Diamminebis[N'-(2-pyrimidinyl)sulfanilamido]copper

Bis[4-amino-N-(pyrimidin-2-yl)benzenesulfonamido]diamminecopper(II): aqua or ammine ligands?

“…Unfortunately, we have not been able to obtain the latter by simple hydrolysis of (I) (see x2.1). There are two more alternatives concerning the relationship between our structural results for (I) and the earlier report by Brown et al (1987): (i) both results could be correct and refer to polymorphs of the same compound; or (ii) the lattice parameters given in the earlier report could be very imprecise, and both reports could in principle refer to crystals of the same compound. We consider this second alternative less likely, because Brown et al report two very different Cu-NH 3 distances; we find two very similar values (Table 2), regardless of whether we use our lattice parameters or those suggested by the earlier authors for refinement.…”

“…If we accept the composition [Cu(sulfa) 2 (NH 3 ) 2 ] for the crystals investigated by Tommasino et al (2011) and in this work, the identity of the sample studied earlier by Brown et al (1987) must be questioned. Although the lattice parameters and metal-ligand distances show similarities, the differences are undoubtedly significant.…”

“…We have recently reinvestigated the common drug sulfadiazine [4-amino-N-(pyrimidin-2-yl)benzenesulfonamide, Hsulfa] (Shin et al, 1974;Joshi et al, 1983;Kokila et al, 1995;Ajibade et al, 2006;Mayer et al, 2000) and its zinc complex (Baenziger et al, 1983;Brown et al, 1985) and obtained experimental charge densities (Pan et al, 2012(Pan et al, , 2013. When we extended our studies to the title compound, [Cu(sulfa) 2 (NH 3 ) 2 ], (I), a Cu II coordination compound of sulfadiazine, we were confronted with two earlier reports concerning isomorphous or allegedly identical structures: Brown et al (1987) published the crystal structure of [Cu(sulfa) 2 (NH 3 ) 2 ] [Cambridge Structural Database (CSD; Allen, 2002) refcode FUTVEV], and Tommasino et al (2011) recently reported [Cu(sulfa) 2 (NH 3 )(H 2 O)] (CSD refcode ORISEO). The earlier structures and our results disagree about the nature and geometry of the ammine and aqua ligands, as summarized in Fig.…”

“…1. An obvious explanation might be that the crystal used in the diffraction experiment by Brown et al (1987) . Unfortunately, we have not been able to obtain the latter by simple hydrolysis of (I) (see x2.1).…”

trans-Diaquabis(ethylenediamine)zinc(II) 2-(sulfanilamido)pyrimidine monohydrate

“…Because the slow release of the metal ions from these drugs is strongly dependent on their binding nature, it is important to understand the coordination environment around the metal. Although interesting structural results have been described in the literature (Baenziger et al, 1983;Built et al, 1981;Brown et al, 1987;Garcia Raso et al, 1997), mixedligand complexes of 2-sulfanilamidopyrimidine have not been prepared and investigated sufficiently to date. Therefore, in the present paper, we report the synthesis and crystal structure of the title Zn II -2-sulfanilamidopyrimidine (H-SD)ethylenediamine (en) complex, (I).…”