Transition metals, terphenyl derivatives

The only other known transition metal terphenyl derivative is the blue, crystalline cobalt species Co(ju.-Br)C6H3-2,6-Mes2(THF) 239 (Fig. 12). It is isostructural to the corresponding magnesium derivative discussed earlier. It was synthesized via the reaction of CoCl2 with the Grignard reagent,... 

In spite of the attention focused on these bulky aryl substituents, especially in main-group chemistry, aryl ligands in which crowding is caused by the presence of ortho-aryl substituents formerly received little attention. In contrast, related terphenyl-substituted phenolate derivatives (e.g., -OC6H3-2,6-Ph2) of the early transition metals have been studied for many years, and zinc terphenolate derivatives have attracted attention (vide infra). A small number of similar aryl thiolate derivatives of transition metals (e.g., Mo, Fe, and Rh) have been characterized and published (vide infra). In addition, the related ligand -C6H2-2,4,6-Ph3 (Triph) had been employed as a ring substituent in bulky porphyrins.24... 

The terphenyl carboxylic acid derivatives have also been employed as supporting ligands in transition metal chemistry. For example, several binu-clear rhodium(II) terphenyl carboxylates (Fig. 20) have been reported.95 These were synthesized using the alternative route described in Eq. (8).96... 

As mentioned earlier, the bulky terphenyl thiolate ligand -SC6H3-2,6-Mes2 has been shown to stabilize nominal two-coordination in transition metal complexes.53,54 Figure 30 represents the X-ray crystal structure of the iron derivative, Fe(SC6H3-2,6-Mes2)2.53... 

In gas chromatography, thermotropic hquid crystals belonging to such groups of chemical compounds as Schiff s base, azo- and azoxy-compounds, esters, derivatives of biphenyls and terphenyls, organic complexes with transition metals, and organic polymers are used. Siloxane polymers of liquid-crystaUine properties are stable within the wide range of temperatures from 50°C to 300°C. 

Terphenyl Metal Halide Derivatives of Transition Metals. 61... 

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