Homopiperazine-1,4-diium bis[hexaaquacobalt(II)] trisulfate

Abstract

In the title compound, (C5H14N2)[Co(H2O)6]2(SO4)3, the cationic framework is built up of mixed organic–inorganic fragments, namely [Co(H2O)6]2+ and [C5H14N2]2+. The [Co(H2O)6]2+ cations form unconnected octa­hedra. Sulfate anions inter­calated between cationic species connect them via N—H⋯O and O—H⋯O hydrogen bonds and electrostatic inter­actions.

Homopiperazine (Hexahydro-1,4-diazepine)

“…At present, it is commercially available from several major suppliers and it has recently found various applications, including as a component of liquids for CO 2 capture [4] and as a component of various organic and organic/inorganic supramolecular ionic salts and transition metal complexes. In these latter applications, the materials are often characterised by X-ray diffraction and so there are a large number of X-ray structures involving a homopiperazinium dication in salts or mixed salts with, for example, carboxylic acids [5][6][7], potassium perchlorate [8], ammonium perchlorate [9], manganese sulfate oxalate [10], cobalt sulfate [11], zinc phosphate [12], arsenic oxide [13], tellurium phosphate [14], cadmium phosphate [15], cadmium chlorides [16,17], lead bromide [18], bismuth iodide [19], uranium fluoride [20] and uranium sulfate [21]. There are also a significant number of structures in which homopiperazine acts as a bidentate ligand on nickel [22,23], copper [24] and platinum [25][26][27][28].…”

Synthesis and characterization of a new Organic – Inorganic sulfate (C5H6N2O)2[Co(H2O)6]3(SO4)4.2H2O

“…There are two independent SO4 2anions in this structure. The geometrical characteristics of these anions are comparable and are not very distinct from these observed in other cobalt-organic complex [12]. These sulfate anions compensate the positive charges of the tris-hexaaquacobalt (II) and ensure the cohesion of the packing.…”

“…The complete complex is generated by the crystallographic inversion center. There are two independent transition metal ions: Co (1) is located in special position on crystallographic inversion center and the second Co (2) [12] (Table 3).…”

Tetraaquabis(piperazin-1-ium)cobalt(II) bis(sulfate) dihydrate

“…For metal-sulfate complexes with piperazinium cations, see: Rekik et al (2005); Pan et al (2003); Sahbani et al (2011); Mrinal et al (2010). For the biological activity of piperazines, see: Bogatcheva et al (2006).…”

“…In view of the importance of piperazines which are found in biologically active materials across a number of areas of therapeutic importance (Bogatcheva et al, 2006), the structural chemistry of metal salts that include piperazine and its derivatives does not cease to develop and continues to be a subject of research in many laboratories. Among the compounds investigated recently are several metal sulfate salts such as piperazinium hexaaquacobalt (II) disulfate (Pan et al, 2003), piperazinedium hexaaquazinc (II) bis sulfate (Rekik et al, 2005) and homopiperazin-1,4-diium bis-hexaaquacobalt (II) trisulfate (Sahbani et al, 2011), among others. In these structures the cobalt atoms are hexacoordinated by six water molecules, and the piperazinium cations are diprotonated and not metal coordinated.…”