220632-01-9

Upstream product

• 366-18-7 [2,2]bipyridinyl 
• 16887-00-6 chloride 
• 127099-85-8 dicyandiamide 
• 1722-09-4 (2-13C)acetonitrile 
• 80937-33-3 oxygen 
• 1020-31-1 3,5-Di-tert-butylcatechol 
• 75-05-8 acetonitrile 
• 32767-18-3 oxygen-18 

Downstream Products

• 138827-23-3 Cu(2,4,6-trimethylphenoxo)2(2,2'-bipyridine) 
• 138827-21-1 Cu(3,4-dimethylphenoxo)2(2,2'-bipyridine) 
• 138827-22-2 Cu(3,5-dimethylphenoxo)2(2,2'-bipyridine) 
• 1258938-65-6 [Cu(2,2'-bipyridine)(1,2-dithiosquarate)] 
• 1258938-62-3 2,2'-bipyridine-1,2-dithiooxalatocopper(II) 

Relevant academic research and scientific papers

Synthesis and structural characterization of ternary Cu (II) complexes of glycine with 2,2′-bipyridine and 2,2′-dipyridylamine. the DNA-binding studies and biological activity

In this study two new complexes [Cu(bpy)(Gly)Cl]·2H2O (1) and [Cu(dpa)(Gly)Cl]·2H2O (2) (bpy = 2,2′-bipyridine; dpa = 2,2′-dipyridylamine, Gly = glycine) have been synthesized and characterized by elemental analysis, IR, TGA, UV-vis and magnetic susceptibility measurements. The binding properties of the complexes with CT-DNA were investigated by electronic absorption spectra. The intrinsic binding constants (Kb) calculated from UV-vis absorption studies were 1.84 × 103 M-1 and 3.1 × 103 M-1 for complexes 1 and 2 respectively. Thermal denaturation has been systematically studied by spectrophotometric method and the calculated ΔTm was nearly 5 °C for each complex. All the results suggest that the interaction modes between the complexes and CT-DNA were electrostatic and/or groove binding. The redox behavior of the two complexes was investigated by cyclic voltammetry. Both complexes, in presence and absence of CT-DNA show a quasi-reversible wave corresponding to CuII/CuI redox couple. The change in E1/2, ΔE and Ipc/Ipa ascertain the interaction of complexes 1 and 2 with CT-DNA. Further insight into the binding of complexes with CT-DNA has been made by gel electrophoresis, where the binding of complexes is confirmed through decreasing the mobility and intensity of DNA bands. In addition, the antitumor activity of the complexes was tested on two cancer cell lines; the breast cancer (MCF7) and the human hepatocellular carcinoma (HEPG2), as well as one normal cell line; the human normal melanocytes (HFB4). The results showed that complex 1 was more potent antitumor agent than complex 2. The in-vitro antimicrobial activity of the two complexes was carried out using the disc diffusion method against different species of pathogenic bacteria and fungi. The activity data showed that complex 2 was more active in inhibiting the growth of the tested organisms.

DNA binding properties and antibacterial activity of heterolyptic transition metal complexes with 2,2-bipyridyl and 2-acetylthiophene thiosemicarbazone

Metal complexes having the composition M(Bipy)Cl2 (where, M = Cu(II), Ni(II) and Co(II); Bipy = 2,2-bipyridyl) are reacted with 2-acetylthiophene thiosemicarbazone (ATT) to produce heteroleptic transition metal complexes with molecular formula [M(Bipy)ATT]. The complexes are characterized by mass spectra, molar conductivity, infrared and electronic spectra. Electrochemical behaviour of these metal complexes was investigated by cyclic voltammetric studies. The metal complexes show quasi reversible cyclic voltammetric responses for the Cu(II)/Cu(I) couple. The binding properties of these complexes with calf-thymus DNA have been investigated by using absorption spectrophotometry. Metal complexes are screened for their antibacterial activity by using agar well diffusion method against pathogenic bacterial strains viz. Escherichia coli and Staphylococcus aureus. Antibacterial activity of the present complexes are comparable with the activity of ciprofloxacin. The Cu(Bipy)Cl2 complex inhibits bacteria more strongly than any other complex. The Ni(Bipy)ATT complex shows more activity than the parent complex, Ni(Bipy)Cl2.

