Syntheses, characterizations, and crystal structures of transition metal complexes based on sulfoxide-containing Schiff base ligands

Abstract

Two sulfoxide-containing Schiff bases, (E)-(((2-(methylsulfinyl phenyl) imino)methyl)-4-nitrophenol (HL1) and (E)-3,5-dibromo-2-(((2-(methylsulfinyl phenyl)imino)methyl)phenol (HL2), were prepared by condensation and subsequent oxidation reactions. In the presence of triethylamine, reactions of HL1 with 0.5 equivalent of copper acetate, cobalt acetate, nickel acetate and zinc acetate in ethanol afforded four metal complexes: (η²-N,O-L1)Cu(η³-O,N,O-L1) (1) and (η³-O,N,O-L1)₂M (M = Co, 2; Ni, 3; Zn, 4), respectively. Similarly, treatment of HL2 with 0.5 equivalent of cobalt acetate and nickel acetate obtained two cobalt/nickel complexes: (η³-O,N,O-L2)₂M (M = Co, 5; Ni, 6). Reactions of HL1 and one equivalent of Ru(PPh₃)₃Cl₂ in tetrahydrofuran in the presence of triethylamine afforded a ruthenium(II) complex, (η³-O,N,S-L1)Ru(PPh₃)₂Cl (7). The molecular structures of HL1 and 1-7 have been confirmed by single-crystal X-ray diffraction. In addition, the UV–Vis, infrared, and fluorescence spectroscopies of 1–7 along with their electrochemical properties were also investigated.

Keywords:

• sulfoxide
• Schiff base
• synthesis
• crystal structure
• transition metal complex

Acknowledgment

This project was supported by the Natural Science Foundation of Anhui Province (2008085MB58) and Key projects funded by Anhui Province for the cultivation of outstanding talents in Colleges and Universities (gxyqZD2021105).

Disclosure statement

No potential conflict of interest was reported by the authors.