Sheka, I. A. published the artcileThe application of dielectric polarization for the determination of the composition of complex compounds in solutions, SDS of cas: 6443-90-9, the publication is Izvest. Sektora Platiny i Drug, Blagorod. Metal., Akad. Nauk S.S.S.R., Inst. Obshcheǐ i Neorg. Khim. (1951), 189-202, database is CAplus.
It has been known for some time that the dielec. polarization P for complexes is more than the simple sum of the compounding mols. By comparing numerous reliable data from the literature, it was noted that not only ΔP will accept a rather large value for the case of complex formation, but Δε also, which is understandable, as ε (dielec. constant) appears in the formula for P. By plotting curves ΔP vs. composition and Δε vs. composition, a maximum in such curves will indicate the formation of a complex. For allyl isothiocyanate and piperidine in benzene these 2 maximum coincided with those for viscosity, deviation of the sp. volume, heat of mixing, n, and the temperature coefficient of the viscosity. For pyridine and ICl in CHCl3 the ΔP and Δε maximum coincided with one of the m.p. maximum in the m.p. diagram of pyridine ICl. Thus the plotting of the ΔP-composition and Δε-composition diagrams may serve to replace other very tedious determinations of other physicochem. values which have been used heretofore to find out the presence or absence of complexes. The maximum in these curves will not occur if merely van der Waals forces are acting. If more than one complex is formed, only one will give rise to a maximum; the other will be indicated by a break in the curve. Thus for the case AlBr3-dioxane the break is found for (AlBr3)2.C4H8O2, whereas the maximum lies at AlBr3.C4H8O2. The higher the maximum in these curves, the more stable the complexes.
Izvest. Sektora Platiny i Drug, Blagorod. Metal., Akad. Nauk S.S.S.R., Inst. Obshcheǐ i Neorg. Khim. published new progress about 6443-90-9. 6443-90-9 belongs to iodides-buliding-blocks, auxiliary class Pyridines, name is Pyridine Iodochloride complex, and the molecular formula is C20H12N2O2, SDS of cas: 6443-90-9.
Referemce:
https://en.wikipedia.org/wiki/Iodide,
Iodide – an overview | ScienceDirect Topics – ScienceDirect.com