Crystal structure and magnetic properties of the single-μ-chloro copper(II) chain [Cu(bipy)Cl2] (bipy = 2,2′-bipyridine)

The crystal and molecular structure of the copper(II) chain [Cu(bipy)Cl2] (1) (bipy = 2,2′-bipyridine) has been determined by X-ray diffraction methods. The crystal structure of 1 consists of neutral single chloro-bridged copper(II) chains with alternating short and long Cu-Cl distances through a screw axis parallel to a. The copper surrounding is best described as distorted square pyramidal, the equatorial plane being built by the two nitrogen atoms of the chelating bipy and two chlorine atoms (one terminal and the other bridging), whereas the apical position is filled by the bridging chlorine atom from the symmetry-related adjacent unit. The equatorial Cu-Cl bonds (2.291(3) and 2.259(3) A) are shorter than the axial one (2.674(3) A). The intrachain copper-copper separation is 4.010(3) A whereas the shortest interchain copper-copper distance is 8.381(3) A. The magnetic properties of 1 have been investigated in the temperature range 1.8-300 K. They reveal the occurrence of a weak intrachain antiferromagnetic coupling, J = -2.3 cm-1 (uniformly-spaced linear chain of local spin S = 1/2). This value is compared to those of related mono- and di-chloro-bridged copper(II) polymers and the available magneto-structural data are discussed in the framework of a simple orbital model.

Fluorescence and electron paramagnetic resonance studies of norfloxacin and N-donor mixed-ligand ternary copper(II) complexes: Stability and interaction with SDS micelles

The stability of ternary copper(II) complexes of a heterocyclic ligand, L (L being 2,2′-bipyridine (bipy) or 1,10-phenanthroline (phen)) and the fluorescent antibacterial agent norfloxacin (NFX) as the second ligand was studied at pH 7.4 and different ionic strengths. Fluorescence quenching upon titration of NFX with the binary complexes allowed to obtain stability constants for NFX binding, Kb, as a function of ionic strength. The Kb values vary by more than two orders of magnitude when buffer concentration varies from 0.5 to 100 mM. It was observed that previously synthesized ternary complexes dissociate in buffer according with the obtained stability constants. This shows that equimolar solutions of NFX and binary complexes are equivalent to solutions of synthesized ternary complexes. The interaction of the ternary copper complexes with anionic SDS (sodium dodecyl sulfate) micelles was studied by fluorescence and electron paramagnetic resonance (EPR). Titration of NFX-loaded SDS micelles with the complexes Cu:L allowed to determine the stability constants inside the micelles. Fluorescence quenching demonstrated that SDS micelles increase the stability constants by factors around 50. EPR spectra gave details of the copper(II) local environment, and demonstrated that the structure of the ternary complexes inside SDS micelles is different from that in buffer. Mononuclear ternary complexes formed inside the micelles, while in buffer most ternary complexes are binuclear. The results show that anionic membrane interfaces increase formation of copper fluoroquinolone complexes, which can influence bioavailability, membrane diffusion, and mechanism of action of the antibiotics.

A promising copper(II) complex as antifungal and antibiofilm drug against yeast infection

