Diphosphine-diarsine chelates

With the latter, an excess of the phosphine had to be used to obtain the tetracoordinated derivatives, while hydrazine without any excess of ligand gave the tricoordinated derivatives 130). Chatt and co-workers (45, 47j 51) obtained the nickel(0), palladium(0), and platinum(0) derivatives with the chelating diphosphines, diarsines, and triphosphines by reduction with sodium tetrahydridoborate or naphthanelide. 

Independently, triangulo-Hg3 compounds with stabilizing chelating diphosphine and diarsine ligands have been prepared, 82-387 crystal-structure analyses have been solved (the Hg—Hg bonds, 280 pm, are longer than before), and careful multinuclear NMR spectra measured and analysed. 

Among chelating P- and As-donors, the diphosphines and diarsines with a general formula 600 are the most propagated. They interact (3.34) with metal salts forming metal-cyclic structures 601 (Sec. 2.2.4.3) ... 

L = PPha, AsPhs, and SbPha D = a, a -dipyridyl, 1,10-phenanthroline and chelating tertiary diphosphines and diarsines). 

The reverse reaction, deprotonation of a vanadium hydride complex to produce an anion, is known. Thus, V(CO)4L2H (L2 = a chelating diphosphine" or diarsine ligand) can be converted to [V(CO)4L2] with OH or NEts. (t -l,3,5-Me3C6H3)V(CO)3H can also be deprotonated with hydroxide ion . 

Complexes of the type [PtCl (MeO)2PO (MeO)2POH L], where L = PEtj or PPhj, can act as anionic ligands when treated with a base to remove the acidic proton. These anionic compounds chelate metal species as Cu(II), Co(II), U02, and Th(IV) through the phosphoryl oxygens furnishing mixed metal species of the type PtCl[(RO)2PO]2L M, where n = 2 for M = Co, Cu, UO2 n = 4 for M = Th [428]. Mixed metal species are also obtained by treatment of mononuclear precursor complexes [Pt (RO)2PO 2L-L], where L-L = diphosphine or diarsine with perchlorates of divalent metals [428]. 

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