[MPy](+) and [MxPy](-) clusters generated by laser ablation and investigated by Fourier transform ion cyclotron resonance mass spectrometry

摘要

Laser (1064 nm) ablation of pressed mixtures of red phosphorus with powders of the metals cobalt or nickel generates positive ions [MPy](+) (y = 2,4,6,8) and negative ions [MxPy](-), monitored by Fourier transform ion cyclotron resonance (FTICR) mass spectrometry. At least 110 negative ions have been identified, more for Co than for Ni. The ions [MxPy](-) are distributed through the range 2 less than or equal to x less than or equal to 16, 4 less than or equal to y less than or equal to 17, with [CoxP8](-) (x = 2, 3, 4, 5), [CoxP10](-) (x = 5, 6, 7), [NixP6](-) (x = 4, 5, 7, 8), and [NixP8](-) (x = 2, 3, 4, 6, 7) as more abundant ions. The best negative ion spectra are obtained with 10:1 M/P mixtures, and high laser powers. The preponderance of even numbers of P atoms suggests that P-2 units are bound to the metals, and this is supported by the collisional dissociation of [MPy](+) ions (M = Co and Ni, y = 2, 4, 6) where loss of P-2 is the major pathway. For both [CoP8](+) and [NiP8](+) initial loss of P-4 is important. The reactions of [MP2](+), [MP4](+) and [MP8](+) with sigma-ligands ammonia and methanol, and pi-ligands C2H2, C2H4 and C6H6, involve addition and substitution processes. [References: 68]