Bidentate group vb ligands. Part XIII. Divalent cobalt, nickel, and palladium complexes of 1,2-bis(methylphenylarsino)ethane and 1,3-bis(methylphenylarsino)propane. Stoichiometric and structural effects of chelate chain length
✍ Scribed by W. Levason; C.A. McAuliffe; S.G. Murray
- Publisher
- Elsevier Science
- Year
- 1977
- Tongue
- English
- Weight
- 690 KB
- Volume
- 24
- Category
- Article
- ISSN
- 0020-1693
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✦ Synopsis
i'hirtyfour complexes of 1,2-bis(methylphenylarsino)ethane (dase) and I ,3-bis(methylphenybsrsino)propane (dasp) have been characterised. Interesting differences are observed in the complexing properties of these chelates. Thus, with cobalt(II) halides [Co-(dase)z] [CoX4], which contain planar cations, and pseudotetrahedral [Co(dasp)Xz] are obtained. Nickel (II) halides form planar [NiLX,] complexes with dase, but with dasp form [Ni(dasp)X,] ,, (X = Cl, Br) which are pseudooctahedral in the solid state and planar in solution, and the pseudotetrahedral [Ni-(dasp)IJ . The [Ni(dasp)za C104 are trigonal bipyramidal in the solid state (X = Cl, Br, I, NCS), but in solution [Ni(dasp),(NCS)] l appears to be square pyramidal, whilst the [Ni(dase)J C104 are square pyramidal in both the solid state and solution. The planar [Ni(dasp)(NCS),] complex differs from the analogous dase species by losing ligand on recrystallisation to form the dimeric Niz(dasp)B-(NCS), moiety. Planar [PdLX,] (L = dase, dasp, X = Cl, Br, I) species are formed, but no [PdLJj ' complexes could be isolated. In the solid state [PdL-(WS)(SCN)] complexes are formed, and the dase species isomerises to [Pd(dase)(SCN)J in dichloromethane. An attempt is made to relate the structural differences in the complexes to the chain length of the chelates.