Synthesis and Crystal Structure of a New Complex of Nickel(II) Nitrate and Ethoxycarbonyl-Substituted (γ-piperidono)aza-14-crown-4-ether

A new coordination compound—derivative of aza-14-crown-4-ether, containing an ethoxycarbonyl subunit, with nickel(II) nitrate, of the [Ni3(NO3)4L4]2(NO3) composition—has been obtained for the first time in the form of single crystals. The presence of nickel atoms in the complex is confirmed by X-ray fluorescence analysis. The complex structure has been studied by precise X-ray diffraction on a laboratory X-ray source. The molecule of this complex is shown to have an intricate geometry and consist of four pairwise symmetric ligand molecules, coordinated by three nickel atoms. Stabilization of the complex molecule is provided by the presence of strong intramolecular hydrogen bonds, involving a crown-ether fragment.