Donor atom sets ligands

A series of mixed-ligand thiosalicylato complexes of the type PtL(PPh3)Y2] (Y2 = thiosalicylate L = pyridine, 4-methylpyridine, picolinic acid hydrazide, imidazole) have been prepared by the reaction of [PtCl2(COD)] with PPh3, thiosalicylic acid, and A-donor ligand in MeOH solution.375 The X-ray structure of the pyridine derivative (162) was determined, the first example of where a platinum atom is coordinated to a N, O, P, and S donor atom set. 

Bidentate Schiff bases have been among those most used in preparing metal complexes. In the following subsections we shall describe the potentially bidentate ligands according to their donor atom set. 

The number of tridentate ligands meeting the identification criteria is small. These ligands exhibit S3, S2N, or S2C donor atom sets and are summarized in Scheme 1. 

The ligands with S2C donor atom sets have been found only in complexes and cannot be isolated in the free state. Sodium amalgam reduction of mononuclear [Ni(S4C3Me2)J leads to removal of benzenedithiolate and formation of trinuclear [Ni(p-S2C3Me2)]3 (Eq. 1) (10). The trinuclear complex shows cleavage and insertion reactions of interest as CO dehydrogenase model reactions (see below). Tetrahydrofurane = THF. 

Other tetradentate SB ligands having either N2P2 or N3P donor atom set containing both hard and soft donors and their complexes with some soft metals have been investigated.116 117... 

Mononuclear iron(II) complexes supported by aminopyridine ligands (TPA and its derivatives) self-assemble into bis-hydroxo-bridged diamond core-like structures under basic conditions. The donor atom sets in these diiron complexes are similar to the coordination environment created by dinucleating ligands such as HPTB. The differences in observed oxygenation rates, detailed below, can be attributed to significant steric hindrance about coordinatively saturated iron centers.73... 

Correia JDG, Domingos A, Santos I, Alberto R, Ortner K (2001) Re tricarbonyl complexes with ligands containing P,N,N and P,N,0 donor atom sets synthesis and structirral characterization. Inorg Chem 40 5147-5151... 

Schiff Bases as Acyclic Polydentate Ligands Table 8 Typical Tridentate Schiff Bases with Different Donor Atom Sets... 

Donor atoms set Stability of metal-ligand bonds Electron configuration of the metal LabUizing effect on other ligands Coordination mode Denticity... 

---