Synthesis, structures and properties of Cu(II) and Mn(II) complexes with 1,10-phenanthroline-2-carboxylic acid and 2,2'-bipyridine ligands

Antiproliferative and antibacterial properties of biocompatible copper(II) complexes bearing chelating N,N-heterocycle ligands and potential mechanisms of action

In an attempt to propose new applications for the biomedical field, complexes with mixed ligands {[Cu(bpy)₂(μ₂OClO₃)]ClO₄}n (1) and [Cu(phen)₂(OH₂)](ClO₄)₂ (2) (bpy: 2,2'-biyridine; phen and 1,10-phenantroline) were evaluated for their antibacterial and cytotoxicicity features and for the elucidation of some of the mechanisms involved. Complex (2) proved to be a very potent antibacterial agent, exhibing MIC and MBEC values 2 to 54 times lower than those obtained for complex (1) against both susceptible or resistant Gram-positive and Gram-negative strains, in planktonic or biofilm growth state. In exchange, complex (1) exhibited selective cytotoxicity against melanoma tumor cells (B16), proving a promising potential for developing novel anticancer drugs. The possible mechanisms of both antimicrobial and antitumor activity of the copper(II) complexes is their DNA intercalative ability coupled with ROS generation. The obtained results recommend the two complexes for further development as multipurpose copper-containing drugs.

Hydrogen bonding-tuned hydroxo-bridged tetra-copper Cu4(bipy)4-cluster supramolecular network to layered coordination polymer

Hydrogen bonds influence the transformation of the Cu₄-cluster⋯ligand hydrogen net to the layered coordination polymer.

A potential Cu/V-organophosphonate platform for tailored void spacesviaterpyridine mold casting

The reaction of appropriate copper and vanadium salts with tetratopic methane tetra-p-phenylphosphonic acid (MTPPA) in the presence of 2,2′:6′:2′′-terpyridine (terpy) yielded the three-dimensional bimetallic copper vanadium phosphonate framework [{Cu(terpy)}4Cu(VO2)4(MTPPA-H)2]·4H2O (1). Terpy has no net contribution to the three-dimensional structure providing a potential platform for void space formationviamold-casting. The structure was characterized by single-crystal X-ray diffraction and thermogravimetric analysis (TGA). Magnetic measurements were performed using a SQUID magnetometer. The crystal structure of the methanol solvate of the free ligand, MTPPA·MeOH, was analysed using Hirshfeld surfaces and fingerprint plots.

Crystal structures of [M(N3)2(phen)2] compounds, M = Mn, Co or Cu and phen = 1,10-phenanthroline

Crystal structures of the title compounds, [Mn(N3)2(phen)2] (1), [Co(N3)2(phen)2] (2) and [Cu(N3)2(phen)2] · 1.5 H2O (3), have been determined at 100 K. Central atoms of the above-mentioned compounds are coordinated by four pyridine nitrogen donor atoms from two 1,10-phenanthroline molecules and two nitrogen donor atoms of terminally coordinated azide anions, which resulted in a distorted {MN6} octahedral geometry. The π-π stacking interactions, as well as weak C—H∙∙∙N hydrogen bonds, were observed in all three compounds. Moreover, complex 3 revealed also supramolecular chains of the complex and water molecules linked together through O—H∙∙∙N hydrogen bonds.

Isolation of a metastable intermediate in a heterometallic Cu(II)-Hg(II) 1D polymeric chain: synthesis, crystal structure, and photophysical properties

A metastable heterometallic intermediate, [Cu2(bpy)2(DIPSA)2Hg2(OAc)4(DIPSA)2]n (1, where OAc = CH3COO(-), bpy = bipyridine, and DIPSA = diisopropylsalicylic acid), has been isolated and characterized during the synthesis of 1D polymer [Cu2(bpy)2(DIPSA)2(CH3CN)2Hg2(OAc)2(DIPSA)4]n (2) at ambient temperature in acetonitrile. Moreover, recrystallization of 2 in methanol results in monomeric [Cu(DIPSA)(bpy)(CH3OH)]·CH3OH (3). Complexes 1-3 have been characterized by elemental analysis, Fourier transform infrared, and UV-vis spectroscopy as well as by their single-crystal X-ray structures. The photophysical study suggests the quenching of fluorescence of DIPSA upon complexation.