Metal-carboxylate complexes and coordination polymers are the fields of research that has risen rapidly over recent years to the forefront of modern chemistry and material science. Simultaneously the crystal engineering of metal carboxylates, especially coordination polymers has been greatly developed in the past decade. Supramolecular architecture of metal carboxylates can be directly constructed by using metal ions existing in various coordination geometries combined with multifunctional ligands. This book presents the synthesis, characterization and structural aspects of some first row transition metal carboxylates along with the study of molecular/anion recognition properties of carboxylic acid derivatives. The synthetic methods, diverse coordination modes, attractive solid-state structures, solution behaviour, as well as their diverse applications are discussed. Special efforts have been made to discuss the formation of different types of the structures and the control over their syntheses.