SYNTHESIS, CHARACTERIZATION AND CATALYTIC APPLICATIONS OF ALKALINE EARTH METAL (Ca, Mg, Sr) COMPLEXES DERIVED FROM AMINO BENZOIC ACIDS

Abstract

The present dissertation describes the synthesis and characterization of Ca, Mg and Sr complexes and coordination polymers (CPs) with amino benzoic acids. Hydrothermal reaction of Ca. Mg and Sr acetate with 4-aminobenzoic acid (4-ABA) and 5-aminoisophthalic acid (5-AlP) in DMF (N,N'-dimethylformamide) or DMA (N,N'-diniethylacetamide) as the solvent results in the formation different complexes. For convenience work presented in this dissertation has been divided in three chapters. First chapter is the introduction and literature survey about various Ca. Mg and Sr complexes and coordination polymers with 5-AlP and 4-ABA and related ligands, as well as their catalytic activity in different organic transformation reactions. Second chapter describes the synthesis of Ca, Mg and Sr complexes with 5-AlP, namely [Ca' 1(5—AlP)( DMA)] , [Mg(1120)4(5—A1P)2( 5—l-IAIP)2] .4DM A and the Sr polymeric chain. Characterization of thecomplexes is achieved by various physicochenuical techniques like IR, electronic (both emission and absorption mode) and thermal studies, single crystal X—ray analysis. The complexes of Ca and Sr are found to be active catalysts for the Na1-1CO3 mediated oxidation of styrene using H202 as an oxidant. Under the optimized reaction conditions we have found that the order of selectivity of styrene oxidation products followed the order: styrene oxide (98%) >benzaldehyde (1.67%) > 2—phenylacetaldehyde (0.33%). Third chapter is devoted to the synthesis of Ca complex of 4-ABA, [Ca "(4-ABA) (CH3COO)(H20)}. Characterization of the complex is done using various spectral (NMR, IR and electronic) and thermal studies, single crystal X—ray analysis. The complex is found to be an active catalyst for the oxidation of cyclohexene in presence of NaI-IC03 and 1-1202. The Catalyst is very specific giving only one product i.e., cyclohexene oxide during the reaction.