Executive Summary : | Activation of small molecules using the Lewis acid-base pair – B(C6F5)3 and PPh3 was pioneered by Stephan co-workers. With the initial success of heterolytic activation H2, a large number of inert chemical bonds have been cleaved employing this Lewis acid-base pair. The positive results from the borane-phosphine Lewis pair has prompted chemists to explore other p-block compounds as Lewis pairs for bond activation processes. Aluminum, a group 13 element is known to exhibit +1 and +3 oxidation state. While Al(I) possesses a pair of electron and can behave as a Lewis base, Al(III) compounds are well established Lewis acids. The potential combination of Al(I)/Al(III) as Lewis pairs can be exploited for the activation of small molecules. However such studies are still in infancy. The proposed project aims to prepare isolectronic Al(I) and Al(III) compounds bearing same ancillary ligand which can act as Lewis acid base pair for activation of small molecules. Reactivity of the synthesized Al(I)/ A(III) Lewis pairs will be probed for the activation of H-H, B-H, C-H, Si-H bonds. Formation of stable tetrahedral aluminum species will be the driving force for the activation of bonds using Al(I)/Al(III) pair. Addition of the heterolytically cleaved species across unsaturated bonds like C=C, C=N and C=O will be explored. These stoichiometric studies will be further extended to catalytic hydroelementation of unsaturated bonds. The investigation on aluminum assumes importance since it is the third most earth-abundant element. |