Crystal Structures, Reaction Rates, and Selected Physical Properties of Halo-Boronsubphthalocyanines (Halo = Fluoride, Chloride, and Bromide)

The physical properties, including the solid state arrangement,
photophysics, solubility, and electrochemical behavior of a series
of halo-BsubPcs (halo = F, Cl, Br) have been measured (IUPAC name
halo-(7,12:14,19-diimino-21,5-nitrilo-5H-tribenzo­(c,h,m)­(1,6,11)­triazacyclopentadecinato)-boron­(III)).
We have found that across the series all are relatively similar in
most regards. Exceptions include that F-BsubPc can be 5 to 25 times
more soluble than Cl-BsubPc in common organic solvents. F-BsubPc was
also found to be hydrolytically stable under the conditions tested,
whereas Cl-BsubPc and Br-BsubPc readily hydrolyzed to form HO-BsubPc.
The relative rates of reaction for the series of halo-BsubPcs under
standard phenoxylation conditions have also been measured. It was
found that F-BsubPc does not undergo phenoxylation, whereas Br-BsubPc
showed a markedly higher reaction rate relative to Cl-BsubPc. Based
on these data some assumptions can be made as to the suitability of
either F-BsubPc or Br-BsubPc to be used in place of the more common
Cl-BsubPc. The data indicate that F-BsubPc is a potential replacement
for Cl-BsubPc in organic electronic materials whereas Br-BsubPc might
be more suitable as a chemical intermediate. Comments on the synthetic
methods used to produce each halo-BsubPc are also made.