Comparative Studies on the Electronic Structures of W2(O2CH)4 and W2(O2CH)4-(CH3)2 by the Relativistic X Alpha-SW Method: A d3-d3 Metal Dimer with a Quadruple Metal-Metal Bond?
Abstract
The bonding in W2(O2CR)4 and in the recently characterized W2(O2CR)4R'2 molecules are compared via Xalpha-SW calculations with quasi-relativistic corrections on the model system W2(O2CH)4 (I) and W2(O2CH)4(CH3)2 (II). Several questions concerning the electronic structure of II have been addressed; in particular, the apparently strong W-W bond in the presence of strong W-C bonds was of interest. It has been found that II is best considered as a W2(O2CH)4 fragment interacting with two CH3 radicals, a description consistent with the photochemical decomposition of W2(O2CEt)4(CH2Ph)2. The resulting W-W bond still remains the essential components of the quadruple bond in I. The W-W bonding remains strong in spite of strong axial ligation because of involvement of a higher-lying s-s sigma bonding orbital, an orbital whose contribution is more important in II than in I. It is the presence of this orbital, which is lower-lying for third-row metals than for first, which is believed to account for the structural difference between CR2(O2CR)4L2 and the W2(O2CR)4R2 systems.
Document Details
- Document Type
- Technical Report
- Publication Date
- Nov 29, 1984
- Accession Number
- ADA148814
Entities
People
- B. E. Bursten
- D. L. Clark
- M. D. Braydich
- M. H. Chisholm
Organizations
- Indiana University