Extractants bidentate oxygen-donor

Bidentate oxygen-donor extractants include the neutral diamide compounds, such as the malonamides used in the French DIAMEX and DIAMEX-SANEX processes, RR N(C=0)-CHR"-(C=0)NRR the bisphosphine oxides, RR (P=0)- CIIR"-(P=0) RR the carbamoyl-(methyl)-phosphinates, R0R 0(P=0)-(CI I On o 0rr(C=0)NRR or the more efficient carbamoyl-methyl-phosphine oxides, RR (P=0)-CHR"-(C=0)... 

Many of the early reports of complexes with bidentate oxygen ligands involved acac complexes and the /3-diketonate and related ligands were discussed in CCC (1987).210 The /3-diketonate complexes of scandium and yttrium and the lanthanides were also discussed in CCC (1987).1 Many reported systems contained adducts formed by the metal /3-diketonate complexes. In solution some of the complexes with bidentate ligands can expand their coordination number to seven by coordination to a suitable donor ligand. A solvent extraction method has been used to show that Sc(acac)3 does not form an adduct with trioctylphosphine oxide but tris(tropolonato)scandium(III) and tris-(ethylmatolato)scandium(III) do coordinate with trioctylphosphine oxide.211... 

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