GROUND STATE AND EXCITED STATE ELECTRON TRANSFER STUDIES OF TRANSITION METAL COMPLEXES
Abstract
The ground state and excited state properties of {Cu(dmp)(PPh(,3))(,2)}('+) have been investigated in MeOH. The complex dissociates in solution according to the following equilibrium reaction which is suppressed by the addition of excess PPh(,3). {Cu(dmp)(PPh(,3))(,2)}('+) (DBLHARR) {Cu(dmp)}('+) + 2 PPh(,3) Cyclic voltammetry studies indicate that the complex has a reduction potential >+0.7 V vs. AgCl/Ag and that its electrochemistry is rather(, ) complicated. The excited state has been characterized as a ('3)CT state having a lifetime of 330 ns at room temperature and a (phi)(,1um) of 0.014. Electron transfer quenching studies indicate that the excited state has a reduction potential of (TURN)-1.0 V. Low temperature studies reveal that in a rigid matrix, the emission can be resolved into two components having very different lifetimes which are attributed to ('3)(pi)-(pi)('*) and ('3)d-(pi)('*) states. Various models from the literature for multiply emitting systems are discussed and applied to the {Cu(dmp)(PPh(,3))(,2)}('+) system. The electrochemical behavior of cis- and trans-Co(IDA)(,2)('-) has been investigated at a HMDE using cyclic voltammetry and has been found to be rather complex. Studies reveal that the trans form rapidly isomerizes to the cis form following reduction so that upon reoxidation only cis-Co(IDA)(,2)('-) is formed at the electrode. In addition, both Co(III) species react directly with the Hg electrode in a chemical reaction which complicates the results, but the addition of excess IDA('2-) has been found to minimize the interference.
Degree
Ph.D.
Subject Area
Chemistry
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