13761-37-0Relevant articles and documents
Synthesis and Electrochemical Properties of 2-(4-R1-Phenyl)-6-(4-R2-phenyl)-4-phenyl-3,4-dihydro1,2,4,5-tetrazin-1(2H)-yls
Akhmatova, A. A.,Balandina, A. V.,Chernyaeva, O. Yu.,Kostryukov, S. G.,Kozlov, A. Sh.,Kraynov, E. V.,Lukshina, Yu. I.,Pryanichnikova, M. K.
, p. 341 - 351 (2020/04/27)
Abstract: A new methodology for creating electroactive components for organic batteries,based on the construction of a molecular platform including stable3,4-dihydro-1,2,4,5-tetrazin-1(2H)-ylradicals was described. A series of2-(4-R1-phenyl)-6-(4-R2-phenyl)-4-phenyl-3,4-dihydro-1,2,4,5-tetrazin-1(2H)-yls with substituents of various nature wasobtained. It was shown that the substituents R1 inthe aromatic ring at position 2 of the tetrazinyl fragment influence the valueof the oxidation potential in the radical, but do not influence the value of thereduction potentials, while the substituent R2 of thearomatic ring at position 6 influence the values of the reduction potentials andpractically do not influence oxidation potential values. Based on the obtainedelectrochemical data, a correlation structure–potential value was revealed forthe cathodic and anodic process, with the help of which triarylsubstituted3,4-dihydro-1,2,4,5-tetrazin-1(2H)-ylradicals with high values of the electrochemical gap were obtained.
Kinetics and mechanisms of the electron transfer reactions of oxo-centred carboxylate bridged complexes, [Fe3(μ3-O)(O 2CR)6L3]ClO4, with verdazyl radicals in acetonitrile solution
Keeney, Lynette,Hynes, Michael J.
, p. 1524 - 1531 (2007/10/03)
A range of oxo-centred, carboxylate bridged tri-iron complexes of general formula [Fe3(μ3-O)(O2CR)6L 3]ClO4 (R = CH2CN, CH2F, CH 2Cl, CH2Br, p-NO2C6H4; L = pyridine, 3-methylpyridine, 4-methylpyridine, 3,5-dimethylpyridine, 3-cyanopyridine and 3-fluoropyridine) have been prepared and characterised. The choice of R and L was dictated by the requirement that the complexes undergo a one-electron reduction when reacted with verdazyl radicals. All except the complexes where L = pyridine and R = CH2CN, CH2Cl and p-NO2C6H4 have not been previously reported. The redox behaviour of these compounds has been investigated using cyclic voltammetry in acetonitrile in the absence and in the presence of free L. In general, all complexes exhibited reversible one-electron reductions. Electrochemical behaviour improved in the presence of an excess of L. The kinetics of the electron transfer reaction observed when acetonitrile solutions of the complexes were reacted with a range of verdazyl radicals were monitored using stopped-flow spectrophotometry. Under the experimental conditions, the reactions were quite rapid and were monitored under second-order conditions. Marcus linear free energy plots indicated that the outer-sphere electron transfer reactions were non-adiabatic in nature. Nevertheless, application of the self-exchange rate constants of the verdazyl radicals, k11, and the tri-iron complexes, k22, to the Marcus cross-relation resulted in calculated values of the cross-reaction rate constant, k12, that were within a factor of five of the experimentally determined value. The Royal Society of Chemistry 2005.
STRENGTH OF N-H BOND IN 2,4-DIPHENYL-6-(4-X-PHENYL)-1,2,3,4-TETRAHYDRO-sym-TETRAZINES (LEUCOVERDAZYLS)
Polumbrik, O.M.,Ryabokon', I.G.,Skorobagat'ko, E.P.,Nesterenko, A.M.,Markovskii, L.N.
, p. 922 - 927 (2007/10/02)
The equilibrium contstants in the reactions of triphenylleucoverdazyls substituted at the para position of the C6-phenyl ring with 2,2,6,6-tetramethyl-4-oxopiperidin-1-oxyl in heptane were determined by spectrophotometry and ESR.At 20 deg C the equilibrium is displaced toward the formation of the more stable verdazyl radicals.The strengths of the N-H bonds in the leucoverdazyls were determined.The enthalpy of solvation of triphenylverdazyl in acetonitrile was obtained (-15.6 kJ/mole).The kinetics of exchange of hydrogen between the triphenylverdazyls and 2,2,6,6-tetramethyl-4-oxopiperidine-1-hydroxylamine in acetonitrile were studied.The mechanism of the reaction, which inlcudes the formation of a hydrogen bond between the reagents in an activated complex, is discussed.It was concluded that the reactivity of the triphenylverdazyls in the abstraction of hydrogen from organic compounds is determined to a significant degree by the strength of the N-H bond which forms in the leucoverdazyls.
