Quinolines polarographic potentials

Quaternary salts, pKa value of, 7] polarographic reduction potentials, 71 Quinaldinium salts, in Mills reaction, 37,45 Quinoline-4)(4-methvlthiazole-2) trimethine cyanine, 62... 

Electron-attracting substituents facilitate electrochemical reduction. The reduction potentials for the polarographic reduction of quinoline and isoquinoline derivatives are much less negative than those for the pyridine analogues. Diazines are reduced electrochemically stepwise, usually as far as tetrahydro derivatives (70AHC(12)262). 

Quinoline and isoquinoline derivatives are polarographically reducible in a way similar to the pyridine compounds, but the reduction potentials required are generally less negative. 

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