Phenoxo ligand

Copper(II) complexes with phenoxo ligands have attracted great interest, in order to develop basic coordination chemistry for their possible use as models for tyrosinase activity (dimeric complexes) and fungal enzyme galactose oxidase (GO) (monomeric complexes). The latter enzyme catalyzes the two-electron oxidation of primary alcohols with dioxygen to yield aldehyde and... 

In order to emphasize the peculiar role of calix[4]arene as a supporting ligand compared to cyclopentadienyl and phenoxo anions, a detailed investigation has... 

Various UV/Vis spectroscopic studies have been described by Reedijk and co-workers, aimed at identifying the proposed dicopper species with bridging methoxide and phenoxide ligands (compare 8) in the absence of neocuproine. Notion is made of two bands, appearing at 420 and 450cm which were attributed to the formation of /z-OMe and /z-phenoxo bridges, respectively. 

Bis-phenoxo-amine-ether ligands, in Ti(IV) dialkyl complexes, 4, 355-356... 

Bis-phenoxo hydrocarbyl complexes, with Ti(IV), 4, 331 Bisphenoxo ligands, on mono-Cp Ti(IV) complexes, 4, 485 Bis(phenoxy-aldehyde) dichlorides, with Zr(IV), 4, 787 Bis(phenoxy-amino) catalysts, in propylene polymerization,... 

Indenyl-fluorenyl systems, propylene polymerization, 4, 1068 Indenylidenes, in ROMP initiation, 11, 633 7]5-Indenyl ligand, in molybdenocene dihalides, 5, 573 Indenyl ligands, in cobalt(III) complexes, 7, 20 7]5-Indenyl ligands, in rhodium alkene complexes, 7, 197 2-(Indenyl)—phenoxo complexes, with mono-Cp Ti(IV),... 

Figure 9 Reversible reaction of 02 giving phenoxo-bridged complex 8, with terminally (or unsymmetrically) bound peroxo ligand.

Sorrell [114] has prepared ligands similar to that found in 8, but possessing pyrazole or mixed pyrazole/pyridine ligands. The corresponding phenoxo-bridged dicopper(I) complexes appear to bind 02 in the same fashion these 02 complexes all exhibit a characteristic purple color with strong 500-510 and 610-630 nm bands that are presumed also to be peroxo-to-Cu(II) LMCT transitions. 

As already mentioned in Section II.C, the complexes [Cu2(R—XYL—H)]2+ (10) react with dioxygen, forming a kinetically describable intermediate dioxygen complex [Cu2(R—XYL—H)(02)]2+ (11), and attack by the peroxo group causes ligand hydroxylation to give the phenoxo and hydroxo-bridged complex [Cu2(R—XYL—0—)—(OH)]2+ (12). Here, we focus on the hydroxylation event, as described by the rate constant k2 (Scheme 13). 

The reactions of alkylidenes (see Alkylidene) and alkylidynes (see Alkylidyne) of niobium and tantalum are typically characterized by nucleophilic alkylidene and alkylidyne ligands. Cp Ta(CH2SiMe3)2(=CHSiMe3) reacts with PhOH to give alkyl phenoxo Cp Ta(CH2SiMe3)3(OPh), and is hydrolyzed in the presence of a trace amount of H2O to give the 0x0 dialkyl derivative [Cp Ta(CH2SiMe3)20] . ... 

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