Chapters authored
Raman Investigations of Atomic/Molecular Clusters and Aggregates
Efforts to tune optic responses of molecular aggregates often alter the characteristics and performance of functional materials, revealing that chemical properties largely rely on molecular stacking and interactions. Although the intrinsic nature of materials is primarily determined by single-molecule structures, molecular aggregation behavior that determines material property resembles the architectural style of a building in which the bricks themselves could be less important. While the establishment of surface-enhanced Raman spectroscopy (SERS) inspired numerous research interest for trace analysis up to single-molecule level, Raman spectroscopy is also recognized for its importance in solving several issues relating to molecule aggregates owing to the capability of non-destructive detection and spectral fingerprints by which chemical structures and aggregation states can be identified. Raman spectroscopy is not only applied to identify chemicals at the gas phase, liquid phase and solid state and to monitor in-situ reactions of materials at reduced sizes but also to probe gas-to-particle conversion in aerosols, microcrystal magnetization and phase transition at aggregated states, which are believed to attract uprising research interest in the near future.
Part of the book: Raman Spectroscopy and Applications
Deep Ultraviolet Single‐Photon Ionization Mass Spectrometry
The requirement of accurate analysis for organic chemicals has stimulated uprising research interest of single‐photon ionization mass spectrometry (SPI‐MS). Considering that ∼90% compounds bear absorption in the deep ultraviolet (DUV) region, it is crucial for SPI‐MS applications to employ effective DUV light sources. Here, we summarize the advances of SPI‐MS by utilizing deep ultraviolet lamps and lasers, including the combination with quadrupole mass spectrometer (QMS), ion‐rap mass spectrometer (ITMS), and time‐of‐flight mass spectrometer (TOFMS) systems. We then emphasize on the newly developed SPI‐MS instrument coupled with an all‐solid‐state deep ultraviolet (DUV) laser at 177.3‐nm wavelength. The advantages of SPI‐MS instruments have been illustrated on several organic compounds, where the capability of low fragmentation enables to identify chemicals from unknown mixtures.
Part of the book: Mass Spectrometry