Geometrical Structures and Dissociation Channels of CuP_2n⁺ (n = 2–11): Studied by Mass Spectrometry and Theoretical Calculations

Abstract

Transition metal phosphorus cluster cations CuP 2 n + (2 ≤ n ≤ 11) were studied by laser ablation mass spectrometry and collision-induced dissociation (CID). The magic-numbered cluster ion of CuP 8 + was identified experimentally, and cluster ions of CuP 14 + and CuP 18 + were also found to be generated with high abundance. CID results show that the dissociation channels of CuP 2 n + ( n = 4 and 6–10) are all characterized by the loss of the P 4 unit. Theoretical calculations combining global minima searching with the basin-hopping method and density functional theory (DFT) optimizations were performed for these clusters. Among them, the magic-numbered cluster CuP 8 + was characterized by a D 2d symmetry, with the Cu atom bridging two P 4 units. The most stable isomer of CuP 14 + was found to be characterized by a C 2v symmetry. Calculations also reflect that the dissociation channels of the loss of the P 4 unit are more energetically favorable than those of the loss of the P 2 unit for CuP 2 n + ( n = 4 and 6–10), which are in good consistent with the experimental results.