Cobalt complexes arsenic ligands

Cobalt(—I) complexes arsenic ligands, 769 bipyridyl, 691 cyanides, 646 phenanthroline, 691 phosphines bidentate, 728 monodentate, 718 multidentate, 738 tridentate, 738 phosphinites, 747 phosphites, 747 phosphonites, 747 terpyridyl, 691 Cobalt(O) Complexes arsenic ligands, 769 bipyridyl, 691 carbon disulfide, 646 cyanides, 646 phenanthroline, 691 phosphines, 718 bidentate, 728 multidentate, 738 tridentate, 738... 

The cobalt complex [ Cp Co(CO)2 /t- -AsJ on heating in xylene at 140°C loses carbon monoxide in two stages, 1 mol after 1 h, the other after 6 h. On losing CO, the cobalt adopts four arsenic ligands as shown in Scheme 11... 

Cobalt complexes, 635-882 ADP, 760 amides, 682 arsenates, 774 arsenic ligands, 767-775 ATP, 760 bipyridyl, 691 bis(dithiolates), 876 carboxylates, 790 cyanates, 679 cyanides reduction, 646 disulfides, 829... 

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. 

The ligands triphos or/ and np in presence of compounds of iron, cobalt, nickel, rhodium, iridium and palladium, by reaction with THF solutions of white phosphorus, P, or yellow arsenic, As, form mononuclear or dinuclear sandwich complexes containing the cyclo-triphosphorus or cyclo-triarsenic units which behave as 3n-electrons rings. 

Half-sandwich complexes of cobalt with intramolecular phosphorous coordination have been known for the cobalt atoms in oxidation state - -l and - -ll (see Sections 7.01.3.3 and 7.01.3.4). Butenschon has published a comprehensive review recently on cyclopentadienyl metal complexes bearing pendant phosphorous arsenic and sulphur ligands. Intramolecular coordination to the cobalt center via a substituted Cp ring also oecurred in a rare reaction which combined C-H and C-F activation at the same time, thus leading to the coupling between a pentafluorophenyl ring and a pentamethylcyclopentadienyl ring (see Scheme 10 above). 

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