The stability of carbonyl complexes of the group 11 chlorides
ClMCO (M = Cu, Ag, Au) is investigated at the
ab initio level using relativistic and nonrelativistic
energy adjusted pseudopotentials for the metal atoms.
The
gold compound ClAuCO is relativistically stabilized resulting in an
increase of the ClAu−CO dissociation energy
of ca. 120 kJ/mol at the coupled cluster level (CCSD(T)).
This explains the unusual stability of this compound
compared to its lighter congeners observed by experimental methods.
Structural data and vibrational frequencies
are predicted. Our calculated results agree well with the few
measured molecular properties available. For example,
the calculated ClAu−CO dissociation energy of 182 kJ/mol is close to
Calderazzo's estimate of 200 kJ/mol. The
unusual blue shift of the CO stretching frequency measured in ClAuCO
compared to free CO is, however, not
due to the effects of relativity as might be expected. A MO
analysis shows that both metal-d and metal-p
contributions are important in metal−ligand bonding in contrast to
the interpretation given from Mössbauer data.
Electric field gradients are discussed which are very sensitive to
relativistic effects and to CO coordination on the
metal center.
ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.