Laser Desorption Time-of-Flight Mass Spectrometry of Inorganic Nanoclusters: An Experiment for Physical Chemistry or Advanced Instrumentation Laboratories

New experiments for the undergraduate laboratory are described using laser desorption time-of-flight (TOF) mass spectrometry to produce and analyze a variety of inorganic nanoclusters. Laser vaporization of solid powder samples of sulfur, phosphorus, and bismuth all produce gas-phase cluster ions with unusual mass spectral patterns. This experiment provides an introduction to TOF mass spectrometry and ultrasmall nanoclusters, as well as hands-on experience in vacuum systems, lasers, oscilloscopes, and pulsed electronics. New concepts in chemical bonding for inorganic materials are explored.