (k = 3.7 · 10-4 s-1). Oxyhemoglobin reacts with evolved NO to form metHb. Complex 1 reduces metHb with a high rate to yield Hb (k = 6.7 · 10-3 s-1) followed by the formation of HbNO (k = 6.5 · 10-3 s-1). Oxidized complex 1 yields NO with a higher rate than the starting complex does. The reaction of HbO2 and metHb (0.02 mmo1 L-1) with complex 1 affords nitrosothiols in micromolar concentration during 5 min, and no nitrosothiol is formed in the case
of Hb. 相似文献
15.
A novel copper(I) azide coordination polymer [Cu(μ-1,1,1,3-N3)]
n
has been synthesized by the low-temperature solution-state reaction. Crystal X-ray analyses reveal that compound [Cu(μ-1,1,1,3-N3)]
n
possesses a type of three-dimensional (3D) framework structure. The polymer was characterized by elemental analyses, IR spectra,
and UV-Vis spectra. The third-order nonlinear optical (NLO) properties were also investigated, and they exhibit good linear
absorption and self-defocusing performance with modulus of the hyperpolarizability (γ) 8.16 × 10−30 esu for [Cu(μ-1,1,1,3-N3)]
n
in a 1.96 × 10−4 mol dm−3 DMF solution. 相似文献
16.
A. E. Galashev 《Russian Journal of General Chemistry》2011,81(13):2625-2633
Interaction of bromine ions absorbed by water cluster with adsorbed oxygen and ozone molecules has been investigated by the
molecular dynamics method. It was shown that the part of O2 molecules was removed from the system by evaporating Br− ions, while all O3 molecules and Br ions were kept in the system during 25 ps. The increase the concentration of the Br− ions in the clusters resulted in a reduction of the absorption intensity and emission in IR spectra at the presence of oxygen,
whereas the absorption intensity in the appropriate IR spectra of ozone-containing systems increased with the growth of a
number of the Br− ions. Raman spectra of oxygen-containing systems were poorly sensitive to the concentration of the Br− ions but the absorption intensity of Raman spectra for systems with ozone considerably decreased with the growth of a number
of bromine ions. 相似文献
17.
Erik Rakovsky ?udmila ?úrková Jaromír Marek 《Monatshefte für Chemie / Chemical Monthly》2002,22(2):277-283
Anhydrous 1,6-hexanediammonium dihydrogendecavanadate ((HdaH2)2H2V10O28, 1) was prepared by reaction of V2O5 with 1,6-hexanediamine in aqueous solution. The crystal structure of 1 was determined, and the proton positions in the H2V10O28 4− anion were calculated by the bond length/bond number method. The protons are bound to the centrosymmetrically oriented μ–OV3 groups of the decavanadate anion. Based on the analysis of IR spectra of 1 prepared from H2O and D2O, the absorption band at 871 cm−1 can be attributed to δ(V–Ob–H) vibrations. 相似文献
18.
Vesna Kuntić Dusěan Malesěev Zorica Radović Vladana Vukojević 《Monatshefte für Chemie / Chemical Monthly》2000,131(7):769-777
Summary. In the present work, rutin (3,3′ ,4′ ,5,7-pentahydrohyflavone-3-rhamnoglucoside) was determinated via a complexing reaction with a titanyloxalate anion. K2[TiO(C2O4)2] and rutin react in 50% ethanol forming a 1:2 complex in a pH range from 4.00 to 11.50, in which the TiO(C2O4)2
2− ion is linked to rutin through the 4-carbonyl and 5-hydroxyl group. The thermodynamic stability constant log β2
0 of the complex is determined to 10.80 at pH = 6.50. The change of the standard Gibbs free energy Δ G0 amounts to −61 kJċ mol−1, indicating that the process of complex formation is spontaneous. The optimal conditions for the spectrophotometric determination
of microconcentrations of rutin are at pH=6.40 and λ= 430 nm, where the complex shows an absorption maximum with a molar absorption coefficient a
430=(60±2)ċ103 dm3ċ mol−1ċ cm−1. The method is applied rutin determination from tablets.
Received January 4, 2000. Accepted (revised) February 17, 2000 相似文献
19.
Lin Yang Xiang-Hua Zhao Hong-Ping Zhou Jie-Ying Wu Jia-Xiang Yang Guo-Quan Shao Yu-Peng Tian 《Transition Metal Chemistry》2008,33(4):431-437
Two bis-(β-diketonate) ligands [H2L1 = 3,6-bis-(4,4,4-trifluorobutane-1,3-dione)-9-butyl-carbazole and H2L2 = 3,6-bis-(4,4,4-trifluorobutane-1,3-dione)-9-hexyl-carbazole] were synthesized, and their corresponding dinuclear ruthenium(II)
complexes [Ru2(bpy)4(L1)](PF6)2 (1) and [Ru2(bpy)4(L2)](PF6)2 (2) (bpy = 2,2′-bipyridine)] were prepared by the reaction of Ru(bpy)2Cl2 · 2H2O with H2L1 and H2L2 in ethanol, respectively. The structure of the ligand H2L2 was determined by single-crystal X-ray diffraction. The spectral properties of the ligands and their complexes have been
studied. The absorption spectra of the complexes exhibit intense ligand-centered bands in the UV region and metal-to-ligand
charge-transfer bands in the visible region. The two-photon absorption (TPA) coefficient β and TPA cross-section σ were determined
by the Z-scan technique, which revealed that the two complexes exhibit strong TPA due to electronic extensive delocalization.
The complexes undergo a reversible or quasi-reversible one-electron metal-centered redox process at E
1/2 = +0.93 V and E
1/2 = +0.92 V, respectively. 相似文献
20.
Vesna Kunti? Dusěan Malesěev Zorica Radovi? Vladana Vukojevi? 《Monatshefte für Chemie / Chemical Monthly》2000,18(5):769-777
In the present work, rutin (3,3′ ,4′ ,5,7-pentahydrohyflavone-3-rhamnoglucoside) was determinated via a complexing reaction with a titanyloxalate anion. K2[TiO(C2O4)2] and rutin react in 50% ethanol forming a 1:2 complex in a pH range from 4.00 to 11.50, in which the TiO(C2O4)2 2− ion is linked to rutin through the 4-carbonyl and 5-hydroxyl group. The thermodynamic stability constant log β2 0 of the complex is determined to 10.80 at pH = 6.50. The change of the standard Gibbs free energy Δ G0 amounts to −61 kJċ mol−1, indicating that the process of complex formation is spontaneous. The optimal conditions for the spectrophotometric determination of microconcentrations of rutin are at pH=6.40 and λ= 430 nm, where the complex shows an absorption maximum with a molar absorption coefficient a 430=(60±2)ċ103 dm3ċ mol−1ċ cm−1. The method is applied rutin determination from tablets. 相似文献