Complexes of Biacetyldihydrazone and Pyridinalhydrazones with Iron(II), Cobalt(II) and Nickel(II)

One‐Dimensional Inorganic Complexes

“…Metal-metal interactions may be possible in the solid statestructures of M(CO)z(GL)(M = Rh, Ir) where G L represents a monoanionic bidentate ligand of substituted acetylacetonates (24,54,56,57,270), /I-ketoiminates (55), topolones (3,24), imidazoles (408a), formazanes (408a), 8-hydroxyquinolines, (218,255,402), and Schiff bases (402, 408a) as well as other ligands containing the N and 0 donor atoms (3,41,441,442,443,512). Numerous additional square planar complexes withN4 (59,63,145,184,188,300,356,369,386,447) 02S2 (22a), or N2Sz (149,191,256,266,383) donor atoms have been prepared but have yet to be fully characterized. UnIess there is evidence for unusual metalmetal interactions and partial oxidation, low conductivity is anticipated.…”

Copper-assisted oxidative coupling of primary alcohol and hydrazone: A novel function model of galactose oxidase

“…The coupling reaction is unprecedented and applicable for universal modular synthesis of 1,1-bis-(hydrazonyl)alkane (BHA) from ketone, hydrazine and alcohol using Cu II as template and catalyst. The oxidation coupling is quite comparable with the ligand behaviour of phenyl 2-pyridyl ketone azine and dipyridyl ketone azine towards Cu II ions, in which the reaction induced by copper(II) salts easily resulted in a complex containing [1][2][3] [11]. Herein is described three structures of the Cu II complexes and possible mechanism for the coupling reaction.…”

“…Therefore on basis of the observations, conclusions can be drawn tentatively that a suggested precursor of 1-3 may play the catalyst for alcohol oxidation and the metal ions in transition state is square pyramidally coordinated. Associated with the consensus mechanism of GOase, a probable transition state was proposed (Scheme 1), where O 2 in air oxidizes the -NH 2 group of hydrazone to form the -NH * radical same to the ring-closure of hydrazone [11]. The H-loss of hydrazone unit is probably favored by the basic medium produced by the excessive hydrazine in our system.…”

“…Besides, when we used CH 3 CN replacing MeOH as solvent, a [1][2][3] triazole-type ligand complex was obtained. Previous results about the formation of triazole revealed that O 2 in air was the oxidant for the ring-closure of hydrazone ligand and Cu II may act as the crucial catalyst [11]. The only difference for two cases is the solvent-selecting, thus we assume two cases have some essential connection in their transition states.…”

Cu(II)-assisted oxidation of quinoline-2-carbaldehyde hydrazone to give [1,2,3]triazolo[1,5-α]quinoline: The first example of Cu(I) complex containing [1,2,3]triazolo-ligand

“…The role of the Cu(II) ion is considered to be very important. Many compounds of 2-formyl-, 2-acetyl-and 2-benzoylpyridine hydrazones (Fe II , Ni II , Co II , Zn II ) with different metal to ligand ratios have been characterized, but the ring-closure reaction of hydrazone was not found [15].…”