Laser desorption ionization of stilbenes in crystalline sponge

The laser desorption (LD) ionization of three stilbenes in the nano porous metal-organic frameworks called "crystalline sponge" is demonstrated. The analyte position in the pore and the interaction between the analyte and the framework that functions as a matrix are discussed based on the results of single- crystal X-ray analysis. It is confirmed that the analyte/ligand ratio of 1:2 is sufficient for the analyte ionization. This method makes it possible to visualize hot spots on a target plate to be irradiated. That the sample requirement is dramatically reduced to the order of femtomoles is also an advantage. The relationship between laser interaction, analyte position in the pore, and analyte/ligand ratio is discussed as a new ionization field to elucidate the molecular structure of the analyte by LD ionization mass spectrometry.