METAL-IONS OF (I-IV) B-GROUPS IN UNSTABLE OXIDATION-STATES (ELECTRON STATE S-2(1/2)) IN GAMMA-IRRADIATED AQUEOUS-SOLUTIONS AT 77-DEGREES-K

The metal ions of (I-IV) B-groups in unusual oxidation states MZ+aq (electron state 2S1/2) have been obtained in aqueous solutions under the conditions of low-temperature radiolysis at 77°K. EPR signals and optical spectra of these particles have been investigated. The constants of hyperfine interaction have been calculated by the Breit-Rabi equation. It has been established that the density of unpaired electron being on the metal ion nucleus increases linearly with charge Z increasing in the isoelectron series of metal ions. With this phenomena the energy of optical transition in maximum of optical absorption bands practically decreases linearly. The analysis of obtained data which was formed on the basis of semiempirical Milliken-Volfsberg-Gelmgolts's method (MVG), is consistent with the supposition that paramagnetic centres are the aquacomplexes of metals [M(OH2)6]Z+. The energies MO a*1g and t*1u have been calculated for mentioned complexes. It has been shown that the transition a*1g → t*1u is responsible for experimentally observed of optical absorption band [M(OH2)6]Z+. Covalent contribution increases when the positive charge of central metal ion increases. © 1979.