O- or S-Donor Ligands

TABLE 74. Selected bond lengths in all-trans [SnR2X2 D2] complexes (two monodentate O- or S-donor ligands)... 

Hydridocarbonyls and carbonyl complexes containing C, N, O or S donor ligands are covered in later sections of this review. 

Arsenic(III) has a considerable affinity for charged O- or S-donor ligands, the latter including dithioacid chelates, but complexes with neutral O, S, or Se donor ligands are much rarer. Here complexes of neutral ligands are discussed first and then complexes with charged anions. 

These monomeric [RuCljLn] complexes (particularly L = PPhj) are very useful precursors for the synthesis of a wide range of Ru" compounds of type [RuCl2Y4, L,j] (x = 1-3 Y = C, N, O or S donor ligands). Complete displacement of the chloride groups with other anionic ligands is also... 

Collectively the available structural and spectroscopic data on the Fe/Mo/S aggregate indicate an asymmetric arrangement of the Fe atoms relative to the Mo, in a cluster that may contain as structural features the FeS2Mo rhombic units. The Fe EXAFS data further suggest that about half of the iron atoms are at close proximity to the Mo atom (at 2.76 A) and terminal ligation to the Fe atoms may involve O or N donor ligands. 

Complexes containing Schiff base chelating ligands have been extensively studied.137-144 Here the ligands include bidentate, tridentate and tetradentate representatives where O or S donors supplement the imine nitrogen. Examples are listed in Tables 2 and 3. Sample ligands include (2), (3) and (4). 

A number of mixed crown ligands have been synthesized combining N, O, or S ligands. The larger, more flexible, ligand systems can show interesting coordination patterns as the zinc binds to its preferred donor set. 

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