Syntheses, structures and magnetic properties of two new one-dimensional cobalt (II) phosphites with organic amines acting as ligands

Two new one-dimensional (1D) inorganic–organic hybrid cobalt (II) phosphites Co(HPO3) (py) (1) and [Co(OH)(py)3][Co(py)2][HPO2(OH)]3 (2) have been prepared under solvothermal conditions in the presence of pyridine (py). Compound 1 crystallizes in the monoclinic system, space group p2(1)/c, a=5.3577(7) Å, b=7.7503(10) Å, c=17.816(2) Å, β=94.327(2)°, V=737.67(16) Å3, Z=4. Compound 2 is orthorhombic, Cmcm, a=16.3252(18) Å, b=15.7005(16) Å, c=13.0440(13) Å, β=90.00° V=3343.4(6) Å3 and Z=4. Compound 1 possesses a 1D ladder-like framework constructed from CoO3N tetrahedral, HPO3 pseudo-pyramids and pyridine ligands. While compound 2 is an unusual inorganic–organic hybrid 1D chain, which consists of corner-shared six-membered rings made of CoO3N3/CoO4N2 octahedra and HPO3 pseudo-pyramids through sharing vertices.