Patent ID: 8574546

Claim:
A positron emitting compound or salt thereof, wherein the compound has the formula: wherein: B is boron; A is a single substituted aromatic ring or an aromatic ring joined to one or more additional rings to form a substituted polycyclic moiety, wherein ring atoms comprise carbon and optionally, one or more heteroatoms, and substituents of the aromatic ring or polycyclic moiety other than B comprise at least one electron-withdrawing group (EWG); each (Y 1 ) n is independently selected from the group consisting of R 1 , 18 F and 19 F, and n=1 or 2; Y 2 is selected from the group consisting of R 1 , 18 F and 19 F; R 1 is a non-interfering substituent with regard to fluorination of B; providing that at least one of (Y 1 ) n and Y 2 is 18 F; providing that σ total for all substituents on the aromatic ring or polycyclic moiety except B is about 0.06 or more when said at least one EWG is positioned ortho to B, or about 0.2 or more when no EWG is positioned ortho to B; and providing that said at least one EWG is not a single bromomethyl group positioned ortho to B.