%0 Journal Article %A Morris, Aimee M. %A Pierpont, Cortlandt G. %A Finke, Richard G. %D 2009 %T Synthesis and Characterization of VV(3,6-DBSQ)(3,6-DBCat)2, a d0 Metal Complex with Dioxygenase Catalytic Activity %U https://acs.figshare.com/articles/journal_contribution/Synthesis_and_Characterization_of_V_sup_V_sup_3_6_DBSQ_3_6_DBCat_sub_2_sub_a_d_sup_0_sup_Metal_Complex_with_Dioxygenase_Catalytic_Activity/2862706 %R 10.1021/ic802122q.s001 %2 https://acs.figshare.com/ndownloader/files/4560532 %K EPR studies %K ligand %K 0 Metal Complex %K UV %K extradiol products %K O 2. %K 2 equiv %K dioxygenase catalysis %K O 2 %K DBBQ %K Initial dioxygenase catalysis studies %K undesired benzoquinone autoxidation product %K dioxygenase precatalyst %K VO %K VV %K 1 equiv %K room temperature %K DBSQ %X Transition-metal complexes containing redox-active quinoid ligands are of interest because of their catalytic capabilities in multielectron, substrate-activation reactions such as dioxygenase catalysis using O2. The new catecholate complex VV(3,6-DBSQ)(3,6-DBCat)2 (where 3,6-DBSQ = 3,6-di-tert-butylsemiquinone and 3,6-DBCat = 3,6-di-tert-butylcatecholate) was synthesized by combining VO(acac)2 with 1 equiv of 3,6-DBBQ (where 3,6-DBBQ = 3,6-di-tert-butylbenzoquinone) and 2 equiv of H2(3,6-DBCat) in dry methanol under an inert atmosphere. The resultant complex was characterized by single-crystal X-ray diffraction, elemental analysis, near-IR, UV/vis, and electron paramagnetic resonance (EPR) spectroscopy. The crystallography as well as the near-IR and EPR studies suggest that the radical spin is localized on the 3,6-DBSQ ligand at room temperature, making VV(3,6-DBSQ)(3,6-DBCat)2 a type 1 mixed-valence complex. Initial dioxygenase catalysis studies reveal that VV(3,6-DBSQ)(3,6-DBCat)2 is a good dioxygenase precatalyst for the substrate H2(3,6-DBCat) with O2 in ca. 600 total turnovers to >93% intra- and extradiol products with only 1−2% of the undesired benzoquinone autoxidation product. %I ACS Publications