Laser ablation of NaN3 and CsN3

Solid sodium azide and cesium azide crystals were irradiated by high power laser pulses; the ablation products were rapidly cooled by a supersonic expansion of helium and detected by a time of flight mass spectrometer. Neutral and positively charged species were separately recorded and analyzed using 15N isotopomers to help in their assignment. Cluster series of the sequences Na(NaN3)n [or Cs(CsN3)n] were observed, as well as clusters containing NaOH and NaCN; the origin of the C, H, and O atoms appears to be water and CO2 occluded in the salt. Addition of D2O increased the intensity of large clusters and added deuterated ones, whereas addition of chloroform leads to formation of clusters of a Na atom with (NaCl)n clusters. Possible mechanisms for the formation of these clusters are discussed.