N-thiophosphorylthiourea containing an aza-18-crown-6 fragment. The crystal structure of bis [N-(N′-diisopropoxythiophosphorylamidothiocarbonyl)- aza-18-crown-6]nickel(II)

N-(N′-Diisopropoxythiophosphorylamidothiocarbonyl)aza-18-crown-6 (HL) was obtained by the reaction of aza-18-crown-6 with diisopropoxythiophosphorylisothiocyanate, and its chelate with NiII was characterised using IR, 1H and 31P NMR spectroscopy and single-crystal X-ray diffraction.