Ab-initio crystal structure of hydroxy adipate of nickel and hydroxy subarate of nickel and cobalt from synchrotron powder diffraction and magnetic properties

Organic–inorganic hybrid compounds Ni(II)5(OH)6(C6H8O4)2 (1), Ni(II)5(OH)6(C8H12O4)2 (2) and Co(II)5(OH)6(C8H12O4)2 (3) have a similar layered structure as determined ab initio from synchrotron powder diffraction analysis. The metal sites are octahedrally coordinated by O atoms. The slabs are built from edge-sharing octahedra in such a way that channels with an average size of 4 Å are formed. Bis-bidentate and bridging dicarboxylate anions lead to a 3D framework. The compounds (1) and (2) order antiferromagnetically below TN=26.5 and 19.3 K, respectively, while (3) is ferrimagnetic with TC=16.2 K. Crystal data for compounds are as follows: (1) a=11.6504(1) Å, b=6.8021(3) Å, c=6.3603(1) Å, α=73.52(1)°, β=99.69(1)°, γ=96.16(1)°, RB=0.070, 668 reflections; (2) a=13.9325(1) Å, b=6.7893(1) Å, c=6.3534(4) Å, α=73.63(1)°, β=95.14(1)°, γ=91.80(1)°, RB=0.052, 804 reflections; (3) a=13.9806(1) Å, b=6.9588(1) Å, c=6.3967(1) Å, α=73.05(1)°, β=94.51(1)°, γ=92.19(1)°, RB=0.048, 410 reflections. The space group is P−1 for the three compounds.