Sulfur donor groups

A number of metal ions in biological situations are bound essentially by sulfur donor groups (50), and thus chelates of type l,3-bis-(o-methylthiophenylthio)propane (S4) (31) have added interest. Apparently this ligand does not form monomeric complexes the only species isolated thus far are the dimeric [Pd2(s4)X4] (X = Cl, Br, I) and [Pt2(s4)X4] (X = Cl, I), and the trimeric Rhg(s4)2Cl9. 

Y is a strongly pi electron donor group. As previously noted in the results section, examples of Y from Table VI include centers of high pi electron charge density at carbon, sulfur, nitrogen, and oxygen. Also included in Table VI are examples of nucleophilic substitution transition states (cf. reactions 21 and 22) of the type... 

Iron-sulfur proteins. In an iroinsulfiir protein, the metal center is surrounded by a group of sulfur donor atoms in a tetrahedral environment. Box 14-2 describes the roles that iron-sulfur proteins play in nitrogenase, and Figure 20-30 shows the structures about the metal in three different types of iron-sulfur redox centers. One type (Figure 20-30a l contains a single iron atom bound to four cysteine ligands. The electron transfer reactions at these centers... 

Reports on the organozinc chemistry with heavier group 16 donor ligands for the reviewed period were limited to sulfur donors. As with the organozinc chemistry of anionic oxygen donors, three themes dominate this area of research, namely the use of organozinc compounds ... 

It should be pointed out that the treatment of phosphorus or sulfur donors bearing ferrocenyl groups with diiodine results in the formation of molecular charge-transfer adducts without simultaneous oxidation of the ferrocenyl groups (Durfey et al. 2000, Gridunova et al. 1982). At the same time, the reaction of 4-ferrocenyl-l,3-dithiolene-2-thione with diiodine leads to a charge-transfer complex in which the iron has been oxidized from Fe" to Fe ". This was confirmed by magnetic measurements and Moessbauer spectroscopy (Allen et al. 2003). 

X.X Acting on reduced flavodoxin as donor. 2. 8. X.X Transferring sulfur-containing groups. 

---