[H2N{B(C6F5)3}2]-:: A new, remarkably stable diborate anion for metallocene polymerization catalysts

The reaction between NaNH2 and B(C6F5)3 affords the amidodiborate anion [H2N{B(C6F5)(3)}(2)](-), the structure of which shows multiple intramolecular NH...F hydrogen bonding. Reaction with HCl affords [H(OEt2)(2)][H2N{B(C6F5)(3)}(2)], while treatment of zirconocene dimethyls with [CPh3][H2N{B(C6F5)(3)}(2)] gives highly active alkene polymerization catalysts.