Synthesis of new multidentate ligands. Carbonyl addition reactions of di-2-pyridyl ketone

Abstract

Ethyienedlamlne and 1,3-dlamlnopropane add slowly to the carbonyl group of di-2-pyridyl ketone (dpk) to form the compounds (py)2C(OH)NHCH2CH2NHC(OH)(py)2 and (py)2C(OH)NHCH2CH2CH2NHC(OH)(py)2, respectively (py = 2-pyrldyl). Under reflux conditions In benzene, using boron trlfluortde etherate as a catalyst, dpk adds to ethyienedlamlne, 1,3-dlamlnopropane, and 1,2-diamlnopropane (with loss of H20) to form the Schlff bases (py)2C=NCH2CH2N=C(py)2, (py)2C=NCH2CH2CH2N=C(py)2, and (py)2C=NCH2CH(CH3)N=C(py)2, respectively. These new multidentate ligands were characterized by elemental analysis and Infrared, NMR, and thermogravlmetric techniques.

Exploring synthetic pathways to cationic heteroleptic cyclometalated iridium complexes derived from dipyridylketone

“…This observation gives hints for understanding why IrL1 is reluctant to react with amines. The corresponding free ligands have been shown to be slightly unstable too, 39 and the coordination to the metal very probably enhances this instability. These negative results are in agreement with similar works that include a class of chelating ligands containing two 2-pyridyl substituents spaced by a single atom.…”