ChemInform Abstract: DIE SYNTHESE VON 1‐ALKYL‐4‐(4‐PYRIDYL)‐PYRIDINIUMSALZEN

Abstract

4,4′‐Dipyridyl (I) und eine Reihe von Alkylbromiden (II) erhitzt man im Rohr längere Zeit (13 ‐ 30 Stdn.) auf 80°C. Es entstehen die Monoquartärsalze (III) mit sehr guten Ausbeuten.

Synthesis and properties of paraquat (methyl viologen) and other herbicidal alkyl homologs

“…Dependence of redox potential (E1p in millivolts) on alkyl inductive effect ( *) of side chains of viologens. £1/2 determined in water (•) from Homer et al (1960) and Khaskin et al (1972) was referenced to a normal hydrogen electrode. £1/2 determined in acetonitrile ( ) from van Dam and Ponjee (1974) was referenced to Ag/AgCl.…”

“…White (1970) demonstrated a correlation between redox potential and Taft's polar substituent inductive effect constant ( *) for short-chain electron-withdrawing nitrogen substituents. Figure 2 is a correlation of * (Fellous et al, 1977) with redox potentials determined in acetonitrile (van Dam and Ponjee, 1974) and water (Khaskin et al, 1972; Homer et al, 1960). The correlation of redox potentials determined in water with * appears anomalous because redox potential changes very little from methyl to hexyl.…”