The high mortality rate of candidemia and the limited option for the treatment of Candida spp. infection have been driving the search for new molecules with antifungal property. In this context, coordination complexes of metal ions and ligands appear to be important. Therefore, this study aimed to synthesize two new copper(II) complexes with 2-thiouracil and 6-methyl-2-thiouracil ligands and to evaluate their mutagenic potential and antifungal activity against Candida. The complexes were synthesized and characterized by infrared vibrational spectroscopy, CHN elemental analysis, UV-Vis experiments and ESI-HRMS spectrometry studies. The antifungal activity was evaluated by broth microdilution against 21 clinical isolates of Candida species. The mutagenic potential was evaluated by the Ames test. The complexes were Cu(Bipy)Cl2(thiouracil) (Complex 1) and Cu(Bipy)Cl2(6-methylthiouracil) (Complex 2). Complex 1 showed fungicidal and fungistatic activities against all isolates. Furthermore, the Minimum Inhibitory Concentration (MIC) from 31 to 125 μg/mL and inhibition percentage of 9.9% against the biofilms of C. krusei and C. glabrata were demonstrated. At the concentrations tested, complex 1 exhibited no mutagenic potential. Complex 2 and the free ligands exhibited no antifungal activity at the concentrations evaluated. Since complex 1 presented antifungal activity against all the tested isolates and no mutagenic potential, it could be proposed as a potential new drug for anti-Candida therapy.

Mixed-ligand copper(II) complexes with tetrazole derivatives and 2,2′-bipyridine, 1,10-phenanthroline: Synthesis, structure and cytotoxic activity

The [Cu2(2,2′-bipy)2(L1)4] (1), [Cu2(1,10-phen)2(L1)4] (2), [Cu(2,2′-bipy)(L2)2]n (3) and [Cu2(1,10-phen)2(L2)4] (4) complexes, where HL1 – 5-phenyltetrazole, and HL2 – 1H-tetrazole, have been synthesized. All complexes have been characterized by elemental analysis, IR, EPR spectroscopy and X-ray diffraction. The complexes possess distorted tetragonal-pyramidal coordination geometry. Compounds 1, 2, 4 show μ-5-phenyl-tetrazole/tetrazole bridged dinuclear structures, while compound 3 reveals polymeric structure. The effect of compounds on viability of the MCF-7 and Hep-2 cell lines was investigated in vitro. The study showed that tetrazole ligands HL1 and HL2 are non-toxic at tested concentrations (1–50 μM), while 1,10-phen and 2,2′-bipy posses cytotoxicity. All of the complexes exhibit significant dose-dependent cytotoxic effect and have the potential to act as efficient cytotoxic drugs. The complexes [Cu(1,10-phen)Cl2] (5) and [Cu(2,2′-bipy)Cl2] (6) have also been obtained to establish the influence of insertion of tetrazole ligands in compounds on their cytotoxic properties.

2,2′-Bipyridine-1,2-dithiolate mixed ligand complexes. Synthesis, characterisation and EPR spectroscopy

A series of new 2,2′-bipyridine/1,2-dithiolate transition metal complexes has been synthesised and characterised. As 1,2-dithiolate ligands 1,2-dithiooxalate (dto) and 1,2-dithiosquarate (dtsq) were used. It follows from the IR spectra that the multidentate dithiolate ligands coordinate exclusively via their sulfur atoms forming anMN2S2 coordination sphere. The central metal ions (M) are Cu2+, Ni2+, Pd 2+, Pt2+, and Zn2+. The complex Cu II(bpy)(dto)) could be studied by EPR spectroscopy and was measured as powder, diamagnetically diluted in the isostructural NiII(bpy) (dto)) host structure. The spin density contribution calculated from the experimental parameters is compared with the electronic situation in the frontier orbitals, namely in the semi-occupied SOMO of the copper complex, derived from quantum chemical calculations on different levels (EHT and DFT).

Oxidative C-H and C-C bond cleavage by a (2,2′-bipyridine)copper(I) chloride complex

Acetonitrile is easily oxygenated at ambient reaction conditions to copper(II) oxalate [Cu(bpy)(ox)]n mediated by copper(I) chloride in the presence of 3,5-di-tert-butylcatechol and 2,2′-bipyridine. In the case of other nitriles (e.g., propionitrile), instead, the unusual and selective 1,4-extradiol cleavage of 3,5-di-tert-butylcatechol occurs to give copper(II) tert-butylmaleate [Cu(bma)(bpy)(H2O)]n in good yield.

