1023595-89-2Relevant academic research and scientific papers
Copper dioxygen adducts: Formation of bis(μ-oxo)dicopper(III) versus (μ-1,2)peroxodicopper(II) complexes with small changes in one pyridyl-ligand substituent
Maiti, Debabrata,Woertink, Julia S.,Sarjeant, Amy A. Narducci,Solomon, Edward I.,Karlin, Kenneth D.
, p. 3787 - 3800 (2008)
The preference for the formation of a particular Cu2O 2 isomer coming from (ligand)-CuI/O2 reactivity can be regulated with the steric demands of a TMPA (tris(2-pyridylmethyl)amine) derived ligand possessing 6-pyridyl substituents on one of the three donor groups of the tripodal tetradentate ligand. When this substituent is an -XHR group (X = N or C) the traditional CuI/O2 adduct forms a (μ-1,2)peroxodicopper(II) species (A). However, when the substituent is the slightly bulkier XR2 moiety {aryl or NR2 (R ≠ H)}, a bis(μ-oxo)dicopper(III) structure (C) is favored. The reactivity of one of the bis(μ-oxo)dicopper(III) species, [{(6tbp)CuIII} 2(O2-)2]2+ (7-O2) (6tbp = (6-tBu-phenyl-2-pyridylmethyl)bis(2-pyridylmethyl)amine), was probed, and for the first time, exogenous toluene or ethylbenzene hydrocarbon oxygenation reactions were observed. Typical monooxygenase chemistry occurred: the benzaldehyde product includes an 18-0 atom for toluene/7-18O 2 reactivity, and a H-atom abstraction by 7-O2 is apparent from study of its reactions with ArOH substrates, as well as the determination of kH/kD ≈ 7 in the toluene oxygenation (i.e., PhCH3 vs PhCD3 substrates). Proposed courses of reaction are presented, including the possible involvement of PhCH2OO ? and its subsequent reaction with copper(I) complex, the latter derived from dynamic solution behavior of 7-O2. External TMPA ligand exchange for copper in 7-O2 and O-O bond (re)formation chemistry, along with the ability to protonate 7-O2 and release of H 2O2 indicate the presence of an equilibrium between [{(6tbp)CuIII}2(O2_)2]2+ (7-O2) and a (μ-1,2)peroxodicopper(II) form.
