Synthesis and Structures of Bis(dithiolene)molybdenum Complexes Related to the Active
Sites of the DMSO Reductase Enzyme Family
Booyong S. Lim
James P. Donahue
R. H. Holm
10.1021/ic9908672.s001
https://acs.figshare.com/articles/dataset/Synthesis_and_Structures_of_Bis_dithiolene_molybdenum_Complexes_Related_to_the_Active_Sites_of_the_DMSO_Reductase_Enzyme_Family/3626139
Structural analogues of the reduced (Mo(IV)) sites of members of the DMSO reductase family of molybdoenzymes
are sought. These sites usually contain two pterin−dithiolene cofactor ligands and one protein-based ligand. Reaction
of [Mo(MeCN)<sub>3</sub>(CO)<sub>3</sub>] and [Ni(S<sub>2</sub>C<sub>2</sub>R<sub>2</sub>)<sub>2</sub>] affords the trigonal prismatic complexes [Mo(CO)<sub>2</sub>(S<sub>2</sub>C<sub>2</sub>R<sub>2</sub>)<sub>2</sub>] (R =
Me (<b>1</b>), Ph (<b>2</b>)), which by carbonyl substitution serve as useful precursors to a variety of bis(dithiolene)molybdenum(IV,V) complexes. Reaction of <b>1</b> with Et<sub>4</sub>NOH yields [MoO(S<sub>2</sub>C<sub>2</sub>Me<sub>2</sub>)<sub>2</sub>]<sup>2-</sup> (<b>3</b>), which is readily oxidized to
[MoO(S<sub>2</sub>C<sub>2</sub>Me<sub>2</sub>)<sub>2</sub>]<sup>1-</sup> (<b>4</b>). The hindered arene oxide ligands ArO<sup>-</sup> afford the square pyramidal complexes
[Mo(OAr)(S<sub>2</sub>C<sub>2</sub>R<sub>2</sub>)<sub>2</sub>]<sup>1-</sup> (<b>5</b>, <b>6</b>). The ligands PhQ<sup>-</sup> afford the trigonal prismatic monocarbonyls [Mo(CO)(QPh)(S<sub>2</sub>C<sub>2</sub>Me<sub>2</sub>)<sub>2</sub>]<sup>1-</sup>
(Q = S (<b>8</b>), Se (<b>12</b>)) while the bulky ligand ArS<sup>-</sup> forms square pyramidal [Mo(SAr)(S<sub>2</sub>C<sub>2</sub>R<sub>2</sub>)<sub>2</sub>]<sup>1-</sup> (<b>9</b>, <b>10</b>). In
contrast, reactions with ArSe<sup>-</sup> result in [Mo(CO)(SeAr)(S<sub>2</sub>C<sub>2</sub>R<sub>2</sub>)<sub>2</sub>]<sup>1-</sup> (<b>14</b>, <b>15</b>), which have not been successfully
decarbonylated. Other compounds prepared by substitution reactions of <b>1</b> and <b>2</b> include the bridged dimers [Mo<sub>2</sub>(μ-Q)<sub>2</sub>(S<sub>2</sub>C<sub>2</sub>Me<sub>2</sub>)<sub>4</sub>]<sup>2-</sup> (Q = S (<b>7</b>), Se (<b>11</b>)) and [Mo<sub>2</sub>(μ-SePh)<sub>2</sub>(S<sub>2</sub>C<sub>2</sub>Ph<sub>2</sub>)<sub>4</sub>]<sup>2-</sup> (<b>13</b>). The complexes <b>1</b>, <b>3</b>−<b>5</b>, <b>7</b>−<b>10</b>,
<b>12</b>−<b>14</b>, [Mo(S<sub>2</sub>C<sub>2</sub>Me<sub>2</sub>)<sub>3</sub>] (<b>16</b>), and [Mo(S<sub>2</sub>C<sub>2</sub>Me<sub>2</sub>)<sub>3</sub>]<sup>1-</sup> (<b>17</b>) were characterized by X-ray structure determinations.
Certain complexes approach the binding arrangements in at least one DMSO reductase (<b>5</b>/<b>6</b>) and its Ser/Cys
mutant, and in dissimilatory nitrate reductases (<b>9</b>/<b>10</b>). This investigation provides the initial demonstration of the
new types of bis(dithiolene)molybdenum(IV) complexes available through [Mo(CO)<sub>2</sub>(S<sub>2</sub>C<sub>2</sub>R<sub>2</sub>)<sub>2</sub>] precursors, some
of which will be utilized in reactivity studies. (Ar = 2,6-diisopropylphenyl or 2,4,6-triisopropylphenyl.)
1999-12-29 00:00:00
dissimilatory nitrate reductases
Certain complexes approach
S 2 C 2 Ph 2
Et 4 NOH yields
prismatic monocarbonyls
bridged dimers
ligand ArS
carbonyl substitution
S 2 C 2 R 2
DMSO Reductase Enzyme Family Structural analogues
complexes 1
S 2 C 2
DMSO reductase family
Mo
ligands PhQ
prismatic complexes
DMSO reductase
binding arrangements
arene oxide ligands ArO
CO
reactivity studies
substitution reactions
Active Sites
forms square
Other compounds