Bare phosphorus and binary phosphide cluster ions generated by laser ablation

Abstract

Both positive and negative phosphorus cluster ions were generated from the laser ablation of a red phosphorus sample. The mass distribution of phosphorus cluster ions was found to be very sensitive to the power density of the ablation laser. The P 7 + species exhibits the highest signal intensity in the recorded mass spectra of bare phosphorus cluster cations, as does P 5 - among the anions. Their special structural stability can be attributed to their planar configuration and their aromatic character. As the phosphorus cluster size increases, the odd/even alternation of the signal intensity becomes more pronounced. For the P n + species with n > 24, the relative abundance varies in the order of 8 and P n + with n = 8k + 1 (k = 3–11) are more intense than their neighbors. For comparison, some binary phosphide cluster ions, including CnP m - , SinP m - , BnP m + and AlnP m + , were produced as well. The mass distribution of binary phosphide cluster ions changes with different components. From analysis of the recorded mass spectra of the phosphide cluster ions, the larger clusters may be in a polyhedral configuration and tend to have all valence electrons paired.