Laser ablation synthesis of phosphorus clusters

Neutrals phosphorus clusters Pn (up to n=40) and their cations Pn+ (up to n=91) have been synthesized in the gas phase by laser ablation of crystalline red phosphorus. The neutral Pn clusters are found to be even-numbered with local abundance maxima at n=8, 10, 14, and 40. An abundance minimum at n=22 indicates the possibility of stable cage-like structures of clusters. By contrast, the cationic clusters are preferentially odd-numbered with P21+ being the most abundant ion. It is suggested that dodecahedral fullerene-like P20, stabilized with an additional phosphorus ion in the laser plasma, can be particularly stable.