The reaction of an aromatic heterocycle with a proton is called a protonation. One of articles about this theory is 《Application of unithiol (Na 2,3-dimercaptopropanesulfonate) in analytical chemistry》. Authors are Vol’f, A. L..The article about the compound:8-Hydroxyquinoline 1-oxidecas:1127-45-3,SMILESS:OC1=CC=CC2=CC=C[N+]([O-])=C12).SDS of cas: 1127-45-3. Through the article, more information about this compound (cas:1127-45-3) is conveyed.
Unithiol (I) (cf. Ptrun’kin, CA 51, 5692h) forms stable complexes with many cations and most of these are soluble in H2O. Zn and Cd were determined by titration with I in the presence of Eriochrome Black T as an indicator with the same degree of accuracy as by titration with Trilon B; alkali metals and Fe up to 5 mg./l. did not interfere. I can be used to block the interference of Zn, Pb, and Hg in the trilonometric determination of Ca and Mg. I forms complexes with the following cations: in neutral media; Pb green, Cu blue, Ni brown, and Bi yellow; in acid media; Cu dark-blue, Ag green, and Mn brown; in NH4OH; Cu blue-violet, Fe red, Ag green, Mn brown-green, Bi yellow, and Sb yellow.
There is still a lot of research devoted to this compound(SMILES：OC1=CC=CC2=CC=C[N+]([O-])=C12)SDS of cas: 1127-45-3, and with the development of science, more effects of this compound(1127-45-3) can be discovered.
Reference:
Quinoxaline – Wikipedia,
Quinoxaline | C8H6N2 | ChemSpider