5-Cyano-6-(4-pyridyl)-2-thiouracil as a building block in transition metal bipyridyl chemistry

Multifunctional ligand 5-cyano-6-(4-pyridyl)-2-thiouracil (LH2) has been prepared and used in the synthesis of polymeric complexes. The general compositions of the complexes (M bpyLH2 Cl2)n. [M=Cu(II) and Zn(II)] have been assigned on the basis of their elemental analysis and spectroscopic (IR, NMR, UV-visible and EPR) data. FAB mass data recorded upto 1000 range also support higher composition of the complexes. Powder X-ray diffraction, optical microscopic and scanning electron microscopic (SEM) studies have also been carried out. Force field calculations have been carried out to simulate the energy minimized structures of the dimeric unit of the complexes. The geometry around each Cu(II) centre has been found to be distorted octahedral whereas Zn(II) complexes possess octahedral geometry. Solid state conductance has also been measured at room temperature as well as at higher temperatures.

One- and two-electron oxidative pathways leading to cyclopropane-containing oxidized porphyrinogens and C-C-coupled porphyrinogens from alkali cation- and transition metal-meso-octaethylporphyrinogen complexes

This report deals with the different transition metal- and alkali cation-assisted oxidation pathways of the meso-octaethylporphyrinogen tetraanion [Et8N4]4-. The two-electron oxidation of [Et8N4Mn{Na(thf)2}2], 4, with Cp2FeBPh4 led to the corresponding monocyclopropane derivative [Et8N4(Δ)Mn], 6, [Δ ≡ cyclopropane], while the one-electron oxidation with CuCl2 or O2 led to the Mn(III)-porphyrinogen [Et8N4Mn][Li(thf)4], 5, which can be further oxidized by an excess of CuCl2 to [Et8N4(Δ)2Mn-Cl]+[Cu 9Cl11]0.5, 7. The formation of 7 does not follow the expected sequence Mn(II) → Mn(III) → Mn(II)-monocyclopropane → Mn(II)-biscyclopropane-porphyrinogen. In the case of iron(II)-porphyrinogen, [Et8N4Fe{Li(thf)2}2], 9, the oxidation led in a preliminary stage to the iron(III) derivative [Et8N4Fe][Li(thf)4], 10, then to the metalated form of the biscyclopropane-porphyrinogen [Et8N4(Δ)2Fe-Cl]{μ-Cu 4Cl5}], 11. The supposed stabilization of the biscyclopropane by the copper(I) cluster was ruled out by carrying the oxidation of [Cy4N4Fe{Li(thf)2}2], 11, to [Cy4N4(Δ)2Fe-Cl][Cu2Cl 4], 14. The stepwise oxidation of [Et8N4M(thf)4] [M = Li, 1; M = Na, 2] with Cp2-FeBPh4 led to [Et8N4(Δ)Li2thf2], 15, [Et8N4(Δ)Li]BPh4, 16, and [Et8N4(Δ)Na]BPh4, 17. The reaction of 1 with 16 leading to 15 showed how the C-C moiety in cyclopropane can be engaged in an intermolecular electron transfer. The reaction of 17 with 18-crown-6 allowed the release of biscyclopropane-porphyrinogen [Et8N4(Δ2)]. Particularly interesting is the thermal rearrangement of 15 to 19 occurring via intra- and intermolecular electron transfers with the transposition of the C-C bond of the cyclopropane to a C-C bridge across the β position of two adjacent pyrroles. In the case of metals, such as Ni(II), which do not undergo oxidation state changes, the primary oxidation product of a metalla-meso-octaalkylporphyrinogen is the monocyclopropane derivative, which reacting with the starting material masks an overall one-electron oxidation. In fact, the reaction of [Et8N4Ni{Li(thf)2}2], 20, with 2 equiv of Cp2FeBPh4 led to the expected [Et8N4(Δ)Ni], 21, while the reaction of 20 with 1 equiv of Cp2FeBPh4 led to the dimer [(β-β)(Et8N4)2Ni2], 22, which forms equally well from the reaction of 20 and 21. Complex 22 is a quite unique metallaporphyrinogen dimer, where the two monomeric units are joined via a C-C bond in the β position of a pyrrole. Such a reaction shows that the methodology can accede to oligomeric forms of metallaporphyrinogens.