Other Chemistry of the Group 13 IIIA Elements

Boron halides can also act as halide ion acceptors when they serve as catalysts— for example, in the Friedel-Crafts alkylation of aromatic hydrocarbons  

Parallels between main group and organic chemistry can be instructive. One of the best known of these parallels is between the organic molecule benzene and the isoelectronic borazine (alias inorganic benzene ), B3N3Hg. Some of the similarities in physical properties between these two are striking, as shown in Table 8-6. 

Source Data from N. N. Greenwood and A. Eamshaw, Chemistry of the Elements, Pergamon Press, Elmsford, NY, 1984, p. 238. 

Despite these parallels, the chemistry of these two compounds is quite different. In borazine, the difference in electronegativity between boron (2.051) and nitrogen (3.066) adds considerable polarity to the B—N bonds and makes the molecule much more susceptible to attack by nucleophiles (at the more positive boron) and electrophiles (at the more negative nitrogen) than benzene. 

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