99mTc(L-L)3+ complexes containing ether analogs of DMPE

Novel 99mTc(L-L)3+ complexes have been investigated for potential use in myocardial perfusion imaging. Bidentate chelators have been prepared that are based on substituent analogs of 1,2-bis(dimethylphosphino)ethane, onto which alkyl ether groups have been incorporated. The new ligands are: (1) MMPE, 1,2-bis(methyl methoxyethyl phosphino)ethane, (2) MIBPE, 1,2-bis(methyl methoxyisobutyl phosphino)ethane, (3) FURPE, 1,2-bis(methyl tetrahydrofuran phosphino)ethane, and (4) PYRPE, 1,2-bis(methyl tetrahydropyran phosphino)ethane. These ligands have been reacted with 99mTc and the resulting complexes evaluated for myocardial imaging properties. 99mTc(MMPE)3+ exhibited the most favorable myocardial imaging characteristics in animal models. Results indicate that pendent ether moieties can improve the myocardial imaging properties of cationic technetium complexes