共查询到20条相似文献,搜索用时 453 毫秒
1.
D. V. Konarev R. N. Lyubovskaya N. V. Drichko V. N. Semkin A. Graja 《Russian Chemical Bulletin》1999,48(3):474-479
Electronic absorption spectra of complexes of C60 and C70 fullerenes with donors, tetrathiafulvalene and pyranylidene derivatives, were studied in solutions and in the solid state.
Charge transfer bands were found in the 680–1300 nm range. The charge transfer energies (hv
ct) for the C60 and C70 complexes in solutions are close and almost independent of the solvent polarity. For the C60 complexes in the solid state, the dependence ofhv
ct on the ionization potential (IP) of donors was found to behv
ct=0.82IP–3.93 eV. In the C60 complexes in the solid state, thehv
ct values are 0.15–0.20 eV lower than those in the solution. The linear dependences ofhv
ct onIP of donors for the C60 complexes lie 0.6–0.7 eV higher than those in the complexes with tetracyanoethylene (TCNE). This is associated with lower
values of the electron affinity of C60 and the energy of the electrostatic interaction in the fullerene complexes as compared to those of the TCNE complexes.
Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 3, pp. 478–483, March, 1999. 相似文献
2.
He‐Rng Zeng 《中国化学》2002,20(12):1546-1551
The photoinduced electron‐transfer reaction of N, N, N', N'‐tetra‐(p‐methylphenyl)‐4,4'‐diamino‐1,1'‐diphenyl ether (TPDAE) and fullerenes (C60/C70) by nanosecond laser flash photolysis occurred in benzonitrile. Transient absorption spectral measurements were carried out during 532 nm laser flash photolysis of a mixture of the fullerenes (C60/C70) and TPDAE. The electron transfer from the TPDAE to excited triplet state of the fullerenes (C60/C70) quantum yields and rate constants of electron transfer from TPDAE to excited triplet state of fullerenes (C60/C70) in benzonitrile have been evaluated by observing the transient absorption bands in the near‐IR region where the excited triplet state, radical anion of fullerenes (C60/C70) and radical cations of TPDAE are expected to appear. 相似文献
3.
Changyuan Lu Side Yao Wenfeng Wang Yongpeng Tong Weizhen Lin Tingwen Rong Nianyun Lin 《中国科学B辑(英文版)》1998,41(3):259-265
Fullerols of C60 and of C70 [C60(OH)n, C70(OH)m], water-soluble fullerene derivatives, unlike some other fullerene derivatives (such as C60 (C4H6O), C60 (C3H7N) and C60 [C(COOEt)2]x), do not result in excited triplet state but in ionization via monophotonic process in aqueous solutions with 248 nm laser.
The quantum yields of formation of hydrated electron (Φe
−) are determined to be 0.08 and 0.11 for fullerols of C60 and of C70 respectively at room temperature (ca. 15°C) with KI solution used as reference. By laser flash photolysis and oxidation of
sulfate radical anion SO4
−, the fullerol radical cation or neutral radical of C60 is confirmed to be existent and the transient absorption spectra of fullerol radical cation of C70 are observed for the first time.
Project supported by the National Natural Science Foundation of China 相似文献
4.
In search of new systems with a photoexcited redox pair which exhibits a strong and stable photoinduced absorption band to understand the photophyscial and photochemical properties of electron transfer between fullernes (C60/C70) and organic donor[N,N,N’,N’-tetra(p-methylphenyl)-4,4’-diamino-1,1’-diphenyl sulphide(TPDAS)],we studied characteristic absorption spectra in the near-IR region obtained from 532nm nanosecond laser flash photolysis of a mixture of the fullerenes (C60/C70) and TPDAS in polar solvents.When fullerenes (C60/C70)were photoexcithed,the rise of the radical anion of fullerenes (C60/C70)with the rapid decay of their excited triplet states were observed in benzonitrile.It can be deduced that the electron transfer reaction does take place from TPDAS to excithed triplet state of rullerens(C60/C70).The rate consants(ket)and quantum yiekls(φet) of this process have been also evaluated. 相似文献
5.
D. V. Khudyakov A. V. Mikhonin I. V. Rubtsov V. A. nadtochenko 《Russian Chemical Bulletin》1997,46(9):1531-1535
The kinetics of the formation and decay of photoexcited radical ion pairs of donoracceptor charge-transfer complexes between
C60 andN,N-diethylaniline (DEA) in chlorobenzene was studied by picosecond laser-induced diffraction gratings. It was established that
the anisotropy of polarization of the diffraction signal decreases as the concentration of DEA increases. The radical ion
states of the photoexcited C60
−...DEA+ complex have zero anisotropy. This effect is likely due to the isotropic intracomplex transfer of an electron from the local
excited state to the radical ion state. The rate constant of quenching of the singlet excited C60 byN,N-diethylaniline (1.4·1010 L mol−1 s−1) and the lifetimes of the solventseparated C60
−...DEA+ and tight [C60
−...DEA+] (95±7 and 31±4 ps, respectively) radical ion pairs were measured.
Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 1605–1610, September, 1997. 相似文献
6.
S. M. Argentine K. T. Kotz T. Rudalevige D. Zaziski A. H. Francis R. Zand J. A. Schleuter 《Research on Chemical Intermediates》1997,23(7):601-620
The spectra of C60 and C70 were examined using low-temperature photoluminescence and quasi-elastic light scattering spectroscopy. A detailed vibronic
analysis of the lowest triplet and singlet excited states of C70 is obtained. The lowest triplet state is identified as a 3E1′ state and the vibronic structure consists primarily of Herzberg-Teller active e2′ modes. The intensity of the electronic origin is comparable to the vibronically induced intensity and is extraordinarily
solvent sensitive. The spectrum of monosubstituted C60 is shown to be qualitatively similar to that of C60 in polar or strongly complexing solvents. The principal effect of solvent interaction or substitution is to induce dipole
intensity in the orbitally forbidden electronic origins of the luminescent states of C60 and C70. The Rayleigh scattering of fullerene solutions illustrates that solute aggregation occurs easily and that aggregate nucleation
is strongly affected by surfaces in contact with the solution. 相似文献
7.
Electrochemistry of hydrofullerene C60H36 was studied by cyclic voltammetry in THF and CH2Cl2 in the −47–14 °C temperature range. Hydrofullerene undergoes reversible one-electron reduction to form a radical anion in
THF (E
0=−3.18 V (Fc0/Fc+), Fc=ferrocene) and irreversible one-electron oxidation in CH2Cl2 (E
p
a
=1.22 V (Fc0/Fc+)). The reduction potential was used to estimate electron affinity of hydrofullerene as EA=−0.33 eV. It was suggested that
C60H36 is an isomer withT-symmetry in which 12 double bonds form four isolated benzenoid rings located in vertices of an imaginary inscribed tetrahedron
on the molecular surface. For hydrofullerene, the “electrochemical gap” is an analog of the energy gap (HOMO−LUMO), equal
to (E
Ox−E
Red)=4.4 V, and indicates that C60H36 is a sufficiently “hard” molecule with a low reactivity in redox reactions.
Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 2083–2087, November, 1999. 相似文献
8.
N-Methyl-2-(N-ethylcarbozole)-fulleropyrro lidine and N-methyl-2-(4′-N,N-diphenylaminophenyl)-fulleropyrrolidine were synthesized by 1,3-dipolar cycloaddition under microwave irradiation, which
were characterized by MS, 1H NMR, IR and UV-Vis. Photoinduced intramolecular electron transfer process from C60 moiety to carbazole moiety has been studied by nanosecond laser flash photolysis. The charge-separated state C60
•−-Cz•+ was observed in the near-IR region with a lifetime of 0.28 μs. The electronic spectrum of the C60-TPA was studied by using ZINDO method on the basis of the optimized geometrics with B3LYP/6-31G* program. The results show
that the calculated absorption was beyond 440nm, essentially consistent with the experimental value 433 nm.
__________
Translated from Acta Chimica Sinica, 2005,63(17)(in Chinese) 相似文献
9.
I. A. Mochalov A. N. Lapshin V. A. Nadtochenko V. A. Smirnov N. F. Goldshleger 《Russian Chemical Bulletin》2006,55(9):1598-1604
Axial coordination of fullerenopyrrolidine bearing the donor imidazolyl group, cis-3-(4-imidazolylphenyl)-1-(pyridin-2-yl)[60]fullereno[1,2-c]pyrrolidine (C60∼Im), with zinc meso-tetraphenylporphyrinate (ZnTPP) in an o-dichlorobenzene solution affords a non-covalently bonded donor-acceptor dyad ZnTPP-C60∼Im. The photochemical behavior of the ZnTPP-C60∼Im complex was studied by fluorescence (excitation at λ = 420 nm) and laser kinetic spectroscopy (excitation at λ = 532 nm,
12 ns). The formation constant of the 1: 1 porphyrin-fullerenopyrrolidine complex determined from quenching of ZnTPP fluorescence
assuming static intracomplex quenching is 1.6·104 L mol−1. Absorption spectra of the excited states in the system consisting of ZnTPP and Im∼C60 (ZnTPP/C60∼Im) were measured in solution from 380 to 1000 nm. The quenching constant of the triplet-excited ZnTPP with fullerenopyrrolidine
C60∼Im was determined. The results obtained indicate the formation of the triplet exciplex {PL}* ⇌ {Pδ+…Lδ−} in the ZnTPP/C60∼Im system upon laser photolysis.
