CARBON-CARBON BOND FORMATION BETWEEN 2 ALPHA-DIIMINES WITH THE SIMULTANEOUS FORMATION OF A METAL-METAL BOND - X-RAY STRUCTURE OF HEXACARBONYLBIS[MU-(1-(ISOPROPYLAMINO)-2-(ISOPROPYLIMINO)ETHANE-N,N')]-DIMOLYBDENUM

Reduction and subsequent oxidation of Mo(CO)4(DAB) (DAB = 1,4-diazabutadiene = α-diimine) yield complexes with the formula Mo2(CO)6(IAE) (IAE =μ -(l-(isopropylamino)-2-(isopropylimino)ethane-N,Ar)). Several methods were developed for the preparation of Mo2(CO)6(IAE) of which one involves a cyclic process with respect to Mn2(CO)10 and one a pseudocatalytic process with Hg2+ as catalyst. All methods have in common the oxidative elimination of CO from (Mo(CO)4(DAB))-, resulting in the generation of the coordinative unsaturated Mo(CO)3(DAB) intermediate for which a structure containing a σ,π-coordinated DAB ligand has been proposed. Dimerization of these 16-electron species yield the Mo2(CO)6(IAE) complexes. The x-ray crystal structure for the isopropyl derivative showed the formation of a carbon-carbon bond between two DAB ligands (l.6l (2) Å) and the formation of a short Mo-Mo single bond (2.813 (3) Å). The crystal was orthorhombic with space group P22,2l and cell constants a = 8.190 (1) Å,b = 10.099 (2) Å, c = 16.844 (2) Å, and Z = 2. © 1979, American Chemical Society. All rights reserved.