Syntheses, crystal structures and antioxidant properties of four complexes derived from a new Schiff base ligand (N~1E,N~2E)-N~1,N~2-bis(1-(pyrazin-2-yl)ethylidene)ethane-1,2 diamine

摘要

Four Ag(I), Cd(II) and Cu(II) complexes, [Ag_2L_2](ClO_4)_2 (1), [CdL(NO_3)_2] (2), [Cd_2L_2C_l4] (3) and [Cu_2L_2 (ClO_4)_3](ClO_4) (4), derived from the new Schiff base ligand (N~1E,N~2E)-N~1,N~2-bis(1-(pyrazin-2-yl)ethylidene) ethane-1,2 diamine (L) have been synthesized and crystallographically characterized. The crystal structural features of 1-4 show that 1 is a ligand-supported dinuclear silver complex, 2 is a mononuclear eight-coordinate complex, 3 is a dinuclear hepta coordinate species and 4, interestingly, discloses two distinctly crystallographically independent groups of mononuclear [Cu(ClO_4)_2L] and a 1D [Cu(ClO_4)L] (ClO_4) unit in one asymmetric group. Furthermore, π...π stacking and/or hydrogen bonding interactions seem to be effective in stabilizing these crystal structures. The antioxidant activities of L and complexes 1-4 have also been studied.