The Coordination Structure of the Extracted Nickel(II) Complex with a Synergistic Mixture Containing Lix63 and Versatic10

Abstract

In the present work, the nickel(II) synergist complex with isobutyric acid (HLI ) and 5‐hydroxy‐4‐octanone oxime (HBI ), which were the corresponding short‐chain analogs of the active synergistic mixture of Versatic10 (HL) and Lix63 (5,8‐diethyl‐7‐hydroxy‐6‐dodecanoneoxime, HB), was prepared and studied by single‐crystal X‐ray diffraction (XRD). The crystal structure of the nickel(II) synergist complex showed that the composition of the complex was Ni(LI )2(HBI )2 with a cis‐form octahedron geometry structure. Both intra‐ and intermolecular hydrogen bonding were observed in the crystal lattice. Compared with the free ligands, similar band shifts of Fourier transform infrared (FT‐IR) spectra assigned to the stretching vibration of carbon–oxygen single bond (CO), the stretching vibration of carbon–nitrogen double bond (CN), and the disappearance of the scissoring vibration of α‐hydroxy (OH) were correspondingly found in both the nickel(II) synergist complex and the extracted nickel(II) complex in the nonpolar organic phase. Combined with the results from ESI‐MS, XRD, and slope analysis, it was concluded that the major species of the extracted nickel(II) complex in the nonpolar organic phase might possess a similar coordination structure [Ni(HB)2(L)2] as the nickel(II) synergist complex, along with the neutral complex [Ni(HB)(B)2].