FORCE CONSTANTS AND ELECTRONIC-STRUCTURE OF CARBONYL GROUPS - D6 CARBONYL HALIDES AND DIHALIDES

Using an approximate molecular orbital calculation to describe the electronic structure of the transition metal carbonyl complexes M(CO)6-Lx (M = Cr, Mn, Fe; L = Cl, Br, I; x = 1, 2), we have been able to correlate the carbonyl force constants with the calculated occupancies of the 5 and 2 orbitals on the carbonyl. These results indicate that, in addition to the degree of back-bonding to the 2 orbital, the degree of donation from the 5 orbital has an important effect on the carbonyl's force constant. The calculations also indicate that the direct donation of electron density from the halogen's orbital to the cis carbonyl's 2 orbital is the most important mechanism by which a change in the halogen effects a change in the carbonyl force constant. 1972, American Chemical Society. All rights reserved.

FORCE CONSTANTS AND ELECTRONIC-STRUCTURE OF CARBONYL GROUPS - D6 CARBONYL HALIDES AND DIHALIDES Academic Article