Synthesis, structures, characterizations and catalytic behaviors for hydrogen evolution of copper(II) and copper(I) complexes supported by diiminodiphosphines

Authors：Yang, Hao; Du, Juan; Wang, Chun-Li; Zhan, Shu-Zhong^*

Source：Inorganic Chemistry Communication, 2021, 130: 108719.

DOI：10.1016/j.inoche.2021.108719

• Copper complexes
• Crystal structures
• Electrocatalytic activity for hydrogen evolution

Reactions of N,N'-bis[o-(diphenylphosphino)benzylidene]ethylenediamine (en-P-2) with Cu(ClO4)(2) or CuClO4 afford two complexes, [Cu-II-en-P-2(NCMe)](ClO4)(2) 1 and [Cu-I-en-P-2]ClO4 2, respectively, which have been characterized by several physico-chemical and spectroscopic methods. The copper atom is five, and fourcoordinated in the copper complexes 1 and 2, respectively. At room temperature, en-P-2 shows photoluminescence at 420 and 560 nm, however, the addition of Cu2+ or Cu+ leads to a decrease on the peak intensities at 420 and 560 nm, respectively. Investigations for magnetic behaviors show that upon cooling from 300 to 2 K, the chi T-M value of both copper complexes 1 and 2 steadily increased. Additionally, electrochemical investigations reveal that both complexes 1 and 2 have electrocatalytic activity for hydrogen evolution from acetic acid or water, and complex 1 shows a more efficient activity than complex 2.