Fluorescent bis-chelated-1,10-phenanthroline-azido-copper(II) complex for selective sensing of aniline

Regulation of π⋯π stacking interactions between triimidazole luminophores and comprehensive emission quenching by coordination to Cu(ii)

Pioneering work demonstrating coordination preferences towards Cu(ii) of unexplored cyclic triimidazole-based luminophores and their favorable stacking patterns in coordination compounds.

(Tetrahydrodibenzo[a,i]phenanthridin-5-yl)phenol as a Fluorescent Probe for the Detection of Aniline

Two (tetrahydrodibenzo[a,i]phenanthridin-5-yl)phenols that differ in their substituents at the para position (P1, R = H and P2, R = NEt₂) were designed and synthesized. The presence of a -NEt₂ group in probe P2 facilitates the twisted intramolecular charge transfer (TICT) process, making P2 emissive, which distinctly coordinated with boron trifluoride in the presence of different amines with different electronic properties. A substantial increase in emission intensity with increasing viscosity of the surrounding environment and smooth formation of a planar complex with boron and Zn²⁺ ions concluded the presence of a TICT process. The selective reactivity of P2 toward a tetracoordinated boron complex has been explored as a potential tool for colorimetric and fluorescent discrimination of aromatic primary amines, i.e., anilines. Selective detection of aniline with probe P2 can be viewed through the naked eye, and the corresponding fluorescence turn-on detection limit was found to be 12.65 nM. In addition, the detection of aniline on precoated aluminum-backed thin-layer chromatography plates and Whatman filter paper strips was found to be in good agreement with the color change of P2 in solution and in vapor phase.

Synthesis and crystal structure of [azido-bis(cis-1,2-diaminocyclohexane)copper(II)] chloride trihydrate

A new copper(II) complex containing cis-1,2-diaminocyclohexane (Dach) and azide as ligands, [Cu(Dach)2(N3)]Cl · 3H2O (1), was prepared and characterized by IR spectroscopy, thermal analysis and X-ray crystallography. The structure of 1 consists of a complex cation, [Cu(Dach)2(N3)]+, a chloride counter-ion and three water molecules. The coordination environment of the copper(II) atom in 1 is distorted square pyramidal attained by four nitrogen atoms of cis-1,2-diaminocyclohexane molecules and an azide ion. Thermogravimetric and differential scanning calorimetric analyses validated the molecular formula of complex 1.

Structural characterization of two solvates of a luminescent copper(II) bis-(pyridine)-substituted benzimidazole complex

Copper(II) complexes of benzimidazole are known to exhibit biological activity that makes them of inter-est for chemotherapeutic and other pharmaceutical uses. The complex bis-(acetato-κO){5,6-dimethyl-2-(pyridin-2-yl)-1-[(pyridin-2-yl)meth-yl]-1H-benzimidazole-κ2N2,N3}copper(II), has been prepared. The absorption spectrum has features attributed to intra-ligand and ligand-field transitions and the complex exhibits ligand-centered room-temperature luminescence in solution. The aceto-nitrile monosolvate, [Cu(C2H3O2)2(C20H18N4)]·C2H3N (1), and the ethanol hemisolvate, [Cu(C2H3O2)2(C20H18N4)]·0.5C2H6O (2), have been structurally characterized. Compound 2 has two copper(II) complexes in the asymmetric unit. In both 1 and 2, distorted square-planar N2O2 coordination geometries are observed and the Cu-N(Im) bond distance is slightly shorter than the Cu-N(py) bond distance. Inter-molecular π-π inter-actions are found in 1 and 2. A weak C-H⋯π inter-action is observed in 1.

Synthesis, crystal structure, DFT/TDDFT calculation, photophysical properties and DNA binding studies of morpholino moiety ligand based two Cu(ii) complexes in combination with carboxylates

Two Cu(II) compounds have been characterized by structure analyses and DFT/TD-DFT calculations. Both the complexes potentially bind with CT-DNA and corresponding binding constants are in the order of 10⁵ M⁻¹.

Synthesis, characterization, TDDFT calculation and biological activity of tetradentate ligand based square pyramidal Cu(ii) complexes

Fluorescent Cu(ii) compounds have been synthesized, and characterized by structure analyses and DFT/TD-DFT calculations. Compounds show catecholase and anticancer activities.

Targeted water soluble copper–tetrazolate complexes: interactions with biomolecules and catecholase like activities

Two new copper–tetrazolate complexes are synthesized and their interaction with DNA, bovine serum albumin (BSA) and catecholase like activity are explored. Interactions of the complexes with DNA are also investigated using DFT.