Competing protonation sites in sulfadiazine: answers from chemistry and electron density

Synthesis of tetrahalide dianions directed by crystal engineering

“…Table S2 †) and thus extend the dimer to a one-dimensional chain along the crystallographic c axis (Fig. The result of our previous experimental charge density study 16 suggested weak interactions between the chloride connectors and the anilinium N atoms in the adjacent layer (red circle in Fig. Although individual hydrogen bonds are only moderately strong, their joint effect renders the 1D chain a reliable synthon.…”

“…We recently undertook a detailed study of the properties of sulfadiazine as a neutral, cationic or anionic residue 16 and as ligand in a metal complex. We recently undertook a detailed study of the properties of sulfadiazine as a neutral, cationic or anionic residue 16 and as ligand in a metal complex.…”

“…We recently undertook a detailed study of the properties of sulfadiazine as a neutral, cationic or anionic residue 16 and as ligand in a metal complex. 16 The analogy between halogen and hydrogen bonds, both highly directional interactions, and the size match between a Cl − ⋯HOC 2 H 4 OH⋯Cl − and Cl − ⋯I-I⋯Cl − group suggested that our sulfadiazine synthon might also be a useful template for stabilizing tetrahalides. A stable supramolecular sulfadiazine macrocycle was able to capture ethanol or ethylene glycol by means of hydrogen bonds.…”

“…The sulfadiazine macrocycle 16 in 1b plays a pivotal role for the stabilization of the tetrahalides in 1a, 2a and 3a; we therefore refer to 1b as the parent compound and shortly recall its construction principles. The underlying basic interactions have been graphically represented in Fig.…”

Systematic Experimental Charge Density: Linking Structural Modifications to Electron Density Distributions

“…67 Sulfadiazines are part of the sulfonamide class of APIs (active pharmaceutical ingredients), and different protonation states have been observed in different structures of sulfadiazine. 68 The diammino Zn(II) complex and silver salt display a deprotonated amido group, while the polymorphs of neutral compounds of the related sulfapyridine have tautomeric forms where the proton is attached to either the amide or pyrimidine nitrogen.…”