Synthesis, crystal structures, and urease inhibitory activities of two azido-bridged polynuclear copper(II) complexes with Schiff bases

Abstract

Two azido-bridged polynuclear Cu(II) complexes with the formulae [Cu(L1)(l 1,3 -N 3 )] n and [Cu(L2)(l 1,3 -N 3 )] n (HL1 = 2-[(2-morpholin-4-ylethylimino)methyl]phenol, HL2 = 2-methoxy-6-[(2-piperidin-1-ylethylimino)methyl]-phenol), have been synthesized and characterized by physico-chemical and spectroscopic methods. The Cu atom in each of the complexes is five-coordinate in a square pyramidal geometry, with one O and two N atoms of a Schiff base ligand and one terminal N atom of a bridging azido ligand defining the base-plane, and with another terminal N atom of a symmetry-related azido ligand occupying the apical position. The molecules are linked through end-to-end azido bridges, forming one-dimensional polymeric chains. Both of the complexes show moderate inhibitory activities against jack bean urease.

Syntheses, Structures, and Magnetic Properties of Three One-Dimensional End-to-End Azide/Cyanate-Bridged Copper(II) Compounds Exhibiting Ferromagnetic Interaction: New Type of Solid State Isomerism

“…In spite of extensive research previously carried out, it is difficult to judge the nature of a metallo–pseudo-halide product to be obtained from a reaction mixture; for a particular pseudo-halide, the composition, topology, and nuclearity of the product depend on the metal ion and its simple salt, organic ligand, solvent, stoichiometric ratio of the reactants, etc., and therefore, new topologies may be attained by modifying these parameters. The tridentate Schiff base ligands, HL 1 and HL 2 (Scheme ), have been previously used to derive some copper(II) and nickel(II) azide compounds. ,,, Derived from HL 2 , only one metal–azide compound, which is a 1-D copper(II)–azide system, has been reported . Interestingly, by changing the reaction conditions or starting metal salt of the same 1:1:1 mixture of HL 1 , metal ion, and azide, one mononuclear and two different 1-D copper(II)-azide compounds have been obtained. ,, On the other hand, a unique single end-to-end (μ 1,3 ) azide-bridged cyclic tetranickel(II) cluster has been obtained from a 1:1:4 mixture of HL 1 , metal ion (Ni II ), and azide.…”

Syntheses, Crystal Structures and Photophysical Aspects of Discrete and Polymeric Azido‐Bridged Zinc(II) and Cadmium(II) Complexes: Sensing Properties and Structural Resemblance

“…It is worth mentioning that neither of the previously reported three zinc(II)/cadmium(II)–azido compounds 5–7 are coordination polymers, while three compounds in this investigation are coordination polymers, revealing again the role of the imino‐amino side chain to determine the structure and topology as well as the beauty of the serendipity and subtle effects in metallo‐azide systems. It is also worth mentioning that a number of not only zinc(II)–azido or cadmium(II)–azido but also metallo–azides of other metal ions have been reported from a number of ether‐phenol‐imine‐amine ligands, similar to HL 1 and HL 2 , obtained on 1:1 condensation of 3‐methoxy/ethoxysalicylaldehyde and a diamine ,,. Only few systems, which are of copper(II), among them are coordination polymers ,,.…”

“…It is also worth mentioning that a number of not only zinc(II)–azido or cadmium(II)–azido but also metallo–azides of other metal ions have been reported from a number of ether‐phenol‐imine‐amine ligands, similar to HL 1 and HL 2 , obtained on 1:1 condensation of 3‐methoxy/ethoxysalicylaldehyde and a diamine ,,. Only few systems, which are of copper(II), among them are coordination polymers ,,. Hence, compounds 2–4 are not only the first examples of zinc(II)/cadmium(II)–azido coordination polymers but also among the rare examples of metallo–azide coordination polymers derived from HL 1 /HL 2 and related ligands.…”

Structurally Diversified Heterocycles and Related Privileged Scaffolds as Potential Urease Inhibitors: A Brief Overview

“…You and co‐workers 92 reported two azido‐bridged polynuclear Cu(II) complexes and evaluated for urease inhibitory activity using the protocol reported by Tanaka et al 93. Both complexes 71 and 72 showed moderate activity with IC 50 values of 51.20 ± 0.72 and 55.45 ± 0.38 µM, respectively, which are slightly higher than the standard acetohydroxamic acid (IC 50 = 42.12 ± 0.08 µM).…”