Polynuclear and one-dimensional cyanide-bridged heterobimetallic complexes: synthesis, crystal structures and magnetic properties

Abstract

Three new heterobimetallic cyanide-bridged complexes, $$\{[\hbox {Ni}(\hbox {L}^{1})][\hbox {Ag(CN)}_{2}]\} [\hbox {Ag(CN)}_{2}]\cdot \hbox {2H}_{2}\hbox {O}$$ (2), $$\{[\hbox {Mn}(\hbox {L}^{2})][\hbox {Ag(CN)}_{2}]\}\cdot 1.5\hbox {H}_{2}\hbox {O}$$ (3) and $$\{[\hbox {Mn}(\hbox {L}^{3})(\hbox {H}_{2}\hbox {O})]_{2}[\hbox {Ag(CN)}_{2}]\} \hbox {ClO}_{4}\cdot \hbox {2H}_{2}\hbox {O}$$ (4) ( $$\hbox {L}^{1 }$$ = 2,7,12-trimethyl-3,7,11,17-tetraazabicyclo[11.3.1]heptadeca-1(17),13,15-triene; $$\hbox {L}^{2}$$ = N,N’-1,3-propylene-bis(5-chlorosalicylideneiminate); $$\hbox {L}^{3}$$ = N,N’-1,2-propylene-bis(5-bromosalicylideneiminate)), have been assembled using for the first time a new polyaza macrocycle nickel(II) compound $$[\hbox {Ni}(\hbox {L}^{1})](\hbox {ClO}_{4})_{2}$$ (1), or Schiff-base manganese(III) compounds and $$\hbox {K}[\hbox {Ag(CN)}_{2}$$ ]. Single crystal X-ray diffraction analysis reveals that complexes 2 and 3 can be characterized as one-dimensional cationic and neutral single chain structure, respectively. Complex 3 forms a three-dimensional network via weak inter-chain Ag...Ag interactions. Complex 4 belongs to a cyanide-bridged bimetallic sandwich-like cationic trinuclear structure containing $$\hbox {Mn}_{2}\hbox {Ag}$$ core with free $$\hbox {ClO}_{4}^{-}$$ as a counter anion, indicating that the Schiff-base ligand has an obvious influence on the structure of the cyanide-bridged complexes formed. Investigation of the magnetic susceptibilities of the cyanide-bridged Ag-Ni(II)/Mn(III) complexes showed the weak anti-ferromagnetic interaction between neighboring paramagnetic Ni(II) or Mn(III) ions bridged by the long NC-Ag-CN unit. From the best-fit of the magnetic susceptibility data of complexes 2 and 4 the magnetic coupling constant was determined to be $$J = -0.51$$ and $$-0.78 \,\hbox {cm}^{-1}$$ , respectively. SYNOPSIS Three new heterobimetallic cyanide-bridged complexes with 1D or polynuclear structures were assembled from polyaza macrocycle nickel(II) or manganese(III) Schiff-base with $$\hbox {K}[\hbox {Ag(CN)}_{2}$$ ] as building block. Investigation over the magnetic susceptibilities of the cyanide-bridged Ag-Ni(II)/Mn(III) complexes showed weak antiferromagnetic interaction between neighboring Ni(II) or Mn(III) ions bridged by the NC-Ag-CN unit.