Appreciable Ni...O interactions at distances almost equal to the sum of the van der Waals radii of the two atoms

摘要

Two new entities [Co(NiL)_2(SCN)_2]_n (1) and [Mn(NiL)_2(NCS)_2]_n (2) were prepared by using a macrocyclic oxamido mononuclear complex ligand NiL,and characterized by X-ray single crystal analyses.L denotes the dianion of dimethyl 5,6,7,8,15,16-hexahydro-6,7-dioxodibenzo[l,4,8,ll]tetraazacyclotetradecine-13,18-dicarboxylate.Ni...O contacts (3.092 A) almost equal to the sum of the van der Waals radii of the two atoms were observed both in 1 and 2,and IR spectra support that appreciable coordination occurs at such long contacts.1 and 2 are 1D coordination polymers incorporating bimetallamacrocycles with the very long Ni...O coordination bonds as a kind of linking interaction.