Copper(II), nickel(II), cobalt(III), rhodium(III) and chromium(III) complexes of 1,4,7,10-tetra-azacyclotridecane([13]aneN4) and kinetic studies of the conversion of cis-[Ni([13]aneN4)(OH2)2]2+ to the planar complex

A variety of complexes of 1,4,7,10-tetra-azacyclotridecane ([13]aneN4 = L) have been prepared and characterized. These complexes include [CuL](ClO4)2, [CuL](CuBr4), [CuL](CuCl4)·H2O, [NiL](ClO4)2, cis-[CoBr2L]Br, cis-[CoCl2L]ClO4, trans-[CoCl(Br)L]Br,O·5H2O, trans-[CoCl2L] Cl, cis-[CrCl2L]Cl·H2O and cis-[Rh2LCl6]. The syntheses, properties, IR and electronic spectra of the complexes are discussed. The blue octahedral complex cis-[Ni([13]aneN4)-(en)](ClO4)2 has been characterized and the isomerisation of cis-[Ni([13]aneN4)(OH2)2]2+ to the planar yellow [Ni([13]aneN4)]2+ studied kinetically. The reaction follows the rate law, rate = kOH[complex] [OH−] with kOH = 2.4 × 103 dm3 mol−1 s−1 at 25 °C and I = 0.1 mol dm−3. The blue folded cis-complexes are likely intermediates in the formation of nickel(II) complexes of tetra-aza macrocycles in aqueous solution.