Metal-dependent assembly of a tetranuclear copper(II) complex versus a 1D chain coordination polymer of cobalt(III) complex with N2O2-chelating Schiff-base ligand: Synthesis, characterization and crystal structures

By changing metal ions in the presence of N2O2-chelating Schiff-base ligand sal2hn [sal2hn = N,N′-bis(salicylidene)-1,2-diaminocyclohexane] and a large excess of NaN3 (reagent ratios (metal:L:N3-) = 2:1:8), tetranuclear copper(II) complex [Cu4(μ-sal2hn)2(μ1,1-N3)2(N3)2] (1) and 1D chain coordination polymer of cobalt(III) complex {Na[Co(μ-sal2hn)(μ1,1-N3)(N3)(H2O)(μ-O)}n (2) have been successfully obtained. Single-crystal X-ray analyses revealed that in complex 1 the copper(II) ions are bridged alternately by end-on (EO) azido and phenoxo-sal2hn ligands, while in complex 2 the cobalt(III) and sodium ions are bridged alternately by end-on (EO) azido and phenoxo-sal2hn ligands. Complex 1 crystallizes in the monoclinic system, space group P21/n, with a = 11.6283(5) Å, b = 19.5997(8) Å, c = 9.1531(4) Å, β = 90.540(6)°, V = 2086.00(15) Å3, and Z = 2, while complex 2 crystallizes in the monoclinic system, space group C21/c, with a = 21.1473(5) Å, b = 14.0604(3) Å, c = 15.0452(6) Å, β = 106.064(3)°, V = 4298.9(2) Å3, and Z = 8.

From the direct reaction of sal2hn with Cu(NO3)2·3H2O or Co(NO3)2·6H2O at the presence a large excess of NaN3, tetranuclear Cu(II) complex [Cu4(μ-sal2hn)2(μ1,1-N3)2(N3)2] (1) and 1D coordination polymer of Co(III) complex {Na[Co(μ-sal2hn)(μ1,1-N3)2]}n (2) were prepared. Single-crystal X-ray analyses revealed that in complex 1 the copper(II) ions are bridged alternately by end-on (EO) azido and phenoxo-sal2hn ligands, while in complex 2 the cobalt(III) and sodium ions are bridged alternately by end-on (EO) azido and phenoxo-sal2hn ligands.Figure optionsDownload as PowerPoint slide