{1-[1-(2-Hy-droxy-phen-yl)ethyl-idene]-2-(pyridin-2-yl-κN)hydrazine-κ2N',O}{1-[1-(2-oxidophen-yl)ethyl-idene]-2-(pyridin-2-yl-κN)hydrazine-κ2N',O}nickelate(II) nitrate hemihydrate

Tetra-nuclear copper(II) complex of 2-hydroxy-N,N'-bis-[1-(2-hy-droxy-phen-yl)ethyl-idene]-propane-1,3-di-amine

The title mol-ecular structure, namely, (μ3-acetato)(μ2-acetato)-bis-(μ3-1,3-bis-{[1-(2-oxidophen-yl)ethyl-idene]amino}-propan-2-olato)tetra-copper(II) monohydrate, [Cu4(C19H19N2O3)2(CH3CO2)2]·H2O, corresponds to a non-symmetric tetra-nuclear copper complex. The complex exhibits one ligand mol-ecule that connects two copper CuII metal centres via its ethano-lato oxygen anion acting in a μ2-mode and one ligand mol-ecule that connects three copper CuII metal centres via its ethano-lato oxygen anion acting in a μ3-mode. One bridging acetate group acting in an η1:η1-μ2-mode connects two copper(II) ions while another bridging acetate group connects three copper(II) ions in an η1:-η2-μ3-mode. A chair-like Cu3O3 structure is generated in which the two CuO4N units are connected by one μ2-O ethano-late oxygen atom. These two units are connected respectively to the CuO3N unit via one μ3-O ethano-late oxygen atom and one μ2-O atom from an acetate group. The μ3-O atom also connects one of the CuO4N units and the CuO3N unit to another CuO3N unit, which is out of the chair-like structure. Each of the two penta-coordinated CuII cations has a distorted NO4 square-pyramidal environment. The geometry of each of the two CuNO3 units is best described as a slightly square-planar environment. A series of intra-molecular O-H⋯O hydrogen bonds is observed. In the crystal, the units are connected by inter-molecular C-H⋯O and O-H⋯O hydrogen bonds, thus forming sheets parallel to the ac plane.

A multi-colorimetric probe to discriminate between heavy metal cations and anions in DMSO-H2O with high selectivity for Cu2+ and CN-: study of logic functions and its application in real samples

A ditopic multi-colorimetric probe based on the phenylpridyl-thioic moiety (EN) was synthesized via a Schiff base reaction mechanism and characterized using ¹H NMR and UV-vis spectroscopy. The colorimetric analyses carried out revealed that EN was capable of discriminating between a number of heavy metal cations via coordination induced charge transfer, as well as between anions through hydrogen bonding induced charge transfer, in DMSO–H₂O (9 : 1). In particular, the ditopic probe could spectrally and colorimetrically recognize the most toxic heavy metal cations of Cd²⁺, Pb²⁺ and Hg²⁺, among others, in DMSO–H₂O. Additionally, EN was selective and sensitive to the presence of CN⁻, F⁻, AcO⁻ and H₂PO₄⁻ in the same solvent system as cations. The reversibility and reproducibility studies showed that EN exhibited complementary IMP/INH logic functions, based on colour and spectral switching (ON/OFF), modulated by F⁻/Al³⁺. The real time application of the probe was tested on food grade products to detect the presence of F⁻ in toothpastes and mouthwash dissolved in water, as well as cations in underground water (normally saline), which displayed substantial responses. Thus, EN displayed an excellent scope of response and can thus be developed for real time sensing kits, which could be used instantly in on-field analysis. Theoretical studies were conducted to complement the experimental work.

A ditopic multi-colorimetric probe based on the phenylpridyl-thioic moiety (EN) was synthesized via a Schiff base reaction mechanism and characterized using ¹H NMR and UV-vis spectroscopy.

Hexanuclear copper(II) complex of 2-hy-droxy-N,N'-bis-[1-(2-hy-droxy-phen-yl)ethyl-idene]propane-1,3-di-amine incorporating an open-cubane core

The title mol-ecular structure, namely, di-aqua-tris-(μ3-1,3-bis-{[1-(2-oxidophen-yl)ethyl-idene]amino}-propan-2-olato)-μ3-hydroxido-dinitrato-hexa-copper(II) ethanol tris-olvate, [Cu6(C19H19N2O3)3(NO3)2(OH)(H2O)2]·3C2H5OH, corres-ponds to a non-symmetric hexa-nuclear copper complex. The complex exhibits one core in which three CuII metal centres are mutually inter-connected, two by two, via three phenolato oxygen anions acting in a μ2-mode. These three copper cations are inter-connected in a μ3-mode by one hydroxyl group. An open-cube structure is generated in which each of the CuII cations of the three CuO4N units is connected by two μ2-O anions from phenolate groups and one μ3-O atom from a hy-droxy anion. Each of the three penta-coordinated CuII cations situated in the open-cube unit has a distorted NO4 square-pyramidal environment. Each of these three CuII centres is inter-connected with another CuII cation via one enolate O atom in μ2-mode, yielding one CuNO4 unit and two CuNO3 units. The penta-coordinated CuII atom has a distorted square-pyramidal environment while the two tetra-coordinated copper(II) cations are situated in a square-planar environment. A series of intra-molecular O-H⋯O hydrogen bonds are observed. In the crystal, the units are connected two by two by inter-molecular C-H⋯O and O-H⋯O hydrogen bonds, thus forming sheets parallel to the ac plane.