The interest in metal-organic materials namely, coordination polymers and metal-organic frameworks has risen dramatically over the past few years. To a certain extent this interest is a consequence of the realization chemists have discovered how to play a form of molecular Lego® in which metal cations or metal clusters represent the bricks (or nodes) and organic ligands such as 4,4-bipyridine (bipy) or benzene-dicarboxylate represents the glue (or spacers). The "node-and-spacer" approach to self-assembly can be invoked in such a manner that a plethora of infinite architectures and discrete polyhedra can be generated from geometric principles, some of which are unprecedented in either natural or synthetic materials. The research presented within this dissertation primarily involves the use of coordination chemistry and supramolecular chemistry in the context of synthesizing metal-organic materials and deals with how subtle variations in reactants and procedures can have dramatic effects upon the materials formed. The effect of aromatic guest molecules on the crystal packing of 1D and 2D "metal-4,4`-bipyridine" coordination polymers has been addressed in terms of structural analysis and fluorescence spectroscopy. The phenomena of supramolecular isomerism resulting from the use of metal-carboxylate clusters as building blocks for a variety of metal-organic materials will be discussed. Finally, an analysis of the Host:Guest and suprasupermolecular properties of discrete nanostructures will be provided.

Network structures based upon metal-organic backbones represent a new class of functional materials that can be rationally constructed by employing the concepts of supramolecular chemistry and crystal engineering. The modularity of design strategies, the diversity of prototypal structures, and the dynamic features of networks have afforded great advantages over traditional materials syntheses. The research presented in this thesis is primarily concerned with developing an in-depth understanding of the basic principles that govern the supramolecular behaviors of metal-organic networks and gaining an experimental control over the structure and function of these new classes of hybrid materials.The use of rigid and angular organic ligands along with transition metal clusters gives rise to a wide variety of novel metal-organic architectures ranging from zero-dimensional nanostructures to three-dimensional frameworks. Conformational analysis of these structural models suggests the geometric foundations for the existence of superstructural diversity. Controlled crystallization experiments further reveal the synthetic factors that might determine the formation of supramolecular isomers.Careful selection of more labile organic components, on the other hand, leads to flexible metal-organic networks exhibiting dynamic characteristics that have not been observed in their rigid counterparts. The guest-dependent closing/opening of cavities and the ease of fine-tuning their chemical environments demonstrate the effectiveness of such a strategy in the context of generating tailored functional materials.

Network structures based upon metal-organic backbones represent a new class of functional materials that can be rationally constructed by employing the concepts of supramolecular chemistry and crystal engineering. The modularity of design strategies, the diversity of prototypal structures, and the dynamic features of networks have afforded great advantages over traditional materials syntheses. The research presented in this dissertation is primarily concerned with developing an in-depth understanding of the basic principles that govern the supramolecular behaviors of metal-organic frameworks and gaining an experimental control over the structure and function of these new classes of hybrid materials. The use of rigid and angular organic ligands along with transition metal clusters gives rise to a wide variety of novel metal-organic architectures ranging from zero-dimensional nanostructures to three-dimensional frameworks. Gas sorption experiments suggest some of these compounds are potentially useful as porous materials. Conformational analysis of these structural models reveals geometrical foundations for the existence of superstructural diversity. Controlled crystallization experiments further indicate synthetic factors that might determine the formation of supramolecular isomers. On the other hand, careful selection of more labile organic components leads to flexible metal-organic frameworks exhibiting dynamic characteristics that have not been observed in their rigid counterparts. The guest-dependent switch-on/off of cavities and the ease of fine-tuning their chemical environments demonstrate the effectiveness of such a strategy in the context of generating tailored functional materials. Discovery and recognition of novel three-periodic metal-organic nets remains a nontrivial exercise. In this context, rigorous topological analysis assists the understanding of complicated nets and application of geometrical principles facilitates desing of new metal-organic structures. Finally, scaled-up metal-organic frameworks are potentially accessible with the aid of existing prototypal structures and a systematic study on ligand design.