The work presented in this dissertation describes the synthesis and characterization of metal-organic frameworks for gas storage and separation applications. A specific class of materials investigated is metal-organic frameworks containing coordinatively-unsaturated metal cation sites, as these sites perform the bulk of the work for the separations discussed. A wide variety of techniques and spectroscopic methods are covered, including gas adsorption, structural analysis, infrared and Mössbauer spectroscopies, and breakthrough experiments.