3295-69-0Relevant articles and documents
The Photoreduction Mechanism of 10-Methylacridinium Chloride in Methanol. The Formation of 9,10-Dihydro-9-methoxy-10-methylacridine and Hydride Transfer
Kano, Koji,Zhou, Bin,Hashimoto, Shizunobu
, p. 1041 - 1048 (1987)
The photolysis of 9,10-dihydro-9-methoxy-10-methylacridine (MeOA), which is a product of the nucleophilic addition of methanol to 10-methylacridinium chloride, yielded 9,10-dihydro-10-methylacridine (AH2) and 10,10'-dimethyl-9,9',10,10'-tetrahydro-9,9'-biacridinyl ((AH)2) in various solvents.The quenching experiment using 1,3-pentadiene indicates that AH2 and (AH)2 are produced from the photoexcited singlet and triplet states of MeOA respectively.The results on the solvent effects and the photolyses in solvent matrices at 77 K suggest that the photochemical reactionof MeOA yielding AH2 occurs via hydride transfer from the methoxide anion to the 10-methylacridinium cation, these ions being generated from the heterolysis of MeOA in the photoexcited singlet state.
A Low-Valent Iron Imido Heterocubane Cluster: Reversible Electron Transfer and Catalysis of Selective C-C Couplings
Lichtenberg, Crispin,Garcia Rubio, Inés,Viciu, Liliana,Adelhardt, Mario,Meyer, Karsten,Jeschke, Gunnar,Grützmacher, Hansj?rg
, p. 13012 - 13017 (2015)
Enzymes and cofactors with iron-sulfur heterocubane core structures, [Fe4S4], are often found in nature as electron transfer reagents in fundamental catalytic transformations. An artificial heterocubane with a [Fe4N4] core is reported that can reversibly store up to four electrons at very negative potentials. The neutral [Fe4N4] and the singly reduced low-valent [Fe4N4]- heterocubanes were isolated and fully characterized. The low-valent species bears one unpaired electron, which is localized predominantly at one iron center in the electronic ground state but fluctuates with increasing temperatures. The electrons stored or released by the [Fe4N4]/[Fe4N4]- redox couple can be used in reductive or oxidative C-C couplings and even allow catalytic one-pot reactions, which show a remarkably enhanced selectivity in the presence of the [Fe4N4] heterocubanes.
Effect of Magnesium Ion distinguishing between One-step Hydrogen- and Electron-transfer Mechanisms for the Reduction of Stable Neutral Radicals by NADH Analogues
Fukuzumi, Shunichi,Tokuda, Yoshihiro,Chiba, Yutaka,Greci, Lucedio,Carloni, Patricia,Damiani, Elisabetta
, p. 1575 - 1577 (1993)
Hydrogen transfer from NADH analogues to indolinone and phenyliminoindolinone aminoxyl radicals proceeds via a one-step hydrogen-transfer process, in which no catalytic effect of Mg2+ has been observed, while the hydrogen transfer to 1,1-diphen
Addition versus oxygenation of alkylbenzenes with 10-methylacridinium ion via photoinduced electron transfer
Fujita, Morifumi,Ishida, Akito,Takamuku, Setsuo,Fukuzumi, Shunichi
, p. 8566 - 8574 (2007/10/03)
Addition of alkylbenzenes with 10-methylacridinium ion (AcrH+) occurs efficiently under visible light irradiation in deaerated acetonitrile containing H2O to yield 9-alkyl-10-methyl-9,10-dihydroacridine selectively. On the other hand, the photochemical reaction of AcrH+ with alkylbenzenes in the presence of perchloric acid in deaerated acetonitrile yields 10-methyl-9,10-dihydroacridine, accompanied by the oxygenation of alkylbenzenes to the corresponding benzyl alcohols. The photooxygenation of alkylbenzenes occurs also in the presence of oxygen, when AcrH+ acts as an efficient photocatalyst. The studies on the quantum yields and fluorescence quenching of AcrH+ by alkylbenzenes as well as the laser flash photolysis have revealed that the photochemical reactions of AcrH+ with alkylbenzenes in both the absence and presence of oxygen proceed via photoinduced electron transfer from alkylbenzenes to the singlet excited state of AcrH+ to produce alkylbenzene radical cations and 10-methylacridinyl radical (AcrH·). The competition between the deprotonation of alkylbenzene radical cations and the back electron transfer from AcrH· to the radical cations determines the limiting quantum yields. In the absence of oxygen, the coupling of the deprotonated radicals with AcrH· yields the adducts. The photoinduced hydride reduction of AcrH+ in the presence of perchloric acid proceeds via the protonation of acridinyl radical produced by the photoinduced electron transfer from alkylbenzenes. In the presence of oxygen, however, the deprotonated radicals are trapped efficiently by oxygen to give the corresponding peroxyl radicals which are reduced by the back electron transfer from AcrH· to regenerate AcrH+, followed by the protonation to yield the corresponding hydroperoxide. The ratios of the deprotonation reactivity from different alkyl groups of alkylbenzene radical cations were determined from both the intra- and intermolecular competitions of the deprotonation from two alkyl groups of alkylbenzene radical cations. The reactivity of the deprotonation from alkylbenzene radical cations increases generally in the order methyl ethyl isopropyl. The strong stereoelectronic effects on the deprotonation from isopropyl group of alkylbenzene radical cations appear in the case of the o-methyl isomer.
