Unusual shift of a nitro group in a phenylhydrazo-β-diketone

摘要

A novel para to meta shift of a nitro group at the phenyl ring of 3-(2-hydroxy-4-nitrophenylhydrazo)pentane-2,4-dione (H_2L~1, 1), with formation of the new 3-(2-hydroxy-3,5-dinitrophenylhydrazo)pentane-2, 4-dione (H_2L~2, 2), occurs upon nitration of 1 with an equimolar amount of NaNO_2, under basic conditions. 2 acts as a polydentate ligand for the synthesis of the polymeric potassium [K(μ_5-HL~2)]_n (3) and monomeric nickel(ii) [Ni(H_2O)_3(L~2)]·H_2O (4) compounds. They have been fully characterized, including single crystal X-ray analysis, and the complexes feature metal-organic (in 3) or supramolecular (in 4) 3D networks. The topological analysis of 3 reveals a uninodal 5-connected underlying net with the point symbol of (4~6.6~4) and a very rare 5/4/t5 topology, which had not yet been observed in coordination polymers. This journal is