New tetrapyrazolic macrocycle. Synthesis and cation binding properties

Pyrazolic tripods synthesis and cation binding properties

The synthesis of two new bipyrazolic tripods with different functionalised arms is described. The complexing properties of these compounds towards heavy metal ions (Hg2+, Cd2+, Pb2+) and alkaline metal ions (K+, Na+, Li+) were studied by a liquid–liquid extraction process and the extracted cation percentage was determined by atomic absorption measurements.

Synthesis, Characterisation and Crystal Structure of a New Bis-tripodal Ligand: N,N,N′,N′-tetrakis[(1,5-dimethylpyrazol-3-yl)methyl]-1,4-phenylenediamine

The synthesis of a new bis-tripodal ligand N,N,N′,N′-tetrakis[(1,5-dimethylpyrazol-3-yl)methyl]-1,4-phenylenediamine is reported and clearly established from its spectroscopic data (IR, 1H NMR, mass spectrometry) and elemental analysis. The X-ray structure of the target compound has been determined and the pyrazolyl ligand crystallises in the space group P-1 [C30H40N10; a = 7.1533(7)Å; b = 9.7541(10)Å; c = 10.7169(10)Å; α = 94.420(8)°; β = 97.920(8)°; γ = 108.088(9)°, Z = 2].

New functionalised C,C-bipyrazoles. Synthesis and cation binding properties

The synthesis of two new C,C-bipyrazoles ligands with a side-arm bearing a functionalised donor-group is reported. The complexation properties of these compounds towards bivalent metal ions (Hg2+, Cd2+, Pb2+, Cu2+, Zn2+) and alkaline metal ions (Li+, Na+, K+) was studied by a liquid–liquid extraction process and the extracted cation percentage was determined by atomic absorption measurements.

Organically modified silica with pyrazole-3-carbaldehyde as a new sorbent for solid-liquid extraction of heavy metals

A new chelating matrix, SiNP, has been prepared by immobilizing 1.5-dimethyl-1H-pyrazole-3-carbaldehyde on silica gel modified with 3-aminopropyl-trimethoxysilane. This new chelating material was well characterized by elemental analysis, FT-IR spectroscopy, cross polarization magic angle spinning solid state 13C-NMR, nitrogen adsorption-desorption isotherm, BET surface area, BJH pore size, and scanning electron microscopy (SEM). The new product exhibits good chemical and thermal stability as determined by thermogravimetry curves (TGA). The new prepared material was used as an adsorbent for the solid-phase extraction (SPE) of Pb(II), Cd(II), Cu(II) and Zn(II) from aqueous solutions using a batch method, prior to their determination by flame atomic adsorption spectrometry. The adsorption capacity was investigated using kinetics and pH effects. Common coexisting ions did not interfere with separation and determination.

Polysiloxane surface modified with bipyrazolic tripodal receptor for quantitative lead adsorption

A new silica gel compound modified N,N-bis(3,5-dimethylpyrazol-1-ylmethyl) amine (SiN(2)Pz) was synthesized and characterized by elemental analysis, FT-IR, (13)C NMR of the solid state, nitrogen adsorption-desorption isotherm, BET surface area and BJH pore sizes. The new surface exhibits good chemical and thermal stability determined by thermogravimetry curves (TGA). The effect of pH and stirring time on the adsorption of Pb(II) were studied. The process of metal retention was followed by batch method and the optimum pH value for the quantitative adsorption of this toxic metal ion was 7. At this pH value, the new functionalized polysiloxane presents further improvements and shows higher affinity (123mg of Pb(2+)/g of silica) for the effective adsorption of Pb(II) compared to others described sorbents. The extracted amounts of Pb(II) were determined by atomic absorption measurements.

New Functionalised C,C-pyridylpyrazoles: Synthesis and Cation Binding Properties

The synthesis of two new C,C-pyridylpyrazole isomers with a functionalised arm is described. The complexation capabilities of these ligands compared to their homologues towards bivalent metals (Hg2+, Cd2+, Pb2+, Cu2+, Zn2+) and alkali metal ions (K+, Na+, Li+) were investigated using a liquid–liquid extraction process. The percentage limits of extraction were determined by atomic absorption measurements.