Alkoxy-Bridged Dicopper(II) Cores Meet Tetracyanonickelate Linkers: Structural, Magnetic, and Theoretical Investigation of Cu/Ni Coordination Polymers

Two heterometallic Cu(II)/Ni(II) coordination polymers, [Cu2(Hbdea)2Ni(CN)4]n (1) and [Cu2(dmea)2Ni(CN)4]n·nH2O (2), were successfully self-assembled in water by reacting Cu(II) nitrate with H2bdea (N-butyldiethanolamine) and Hdmea (N,N-dimethylethanolamine) in the presence of sodium hydroxide and [Ni(CN)4]2-. These new coordination polymers were investigated by single-crystal and powder X-ray diffraction and fully characterized by FT-IR spectroscopy, thermogravimetry, elemental analysis, variable-temperature magnetic susceptibility measurements, and theoretical DFT and CASSCF calculations. Despite differences in crystal systems, in both compounds, each dinuclear building block [Cu2(μ-aminopolyalcoholate)2]2+ is bridged by diamagnetic [Ni(CN)4]2- linkers, resulting in 1D (1) or 2D (2) metal-organic architectures. Experimental magnetic studies show that both compounds display strong antiferromagnetic coupling (J = -602.1 cm-1 for 1 and -151 cm-1 for 2) between Cu(II) ions within the dimers mediated by the μ-O-alkoxo bridges. These results are corroborated by the broken symmetry DFT studies, which also provide further insight into the electronic structures of copper dimeric units. By reporting a facile self-assembly synthetic protocol, this study can be a model to widen a still limited family of heterometallic Cu/Ni coordination polymer materials with different functional properties.

Metalo components exhibiting significant anticancer and antibacterial properties: a novel sandwich-type like polymeric structure

Four new dicyanoargentate(I)-based complexes 1-4 were synthesized from certain metal ions with a tetradentate ligand [N, N-bis (2-hydroxyethyl) -ethylenediamine; N-bishydeten] and determined by diverse procedures (elemental, thermal, FT-IR, ESI-MS for 1-3 and, magnetic susceptibility and EPR for 1, and 2) including crystal analysis of 4. The crystal method revealed that complex 4 has a sandwich-type like polymeric chemical structure with layers formed by [Cd(N-bishydeten)2]2+ cations and [Ag(CN)2]- anions. The complexes were further characterized by fluorescence and UV spectroscopy to determine their physicochemical features. The complexes displayed a DNA binding activity within the same range as found for cisplatin, in addition to their strong stability in the presence of the physiological buffer system. The complexes were also investigated for pharmacological properties like interaction with DNA/Bovine serum albumin, anticancer and antibacterial activities. Physicochemical studies of DNA with the complexes suggested that the interaction mode between them are possibly both intercalative and groove binding types. These spectroscopic measurements also show that there may be a binding tendency between BSA and the complexes via hydrogen or Van der Waals bonds. The viability tests demonstrated that all the complexes exhibited antibacterial (1-4) and anticancer effects (2-4) toward ten diverse bacterial strains and three tumor cells (HT-29 colon adenocarcinoma, HeLa cervical cancer, and C6 glioma), respectively.

Redox-Inactive Metal Ions That Enhance the Nucleophilic Reactivity of an Alkylperoxocopper(II) Complex

The importance of redox-inactive metal ions in modulating the reactivity of redox-active biological systems is a subject of great current interest. In this work, the effect of redox-inactive metal ions (M³⁺ = Sc³⁺, Y³⁺, Yb³⁺, La³⁺) on the nucleophilic reactivity of a mononuclear ligand-based alkylperoxocopper(II) complex, [Cu(ⁱPr₂-tren-C(CH₃)₂O₂)]⁺ (1), was examined. 1 was prepared by the addition of hydrogen peroxide and triethylamine to the solution of [Cu(ⁱPr₃-tren)(CH₃CN)]⁺ (ⁱPr₃-tren = tris[2-(isopropylamino)ethyl]amine) via the formation of [Cu(ⁱPr₃-tren)(O₂H)]⁺ (2) in methanol (CH₃OH) at 30 °C. 1 was characterized using density functional theory (DFT) calculations and spectroscopic methods such as UV-vis, resonance Raman (rR), and electron paramagnetic resonance (EPR). DFT calculations support the electronic structure of 1 with an intermediate geometry between the trigonal-bipyramidal and square-pyramidal geometries, which is consistent with the observed EPR signal exhibiting a signal with g_⊥ = 2.03 (A_⊥ = 16 G) and g_|| = 2.19 (A_|| = 158 G). The Cu-O bond stretching frequency of 1 was observed at 507 cm^-1 for ¹⁶O₂ species (486 cm^-1 for ¹⁸O₂ species), and its O-O vibrational energy was determined to be 799 cm^-1 for ¹⁶O₂ species (759 cm^-1 for ¹⁸O₂ species) by rR spectroscopy. The reactivity of 1 was investigated in oxidative nucleophilic reactions. The positive slope of the Hammett plot (ρ = 2.3(1)) with para-substituted benzaldehydes and the reactivity order with 1°-, 2°-, and 3°-CHO demonstrate well the nucleophilic character of this copper(II) ligand-based alkylperoxo complex. The Lewis acidity of M³⁺ improves the oxidizing ability of 1. The modulated reactivity of 1 with M³⁺ was revealed to be an opposite trend of the Lewis acidity of M³⁺ in aldehyde deformylation.

{CoIIIMnIII}ncorrugated chains based on heteroleptic cyanido metalloligands

The use of cyanide-bearing complexes affords one-dimensional coordination polymers with the formulas {[Mn^III(salen)(μ-NC)₂Co^III(4,4-dmbipy)(CN)₂]·H₂O}_n(1) and {[Mn^III(salen)(μ-NC)₂Co^III(dmphen)(CN)₂]}_n(2) .

Five novel dicyanidoaurate(i)-based complexes exhibiting significant biological activities: synthesis, characterization and three crystal structures

Herein the anticancer, antibacterial, and antifungal effects of the five novel dicyanidoaurate(i)-based complexes have been reported.