Synthesis of an N2S-cyclodecane macrocycle and its nickel(II) complex

Abstract

The ligand 1-thia-4,8-diazacyclodecane ([10]aneN₂S, L¹) and its nickel(II) complex have been synthesised and characterised. The complex [Ni([10]aneN₂S)₂]Br₂ crystallised in the space group P2₁/n(no. 14) with a= 11.419(3), b= 9.439(2), c= 10.288(3)Å and β= 96.66(3)°. Refinement converged with R= 0.0411 (R′= 0.0472) for 115 parameters using 1559 reflections with I > 3σ(I). The metal-ion complex is nominally octahedral with mean Ni–N and Ni–S bond lengths of 2.142(5) and 2.395(1)Å respectively. Oxidation of the nickel(II) complex results in the formation of a nickel(III) species which exhibits a tetragonally elongated geometry according to the ESR spectrum obtained. Spectroscopic and redox properties of the complex are compared with those of other ligands in the ten-membered series and with the nine-membered ring analogues.