Compounds having the general formula III′, or IV′ wherein R1 can be a radical of an optionally substituted C-4 to C-7 N-containing heterocycle or a radical of an optionally substituted cyclic or acyclic tertiary amine or isoindoline-1,3-dione: R2,4,5,6 can each independently be any one or combinations of the following moieties, cyano, nitro, acyl, alkyl, amido, azido, isothiocyanate, isocyanate, optionally substituted anilino, halogens, ethers, sulfonamides, thioacyl, nitro, aromatic, heterocyclic, olefinic, acetylene, deuterium, or tritium; Y is S; Z can be either H, O, S, S—R or NR where R groups can be either H, aryls, alkyls, or cycloalkyls; “n” can be 1 to 5 carbons in length and stereoisomers, functional analogs, and pharmaceutically acceptable salts thereof and wherein the moiety bridging R1 and N can be a substituted alkylene, optionally substituted alkenylene or optionally substituted alkynylene and where the alkylene group can include an inserted C3-C5 cycloalkyl group, aromatic, and heterocyclic group; and wherein X is C1-C4 radiohaloalkyl.