Coordination chemistry oxygen donor

The generally high oxophilicity of the alkali and alkaline-earth elements gives oxygen donor ligands a prominent place in 5-block coordination chemistry. Oxygen donor ligands, of which... 

Structural aspects and coordination chemistry of metal porphyrin complexes with emphasis on axial ligand binding to carbon donors and mono- and di-atomic nitrogen and oxygen donors. P. D. Smith, B. R. James and D. H. Dolphin, Coord. Chem. Rev., 1981,39, 31-75 (170). 

General aspects of the coordination chemistry of the lanthanides with reference to the complexes of neutral oxygen donor ligands are dealt with in this section. For con venience, this section is subdivided into three parts 1. synthetic procedures, 2. stoichiometry, and 3. coordination numbers and coordination polyhedra. 

As hard metal centers, lanthanide(III) ions have a general preference for hard donor atoms (33,34). Much of their early coordination chemistry involved anionic oxygen donors and it is well established that carboxylates and (3-diketonates are very good at coordinating lanthanide ions. 

Due to the presence of hard anionic oxygen atoms, phenolate and carboxylate groups are often employed as donors in lanthanide coordination chemistry. Ligand [L18]4- is reported as an excellent triplet sensitizer for lanthanide luminescence (61). Indeed aqueous lifetimes of 0.57 and 1.61 ms are reported for europium and terbium, respectively quantum yields of 0.20 and 0.95 respectively refer to the efficiency of the energy transfer process alone. 

Cationic complexes of Tl3+ with oxygen donors are known, and can be regarded as substitution products of [T1(C)H2)6]3+ (c/. Section 25.2.8.3.1). The DMSO product has been characterized with various anions,403 and there seems no reason to suppose that similar compounds cannot be prepared with donor ligands which are resistant to oxidation. The cation [Tl(pyNO)8]3+ (prepared as the perchlorate) may be an indication that eight-coordinate compounds are also accessible in thallium(III) chemistry.404... 

N Si coordination (76, 7776 78a77 ) and most recently also with oxygen (78b,78 7 979), sulfur (78c),78 and phosphorus (78d)78 donor-ligands. The present section describes the chemistry of donor-stabilized silyl cations with hydrazido chelates. 

Nitrogen is, after oxygen, the most frequently encountered donor atom in the coordination chemistry of osmium. There is a large and growing body of work on the ammine, pyridine, ethylenediamine and porphyrin complexes, but the most popular and rapidly growing field of study at the present time is that of the polypyridyls , the 2,2 -bipyridyl, 1,10-phenanthroline and 2,2,2,6 - terpyridyl complexes of the metal. 

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