Nitrogen and Oxygen Donor Ligands

Two five-coordinate Mn =0 complexes with N2O2 tetradentate ligands Ph4P[MnOL] (L= 1,2-bis(2-methyl-2-oxypropanamido)benzene and 1,2-bis(2,2-diphenyl-2-hydroxyethanamido)benzene) have been prepared and structurally characterized (12) and (13), respectively.These complexes and the 0x0 complexes discussed in the next section may have utility in oxo-transfer reactions to organic substrates such as olefins and ethers. 

---

Silver(II) complexes in the gas phase have been prepared with several nitrogen- and oxygen-donor ligands including pyridine, tetrahydrofurane, benzene, C02, etc. The complexes are of the type [AgLra]2+, and the compound [Ag(C02)4]2+ is particularly stable.216... 

Tetrahedral and octahedral complexes of zinc, cadmium, and mercury with a wide variety of nitrogen and oxygen donor ligands have been reported. Metal complexes... 

An interesting part of chemistry comprises the divalent complexes of the Group 14 elements, germanium, tin and lead, supported by tetradentate nitrogen and oxygen donor ligands. The [Salen ] ligand system, obtained by condensation of a salicylaldehyde... 

Mercury is the only group 12 member to have a substantial chemistry in the -1-1 oxidation state, in which Hg2 +, the most common of all metal polycations, is formed. This ion was the first one known to exhibit metal-metal bonding. Its chloride salt is the material present in the standard calomel reference electrode. In addition to halides and oxy salts, nitrogen and oxygen-donor ligand complexes of mercury(I) are known, but far fewer than of mercury(II). 

Oxidative carbonylation of amines to carbamates and ureas in the presence of cobalt complexes was recently reported (24-25), We have found that Co(II) complexes bearing nitrogen and oxygen-donor ligands such as carboxylates, acetylacetonates and Schiff bases produce DMC with high selectivity in methanol under CO and Oj. (Table VII) (26-27),... 

---