Synthesis and NMR structural studies of allyl(polypyrazolylborate)palladium and platinum complexes

✍ Scribed by Kenzo Ohkita; Hideo Kurosawa; Takeya Hasegawa; Tomohide Shirafuji; Isao Ikeda

• Book ID: 104138770
• Publisher: Elsevier Science
• Year: 1992
• Tongue: English
• Weight: 708 KB
• Volume: 198-200
• Category: Article
• ISSN: 0020-1693
• DOI: 10.1016/s0020-1693(00)92370-3

✦ Synopsis

Mono-and binuclear palladium and platinum complexes containing the tetrakis(pyrazolyl)borate ligand were prepared. The solution structure and dynamic properties of these complexes were investigated with NMR techniques. In the mononuclear triphenylphosphine platinum complexes, PtX(PPh,)(BPz,), the activation energy for inversion of the boat-like B(N-N),Pt ring decreased in the order, X=1> Cl> Br> $-methallyl, as a result of the combined effects exerted by the electronic and steric requirements. Complexes M($-methallyl)(BPz,) (M=Pd, Pt) accepted metal ions (Ag+, [(T3-methallyl)M]+) to give the binuclear complexes. 1D and 2D NOE spectra of the complex [(~3-methallyl)Pt(BPz.,)Pt( )9-methallyl)]BF4

suggested the occurrence of a fast intramolecular interconversion between some conformational isomers arising from the Pt(N-N)2B ring inversion. of Pt(I1) derived from ~3-allylplatinum complexes. For comparison analogous allylic palladium complexes of polypyrazolylborates were also studied.

Results and discussion

Synthesis of complexes