In the past decades, great efforts have been devoted to the rational design and synthesis of inorganic-organic hybrid architectures and metal organic frameworks (MOFs). A common feature of such design approaches is to employ poly-functional organic ligands such as dicarboxylic acids and combine them with polyoxometallate (POMs) and N-donor co-ligands to prepare inorganic-organic hybrids and metal organic frameworks, respectively. These crystal structures have high structural stability and infinite variety of unique chemical, physical, and adsorption properties. Due to importance of this field, a novel series of inorganic-organic hybrid and MOFs architectures based on dicarboxylate/POMs and dicarboxylate/N-donor bases have been synthesized under mild, hydrothermal, and sonochemical conditions [1-4]. The objective of the present speech is to explore the effect of organic ligands, POMs charge density and synthetic conditions in final structures. The magnetic properties of some of these compounds have been investigated. Monte Carlo simulation has been employed for predicting the ability of some of these compounds to capture CH4 and CO2 and also to separate CH4/H2 and CO2/N2 mixtures.

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