A comparison of charge-transfer complexes of iodine with some antibiotics formed through two different approaches (liquid-liquid vs solid-solid)

In this work, we compare CT complexes obtained from liquid starting materials to those generated in solid form. Specifically, iodine was complexed with four pharmaceutical compounds: trimethoprim (TMP), moxifloxacin (MOX), ceftriaxone (CTX), and sulfamethoxazole (SMZ). The synthesis approaches differed only by the phase of the starting materials (liquid-liquid vs solid-solid). The solid-solid approach successfully yielded the remaining three iodine CT complexes, which formed via a tri-iodide complex formulated as [D center dot I+]I-3(-) (D: investigated pharmaceutical compound). Comparing the two approaches, we found that the solid-solid approach is faster, simpler, doesn't require a purification process, and does not consume large amounts of solvent or time relative to its liquid-liquid counterpart. More interesting, the solid-solid approach can generate iodine CT complexes with compounds that are very poorly soluble in a suitable organic solvent, which cannot be produced using the liquid-liquid approach. (C) 2021 Elsevier B.V. All rights reserved.