Ultraviolet-visible molecular introduction

Since the photochemical reaction is initiated by absorption of light in the visible, ultraviolet, and vacuum ultraviolet regions, an understanding of atomic and molecular spectroscopy is required. Chapter I gives a brief introduction to the electronic stales and transitions in atoms and simple molecules. 

Elementary Introduction to Molecular Spectra, B. Bak, (Interscience) John Wiley Sons, Inc. (1962). Microwave, infrared, visible, ultraviolet, and magnetic-resonance spectroscopy is discussed. 

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