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

Three new heterobimetallic cyanide-bridged complexes, $\left\{\right[\text{Ni}\left({\text{L}}^1\right)\left]\right[{\text{Ag(CN)}}_2\left]\right\}\left[{\text{Ag(CN)}}_2\right]\cdot {\text{2H}}_2\text{O}$ (2), $\left\{\right[\text{Mn}\left({\text{L}}^2\right)\left]\right[{\text{Ag(CN)}}_2\left]\right\}\cdot 1.5{\text{H}}_2\text{O}$ (3) and $\left\{\right[\text{Mn}\left({\text{L}}^3\right)\left({\text{H}}_2\text{O}\right){]}_2\left[{\text{Ag(CN)}}_2\right]\}{\text{ClO}}_4\cdot {\text{2H}}_2\text{O}$ (4) (${\text{L}}^1$= 2,7,12-trimethyl-3,7,11,17-tetraazabicyclo[11.3.1]heptadeca-1(17),13,15-triene; ${\text{L}}^2$ = N,N'-1,3-propylene-bis(5-chlorosalicylideneiminate); ${\text{L}}^3$ = N,N'-1,2-propylene-bis(5-bromosalicylideneiminate)), have been assembled using for the first time a new polyaza macrocycle nickel(II) compound $\left[\text{Ni}\right({\text{L}}^1\left)\right]({\text{ClO}}_4{)}_2$(1), or Schiff-base manganese(III) compounds and $\text{K}[{\text{Ag(CN)}}_2$]. 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 ${\text{Mn}}_2\text{Ag}$ core with free ${\text{ClO}}_4^{-}$ 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 $-0.78{\text{cm}}^{-1}$, respectively.

Graphical Abstract

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 $\text{K}[{\text{Ag(CN)}}_2$] 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. .