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 1541–1547, September, 2006. 相似文献
10.
Fullerenes C60 and C70 have high electron affinity ( 2.6 - 2.8 ev ) and readily form anions on electronchemical reduction1, which were famous as electron acceptor in photo-excitation because of symmetrical shape, large size, and properties of its p - electron system2. After observation of molecular ferromagnetism3 in the tetrakis (dimethylamino ) ethylene salt of C60 as well as the occurrence of ultra-fast photoinduced electron transfer within the dimethyl aniline - C60 complex4, prompted us… 相似文献
11.
He Ping ZENG 《中国化学快报》2002,13(12)
Photoinduced electron transfer processes between fullerenes (C60 / C70) and N, N, N′, N′- tetra - ( p-methylphenyl ) - 4, 4′- diamino - 1, 1′- diphenyl ether ( TPDAE ) have been studied by nanosecond laser flash photolysis. Quantum yields and rate constants of electron transfer from TPDAE to excited triplet state of fullerenes (C60 / C70 ) in benzonitrile have been evaluated by observing the transient absorption bands in the near-IR region where the excited triplet state, radical anion of fullerenes ( C60 / C70 ) and radical cations of TPDAE appear. 相似文献
12.
Photoinduced electron transfer (ET) between C60 and porphyrin (P) in a new polymer containing porphyrin, poly(p-phenylenevinylene), and pendant fullerene units has been investigated by nanosecond transient absorption and phosphorescence spectroscopy. Compared to the physically doping material systems, binding porphyrin/C60 through chemical bonds in a polymer detains the formation of the triplet states of porphyrins and C60. The formation of intermediate charge transfer state (CSS) of P+-C60 ? was observed, which led to the delayed formation of triplet states of porphyrins and C60. The reduced opto-electronic properties, such as optical limiting performance, were also observed, which resulted from the delayed formation of triplet states. The results presented in this article are significant in understanding the complicated spectral characteristics of the triplet state and charge transfer of the porphyrin and C60 complexes, and are therefore related to the controllable performance of the new materials in applications. 相似文献
13.
E. I. Yudanova D. V. Konarev L. L. Gumanov R. N. Lyubovskaya 《Russian Chemical Bulletin》1999,48(4):718-721
Complexes of fullerenes C60 and C70 with cobalt(II) and manganese(II) tetraphenylporphyrinates of compositions Mn(TPP)·(C60)2(CS2)1.5 (1), Mn(TPP)·C70(CS2)
x
, wherex<=1.25 (2), Co(TPP)·C60(CS2)0.5 (3), and Co(TPP)·C70(CS2)
x
, wherex<0.25 (4), were synthesized and studied by ESR spectroscopy. At 77 K, complexes1 and2 have singlet ESR spectra characteristic of the low-spin (S=1/2) state of MnII, withg=2.002 and linewidths of 250 G and 300 G, respectively, and differing significantly from that of the initial MnII(TPP) (g
1=5.9 andg=2.0,S=5/2). The spectra of complexes1 and2 exposed to oxygen exhibit hyperfine structure due to interaction with55Mn and14N nuclei. The ESR spectra of complexes3 and4 are asymmetric (<g>=2.4, ΔH
pp=(500–600) G), which is due to the overlap of parallel and perpendicular spectral components. The absence of ESR signals from
C60
.− and C70
.− radical anions makes it possible to conclude that the formation of complexes1–4 is not accompanied by electron transfer from Co(TPP) and Mn(TPP) to fullerences C60 and C70.
Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 4, pp. 722–725, April, 1999. 相似文献
14.
富勒烯(C60/C70)与N,N,N’,N’-四-(对甲苯基)-4,4’-二胺-1,1’-二 苯硒醚(TPDASe)间在激光光诱导条件下,发生了分子间的电子转移过程.在可见- 近红外区(600-1200nm),观测到了TPDASe阳离子自由基、富勒烯(C60/C70)激发三 线态和阴离子自由基,在苯腈溶液中,观测瞬态谱测定了电子从TPDASe转移到富勒 烯(C60/C70)激发三线态的量子转化产率(Φet^T)和电子转移常数(Ket). 相似文献
15.
Piotr Filipiak Gordon L. Hug Krzysztof Bobrowski Marek Pietrzak Jerzy Paczkowski Bronislaw Marciniak 《Research on Chemical Intermediates》2009,35(4):389-399
Pulse radiolysis of acetonitrile solutions of tetra-n-butyl ammonium salts of 2- and 4-carboxybenzophenones [BP-COO−···N+(C4H9)4] were performed in order to generate directly the reduced forms of the benzophenone moieties within pre-formed ion pairs.
