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Download or read book Photoionization and Photoelectron Studies of Transient Molecules and Radicals & High-level Ab Initio Calculations of Molecular Energetic and Spectroscopic Properties and Benchmarking with Experiments written by Chow-shing Lam and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Single-photon vacuum ultraviolet (VUV) and two-color laser photoionization and pulsed field ionization-photoelectron (PFI-PE) measurements have been applied to the studies of transient radicals and metal-containing molecules generated by various in situ production schemes. Phenoxyl radical (C6H5O) has been prepared by flash pyrolysis of allyl phenyl ether in a hyperthermal pyrolysis nozzle of the Chen design. A Smalley-type ablation source has been installed and developed for the production of diatomic iron carbide (FeC) for two-color laser excitation-photoionization experiment. Sulfur monoxide radical (SO) has been prepared by using a supersonically cooled radical beam source based on the 193 nm excimer laser photodissociation of SO2. Based on the simulation of the rotational structures resolved in the PFI-PE bands of these species, highly accurate ionization energies (IEs) and spectroscopic constants are determined. These values are compared to IEs predicted by high-level ab initio quantum chemical calculations using the wave function based CCSDTQ(Full)/CBS approach (and its variations), which involves the approximation to the complete basis set (CBS) limit at the coupled cluster level up to full quadruple excitations. By benchmarking theoretical predictions with experimental results, a wide applicability of the CCSDTQ(Full)/CBS procedure in quantum chemical calculations of molecular energetic and spectroscopic properties have been demonstrated.