The main theme of the thesis is to design new porous-crystalline materials for application in carbon dioxide capture. This class of porous materials is highly crystalline and has pores like a sponge but which are much smaller. A library of new crystalline materials was designed through judicious selection of their chemical components to be specifically useful for this particular application. These materials have promising features towards achieving the ultimate goal of capturing carbon dioxide, by virtue of adding groups in their interior to specifically interact with the gas. An understanding of the structural chemistry of these new compounds is demonstrated.