A facile synthesis of Cu(II) diethyldithiocarbamate from monovalent copper-cysteamine and disulfiram

• Published in: Inorganic chemistry communications 2022-03, Vol.137, p.109246, Article 109246
• Main Authors: Wang, Lingyun, Chen, Zeliang, Ran, Xueguang, Tang, Hao, Cao, Derong
• Format: Article
• Language: English
• Subjects: Copper(I) cysteamine (Cu(I)Cy); Copper(II) diethyldithiocarbamate (Cu(DDC)2); Disulfiram (DSF); Photolysis; Synthesis
• ISSN: 1387-7003; 1879-0259
• DOI: 10.1016/j.inoche.2022.109246

An efficient, atom-economic synthesis of Cu(II) diethyldithiocarbamate from a monovalent copper-cysteamine and disulfiram was developed. [Display omitted] •An efficient and atom-economic synthesis of Cu(DDC)2 from DSF and monovalent copper cysteamine (CuCy) is reported.•The chemical structure, proposed reaction mechanism and the optimal reaction conditions were investigated.•The photochemical reactions of Cu(DDC)2 in five solvents and the possible reaction mechanism were discussed. The copper(II) diethyldithiocarbamate (Cu(DDC)2) complex prepared from disulfiram and Cu(II) species has shown excellent anticancer activity. However, general synthetic methods largely rely on tedious procedures and limited reaction types with undesirable by-products. In this paper, we reported an efficient and atom-economic synthesis of Cu(DDC)2 from disulfiram and monovalent copper cysteamine (Cu(I)Cy) via a one-step oxidation–reduction reaction. Cu(DDC)2 was fully characterized by nuclear magnetic resonance (NMR), mass spectrometry (MS), infrared spectroscopy (IR), scanning electron microscope (SEM), X-ray diffraction (XRD), ultraviolet and visible (UV–Vis) spectrophotometry, X-ray photoelectron spectroscopy (XPS), electron paramagnetic resonance (EPR) and single crystal X-ray diffraction. The proposed reaction mechanism and the effect of reaction conditions on the Cu(DDC)2 synthesis were investigated. The photochemical reactions of Cu(DDC)2 was studied in acetone, DMF, toluene, CCl4, CHCl3 under 254, 365 nm alone or combined 254 & 365 nm irradiation based on UV–vis and EPR measurements. The photolysis rate followed in this order: CCl4 > CHCl3 > DMF > toluene > acetone. The final photolysis products in CHCl3 were DSF and Cu2(DDC)2Cl2.