A recent paper305 describes “an interesting dichotomy concerning the ligating properties of NS and NO” in (η306-C5H5)Cr(CO)2NO and -NS complexes. The authors point out that “on the one hand, IR and electron-impact data suggest that NS is a better remover of electron density from the chromium atom than is NO. On the other hand, NMR and ionization potential measurements imply that it is a better provider of electrons to the metal center. A similar contradiction in experimental observations has been reported for the related complexes (η5-C5H5)Mn(CO)2CS and (η5-C5H5)Mn-(CO)3,” From our previous results of valence photoelectron and parameter-free molecular orbital studies of thiocarbonyl complexes, we have shown that the NMR and ionization potential shifts from the carbonyl to the thiocarbo'nyl complexes are not inconsistent with a decrease of electron density at the metal center.307 The important feature is a more strongly interacting x-bonding orbital (bonding between carbon and sulfur) of the CS ligand.
ASJC Scopus subject areas
- Physical and Theoretical Chemistry
- Inorganic Chemistry