| dc.description.abstract | The method of synthesizing metal-carbonyl-dppm complexes [dppm = bis(diphenylphosphino)methane)
devised by Holah and Hughes has been extended to include palladium. Specifically, reductions of
palladium salts by NaBH4 in the presence of dppm and CO lead to any one
or more of five different palladium-dppm complexes. Two of these complexes, (see document) were identified spectroscopically and have been
previously prepared by other less convenient
routes.
Three new palladium complexes are also reported. The hexameric Pd 6 ( µ- dppm) 3 ( µ- C0) 6 , 3,
has been identified spectroscopically and crystallographically. The X-ray crystal structure of 3
shows that crystals of this complex lie in the space group Pna2 1 and are orthorhombic with unit
cell dimensions of a, 39.836(13)
A; b, 15.587(4) A; c, 12.1654 A. The other two unidentified complexes 4a and 5a were only partially
characterized spectroscopically. Two possible
structures, (see document) are proposed for 4a and
these proposals are based largely on spectroscopic and
analytical evidence. An X-ray quality crystal of 4a
has been obtained very recently. It has been found to
diffract satisfactorily and data are currently being
collected as of this report. The unidentified complex
5a was characterized only partially. Complex 5a is a
fluxional molecule at room temperature and is thought to
contain at least 3 Pd trimeric units. The
inter-relationships between 3, 4a and 5a are discussed. | |
