Ion-selective electrodes in titrations involving azo-coupling reactions: Part 2. Titrations with diazonium salts derived from 1-aminonaphthalenes and 1-amino-9,10-anthraquinone

Lipophilic arenediazonium salts dreived from 1-aminonaphthalene, 1-amino-4-bromonaphthalene, 1-amino-4-nitronaphthalene and 1-amino-9,10-anthraquinone were tested as titrants for determination of aromatic hydroxy compounds, amines, and compounds containing active methylene groups, usually at the 10^?2 M level. The potentiometric titrations were monitored with indicator electrodes selective for organic cations which were based on PVC membranes plasticized with 2-nitrophenyl alkyl ethers (where alkyl is n-octyl or 2-ethylhexyl). Titrations of 11 compounds ranging from 1,2-diaminotoluene to 1-phenyl-3-methyl-5-pyrazolone were examined; 4-bromo-1-naphthalenediazonium chloride seemed to be the most widely applicable titrant.