In earlier studies on photochemical electron transfer reactions, ion pairs containing a tetraalkyl ammonium cation and a benzophenone
radical anion were formed in an electron transfer to the triplet BP from a quencher consisting of a tetraalkyl ammonium salt
of (phenylthio)acetic acid. In the current work, the [BP•−COO−···N+(C4H9)4] ion pairs were formed by direct reduction of the salts without the complication of a third moiety, i.e., the (phenylthio)acetic
anion. The spectra and kinetic parameters of the radiolytically-reduced salts were compared to the behavior of reduced forms
of the 2- and 4-COOH substituted benzophenones. The results from the pulse radiolysis and photochemistry were compared and
explained in terms of the different structures of the ion pairs. 相似文献
16.
A. S. Lobach A. A. Perov A. I. Rebrov O. S. Roshchupkina V. A. Tkacheva A. N. Stepanov 《Russian Chemical Bulletin》1997,46(4):641-648
Fullerene hydrides were prepared by hydrogenation of fullerences C60 and C70 using proton transfer from 9,10-dihydroanthracene to fullerene and were studied by mass spectrometry (electron impact, field
desorption), IR, UV, and1H and13C NMR spectroscopy. The main product of the hydrogenation of C60 is C60H36, which is sufficiently stable. Hydrogenation of fullerene C70 gives a series of polyhydrides C70H
n
(n=36–46), and the main product is C70H36. The dehydrogenation of C60H36 by 2,3-dichloro-5,6-dicyano-1,4-benzoquinone is not quantitative and results in the formation of fullerene derivatives along
with C60. The comparison of the IR and1H and13C NMR spectral data for solid C60H36 with the theoretical calculations suggests that the fullerene hydride has aT-symmetric structure and contains four isolated benzenoid rings located at tetrahedral positions on the surface of the closed
skeleton of the molecule.
Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya. No. 4, pp. 671–678, April, 1997. 相似文献
17.
The possibility of hydrogen transfer from hydrofullerene C60H36 to electrogenerated radical anion C60
.− or dianion C60
2− in propylene carbonate-toluence (3∶2, v/v) was demonstrated by cyclic voltammetry. The process affords C60H2 as the product. The reaction found is the typical redox-induced process.
Translated fromIzvestiya Akodemii Nauk. Seriya Khimicheskaya, No. 6, pp. 1136–1139, June, 1998. 相似文献
18.
Lebedev B. V. Bykova T. A. Lobach A. S. 《Journal of Thermal Analysis and Calorimetry》2000,62(1):257-265
The temperature dependence of the molar heat capacity (C0
p) of hydrofullerene C60H36 between 5 and 340 K was determined by adiabatic vacuum calorimetry with an error of about 0.2%. The experimental data were
used for the calculation of the thermodynamic functions of the compound in the range 0 to340 K. It was found that at T=298.15 K and p=101.325 kPa C0
p (298.15)=690.0 J K−1 mol−1,Ho(298.15)−Ho(0)= 84.94 kJ mol−1,So(298.15)=506.8 J K−1 mol−1, Go(298.15)−Ho(0)= −66.17 kJ mol−1. The standard entropy of formation of hydrofullerene C60H36 and the entropy of reaction of its formation by hydrogenation of fullerene C60 with hydrogen were estimated and at T=298.15 K they were ΔfSo= −2188.4 J K−1 mol−1 and ΔrSo= −2270.5 J K−1mol−1, respectively.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
19.
富勒烯(C_(60)/C_(70))与三苯基胺间的光诱导电子转移过程研究 总被引:4,自引:0,他引:4
用激光光解方法研究了富勒烯(C_(60)/C_(70))与三苯基胺(TPA)间的光诱 导电子转移过程。在近红外区,观测到TPA阴离子自由基,富勒烯(C_(60)/C_(70) )激发三线态和阴离子自由基。在苯腈溶液中,利用瞬态谱测定了电子从TPA转移 到富勒烯(C_(60)/C_(70))激发三线态的量子转化产率(Φ_(et))和电子转移常 数(k_(et))。 相似文献
20.
S. Michaeli V. Meiklyar B. Endeward K. Möbius H. Levanon 《Research on Chemical Intermediates》1997,23(6):505-517
Fourier transform EPR spectroscopy was employed in studying the electron transfer (ET) reaction and the quenching mechanisms
of the photoexcited triplet state of C60 as electron acceptor and N,N,N′,N′-tetramethylbenzidine (NTMB) as electron donor in benzonitrile solution. The ET reaction
product, the cation radical NTMB*+, interacts with 3*C60, leading to photoinduced electron polarization of NTMB*+ via triplet-doublet mixing mechanism combined with triplet mechanism. The quenching of 3*C60 and the polarization behavior of NTMB*+ are discussed. 相似文献