Experimental and theoretical investigations of the NiII complex with N-phosphorylated thiourea iPrNHC(S)NHP(O)(OPh)2

Abstract

The N-phosphorylated thiourea iPrNHC(S)NHP(O)(OPh)₂ (HL) has been synthesized by the reaction of iPrNH₂ and (PhO)₂P(O)NCS. Recrystallization of HL from aqueous acetone leads to [iPrNH₃]⁺[P(O)₂(OPh)₂]⁻ in a quantitative yield. Reaction of the deprotonated HL with NiCl₂ leads to violet [NiL₂] crystals with a 1,3-N,S-coordination mode of the ligands. Static DFT and ab initio molecular dynamics studies indicated that [NiL₂] is stabilized predominantly by intramolecular N–H⋯OP hydrogen bonding and dynamically by secondary C_Ph–H⋯S interactions. All compounds have been characterized by IR, diffuse reflectance, UV-vis and NMR spectroscopy, single crystal X-ray diffraction analysis and elemental analysis. Thermal properties investigated in an air atmosphere by means of TGA revealed a residue corresponding to NiPS₃.