Four novel polypyridine cobalt(II) complexes were developed based on a hexadentate ligand scaffold bearing either electron-withdrawing (−CF3) or electron-donating (−OCH3) groups in different positions of the ligand. Experiments and theoretical calculations combined to perform systematic investigation effect modification hydrogen evolution reaction. The results indicated that position, rather th...

A family of ditopic hexadentate ligands based on the parent compound 2,6-bis(6-(pyrazol-1-yl)pyridin-2-yl)-1,5-dihydrobenzo[1,2-d:4,5-d’]diimidazole (L) was developed and synthesized by using a straightforward condensation reaction, which forms interlinking central benzo[1,2-d:4,5-d’]diimidazole bridge in ligand backbone. The two secondary amine groups benzodiimidazole unit tautomerize allow fo...

Zn(2+)-induced fluorescence enhancement of the TPEN (N,N,N',N'-tetrakis(2-pyridylmethyl)ethylenediamine)-based ligand, N,N-bis(1-isoquinolylmethyl)-N',N'-bis(pyridylmethyl)ethylenediamine (N,N-1-isoBQBPEN, 1b), has been investigated. Upon Zn(2+) binding, 1b shows a fluorescence increase (ϕZn = 0.028) at 353 and 475 nm. The fluorescence enhancement at longer wavelengths is due to intramolecular ...

The limitations of current therapies for the treatment of iron overload or radioisotope contamination have stimulated efforts to develop new orally bioavailable iron and actinide chelators. Siderophore-inspired tetradentate, hexadentate and octadentate terephthalamidate and hydroxypyridonate ligands were evaluated in vivo as selective and efficacious iron or actinide chelating agents, with seve...

A hexadentate Schiff base tripodal ligand is synthesized by the condensation of tris (2-aminoethyl) amine with 2-hydroxy-1-naphthaldehyde and characterized by various spectroscopic techniques like UV-VIS, IR, NMR, MASS, and elemental analysis. The solution studies by potentiometric and spectrophotometric methods are done at 25 ± 1°C, µ = 0.1 M KCl, to calculate the protonation constants of the ...

The reaction of Mn(OAc)2 x 4H2O with 2,6-dimethoxybenzoylsalicylhydrazide (H3dmbshz) leads to a dodecanuclear manganese metallamacrocycle [Mn12(dmbshz)12(EtOH)6], 1. The successive manganese centers are connected by the hydrazide N-N groups of the ligands in an alternating pentadentate binding mode, hexadentate binding mode. The alternation results in two alternating chelation modes around the ...

The complex of Ce(III), [ Ce (PHENSC) (H 0) ] (C10 ) , was synthesized using the PHENSC, a hexadentate ligand,2,9-diformyl-1,lO- Phenanthroline bis (semicarbazone), and characterized by X-ray diffraction. The cerium atom has an unusual coordination number of ten involving six donor atoms of the planar ligand in the equatorial plane and four oxygen atoms from four axial water molecules. The...

This paper reports the syntheses, crystal structures, magnetics and spectroscopic properties of high-spin (HS) salts formula [Mn(salk-N-1,5,8,12)]Y·S (Y = AsF6 for 1, Y BF4, S CH3OH 2, PF6, 3), where (salk-N-1,5,8,12)2− (2,2ʹ-((2E,14E)-3,7,10,14-tetraazahexadeca-2,14-diene-2,15-diyl)diphenolate) is a hexadentate Schiff-base ligand. Crystal structural analysis indicates that extensive hydrogen b...