Chemical constitution and activity of bipyridylium herbicides: IV.—Diquaternary salts of methyl substituted 1,10‐phenanthrolines

Abstract

Eight bridged diquaternary salts of methyl substituted 1,10‐phenanthrolines have been prepared. They are reduced in aqueous solution to radical cations at about the same potential as diquat by a one electron transfer which is largely reversed by air. in herbicidal tests they showed slight activity at a rate equivalent to 8 lb/acre. Their relatively poor phytotoxic properties are considered to be due to their large size which hinders their reaching the site of biological action of the bipyridylium herbicides.

Imprinted Polymer – Modified Hanging Mercury Drop Electrode for Differential Pulse Adsorptive Stripping Voltammetric Analysis of a Diquat Herbicide

“…The template diquat herbicide (DHPPCl 2 ) was prepared and characterized by following the known recipe [20].…”

Determination of diquat herbicide by selective enrichment by column chromatography on imprinted polymer immobilised on silica gel

“…The template analyte, DHPPC12, was prepared and characterized by following a reported procedure [22].…”

Stable radical cation from a diquaternary salt of 2,2′‐biquinoline

“…Certain diquaternary salts of bipyridines, for example the salt V, show considerable herbicidal activity (7) but the salt I, when tested as a post-emergence herbicide a t 8 Ibs/acre on six plant species was inactive. The lack of phytotoxicity shown by I is probably due to its large size (2). The nmr spectrum (deuterium oxide) showed singlets at 6 3.65 ppm (6 methosulphate H) and 4.6 (6 N-methyl H), a complex multiplet at 8.15-8.8 (10 aromatic H), and a doublet at 9.55-9.7 ( 2 aromatic H).…”