Nickel(II) and cobalt(II) nitrate and chloride networks with 2-aminopyrimidine

The coordination chemistry of 2-aminopyrimidine (PymNH₂) with nickel(II) and cobalt(II) nitrate and chloride is reported, including seven new X-ray crystal structures. Two Ni(NO₃)₂(PymNH₂)₂(OH₂)] isomers were found (A: C2/c, a=13.3006(5), b=7.9727(3), c=28.5453(11), β=101.758(2), V=2963.48(19), Z=8 and B·1/2 acetone: P2₁/c, a=7.66060(10), b=10.6792(2), c=20.6790(3), β=100.2970(10), 1664.48(5), Z=4). In both cases one nitrate is monodentate and the other is chelating and the PymNH₂ ligands coordinate through ring nitrogen atoms. Hydrogen bonding results in double sheet structure for isomer A, and a three dimensional channeled network for isomer B. Co(NO₃)₂(PymNH₂)₂(OH₂)] (C2/c, a=13.3507(2), b=7.99520(10), c=28.6734(3), β=102.3540(10), V=2989.77(7), Z=8) is isostructural to Ni isomer A. CoCl₂(PymNH₂)] (Cmcm, a=3.6139(2), b=14.3170(7), c=12.9986(7), V=672.55(6), Z=4) is a sheet coordination network, consisting of corner-sharing chains of Co₂(μ-Cl)₂ bridged by PymNH₂ through ring nitrogen atoms; CoCl₂(PymNH₂)₂] (C2/c, a=11.2774(6), b=6.5947(4), c=16.5687(9), β=92.269(3), V=1231.27(12), Z=4) is a tetrahedral molecule knit into a ribbon structures through pairs of hydrogen bonds. Isostructural trans-NiCl₂(PymNH₂)₄] (C2/c, a=7.67760(10), b=18.7224(3), c=15.0418(2), β=99.6740(10), V=2131.41(5), Z=4) and trans-CoCl₂(PymNH₂)₄] (C2/c, a=7.69120(10), b=18.5957(2), c=15.1091(2), β=99.5280(10), V=2131.14(5), Z=4) are simple octahedral molecules, with hydrogen-bonding producing sheet structures.