The macrocyclic ligand(L) and its dinuclear copper(Ⅱ) and zinc(Ⅱ) complexes have been synthesized. The crystal structure of [Cu 2L(Him) 2](ClO 4) 4·2H 2O has been determined by single crystal X ray diffraction. It crystallizes in a monoclinic system, the space group P2 1/c , a =0.951 2(2) nm, b =2.010 4(4) nm, c =1.202 5(2) nm, β =98.89(3)°, V =2.271 9(8) nm 3, Z=2, D c=1.599 Mg/m 3 , F (000) = 876 , R =0.059 1, wR =0.173 3, GOF(F)=1.009. The copper(Ⅱ) atom is five coordinated with four nitrogen atoms of the macrocyclic ligand and one nitrogen atom of imidazole. The stepwise stability constants of the 1∶1 and 2∶1 molar ratios of Cu to L and Zn to L complexes were determined by potentiometric titration in KCl supporting electrolyte(0.100 mol/L) at 25 ℃. The results indicated that zinc(Ⅱ) ion can form hydroxide bridged dinuclear complex [Zn 2(OH)L] 3+ , while the copper(Ⅱ) ion can only form dinuclear complex 3+ with macrocyclic ligand.
A novel nickel(Ⅱ)complex[Ni(C22H34N6)](ClO4)2 had been synthesized and characterized by elementary analysis and signal-crystal X-ray diffraction analysis.The results showed that the complex crystallizes in a triclinic system,the space group P1-with a=10.209(1),b=11.617(1),c=11.916(1),α=87.633(2),β=75.940(2)°,γ=88.501(2)°,V=1369.5(2)3,Z=2,F(000)=668,Dc=1.552g/cm3,R1=0.036,wR2=0.105.In the crystal there are two independent Ni(II)centres.Each Ni(II)ion is coordinated by four secondary nitrogen atoms from one macrocycle and two oxygen atoms from two perchlorate anions to form a distorted octahedron geometry.
The macrocyclic dinuclear copper(Ⅱ) complex Cu\-2LCl\-2·2H\-2O was prepared in anhydrous ethanol, and characterized by means of element analysis, IR.The stepwise stability constants of the 1∶1 and 2∶1 ([Cu]/[L]) complexes were determined by potentiometric titration in KCl supporting electrolyte (0 100 mol/L) at 25 ℃.The results indicate that L shows unusual high stability to dinuclear copper(Ⅱ) ions.