Experimental and Theoretical Study on Pyrolysis of Isopsoralen

The pyrolysis of isopsoralen was studied by synchrotron vacuum ultraviolet photoionization mass spectrometry at low pressure. The pyrolysis products were detected at different photon energies, the ratios of products to precursor were measured at various pyrolysis temperatures. The experimental results demonstrate that the main pyrolysis products are primary CO and sequential CO elimination products (C₁₀H₆O₂ and C₉H₆O). The decomposition channels of isopsoralen were also studied by the density functional theory, then rate constants for competing pathways were calculated by the transition state theory. The dominant decom-position channels of isopsoralen and the molecular structures for corresponding products were identified by combined experimental and theoretical studies.