Synthesis of hexacarbonyl derivatives of group 5 metals and electron-transfer processes. Crystal and molecular structure of tetracarbonyl(1,2-bis(diphenylphosphino)ethane)iodotantalum
Calderazzo, Fausto,Pampaloni, Guido,Pelizzi, Giancarlo,Vitali, Francesca
, p. 1083 - 1092 (2008/10/08)
Vanadium, niobium, and tantalum hexacarbonylmetalate(-I) derivatives of several heterocyclic nitrogen bases, RnB[M(CO)6]n (R = H, Me; n = 1, 2), have been synthesized. In some cases an electron transfer from the hexacarbonylmetalate to the protonated or methylated BRnn+ cation has been observed. Pyridinium halides react with Na[M(CO)6] (M = Nb, Ta) in the presence of 1 equiv of 1,2-bis(diphenylphosphino)ethane (diphos) to give high yields of the halo tetracarbonyl derivatives MX(CO)4(diphos). The red-orange TaI(CO)4(diphos) complex has been studied by X-ray diffraction methods. Crystal data: space group P21/n; Mr 818.3; a = 14.864 (10) ?, b = 9.875 (7) ?, c = 19.335 (13) ?; β = 105.61 (2)°; U = 2733 (3) ?3; Z = 4; Dcalcd = 1.988 g cm-3; F(000) = 1568; μ(Mo Kα) = 52.4 cm-1. The geometry of the seven-coordinate tantalum atom is best described as a capped trigonal prism with the iodide ligand in the capping position. By reaction of Na[Ta(CO)6] with 1 equiv of hydrogen chloride and diphos in toluene, the hydride TaH(CO)4(diphos) has been isolated in good yield.
Kinetics and mechanism of oxidation of N,N'-dimethyl-9,9'-biacridanyl by some ? acceptors and a one-electron oxidant
Colter, Allan K.,Lai, Charles C.,Parsons, A. Gregg,Ramsay, N. Bruce,Saito, Gunzi
, p. 445 - 451 (2007/10/02)
Oxidation of N,N'-dimethyl-9,9'-biacridanyl (DD) has been investigated as a model for single electron transfer (SET)-initiated oxidation of NADH coenzyme models such as N-methylacridan (DH).Oxidants investigated cover a 1010-fold range of reactivity in acetonitrile and include the ? acceptors 1,4-benzoquinone (BQ), 2,6-dichloro-1,4-benzoquinone (DClBQ), p-chloranil (CA), 2,3-dicyanobenzoquinone (DCBQ), 2,3-dicyano-1,4-naphthoquinone (DCNQ), 2,3-dicyano-5-nitro-1,4-naphthoquinone (DCNNQ), 9-dicyanomethylene-2,4,7-trinitrofluorene (DCMTNF), 9-dicyanomethylene-2,4,5,7-tetranitrofluorene (DCMTENF), 7,7,8,8-tetracyanoquinodimethane (TCNQ), and tetracyanoethylene (TCNE), and the one-electron oxidant tris((2,2'-bipyridyl)cobalt(III), Co(bipy)33+.The oxidation product is, in every case, N-methylacridinium ion (D+).A mechanism involving a rate-determining electron transfer with simultaneous fragmentation to D+ and N-methyl-9-acridanyl radical (D.) is proposed.This mechanism is supported by the observed dependence of the rate on oxidant reduction potential, by spin-trapping experiments, by kinetic isotope effects in oxidation of 9,9'-dideuterio-DD, and by substituent effects in oxidation of 2,2'- and 3,3'-dimethoxy-DD.The rate of oxidation of DD relative to that of DH is 3.4 * 102 with Co(bipy)33+, and with the ? acceptors varies from ca. 0.3 (BQ) to 8.1 * 104 (DCMTENF).The results rule out a SET-initiated mechanism for oxidation of DH by all of the oxidants studied except TCNQ and DCMTENF.
