Jf. Goellner et al., Structure and bonding of a site-isolated transition metal complex: Rhodiumdicarbonyl in highly dealuminated zeolite Y, J AM CHEM S, 122(33), 2000, pp. 8056-8066
The structure and bonding of rhodium dicarbonyl bonded to highly dealuminat
ed zeolite Y has been determined by the combined application of extended X-
ray absorption fine structure (EXAFS) and infrared spectroscopies and quant
um chemical calculations based on density functional theory. The EXAFS and
infrared spectra indicate the existence of nearly unique rhodium dicarbonyl
species bonded at structurally equivalent positions in the zeolite pores.
However, even this anchored structure, one of the simplest known, is not de
termined fully by the experimental results, and quantum chemical calculatio
ns were needed to eliminate the ambiguity. Taken together, the experimental
and theoretical results indicate Rh+(CO)(2) located at a four-ring of the
faujasite framework; the rhodium center is bonded to two oxygen centers of
the framework near an aluminum center with a Rh-O distance of 2.15-2.20 Ang
strom. The results show how spectroscopy and theory used in combination can
determine the structure and location of a metal complex anchored to a stru
cturally uniform support.