Borabenzene anions

Boraanthracene — see Dibenzo[6,e]borin 9-Boraanthracene anions nomenclature, 1, 631 Borabenzene anions nomenclature, 1, 631... 

Boron. Earlier papers reviewed the properties of the borabenzene anion and discussed its potential aromaticity.130 182 A few examples have been shown in Schemes 31 and 53. The borabenzene anion (borinate) 141, with R = phenyl or methyl, gives complexes with transition metals such as Co (142) and Mn (143) (Scheme 61).183 Aza- and polyaza-... 

There are a number of heteroatom six-membered aromatic rings which are analogous to benzene in that they can donate six electrons to a metal. These include phosphabenzene. borabenzene anion, bomzire. and arsabenzene shown in Fig. I5.42.uv... 

Borabenzene anions can serve as n ligands to a thallium(I) center, as demonstrated by the work of Herberich et al. (183). Reaction of alkali metal borinates with thallium(I) chloride yields the pale yellow, sublimable complexes LVIa,b [Eq. (16)] (see Fig. 11), which are only sparingly soluble in nonpolar aprotic solvents but easily soluble in pyridine and dimethylsulfoxide (183). 

The classic aromatic systems are planar molecules. Solid-state structural data have been obtained only for heavily substituted arsenic derivatives and for the borabenzene anion in a transition metal complex. The following data were obtained for these systems (1, 171, 303) ... 

The data obtained for arsenin seem to support the premise of aromatic character however, the evidence is more tenuous for borabenzene anion. Future synthetic studies may produce a neutral, uncomplexed borabenzene derivative useful for structural analysis. This will be necessary before the presence or absence of aromaticity can be established. 

This opens a route to the borabenzene anion, which behaves analogously to the cyclopentadienyl anion . 

The borabenzene anion is a potential six-jr-electron structure which has received attention only recently. PMR and nB-NMR data have... 

Borabenzene (C5H5BR ) (see Table 15.2) is an anion which tends to form a complex and iron bonds to two borabenzene anions to form a // -complex of Fe " [63]. 

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