Electrochemical studies of methyl-3-benzoyl indolizine carboxylates
Indolizine derivatives have been used in medicine and pharmacology due to their biological activity and therapeutical effects. Their capacity to form surface films and to be used as sensors in modern technologies makes them interesting to be studied. This work is devoted to the study of methyl-3-benzoyl indolizine carboxylates by cyclic voltammetry (CV) and differential pulse voltammetry (DPV). It is pursued the influence of concentration on CV and DPV curves and that of the scanning domain and rate on the CV curves. The CV and DPV results are in good agreement. There are established the number and characteristics of the redox processes for each compound. The common features and differences between their electrochemical behaviour were analyzed.
Electrochemical studies of biologically active indolizines
Abstract The electrochemical behavior of indolizine ethers, esters, tosylates, sulfonates and other indolizine and azaindolizine derivatives has been investigated by cyclic voltammetry and preparative electrolysis. The cyclic voltammetric data show that the E ° values, taken as the midpoints between the anodic and cathodic peak potentials, are sensitive to the identities of the substituents at C-1, C-2 and C-7 positions. The E ° values have been correlated with the Hammett substituent parameters. As expected, low E ° values are seen for electron donating substituents and higher E ° values are seen for electron withdrawing substituents. The cyclic voltammograms of indolizine derivatives with an oxygen atom connected to the C-1 position exhibit a one-electron reversible oxidation and a further, less well-defined, one-electron irreversible oxidation at higher E ° values. The cyclic voltammograms of indolizines with hydrogen atom or thienyl substituents connected to the C-1 position exhibit only a one-electron irreversible oxidation. Electrochemical bulk oxidations of indolizines with an oxygen atom at the C-1 position afforded oxoindolizinium salts in decent yields, whereas indolizines with a hydrogen atom at C-1 afforded 1,1′ dimers of indolizines as products in good yields. Bulk oxidation of 1-(α-hydroxybenzyl)-2,3-diphenylindolizine-7-carbonitrile afforded an unexpected ketone product in which the carbonyl group of the indolizine is connected at C-8 instead of at the C-1 position of the starting material. The findings described herein support our hypothesis that certain indolizine derivatives may inhibit lipid peroxidation by an electron transfer mechanism.
Population and Settlement
Part 1 Population distribution: world population distribution variations in world population distribution population distribution in the Highlands and Islands population distribution in Japan population distribution in Brazil. Part 2 Population growth and movement: population structure the world population explosion variations in population growth migration why do people migrate types of migration in North and West Africa West German migration populating the USSR populating Australia attitudes to population control population and natural resources. Part 3 Settlements: location of settlement settlement types settlement functions settlement patterns South Wales valley settlements the changing village. Part 4 Urbanization: million cities world urbanization rural-urban migration in the developing world urban land use inner city problems urban transport the Tyneside metro spheres of influence changing shopping habits the Dutch Randstad Lagos - a city in the developing world new and expanding towns in the UK new settlements in developing countries green belts or red bricks? Part 5 Further studies: UK population migration Kenya's population problems Sheffield Washington New Town.