Bidentates selenium-sulfur ligands

The number and variety of coordination complexes of palladium(II) with sulfur-containing bidentate or multidentate ligands is legion, and it is possible here only to summarize the different kinds of complexes formed and to guide the reader into the literature. Table 2 contains a selection of typical palladium(II) complexes of bi- or multi-dentate sulfur or selenium donor ligands, and comments on pertinent aspects of particular complexes. Chelate... 

A number of compounds of the p-block elements containing two bidentate ligands can be considered to be five-coordinate and trigonal bipyramidal if a non-bonding pair of electrons occupies one of the equatorial sites, for example [Sn(S2CNR2)2(lone pair)] and [Pb(RCOCH-COR)2(lone pair)].4 The greater repulsion observed from this line pair implies R(lone pair/bidentate) values of 0.6 for sulfur(IV) compounds, decreasing to 0.4 for selenium(IV) and 0.2 for tellurium(IV), antimony(III), tin(II) and lead(II).4... 

Some complexes which satisfy this definition are dealt with elsewhere, however. Those with X or Y as the Group V donors P, As or Sb are dealt with in Chapter 14 of this volume. Those with X or Y = Hg are described in Chapter 11 and the Group IV donors Si, Ge, Sn and Pb are included in Chapter 12.2, With very few exceptions this means that the relevant X,Y combinations are pairs derived from nitrogen, oxygen, sulfur or selenium donor groups. However, some specific examples of these combinations also occur elsewhere in this work. Amino acids (generally N—O bidentates) are covered in Chapter 20.2, Schiff base ligands (N—O or N—S) in Chapter 20.1, and several S—O... 

Complexes of Anionic Bidentate Sulfur, Selenium, or Tellurium Ligands... 

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