Adventitiously-charged systems

In 2005, a selection of pre-catalysts were employed in the vanadium-catalyzed oxygenation of 3,5-ditert-butylcatechol. ESI-MS experiments that were conducted on the post-reaction solutions led to the detection of two common negative ions [V0(DTBC)2]- (Eig. 2C) and [V(DTBC)3]- (DTBC = 3,5-di-tert-butylcatecholate dianion) [41]. Through kinetic experiments the species corresponding to [V(DTBC)3] was ruled out as the catalytically active species and the neutral species that was shown to correspond to [VO(DTBC)2] , namely (VO(DBSQ)(DTBC))2 (DBSQ=3,5-di-tert-butylsemiquinone anion), was reported as a common catalyst for this reaction. While this study describes an adventitiously-charged system (the proposed active catalyst is in fact neutral), it is described here along with the other vanadium-catalyzed systems for cohesion. 

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