Monomeric Copper-Dioxygen Adducts

The molecular structure of [Cu(II)Tp (02)], determined using XRD methods, supports a monomeric Cu(If)-02 complex (Fig. 6.13) [34]. The reported struc- 

Masuda reported the isolation of another mononuclear Cu(II)-superoxo complex generated from dioxygen that appeared soon after [Cu(II)Tp (02)] was published [37]. In an effort to simulate the secondary coordination found in re- 

More recently, Tolman has reported the formation of mononuclear CU-O2 adducts using /9-diketiminate ligands, which are dependent on the steric properties of these ancillary ligands (Fig. 6.15) [39]. Relatively unhindered -diketiminate hgands afford complexes with Cu(lll)(//-0)2Cu(lII) cores, whereas with sufficiently bulky ligands, 1 1 adducts are formed with discreet Ca(rf -0- units. Resonance Raman data support side-on coordination, with bands at 968 and 917 cm for the 02/ 02-labeled isotopomers. In addition, the mixed isotope adduct has only a single peak at v( 0 0)=943cm . Disorder problems hamper the molecular structures determined by XRD on the initially reported complexes, yet more recent studies confirm the formation of the Cu(// -02) unit with an 0-0 distance of 1.392(3) A [40]. Moreover, these complexes can be used as synthons to prepare unsymmetrical Cu(III)(//-0)2Cu(III) complexes. While 

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