Intermolecular Pb··· N interactions in lead(ll) dimers producing a supramolecular two-dimensional metalorganic compound: bis[μ_2-N'-(2-oxidobenzyl-idene)benzohydrazidato-κ~4O:OrN'O']dilead(ll)

摘要

Aroylhydrazones of ortho-hydroxy aldehydes are Schiff base ligands that typically coordinate as a chelate in an O,N,O'-manner. Dinuclear complexes are normally observed, with the phenolate O atom acting as the bridging atom. The switchable protonation state of the tridentate N'-(2-hydroxybenzylidene)benzo-hydrazide (H_2sabhz) ligand can lead to variations in the resulting supra-molecular structure. The title compound, [Pb_2(C_14H_10N_2O_2)_2], was prepared by the reaction of [Pb(OAc)_2]-3H_2O (OAc is acetate) with the benzoylhydrazone derivative of salicylaldehyde, i.e. H_2sabhz, in the presence of triethylamine in methanol. In the crystal structure, each Pb~II atom of the dimer has an NO_3 coordination environment, with one sabhz ligand coordinating in an O,N,O'-manner and with the second sabhz ligand coordinating via the bridging phenolate O atom, since the dimers are located on a centre of inversion. It has been found that the dimers are connected by Pb···N interactions, resulting in a two-dimensional supramolecular network which shows the [3~2.5~2,3.5~3] net topology. The s~2 electron pair of the Pb~II ion clearly influences the observed intermolecular interactions.