Phosphorus and arsenic ligands

Phosphorus and arsenic ligands. Five-co-ordinate complexes [Ir(PPh3)(L L3)] of the tripod-like ligand (49 L, = P. As) have been obtained by refluxing 

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Polar, aprotic solvents such as DMF were necessary for the formation of (126). [Pd(diphos)2] (104) gave the best performance as catalyst. Using [Pd(DBA)2] (105) as palladium source, a number of mono- and bi-dentate nitrogen, phosphorus and arsenic ligands were investigated and Me2PCH2CH2PMe2 was found to be nearly as effective as diphos. The reaction of C02 with a bis(i73-allyl) complex of palladium was believed to be a key step in the process (equation 158). 

Phase-transfer catalysis can effectively promote the substitution of group 6 metal carbonyls by nitrogen, phosphorus, and arsenic ligands. Reaction of M(CO) [M = Cr, Mo, W] with a group 5 ligand and tetra-n-butylammonium iodide in benzene-sodium hydroxide (50%), at 25-80°C... 

The anionic complexes containing phosphorus and arsenic ligands are shown in Table 61. It will be noted that there are no anionic complexes containing antimony ligands. 

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