Rhenium diazenide ternary complexes with dithiocarbamate ligands: Towards new rhenium radiopharmaceuticals

Abstract

The reaction of the mono-diazenide core, [ReCl2(NNC 6H4-4-OCH3)(NCCH3)(PPh 3)2], with four equivalents of the sodium or potassium salts of dithiocarbamate (dtc) ligands gives neutral complexes of the formula [Re(NNC6H4-4-OCH3)(dtc)2(PPh 3)]. It is possible to use a wide range of dithiocarbamate ligands (S2CNRR′) with a variety of R groups (R = R′ = methyl, phenyl or ethyl; R = methyl, R′ = phenyl and R = R′ = morpholino). Substitution reactions with dtc ligands on the mono-diazenide derived from 2-hydrazinopyridine, [ReCl2(NNC5H4N)(PPh 3)2, give the analogous complexes, [Re(NNC 6H5N)(dtc)2(PPh3)]. The new complexes have been characterised by a combination of NMR spectroscopy, mass spectromet..