Abstract

This paper reports that FE(CO)₅ muitiphoton ionization mass spectroscopy induced by a XeCl excimer laser was investigated, with a diffuse molecular beam and a modified quadrupole mass spectrometer. Various fragment ions, such as Fe⁺, CO⁺, FeC⁺, ${\text{Fe}}_2{(\text{CO})}_4^{+}$, and $\text{Fe}{(\text{CO})}_n^{+}(n=1,2,\dots 5)$ were observed. The Fe⁺ signal is much larger than other ion signals, and the Fe(CO)⁺ signal is weakest among $\text{Fe}{(\text{CO})}_n^{+}(n=1,2,\dots 5)$. The dependence of the ion signals on pressure and laser intensity was measured. For $\text{Fe}{(\text{CO})}_n^{+}(n=1,2,\dots 5)$, the pressure-dependent signals show a double index first and become linear as the pressure increases; the power indices of laser-intensity-dependent signals vary between 2 and 4, closing to that of the Fe⁺ signal; the power indices decrease and become saturated with increasing laser intensity.

© 1986 Optical Society of America