Tridentate Chelate Compounds. I

Spectroscopic and biological activity studies on tridentate Schiff base ligands and their transition metal complexes

“…Schiff bases are an important class of ligands, such ligands and their metal complexes had a variety of applications including biological, clinical, analytical and industrial in addition to their important roles in catalysis and organic synthesis [2][3][4][5]. In early work closely related to the system of interest here, Lions and Martin [6] synthesized Schiff base ligands from 2,6-pyridinedicarboxaldehyde (PDC) with aniline and benzylamine and noted that the free ligands were crystalline materials. Therefore, studies ensued in which this same pair of Schiff base linkages was incorporated in many different kinds of polydentate ligands, including various macrocyclic ligands [7,8].…”

Cobalt(II)-mediated synthesis of 2,6-bis[5,7-di-tert-butyl-1,3-benzoxazol-2-yl]-pyridine: Structural analysis and coordination behavior

“…UV-Vis-NIR spectra (diffuse reflectance, 40,000-5000 cm À1 ) were obtained using a Cary 5000 (Varian) spectrophotometer. 1 The synthetic procedure was previously reported [21] and was followed with minor modifications, as described below: To a solution of 2,6-pyridinedicarboxaldehyde (560 mg, 4 mmol) in absolute ethanol (20 mL) was successively added 2-amino-4,6-di-tertbutylphenol (2.23 g, 8 mmol) [28], and the resulting mixture was refluxed for 6 h over molecular sieves (4 Å). 2,6-Pyridinedicarboxaldehyde was synthesized according the reported procedures [29].…”

“…The 2,6-bis(arylimino)pyridine family of Schiff base ligands are known for more than 60 years [1]. Since then, several studies related to the coordination properties of these versatile compounds have been fully described along with their chemical interaction with metal ions and their catalytic properties; some examples are given in Scheme 1 [2][3][4][5][6][7][8][9][10].…”

Iron(II) and cobalt(II) complexes bearing N-((pyridin-2-yl)methylene)-quinolin-8-amine derivatives: Synthesis and application to ethylene oligomerization

“…However, those compounds were not stable well for purification [11,13], one-pot template synthesis was employed in the synthesis of the Fe(II) and Co(II) complexes [14]. Closer to this work, their nickel analogues were synthesized using nickel template reaction [11].…”