Development of Main Group Systems for Small Molecules Activation

Frustrated Lewis pairs (FLP) have been introduced as an alternative to transition metal catalyst. Since the first discovery in 2006, FLP has found diverse applications in areas such as small molecules activation and catalysis. The present thesis has two major directions: 1) find new types of FLP; 2) demonstrate their unusual reactivity. Alkali metal species are shown to mimic FLP behavior. The combinations of Lewis acidic alkali metal cations with hydride (H-), carbanions (R3C-), amides (R2N-) or phosphides (R2P-) are shown to activate H2 reversibly and hydrogenate unsaturated molecules. In addition, the reaction of alkali metal species with CO affords the transient anionic carbene intermediate, which can either undergo CO polymerization or react with H2 to form the Fischer-Tropsch type of products. In a different approach, we showed compounds contain covalently bonded group 13 and 15 elements remain reactive towards CO2 activation. For example, indium amide systems (R2In-NR’2) are shown to readily activate CO2 and has been developed as catalysts for the synthesis of 1,3-disubstituted ureas.Ph.D