Bis(1-ammonioethane-1,1-diyldiphosphonato-κ²O,O′)diaquacobalt(II) nonahydrate

Abstract

In the title compound, [Co(C2H8NO6P2)2(H2O)2]·9H2O, the CoII atom has a slightly distorted octa­hedral coordination environment consisting of four deprotonated phospho­nate O atoms of two independent 1-amino­ethyl­idendiphospho­nate anions and complemented by the O atoms of two water mol­ecules in cis positions. The anions exists in the zwitterionic form (protonated amino group and two deprotonated phospho­nate O atoms) and constitute two six-membered chelate rings. The crystal structure also contains nine partly disordered uncoordinated water mol­ecules, which create an extensive three-dimensional network of strong O—H⋯O and N—H⋯O hydrogen bonds.

Crystal structure of bis[(1-ammonio-1-phosphonoethyl)phosphonato]tetraaquacadmium dihydrate: a powder X-ray diffraction study

“…1), contains one half of the complex molecule [CdL 2 (H 2 O) 4 ] [L = (1-ammonio-1-phosphonoethyl)phosphonate] and one lattice water molecule. All bond lengths and angles in (I) are normal and correspond to those observed in bisphosphonate complexes with transition metals (Shkol'nikova et al, 1991;Sergienko et al, 1997Sergienko et al, , 1999Yin et al, 2005;Li et al, 2006;Lin et al, 2007;Xiang et al, 2007;Dudko et al, 2009Dudko et al, , 2010Bon et al, 2010;Tsaryk et al, 2010Tsaryk et al, , 2011. The Cd II atom occupies a special position on an inversion centre and shows a slightly distorted octahedral coordination environment formed by two phosphonic O atoms in trans positions and four aqua O atoms in the equatorial plane.…”

Diaquabis(dihydrogen 3-azaniumyl-1-hydroxypropylidene-1,1-diphosphonato-κ2O,O′)cobalt(II)

“…For applications of bisphosphonate metal complexes in medicine, see: Matkovskaya et al (2001). For a related structure, see: Bon et al (2010). For bond-length data, see: Allen et al (2004).…”