Watari, Fumio published the artcileInfrared absorption spectra of molecular complexes of pyridine. III. Molecular complexes with iodine and iodine halides, Synthetic Route of 6443-90-9, the publication is Sci. Rept. Res. Inst., Tohoku Univ. (1962), Ser. A 14(No. 1), 64-9, database is CAplus.
cf. CA 56, 9594a. When I, ICl, or IBr were dissolved in pyridine (I), new bands were observed at 627-624, 1012-1007, 1213, 1246 and 1454 cm.-1, which were assigned as the shifted bands of ν6a, ν1, ν3, 2ν6a, and ν19b, resp., of I. They are well defined: others appear only as a shoulder of the pure I band; some may mutually enhance their intensity, others remain almost unaffected. The rest of the absorptions of the I solution were nearly the same in band location and intensity as those of pure I. Spectra of the solid complexes are analogous to the solution spectra, though in the latter there are the shifting and intensity-changing effects in the case of liquid I. The difference of shift of 624-627 and 1007-1012 cm.-1 is parallel to the electronegativities of the added interhalogen compounds; ICl shifts a band most markedly from the pure I spectrum.
Sci. Rept. Res. Inst., Tohoku Univ. 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 C14H28O5S, Synthetic Route of 6443-90-9.
Referemce:
https://en.wikipedia.org/wiki/Iodide,
Iodide – an overview | ScienceDirect Topics – ScienceDirect.com