摘要:
Chiral and racemic Salen-type Schiff-base ligands (H(2)L(1), H(2)L(2) and H(2)L(3)), condensed between D-(+)- and D,L-camphoric diamine (also known as (1R,3S)-1,2,2-trimethylcyclopentane-1,3-diamine) and 2-hydroxybenzaldehyde or 3,5-dibromo-2-hydroxybenzaldehyde with a 1,2 molar ratio, have been synthesized and characterized. A series of new nickel(II), palladium and copper(II) complexes of these chiral and racemic ligands exhibiting different coordination number (4, 5 and 6) have been characterized with the formulae [NiL(1)]CH(3)OH (3), [NiL(1)]H(2)O (4), [NiL(2)] (5), [PdL(2)] (6), [Cu(2)(L(2))(2)(H(2)O)] (7) and [NiL(3)(DMF)(H(2)O)] (8) Different solvent molecules in 3 and 4 (methanol and water molecules) as well as different apical ligands in 7 and 8 (water and DMF molecules) are involved in different O-H O hydrogen bonding interactions to further stabilize the structures. UV-Vis (W-Vis), circular dichroism (CD) spectra and thermogravimetric (TG) analyses for the metal complexes have also been carried Out. (C) 2009 Elsevier Ltd. All rights reserved