The sterically hindered Fe(II) thiolate dimer Fe-2(mu-STriph)(2)(STriph)(2) (1;[STriph](-) = 2,4,6-triphenylbenzenethiolate) reacts with primary amines ((BuNH2)-Bu-t, aniline) and N2H4 to form the structurally characterized addition complexes Fe(STriph)(2)(NH(2)tBu)(2), Fe-2(mu-STriph)(2)(STriph)(2)(NH2Ph)(2), and Fe-2(mu-eta(1):eta(1)-N2H4)(2)(N2H4)(4)(STriph)(4) in high yield. Chemical and NMR spectroscopic evidence indicate that the binding of these nitrogen donors is labile in solution and multispecies equilibria are likely. With arylhydrazines, 1 catalytically disproportionates 1,2-diphenylhydrazine to aniline and azobenzene, and it rearranges 1-methyl-1,2-diarylhydrazines to give, after treatment with alumina, mononuclear, trigonal bipyramidal Fe(III) complexes of composition Fe(ISQ)(2)(STriph), where [ISQ](-) denotes an appropriately substituted bidentate o-diiminobenzosemiquinonate ligand. Complex 1 shows no reaction with hindered 1,2-dialkylhydrazines (isopropyl or tert-butyl) or tetrasubstituted 1,2-dimethyl-1,2-diphenylhydrazine.