Please Note:

The Open Access Repository will be moving to a new authentication system on the 1st of November.

From this date onwards, account holders will be required to login using their University of Tasmania credentials.
If your current repository username differs from your University username, please email E.Prints@utas.edu.au so we can update these details on your behalf.

Due to the change, there will be a short outage of the repository from 9am on the morning of the 1st of November

Open Access Repository

Rationalizing the different products in the reaction of N2 with three-coordinate MoL3 complexes

Downloads

Downloads per month over past year

Christian, G and Stranger, R and Yates, BF and Cummins, CC (2007) Rationalizing the different products in the reaction of N2 with three-coordinate MoL3 complexes. Dalton Transactions, 19. pp. 1939-1947. ISSN 1477-9226

[img] PDF
4240.pdf | Request a copy
Full text restricted

Abstract

The reaction of N2 with three-coordinate MoL3 complexes is known to give rise to different products, N–MoL3, L3Mo–N–MoL3 or Mo2L6, depending on the nature of the ligand L. The energetics of the different reaction pathways are compared for L = NH2, NMe2, N(iPr)Ar and N(tBu)Ar (Ar = 3,5-C6H3Me2) using density functional methods in order to rationalize the experimental results. Overall, the exothermicity of each reaction pathway decreases as the ligand size increases, largely due to the increased steric crowding in the products compared to reactants. In the absence of steric strain, the formation of the metal–metal bonded dimer, Mo2L6, is the most exothermic pathway but this reaction shows the greatest sensitivity to ligand size varying from significantly exothermic, –403 kJ mol–1 for L = NMe2, to endothermic, +78 kJ mol–1 for L = N(tBu)Ar. For all four ligands, formation of N–MoL3via cleavage of the N2 bridged dimer intermediate, L3Mo–N–N–MoL3, is strongly exothermic. However, in the presence of excess reactant MoL3, formation of the single atom-bridged complex L3Mo–N–MoL3 from N–MoL3 + MoL3 is both thermodynamically and kinetically favoured for L = NMe2 and N(iPr)Ar, in agreement with experiment. In the case of L = N(tBu)Ar, the greater steric bulk of the tBu group results in a much less exothermic reaction and a calculated barrier of 66 kJ mol–1 to formation of the L3Mo–N–MoL3 dimer. Consequently, for this ligand, the energetically and kinetically favoured product, consistent with the experimental data, is the nitride complex L3Mo–N.

Item Type: Article
Journal or Publication Title: Dalton Transactions
Publisher: Royal Society of Chemistry
Page Range: pp. 1939-1947
ISSN: 1477-9226
Identification Number - DOI: 10.1039/b701050h
Date Deposited: 07 Apr 2008 14:29
Last Modified: 18 Nov 2014 03:35
Item Statistics: View statistics for this item

Actions (login required)

Item Control Page Item Control Page
TOP