New redox-active layer create via epoxy-amine reaction - The base of genosensor for the detection of specific DNA and RNA sequences of avian influenza virus H5N1.

Complexes of copper and 1,10-phenanthroline have been utilized for organic transformations over the last 50 years. In many cases these systems are impacted by reaction conditions and perform best under an inert atmosphere. Here we explore the role the 1,10-phenanthroline ligand plays on the electronic structure and redox properties of copper coordination complexes, and what benefit related ligands may provide to enhance copper-based coupling reactions. Copper(II) triflate complexes bearing 1,10-phenanthroline (phen), ([Cu(phen)2(OTf)]OTf, 1) and oxidized derivatives of phen including [Cu(edhp)2](OTf)2 (2), [Cu(pdo)2](OTf)2 (3), [Cu(dafo)2](OTf)2 (4) were prepared and characterized. X-ray crystallographic data show these related ligands subtly impacted the coordination geometry of the copper(II) ion. Complexes 1-3 had only incremental changes to the redox properties of the copper ions, complex 4 showed a drastically different redox potential affording a remarkably air stable copper(I) complex. These complexes 1-4 were then used to catalyze the C-N bond forming cross coupling between imidazole and various boronic acid substrates, where the increased stability of the copper(I) species in complex 4 appears to better support these CEL cross couplings.

Tuning the Copper(II)/Copper(I) Redox Potential for More Robust Copper-Catalyzed C–N Bond Forming Reactions

A new copper(II) complex, [Cu(epoxy)(phen)(NO3)](NO3)·H2O (epoxy = 5,6-dihydro-5,6-epoxy-1,10-phenanthroline, phen = 1,10-phenanthroline), has been synthesized and characterized by elemental analysis, IR and UV–vis spectroscopy, and single crystal X-ray diffraction. The complex crystallized in a monoclinic system with space group P21/n, a = 13.3199(8) A, b = 11.2917(7) A, c = 16.0832(9) A, α = 90°, β = 107.827(4)°, and γ = 90°. The complex cation possesses a distorted octahedral geometry, with Jahn–Teller distortion occurring in the CuN4O2 core. The binding interaction with calf thymus DNA (CT–DNA) was investigated by UV–vis and fluorescence spectroscopy, cyclic voltammetry, and viscometry. The results support a partially intercalative binding mode. Efficient cleavage of plasmid DNA by the complex was observed by gel electrophoresis.

Synthesis and DNA studies of a copper(II) complex of 5,6-dihydro-5,6-epoxy-1,10-phenanthroline

Silver(I) complexes with 1,10-phenanthroline-based ligands: The influence of epoxide function on the complex structure and biological activity

A copper(II) complex with a Cu–S8 bond. Attenuated total reflectance, electron paramagnetic resonance, resonance Raman and atoms-in-molecule calculations

Homoleptic copper(II) and copper(I) complexes of 5,6-dihydro-5,6-epoxy-1,10-phenanthroline. Six-coordinate copper(I) in solution

[Cu(phen)2(CH3COO)](ClO4)·2H2O ( 1 ) and [Cu(bipy)2(CH3COO)](ClO4)·H2O ( 2 ) (phen = 1,10-phenanthroline, bipy = = 2,2′-bipyridine) were synthesized and characterized. The complexes were characterized by employing elemental analyses, infrared and UV–Vis spec­troscopy, room tempe­rature magnetic measurements and the crystal structures were elucidated using X-ray diffraction experiments. The redox properties of the complexes were also investigated. Both structures have a square pyramidal CuN4O chromophore, which exhibit significant distortions due to long Cu–O (2.217(3) A for 1 and 2.179(1) A for 2 ) and Cu–N (2.631(2) A for 1 and 2.714(1) A for 2 ) bonds. This distortion was further shown by the O–Cu–N bond angles (147.71(8)° for 1 and 153.40(5)° for 2 ). Elemental analyses further supported the structural details unveiled by the single crystal X-ray diffraction analysis. The infrared spectra show the acetate vibrational frequencies at 1587, 1428 and 1314 cm-1 for 1 , 1571, 1441 and 1319 cm-1 for 2, and the perchlorate bands at 1059 and 720 cm-1 for 1 and 1080 and 768 cm-1 for 2 . The broad d–d bands for the copper ion at 14.514 cm-1 for 1 and 14535 cm-1 for 2 support the adoption of square pyramid geometries. The magnetic moments for the two complexes were 1.83 m B for 1 and 1.72 m B for 2 . The peak-to-peak values of the two complexes show that the electrode reactions are quasi-reversible with Δ E p of 0.023 V for 1 and 0.025 V for 2 . In both structures, there are π–π intermolecular interactions in addition to hydrogen bonding between the units.

/pdf/synthesis-characterization-electrochemical-studies-and-x-ray-divrant8zj.pdf

F.A. Oluwafunmilayo Adekunle

Papers

Homoleptic copper(II) and copper(I) complexes of 5,6-dihydro-5,6-epoxy-1,10-phenanthroline. Six-coordinate copper(I) in solution

Synthesis, characterization, electrochemical studies and X-ray structures of mixed-ligand polypyridyl copper(II) complexes with the acetate