The influence of an intramolecular hydrogen bond on the 1,3-N,S-coordination of crown ether-containing N-phosphorylthiourea with NiII

Abstract

Reaction of the lithium salt of N-phosphorylated thiourea [4′-benzo-15-crown-5]NHC(S)NHP(O)(OiPr)₂ (HL^I) with Ni^II leads to the chelate complex [NiL^I₂]. The metal center is found in a square-planar N₂S₂ environment formed by the CS sulfur atoms and the P–N nitrogen atoms of two deprotonated L^I ligands. Reaction of [NiL^I₂] and its non-crown ether-containing analog Ni[PhNHC(S)NP(O)(OiPr)₂]₂ ([NiL^II₂]) with 2,2′-bipyridine (bipy) and 1,10-phenanthroline (phen) leads to the [Ni(bipy)L^I,II₂] and [Ni(phen)L^I,II₂] heteroligand complexes. The coordination mode is preserved for the phosphorus-containing ligands. The extraction properties of the crown ether-containing compounds towards alkali metal picrates were investigated. The molecular structures of HL^I, [NiL^I₂] and [Ni(bipy)L^II₂] were elucidated by X-ray diffraction.