Phenoxide ligand

Consequently, addition of a further phenoxide ligand should be possible, and this has indeed been realized in the anion of the compound K(thf)6][Cd(OC6H3t-Bu2)3], with planar three-coordinate Cd (/-av(Cd—O) 207.1pm).269... 

More active zinc phenoxide initiators of the type [Zn(0Ar)2(Et20)2]956 were found to catalyze both the copolymerization of CHO with C02 and the terpolymerization of CHO, PO, and C02 attempts to copolymerize PO and C02 yielded predominantly cyclic carbonates. For example, (332) copolymerizes CHO and C02 at 80 °C and 800 psi to give a copolymer containing 91% syndiotactic polycarbonate linkages (and 9% polyether junctions due to the non-insertion of C02) with good activity (>350g polymer/g [Zn] in 69 h).957 However, the polymerization is not well-controlled (Mw/Mn>2.5). Variation of the phenoxide ligands revealed that (333) is 4 times... 

The sterically hindered dianionic bidentate phenoxide ligand (205) gives several tetrahedral iron(II) complexes, e.g., [Fe (205)(THF)2], [Fe (205)(py)2], [Fe (205)(bipy)], and [Fe (205)(2,6-xylylNC)2]. The first of these is prepared from FeCl2 and (205)H2 in tetrahydrofuran the others are prepared from the dimer [Fe2(205)2]. The 2,6-xylylNC complex is low-spin, the others high-spin. There is also a five-coordinate iron(III) complex, red-black [Fe(205)(bipy)Cl], whose structure is intermediate between trigonal bipyramidal and square pyramidal." ... 

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. 

The extent of delocalization in VO(IV)—O—VO(V) is sensitive to the Kgands present in the molecule. A series of complexes based on tetradentate TAN Kgands showed Robin and Day Class 1 delocalization when the pendant donor site was a carboxyl ligand, but showed Class 3 delocalization when the donor site was a phenoxide ligand [99]. 

Very few reactions of C02 complexes with nucleophiles have been reported. One of the rare examples of nucleophilic attack at C02 has been provided by Aresta et al. [81], in a study of the coordination chemistry of phenoxide ligands to Mn ... 

Whilst the chiral manganese complexes can epoxidize alkenes with high enantioselectivity (> 90% e.e.), they are not particularly stable. This instability is probably due to the easily oxidizable imine and phenoxide ligands on the complex. Attempts are currently being made to immobilize Schiff-bases in order to increase their stability in a similar manner to the metalloporphyrins discussed earlier. 

Fig. 24. ORTEP drawing (50% probability level) of Ca,(OPh)5[OP(NMe2)3]f, looking down the pseudo-threefold axis that intersects the /x -oxygen atoms of the phenoxide ligands. The compound has a distorted octahedral coordination geometry around each calcium atom, with Ca—O bond distances of 2.38(l)-2.44(l) A (fj-j), 2.33(0-2.36(1) A and...

The Gp-phenoxo dichloro complexes shown in Scheme 406 have been prepared by the reaction of TiCl4 with the dilithio salt of the corresponding Gp-phenoxide ligands. Alternatively, the treatment of the cyclopentadienylphenols with TiCl4 in 1 1 molar ratio forms the coordination intermediates which are converted into the final products by... 

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