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Palladium and Platinum Units Grafted on the Periphery of Carbosilane Dendrimers
Author(s) -
Benito Mónica,
Rossell Oriol,
Seco Miquel,
Muller Guillermo,
Ordinas Juan I.,
FontBardia Mercè,
Solans Xavier
Publication year - 2002
Publication title -
european journal of inorganic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.667
H-Index - 136
eISSN - 1099-0682
pISSN - 1434-1948
DOI - 10.1002/1099-0682(200209)2002:9<2477::aid-ejic2477>3.0.co;2-u
Subject(s) - chemistry , palladium , dendrimer , platinum , catalysis , nuclear magnetic resonance spectroscopy , polymer chemistry , styrene , crystallography , stereochemistry , organic chemistry , copolymer , polymer
The reaction of a series of phosphanyl‐terminated carbosilane dendrimers with palladium and platinum complexes was carried out. The new metallodendrimers containing PdCl(η 3 ‐2‐MeC 3 H 4 ) and PtCl 2 or Pt(C≡CPh) 2 as peripheral groups were characterized by 1 H, 13 C, 29 Si, 31 P, and 195 Pt NMR spectroscopy, and, in some cases, by mass spectrometry. The PtCl 2 ‐containing species of the second‐generation carbosilane dendrimer displays only one of the two possible stereoisomers. By comparison with the 31 P NMR spectra of the model compounds cis ‐[PtCl 2 (PPh 2 CH 2 SiMe 3 ) 2 ] ( 4 ) and cis ‐[PtCl 2 {Me 2 Si(CH 2 PPh 2 ) 2 }] ( 5 ), it was deduced that the PtCl 2 units are bound on the surface of the dendrimer through two phosphorus atoms belonging to the same branch. The palladium dendrimers were tested as catalysts in the hydrovinylation of styrene, and their activity was compared with that of the model catalyst [PdCl(η 3 ‐2‐MeC 3 H 4 )(PPh 2 CH 2 SiMe 3 )]. The crystal structures of 4 , 5 , and [Pt(C≡CPh) 2 {Me 2 Si(CH 2 PPh 2 ) 2 }] ( 6 ) were solved by X‐ray diffraction analysis. (© Wiley‐VCH Verlag GmbH, 69451 Weinheim, Germany, 2002)