Manganese complexes arsenates

Although trialkyl- and triarylbismuthines are much weaker donors than the corresponding phosphoms, arsenic, and antimony compounds, they have nevertheless been employed to a considerable extent as ligands in transition metal complexes. The metals coordinated to the bismuth in these complexes include chromium (72—77), cobalt (78,79), iridium (80), iron (77,81,82), manganese (83,84), molybdenum (72,75—77,85—89), nickel (75,79,90,91), niobium (92), rhodium (93,94), silver (95—97), tungsten (72,75—77,87,89), uranium (98), and vanadium (99). The coordination compounds formed from tertiary bismuthines are less stable than those formed from tertiary phosphines, arsines, or stibines. 

Arsenic is most prone to form surface complexes by adsorption on metal (mostly iron and manganese) (oxy)(hydr)oxides, followed by clays and feldspars (Lin and Puls, 2003). As discussed in Chapters 3 and 7, iron (oxy)(hydr)oxides are groups of Fe(III) Fe(II) (hydrous) oxides, (hydrous) hydroxides, and (hydrous) oxyhydroxides. Individual compounds, such as ferrihydrite, often have highly variable and... 

Iron and manganese have a strong influence on the availability of trace metal pollutants through precipitation-dissolution reactions (Burdige, 1993 Cornell and Schwertmann, 1996). Trace metals form surface complexes or co-precipitate with Fe(III) and Mn(IV) oxides, and they are released upon Fe(III) and Mn(IV) reduction (Zachara et al., 2001). For example, processes that oxidize Fe(II) retain arsenic in sediments... 

Early work on the catalytic autoxidation of carboxythiols confirmed the effectiveness of manganese, iron, cobalt, copper, and arsenic, but the first major assault on the mechanism of the reaction was due to Michaelis and Barron [123,124]. The oxidation of cysteine at pH 7—8 was found to be zero order in cysteine and to involve metal—cysteine complexes as active intermediates. Several studies of metal—thiol complexes have been... 

Manganese(tl) complexes,, 3, 9-82 acctylacetonates, 48 acetylides, 14 alcohols, 37 alkoxides, 37 alkyl phosphines, 13 alkyls, 12 amides, 15, 16 amine oxides, 39 amines, 16 amino acids, 43, 62 sulfur containing, 70 ammines, 15 antimony ligands, 31-34 arsenates, 4,5, 46 arsenic ligands, 31-34 arsenic oxides, 39 aryls, 12, 14 azides, 22 binary alkyls, 13 bipyridyl, 24, 25 anions, 25... 

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