| Heteropolymetallic complexes are of considerable current interest in relating to the nature of magnetic exchange interactions between metal ions through bridging ligands and as models for the active sites of metalloenzymes. One of the most successful and usual strategy for preparing heteronuclear complexes is"Complex as ligand"method. The"Complex ligand"contains potential donor atoms for another metal ion or metal complex with empty coordination sites.The Schiff base ligands (H3L) derived from the condensation of salicylaldehyde and its derivatives with simple peptides containing carboxylate groups, which is able to accommodate a copper(Ⅱ) or nickel(Ⅱ) ion at the inner ONNO coordination site, leading to the mononuclear complexes [CuL]- or [NiL]-. It is noteworthy that these mononuclear complexes contain unbridged carboxylate groups so that they can act as potential'ligands'to bind alkaline earth metal and transition metal cations to give the heterometallic complexes.In this paper, a series of carboxylate-bridged heteronuclear compounds containing dipepides and salicylaldehyde (its derivatives) has been synthesized and characterized by IR, UV-Vis, single crystal X-ray analysis.1,The Schiff base ligand derived from the condensation of 4-methoxysalicylaldehyde and glycylglycine, which is able to accommodate a copper (Ⅱ) ion at inner ONNO coordination site, leading to the mononuclear complex. It can act as potential'ligand'to bind other metal ions to give six heterometallic complexes [Co(H2O)6][CuL]2·6H2O(1),[Ni(H2O)6][CuL]2·6H2O(2),[Zn(H2O)6][CuL]2·6H2O(3),[Cd (H2O)3][CuL]2·2H2O(4),{[(CuL)Sr(H2O)4][CuL]·2H2O}n (5).Complexes(1)-(3)formed cation columns [M(H2O)6]2+(M=Co,Ni,Zn) and anion columns [CuL]- arrangement and are hold together via different hydrogen-bondings, and from 3-D network structures. Complex (4) formed a Cu-Cd-Cu trinuclear complex via carboxylate bridged. Compare to complex(1)-(4),there are some differences between alkaline earth metal and transition metal cation complexes,complex(5)through carbonyl oxygen coordinate to strontium formed a 1D chain heterpolymetallic complex.2,The mononuclear copper (Ⅱ) complex of Schiff base derived from the condensation of salicylaldehyde haloid and glycylglycine , It can act as potential'ligand'to bind alkaline earth metal and transition metal cations to give six the heterometallic complexes [Sr(H2O)4]2[CuL1]4·10H2O(6),[Ba(H2O)4]2[CuL1]4·10H2O(7), [Pb(H2O)3]2[CuL1]4·2H2O(8),[Zn(H2O)6][CuL2]2·7.5H2O(9),[Ni(H2O)6][CuL2]2-·10H2O(10) and {[Ba2(H2O)8(CuL2)4]·2H2O}n(11). Complexes (6-8) are hexanuclear complexes via carboxylate bridged. In the complexes (9)-(10), complexes formed cation layers [M(H2O)6]2+(M=Ni, Zn) and anion layers [CuL]- arrangement and are hold together via different hydrogen-bondings, and from 3-D network structures. Complex (11) through carbonyl oxygen ligand to barium formed a 1D chain heterpolymetallic complex.3,Three complexes [Co(H2O)6][NiL]2·6H2O(12),[Ni(H2O)6][NiL]2·6H2O (13), [Cu(H2O)6][NiL]2·6H2O(14)of Schiff base derived from salicylaldehyde derivatives have been synthesized and characterized. The three complexes have the similar crystal structures. Complexes formed cation columns [M(H2O)6]2+(M=Co, Ni, Cu) and anion columns [CuL]- arrangement and are hold together via different hydrogen-bonding models , and formed 3-D network structures.4,The Schiff base ligand derived from the condensation of 5-sulfonylsalicylaldehyde and glycylglycine, which is able to accommodate a copper(Ⅱ) ion at inner ONNO coordination site , leading to the mononuclear complex . It can act as potential'ligand'to bind alkaline earth metal cations M2+(Ca2+,Sr2+,Ba2+) leading to 1D ladder-like polymer {[Ca(H2O)4][CuL]·2H2O}n (15), 3D network polymer {[Sr(H2O)2][ CuL]}n (16) and {[Ba(H2O)4][CuL)]}n (17). Complex (15) formed 1D ladder-like polymer via carboxylate oxygen and one sulfonate oxygen atoms. In the complex (16), there are two sulfonate oxygen and one carboxylate oxygen atoms coordinate to Sr2+, formed 3D network polymer. Compared to (16), in complex (17) three sulfonate oxygen atoms coordinate to Ba2+ leading to a 3D network heteropolymetallic complex.
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