Tetracyano Complexes Containing Oxo or Nitrido Ligands

Tetracyano Complexes Containing Oxo or Nitrido Ligands A. Synthesis 

The [M02(CN)4] complexes for Mo and W can be prepared photo-chemically (124, 142, 143, 145, 164) or thermally (155, 156). A very effective form of preparation specifically involves the photolysis of basic solutions of the [M(CN)a] complexes, which produces the corresponding dioxotetracyano-metalate(IV) complexes in 90% yield (143,164). In the absence of a high-intensity photochemical source, sunlight has been found to be more than adequate (165, 166). A disadvantage of this method is that it first involves the preparation of the octacyanomet-alates. Procedures for the effective preparation of these [M(CN)g] ions, involving the reduction of the [M04] ions by in the 

A series of procedures for the preparation of [Re02(CN)4] that involves cyanide ion substitution of more labile ligands such as py (171) and PPhs (172) from the Re(V) center has been described. A convenient procedure that, as in the case of the Mo(IV) and W(IV) systems described above, produces acceptable yields of dioxotetracya-norhenate(V) directly from the Re04 ion has been described (173). 

The process is again based on the H /BH4 reduction of Re04 , followed by careful temperature and pH manipulation. 

The preparation of [MN(CN)4(H20)], the nitrido complex of Re(V) (176,177), Tc(V) (178), and Os(IV) (179,180), is achieved by first introducing the nitrido ligand to the metal center by reflux with acidic sodium azide, with the formation of tetrahalometalate, [MNX4] (177-179). Ligation of the halide ions by cyanide ion produces the tetracyanonitridometalate complexes, which can be isolated with a selected cation (176,178,181,182), such as tetraphenylphosphonium, in yields greater than 80%. 

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Bicyclo(4.4.1 Jundecapentaene complexes with group VI B metals, 12 237 Bidentate ligands, reactions with tetracyano complexes containing oxo or nitrido ligands, 40 310-313 Bidentate oligopyridines, 30 72-73 Bidentate polysulfide complexes, bond lengths, 31 114... 

Monodentate ligands, reactions with tetracyano complexes containing oxo or nitrido ligands, 40 297-310... 

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