Layered cobalt phosphates by the amine phosphate route

Abstract

Two layered cobalt phosphates, I, [NH₃CH₂CH(OH) CH₂NH₃][Co₂(PO₄)₂], and II, [NH₃CH₂CH(OH)CH₂NH₃] [Co₂(HPO₄)₃], have been hydrothermally synthesized employing the reaction of 1,3-diammonium-2-hydroxy propane with CoII ions. While in I, the layers are made of 3- and 4-membered rings, they are made by 4- and 12-membered rings in II. The layers are held together by strong hydrogen bond interactions between the amine and the framework. I contains Co-O-Co linkages and becomes ferrimagnetic around 30 K, unlike II with only Co-O-P linkages which is paramagnetic. Crystal data are as follows: I, orthorhombic, a=22.894(2), b=7.568(1), c=6.697(1) Å, V=1160.3(2) Å3, space group=Pbcn (no. 60), Z=8, M=399.87, D_calc.=2.287 gcm⁻³, μ(MoKα)=3.176 mm⁻¹, λ=0.71073 Å, R₁=0.06, S=1.27; II, monoclinic, a=8.608(3), b=9.640(3), c=17.258(2) Å,β=93.23(1)°, V=1429.9(2) ų, space group=P2₁/c (no. 14), Z=4, M=497.94, D_calc.=2.313 gcm⁻³, μ(MoKα)=2.729 mm⁻¹, λ=0.71073 Å, R₁=0.03, S=1.05.