Silver diaquacobalt(II)catena-borodiphosphate(V) hydrate, (Ag_0.79Co_0.11)Co(H₂O)₂[BP₂O₈]·0.67H₂O

Abstract

The structure of the title compound, (Ag0.79Co0.11)Co(H2O)2[BP2O8]·0.67H2O is isotypic to that of its recently published counterparts AgMg(H2O)2[BP2O8]·H2O and (Ag0.57Ni0.22)Ni(H2O)2[BP2O8]·0.67H2O. It consists of infinite borophos­phate helical ribbons [BP2O8]3−, built up from alternate BO4 and PO4 tetra­hedra arranged around the 65 screw axes. The vertex-sharing BO4 and PO4 tetra­hedra form a spiral ribbon of four-membred rings in which BO4 and PO4 groups alternate. The ribbons are connected through slightly distorted CoO4(H2O)2 octa­hedra whose four O atoms belong to the phosphate groups. The resulting three-dimensional framework is characterized by hexa­gonal channels running along [001] in which the remaining water mol­ecules are located. The main difference between the Mg-containing and the title structure lies in the filling ratio of Wyckoff positions 6a and 6b in the tunnels. The refinement of the occupancy rate of the site 6a shows that it is occupied by water at 67%, while the refinement of that of the site 6b shows that this site is partially occupied by 78.4% Ag and 10.8% Co, for a total of 82.2%. The structure is stabilized by O—H⋯O hydrogen bonds between water mol­ecules and O atoms that are part of the helices.

KCo(H2O)2BP2O8·0.48H2O and K0.17Ca0.42Co(H2O)2BP2O8·H2O: two cobalt borophosphates with helical ribbons and disordered (K,Ca)/H2O schemes

“…The lithium-and sodium-cobalt members of the helical BPO family were reported previously (Shi, Shan, Dai et al, 2003;Menezes et al, 2008b). In addition, Zouihri et al (2012) have recently reported the structure of (Ag 0.79 Co 0.11 )Co(-H 2 O) 2 BP 2 O 8 Á0.67H 2 O, where Co and Ag share the same site. We report here the structures of the potassium and potassiumcalcium cobalt borophosphates, KCo(H 2 O) 2 BP 2 O 8 ÁyH 2 O (y ' 0.5), (I), and K 0.17 Ca 0.42 Co(H 2 O) 2 BP 2 O 8 ÁH 2 O, (II), grown hydrothermally and characterized by qualitative energydispersive X-ray (EDX) spectroscopic analysis and singlecrystal X-ray diffraction.…”

Chain caesium borophosphates with B:P ratio 1:2: synthesis, structure relationships and low-temperature thermodynamic properties

“…Within the A x M y (H 2 O) 2 [BP 2 O 8 ]Áz(H 2 O) series, borophosphates with the following cations have been reported: A I = Li, Na, K, Rb, Cs, H 3 O, Ag and NH 4 ; A II = Ca; M II = Mg, Sc, Mn, Fe, Co, Ni, Cu, Zn, Cd; and M III = Fe, In (Ge et al, 2003(Ge et al, , 2005Yang et al, 2010;Yilmaz et al, 2000Yilmaz et al, , 2005Wang, 2008;Boy & Kniep, 2001a,b;Menezes et al, 2007Menezes et al, , 2008Zouihri et al, 2011aZouihri et al, ,b, 2012Guesmi & Driss, 2012;Zheng & Zhang, 2009;Ewald et al, 2006;Baykal et al, 2000;Boy et al, 2001a,b;Boy, Stowasser et al, 2001;Kniep et al, 1997;Zhuang et al, 2008;Engelhard, 2000;Schä fer et al, 2002;Lin et al, 2008). However, the structural data for members of this family with large alkaline cations Rb + and Cs + have not been presented in the literature, to our knowledge.…”