%0 Journal Article
%A Robinson, Robert
%A Abbasi, Kiana Khadem
%A Ariafard, Alireza
%A Stranger, Robert
%A Yates, Brian F.
%D 2015
%T Sulfur Dioxide Activation: A Theoretical Investigation
into Dual SO Bond Cleavage by Three-Coordinate Molybdenum(III)
Complexes
%U https://acs.figshare.com/articles/journal_contribution/Sulfur_Dioxide_Activation_A_Theoretical_Investigation_into_Dual_S_O_Bond_Cleavage_by_Three_Coordinate_Molybdenum_III_Complexes/2214682
%R 10.1021/ic502298j.s001
%2 https://acs.figshare.com/ndownloader/files/3850261
%K MoL
%K L 3Mo
%K doublet
%K bond
%K formation
%K adduct
%K Sulfur Dioxide Activation
%K NH
%K 2 cleavage reaction
%K 6H
%K surface
%K mechanism
%K AF
%K molecule
%X Cummins
et al. have observed that 3 equiv of Mo(N[R]Ar)3 (R = C(CD3)2CH3, Ar = 3,5-C6H3Me2) are required for dual SO
bond cleavage within a SO2 molecule. Using density functional
theory calculations, this theoretical study investigates a mechanism
for this SO2 cleavage reaction that is mediated by MoL3, where L = NH2 or N[tBu]Ph. Our results indicate that an electron transfers into the SO2 ligand, which leads to Mo oxidation and initiates SO2 coordination along the quartet surface. The antiferromagnetic
(AF) nature of the (NH2)3Mo–SO2 adduct accelerates intersystem crossing onto the doublet surface.
The first SO bond cleavage occurs from the resulting doublet
adduct and leads to formation of L3MoO and SO.
Afterward, the released SO molecule is cleaved by the two remaining
MoL3, resulting in formation of L3MoS
and an additional L3MoO. This mononuclear mechanism
is calculated to be strongly exothermic and proceeds via a small activation
barrier, which is in accordance with experimental results. An additional
investigation into a binuclear process for this SO2 cleavage
reaction was also evaluated. Our results show that the binuclear mechanism
is less favorable than that of the mononuclear mechanism.
%I ACS Publications