Fig. 1: Structural characteristic of TPP3Cu2Br2.

a Single crystal structure of TPP3Cu2Br2. b Schematic diagram of the structure of TPP3Cu2Br2. Inset: Micrograph of the TPP3Cu2Br2 single crystal under ambient light, schematic diagram of the structure of triphenylphosphine and [Cu2Br2] dimer. c PXRD pattern of TPP3Cu2Br2 and simulated pattern from the single crystal. d High-resolution XPS spectrum of Cu 2p in TPP3Cu2Br2. e TGA and DTA curves for the TPP3Cu2Br2 powder