Metal Organic Frameworks (MOFs) are novel organic-inorganic crystalline materials, which promise to become a powerful and flexible family for different industrial uses within catalysis, adsorption and sensor technology, overcoming many of the limitations of Zeolites: MOFs may display very high porosity and surface areas, and their functionalities can be tailored. The present book describes the characterization results obtained for this class of materials. The aim of the work was to understand at the molecular level the interaction governing the stability and adsorption properties of the frameworks by combined use of experimental and theoretical modeling efforts. The value of the work goes further to the fact that nice set of data have been collected describing in detail the properties of the materials and their interaction with some relevant gases. The book is divided in to six chapters and mainly discusses the vibrational and Uv-Visible spectroscopy results.