Dynamic effects in ESR spectra of 4-triphenylmethyl-6-tert-butyl-2-hydroxyphenoxyl and 4-triphenylmethyl-6-phenyl-2-hydroxyphenoxyl

Conclusions In the ESR spectra of 6-triphenylmethyl-4-tert-butyl-2-hydroxyphenoxyl and 6-triphenylmethyl-4-phenyl-2-hydroxyphenoxyl and their deuterated analogs, temperature-dependent dynamic effects have been found; these are explained from the standpoint of a reversible intramolecular transition between different conformations of the radicals, differing in the spin density distribution, owing to direct interaction of the unpaired electron with the orbitals of the phenyl rings of the triphenylmethyl substituent.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 7, pp. 1513–1517, July, 1985.     

Investigation of ligand-substitution reactions in paramagnetic o-quinone-tetracarbonylmanganese and o-quinone-tetracarbonylrhenium complexes

Conclusions The lability of the CO groups in complexes of o-quinones with manganese tetracarbonyl is considerably greater than in Mn₂(CO)₁₀.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 3, pp. 550–555, March, 1982.     

Epr investigation of the adducts of element-centered radicals with polyhedral carbon clusters (fullerenes)

A. N. Nesmeyanov Institute of Heteroorganic Compounds, Russian Academy of Sciences, 117813 Moscow. Translated fromIzvestiya Akademii Nauk, Seriya Khimicheskaya, No. 6, pp. 1457–1458, June, 1992.     

An ESR study of the products of multiple addition of diisopropoxyphosphoryl radicals to C60

The ESR spectra of the radicals resulting from the multiple addition of diisopropoxyphosphoryl radicals to C₆₀ have been studied. The formation of six different types of radical adducts was detected. A structure for the stable product, characterized by hyperfine coupling of the unpaired electron with two phosphorus nuclei, was proposed. The unpaired electron in C₆₀P(O)(OPrⁱ)₂ is delocalized in the same way as in alkylfullerenyl radicals,i.e., mainly over the two six-membered rings adjacent to the C-CP(O)(OPrⁱ)₂ bond.Translated fromIzvestiya Akademii Nauk. Seriva Khimicheskaya, No. 11, pp. 2679–2682, November, 1996.     

Allylic radicals as intermediates of free-radical phosphorylation of fullerene-70

Multiple addition of photochemically generated · P(O)(OMe)₂ radicals to C₇₀ results in the formation of allylic radicals with three and five phosphoryl groups.Translated fromIzvestiya Akademii Nauk, Seriya Khimicheskaya, No. 1, pp. 222–223, January, 1993.     

ESR spectra of spin-adducts of hydroxyalkyl radicals with perfluoro-4-methyl-2-pentene

A study was carried out on the ESR spectra of the spin-adducts of hydroxyalkyl radicals with perfluoro-4-methyl-2-pentene (I) formed upon the photolysis of alcoholic solutions of this perfluoroolefin. The stable conformational positions of the substituents in the spin-adducts depend on the structure of the hydroxyalkyl radicals. The spin-adducts are annihilated as a consequence of hydrogen atom abstraction as indicated in a preparative experiment.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 3, pp. 730–732, March, 1991.     

The ESR study of reactivity of perfluoroacetyldiisopropylmethyl radical

The kinetics of hydrogen abstraction from hydrocarbons by the air-stable perfluoroacetyldiisopropylmethyl radical was studied by ESR, and a reaction mechanism was proposed. The degree of delocalization of the unpaired electron in the model C(5)F₃−C(1)·[C(2)(O(4))C(3)F₃]C(6)F₃ radical was calculated by the MNDO/PM3 method in the UHF approximation. For the conformation in which the CO group lies in the plane passing through the C(1), C(2), and C(5) atoms, the electron density on the O atom is 0.22. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 1954–1957, November, 1997.     

Rate constants for addition of the OP·(OPri)2, Me3C·, and Me(CH2)3 ·CH2 radicals to methano[60]fullerenes C60CX1X2 (X1 = X2 = CO2Et; X1 = CO2Me,X2 = OP(OMe)2; X1 = X2 = OP(OEt)2)

The rate constants for the addition of the OP^·(OPrⁱ)₂, Me₃C^·, and Me(CH₂)₃ ^·CH₂ radicals to the methano[60]fullerenes C₆₀CX¹X² (X¹ = X² = CO₂Et; X¹ = CO₂Me, X² = OP(OMe)2; X¹ = X² = OP(OEt)₂) were determined by ESR spectroscopy. Methanofullerenes are more reactive toward these radicals than C₆₀ fullerene.