A study on mono-, bis- and tris-N-functionalized 1,4,7-triazacyclononane with benzimidazolyl groups and their nickel(II) complexes

Three new ligands, 1-(benzimidazolyl-2-methyl)-1,4,7-triazacyclononane L1, 1,4-bis(benzimidazolyl-2-methyl)-1,4,7-triazacyclonone L2, and 1,4,7-tris-(benzimidazolyl-2-methyl)-1,4,7-triazacyclonane L3, were synthesized by a straightforward one-pot method. Their nickel(II) complexes View the MathML source[Ni2L21Cl2]·(ClO4)2, [NiL2CH3CN](ClO4)2 · 2CH3OH · H2O (or [NiL2Cl] · ClO4) and [Ni(H−2L3)] · H2O were obtained and characterized by electrospray mass spectrum, 1H NMR, CV and other physical methods. Their crystal structures were determined by X-ray analyses. The crystal structure of the nickel(II) complex of L1 shows that two Ni(II) atoms are bridged by two Cl− anions. A ferromagnetic exchange coupling and zero-field splitting effect exist in complex 1.